9709 lines
No EOL
303 KiB
C#
9709 lines
No EOL
303 KiB
C#
using System;
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using System.Diagnostics;
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using System.Text;
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using i64 = System.Int64;
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using Pgno = System.UInt32;
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using sqlite3_int64 = System.Int64;
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using u16 = System.UInt16;
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using u32 = System.UInt32;
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using u64 = System.UInt64;
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using u8 = System.Byte;
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namespace Community.CsharpSqlite
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{
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using DbPage = Sqlite3.PgHdr;
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public partial class Sqlite3
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{
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/*
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** 2004 April 6
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**
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** The author disclaims copyright to this source code. In place of
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** a legal notice, here is a blessing:
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**
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** May you do good and not evil.
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** May you find forgiveness for yourself and forgive others.
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** May you share freely, never taking more than you give.
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**
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** This file implements a external (disk-based) database using BTrees.
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** See the header comment on "btreeInt.h" for additional information.
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** Including a description of file format and an overview of operation.
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*************************************************************************
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** Included in SQLite3 port to C#-SQLite; 2008 Noah B Hart
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** C#-SQLite is an independent reimplementation of the SQLite software library
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**
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** SQLITE_SOURCE_ID: 2011-06-23 19:49:22 4374b7e83ea0a3fbc3691f9c0c936272862f32f2
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**
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*************************************************************************
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*/
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//#include "btreeInt.h"
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/*
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** The header string that appears at the beginning of every
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** SQLite database.
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*/
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private static byte[] zMagicHeader = Encoding.UTF8.GetBytes(SQLITE_FILE_HEADER);
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/*
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** Set this global variable to 1 to enable tracing using the TRACE
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** macro.
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*/
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#if TRACE
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static bool sqlite3BtreeTrace=false; /* True to enable tracing */
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//# define TRACE(X) if(sqlite3BtreeTrace){printf X;fflush(stdout);}
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static void TRACE(string X, params object[] ap) { if (sqlite3BtreeTrace) printf(X, ap); }
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#else
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//# define TRACE(X)
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private static void TRACE(string X, params object[] ap)
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{
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}
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#endif
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/*
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** Extract a 2-byte big-endian integer from an array of unsigned bytes.
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** But if the value is zero, make it 65536.
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**
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** This routine is used to extract the "offset to cell content area" value
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** from the header of a btree page. If the page size is 65536 and the page
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** is empty, the offset should be 65536, but the 2-byte value stores zero.
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** This routine makes the necessary adjustment to 65536.
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*/
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//#define get2byteNotZero(X) (((((int)get2byte(X))-1)&0xffff)+1)
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private static int get2byteNotZero(byte[] X, int offset)
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{
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return (((((int)get2byte(X, offset)) - 1) & 0xffff) + 1);
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}
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#if !SQLITE_OMIT_SHARED_CACHE
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/*
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** A list of BtShared objects that are eligible for participation
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** in shared cache. This variable has file scope during normal builds,
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** but the test harness needs to access it so we make it global for
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** test builds.
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**
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** Access to this variable is protected by SQLITE_MUTEX_STATIC_MASTER.
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*/
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#if SQLITE_TEST
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BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;
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#else
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static BtShared *SQLITE_WSD sqlite3SharedCacheList = 0;
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#endif
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#endif //* SQLITE_OMIT_SHARED_CACHE */
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#if !SQLITE_OMIT_SHARED_CACHE
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/*
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** Enable or disable the shared pager and schema features.
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**
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** This routine has no effect on existing database connections.
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** The shared cache setting effects only future calls to
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** sqlite3_open(), sqlite3_open16(), or sqlite3_open_v2().
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*/
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int sqlite3_enable_shared_cache(int enable){
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sqlite3GlobalConfig.sharedCacheEnabled = enable;
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return SQLITE_OK;
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}
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#endif
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#if SQLITE_OMIT_SHARED_CACHE
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/*
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** The functions querySharedCacheTableLock(), setSharedCacheTableLock(),
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** and clearAllSharedCacheTableLocks()
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** manipulate entries in the BtShared.pLock linked list used to store
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** shared-cache table level locks. If the library is compiled with the
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** shared-cache feature disabled, then there is only ever one user
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** of each BtShared structure and so this locking is not necessary.
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** So define the lock related functions as no-ops.
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*/
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//#define querySharedCacheTableLock(a,b,c) SQLITE_OK
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private static int querySharedCacheTableLock(Btree p, Pgno iTab, u8 eLock)
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{
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return SQLITE_OK;
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}
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//#define setSharedCacheTableLock(a,b,c) SQLITE_OK
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//#define clearAllSharedCacheTableLocks(a)
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private static void clearAllSharedCacheTableLocks(Btree a)
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{
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}
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//#define downgradeAllSharedCacheTableLocks(a)
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private static void downgradeAllSharedCacheTableLocks(Btree a)
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{
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}
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//#define hasSharedCacheTableLock(a,b,c,d) 1
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private static bool hasSharedCacheTableLock(Btree a, Pgno b, int c, int d)
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{
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return true;
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}
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//#define hasReadConflicts(a, b) 0
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private static bool hasReadConflicts(Btree a, Pgno b)
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{
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return false;
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}
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#endif
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#if !SQLITE_OMIT_SHARED_CACHE
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#if SQLITE_DEBUG
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/*
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**** This function is only used as part of an assert() statement. ***
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**
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** Check to see if pBtree holds the required locks to read or write to the
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** table with root page iRoot. Return 1 if it does and 0 if not.
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**
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** For example, when writing to a table with root-page iRoot via
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** Btree connection pBtree:
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**
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** assert( hasSharedCacheTableLock(pBtree, iRoot, 0, WRITE_LOCK) );
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**
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** When writing to an index that resides in a sharable database, the
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** caller should have first obtained a lock specifying the root page of
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** the corresponding table. This makes things a bit more complicated,
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** as this module treats each table as a separate structure. To determine
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** the table corresponding to the index being written, this
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** function has to search through the database schema.
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**
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** Instead of a lock on the table/index rooted at page iRoot, the caller may
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** hold a write-lock on the schema table (root page 1). This is also
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** acceptable.
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*/
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static int hasSharedCacheTableLock(
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Btree pBtree, /* Handle that must hold lock */
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Pgno iRoot, /* Root page of b-tree */
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int isIndex, /* True if iRoot is the root of an index b-tree */
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int eLockType /* Required lock type (READ_LOCK or WRITE_LOCK) */
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){
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Schema pSchema = (Schema *)pBtree.pBt.pSchema;
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Pgno iTab = 0;
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BtLock pLock;
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/* If this database is not shareable, or if the client is reading
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** and has the read-uncommitted flag set, then no lock is required.
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** Return true immediately.
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*/
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if( (pBtree.sharable==null)
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|| (eLockType==READ_LOCK && (pBtree.db.flags & SQLITE_ReadUncommitted))
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){
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return 1;
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}
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/* If the client is reading or writing an index and the schema is
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** not loaded, then it is too difficult to actually check to see if
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** the correct locks are held. So do not bother - just return true.
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** This case does not come up very often anyhow.
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*/
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if( isIndex && (!pSchema || (pSchema->flags&DB_SchemaLoaded)==0) ){
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return 1;
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}
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/* Figure out the root-page that the lock should be held on. For table
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** b-trees, this is just the root page of the b-tree being read or
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** written. For index b-trees, it is the root page of the associated
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** table. */
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if( isIndex ){
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HashElem p;
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for(p=sqliteHashFirst(pSchema.idxHash); p!=null; p=sqliteHashNext(p)){
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Index pIdx = (Index *)sqliteHashData(p);
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if( pIdx.tnum==(int)iRoot ){
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iTab = pIdx.pTable.tnum;
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}
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}
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}else{
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iTab = iRoot;
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}
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/* Search for the required lock. Either a write-lock on root-page iTab, a
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** write-lock on the schema table, or (if the client is reading) a
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** read-lock on iTab will suffice. Return 1 if any of these are found. */
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for(pLock=pBtree.pBt.pLock; pLock; pLock=pLock.pNext){
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if( pLock.pBtree==pBtree
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&& (pLock.iTable==iTab || (pLock.eLock==WRITE_LOCK && pLock.iTable==1))
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&& pLock.eLock>=eLockType
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){
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return 1;
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}
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}
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/* Failed to find the required lock. */
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return 0;
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}
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#endif //* SQLITE_DEBUG */
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#if SQLITE_DEBUG
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/*
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** This function may be used as part of assert() statements only. ****
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**
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** Return true if it would be illegal for pBtree to write into the
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** table or index rooted at iRoot because other shared connections are
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** simultaneously reading that same table or index.
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**
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** It is illegal for pBtree to write if some other Btree object that
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** shares the same BtShared object is currently reading or writing
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** the iRoot table. Except, if the other Btree object has the
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** read-uncommitted flag set, then it is OK for the other object to
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** have a read cursor.
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**
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** For example, before writing to any part of the table or index
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** rooted at page iRoot, one should call:
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**
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** assert( !hasReadConflicts(pBtree, iRoot) );
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*/
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static int hasReadConflicts(Btree pBtree, Pgno iRoot){
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BtCursor p;
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for(p=pBtree.pBt.pCursor; p!=null; p=p.pNext){
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if( p.pgnoRoot==iRoot
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&& p.pBtree!=pBtree
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&& 0==(p.pBtree.db.flags & SQLITE_ReadUncommitted)
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){
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return 1;
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}
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}
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return 0;
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}
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#endif //* #if SQLITE_DEBUG */
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/*
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** Query to see if Btree handle p may obtain a lock of type eLock
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** (READ_LOCK or WRITE_LOCK) on the table with root-page iTab. Return
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** SQLITE_OK if the lock may be obtained (by calling
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** setSharedCacheTableLock()), or SQLITE_LOCKED if not.
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*/
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static int querySharedCacheTableLock(Btree p, Pgno iTab, u8 eLock){
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BtShared pBt = p.pBt;
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BtLock pIter;
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Debug.Assert( sqlite3BtreeHoldsMutex(p) );
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Debug.Assert( eLock==READ_LOCK || eLock==WRITE_LOCK );
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Debug.Assert( p.db!=null );
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Debug.Assert( !(p.db.flags&SQLITE_ReadUncommitted)||eLock==WRITE_LOCK||iTab==1 );
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/* If requesting a write-lock, then the Btree must have an open write
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** transaction on this file. And, obviously, for this to be so there
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** must be an open write transaction on the file itself.
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*/
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Debug.Assert( eLock==READ_LOCK || (p==pBt.pWriter && p.inTrans==TRANS_WRITE) );
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Debug.Assert( eLock==READ_LOCK || pBt.inTransaction==TRANS_WRITE );
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/* This routine is a no-op if the shared-cache is not enabled */
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if( !p.sharable ){
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return SQLITE_OK;
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}
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/* If some other connection is holding an exclusive lock, the
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** requested lock may not be obtained.
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*/
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if( pBt.pWriter!=p && pBt.isExclusive ){
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sqlite3ConnectionBlocked(p.db, pBt.pWriter.db);
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return SQLITE_LOCKED_SHAREDCACHE;
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}
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for(pIter=pBt.pLock; pIter; pIter=pIter.pNext){
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/* The condition (pIter.eLock!=eLock) in the following if(...)
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** statement is a simplification of:
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**
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** (eLock==WRITE_LOCK || pIter.eLock==WRITE_LOCK)
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**
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** since we know that if eLock==WRITE_LOCK, then no other connection
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** may hold a WRITE_LOCK on any table in this file (since there can
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** only be a single writer).
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*/
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Debug.Assert( pIter.eLock==READ_LOCK || pIter.eLock==WRITE_LOCK );
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Debug.Assert( eLock==READ_LOCK || pIter.pBtree==p || pIter.eLock==READ_LOCK);
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if( pIter.pBtree!=p && pIter.iTable==iTab && pIter.eLock!=eLock ){
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sqlite3ConnectionBlocked(p.db, pIter.pBtree.db);
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if( eLock==WRITE_LOCK ){
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Debug.Assert( p==pBt.pWriter );
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pBt.isPending = 1;
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}
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return SQLITE_LOCKED_SHAREDCACHE;
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}
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}
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return SQLITE_OK;
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}
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#endif //* !SQLITE_OMIT_SHARED_CACHE */
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#if !SQLITE_OMIT_SHARED_CACHE
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/*
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** Add a lock on the table with root-page iTable to the shared-btree used
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** by Btree handle p. Parameter eLock must be either READ_LOCK or
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** WRITE_LOCK.
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**
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** This function assumes the following:
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**
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** (a) The specified Btree object p is connected to a sharable
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** database (one with the BtShared.sharable flag set), and
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**
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** (b) No other Btree objects hold a lock that conflicts
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** with the requested lock (i.e. querySharedCacheTableLock() has
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** already been called and returned SQLITE_OK).
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**
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** SQLITE_OK is returned if the lock is added successfully. SQLITE_NOMEM
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** is returned if a malloc attempt fails.
|
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*/
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static int setSharedCacheTableLock(Btree p, Pgno iTable, u8 eLock){
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BtShared pBt = p.pBt;
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BtLock pLock = 0;
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BtLock pIter;
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Debug.Assert( sqlite3BtreeHoldsMutex(p) );
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Debug.Assert( eLock==READ_LOCK || eLock==WRITE_LOCK );
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Debug.Assert( p.db!=null );
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|
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/* A connection with the read-uncommitted flag set will never try to
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** obtain a read-lock using this function. The only read-lock obtained
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** by a connection in read-uncommitted mode is on the sqlite_master
|
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** table, and that lock is obtained in BtreeBeginTrans(). */
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Debug.Assert( 0==(p.db.flags&SQLITE_ReadUncommitted) || eLock==WRITE_LOCK );
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/* This function should only be called on a sharable b-tree after it
|
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** has been determined that no other b-tree holds a conflicting lock. */
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Debug.Assert( p.sharable );
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Debug.Assert( SQLITE_OK==querySharedCacheTableLock(p, iTable, eLock) );
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|
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/* First search the list for an existing lock on this table. */
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for(pIter=pBt.pLock; pIter; pIter=pIter.pNext){
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if( pIter.iTable==iTable && pIter.pBtree==p ){
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pLock = pIter;
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break;
|
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}
|
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}
|
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|
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/* If the above search did not find a BtLock struct associating Btree p
|
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** with table iTable, allocate one and link it into the list.
|
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*/
|
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if( !pLock ){
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pLock = (BtLock *)sqlite3MallocZero(sizeof(BtLock));
|
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if( !pLock ){
|
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return SQLITE_NOMEM;
|
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}
|
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pLock.iTable = iTable;
|
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pLock.pBtree = p;
|
|
pLock.pNext = pBt.pLock;
|
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pBt.pLock = pLock;
|
|
}
|
|
|
|
/* Set the BtLock.eLock variable to the maximum of the current lock
|
|
** and the requested lock. This means if a write-lock was already held
|
|
** and a read-lock requested, we don't incorrectly downgrade the lock.
|
|
*/
|
|
Debug.Assert( WRITE_LOCK>READ_LOCK );
|
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if( eLock>pLock.eLock ){
|
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pLock.eLock = eLock;
|
|
}
|
|
|
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return SQLITE_OK;
|
|
}
|
|
#endif //* !SQLITE_OMIT_SHARED_CACHE */
|
|
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
/*
|
|
** Release all the table locks (locks obtained via calls to
|
|
** the setSharedCacheTableLock() procedure) held by Btree object p.
|
|
**
|
|
** This function assumes that Btree p has an open read or write
|
|
** transaction. If it does not, then the BtShared.isPending variable
|
|
** may be incorrectly cleared.
|
|
*/
|
|
static void clearAllSharedCacheTableLocks(Btree p){
|
|
BtShared pBt = p.pBt;
|
|
BtLock **ppIter = &pBt.pLock;
|
|
|
|
Debug.Assert( sqlite3BtreeHoldsMutex(p) );
|
|
Debug.Assert( p.sharable || 0==*ppIter );
|
|
Debug.Assert( p.inTrans>0 );
|
|
|
|
while( ppIter ){
|
|
BtLock pLock = ppIter;
|
|
Debug.Assert( pBt.isExclusive==null || pBt.pWriter==pLock.pBtree );
|
|
Debug.Assert( pLock.pBtree.inTrans>=pLock.eLock );
|
|
if( pLock.pBtree==p ){
|
|
ppIter = pLock.pNext;
|
|
Debug.Assert( pLock.iTable!=1 || pLock==&p.lock );
|
|
if( pLock.iTable!=1 ){
|
|
pLock=null;//sqlite3_free(ref pLock);
|
|
}
|
|
}else{
|
|
ppIter = &pLock.pNext;
|
|
}
|
|
}
|
|
|
|
Debug.Assert( pBt.isPending==null || pBt.pWriter );
|
|
if( pBt.pWriter==p ){
|
|
pBt.pWriter = 0;
|
|
pBt.isExclusive = 0;
|
|
pBt.isPending = 0;
|
|
}else if( pBt.nTransaction==2 ){
|
|
/* This function is called when Btree p is concluding its
|
|
** transaction. If there currently exists a writer, and p is not
|
|
** that writer, then the number of locks held by connections other
|
|
** than the writer must be about to drop to zero. In this case
|
|
** set the isPending flag to 0.
|
|
**
|
|
** If there is not currently a writer, then BtShared.isPending must
|
|
** be zero already. So this next line is harmless in that case.
|
|
*/
|
|
pBt.isPending = 0;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function changes all write-locks held by Btree p into read-locks.
|
|
*/
|
|
static void downgradeAllSharedCacheTableLocks(Btree p){
|
|
BtShared pBt = p.pBt;
|
|
if( pBt.pWriter==p ){
|
|
BtLock pLock;
|
|
pBt.pWriter = 0;
|
|
pBt.isExclusive = 0;
|
|
pBt.isPending = 0;
|
|
for(pLock=pBt.pLock; pLock; pLock=pLock.pNext){
|
|
Debug.Assert( pLock.eLock==READ_LOCK || pLock.pBtree==p );
|
|
pLock.eLock = READ_LOCK;
|
|
}
|
|
}
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_SHARED_CACHE */
|
|
|
|
//static void releasePage(MemPage pPage); /* Forward reference */
|
|
|
|
/*
|
|
***** This routine is used inside of assert() only ****
|
|
**
|
|
** Verify that the cursor holds the mutex on its BtShared
|
|
*/
|
|
#if SQLITE_DEBUG
|
|
|
|
private static bool cursorHoldsMutex(BtCursor p)
|
|
{
|
|
return sqlite3_mutex_held(p.pBt.mutex);
|
|
}
|
|
|
|
#else
|
|
static bool cursorHoldsMutex(BtCursor p) { return true; }
|
|
#endif
|
|
|
|
#if !SQLITE_OMIT_INCRBLOB
|
|
/*
|
|
** Invalidate the overflow page-list cache for cursor pCur, if any.
|
|
*/
|
|
static void invalidateOverflowCache(BtCursor pCur){
|
|
Debug.Assert( cursorHoldsMutex(pCur) );
|
|
//sqlite3_free(ref pCur.aOverflow);
|
|
pCur.aOverflow = null;
|
|
}
|
|
|
|
/*
|
|
** Invalidate the overflow page-list cache for all cursors opened
|
|
** on the shared btree structure pBt.
|
|
*/
|
|
static void invalidateAllOverflowCache(BtShared pBt){
|
|
BtCursor p;
|
|
Debug.Assert( sqlite3_mutex_held(pBt.mutex) );
|
|
for(p=pBt.pCursor; p!=null; p=p.pNext){
|
|
invalidateOverflowCache(p);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This function is called before modifying the contents of a table
|
|
** to invalidate any incrblob cursors that are open on the
|
|
** row or one of the rows being modified.
|
|
**
|
|
** If argument isClearTable is true, then the entire contents of the
|
|
** table is about to be deleted. In this case invalidate all incrblob
|
|
** cursors open on any row within the table with root-page pgnoRoot.
|
|
**
|
|
** Otherwise, if argument isClearTable is false, then the row with
|
|
** rowid iRow is being replaced or deleted. In this case invalidate
|
|
** only those incrblob cursors open on that specific row.
|
|
*/
|
|
static void invalidateIncrblobCursors(
|
|
Btree pBtree, /* The database file to check */
|
|
i64 iRow, /* The rowid that might be changing */
|
|
int isClearTable /* True if all rows are being deleted */
|
|
){
|
|
BtCursor p;
|
|
BtShared pBt = pBtree.pBt;
|
|
Debug.Assert( sqlite3BtreeHoldsMutex(pBtree) );
|
|
for(p=pBt.pCursor; p!=null; p=p.pNext){
|
|
if( p.isIncrblobHandle && (isClearTable || p.info.nKey==iRow) ){
|
|
p.eState = CURSOR_INVALID;
|
|
}
|
|
}
|
|
}
|
|
|
|
#else
|
|
/* Stub functions when INCRBLOB is omitted */
|
|
|
|
//#define invalidateOverflowCache(x)
|
|
private static void invalidateOverflowCache(BtCursor pCur)
|
|
{
|
|
}
|
|
|
|
//#define invalidateAllOverflowCache(x)
|
|
private static void invalidateAllOverflowCache(BtShared pBt)
|
|
{
|
|
}
|
|
|
|
//#define invalidateIncrblobCursors(x,y,z)
|
|
private static void invalidateIncrblobCursors(Btree x, i64 y, int z)
|
|
{
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_INCRBLOB */
|
|
|
|
/*
|
|
** Set bit pgno of the BtShared.pHasContent bitvec. This is called
|
|
** when a page that previously contained data becomes a free-list leaf
|
|
** page.
|
|
**
|
|
** The BtShared.pHasContent bitvec exists to work around an obscure
|
|
** bug caused by the interaction of two useful IO optimizations surrounding
|
|
** free-list leaf pages:
|
|
**
|
|
** 1) When all data is deleted from a page and the page becomes
|
|
** a free-list leaf page, the page is not written to the database
|
|
** (as free-list leaf pages contain no meaningful data). Sometimes
|
|
** such a page is not even journalled (as it will not be modified,
|
|
** why bother journalling it?).
|
|
**
|
|
** 2) When a free-list leaf page is reused, its content is not read
|
|
** from the database or written to the journal file (why should it
|
|
** be, if it is not at all meaningful?).
|
|
**
|
|
** By themselves, these optimizations work fine and provide a handy
|
|
** performance boost to bulk delete or insert operations. However, if
|
|
** a page is moved to the free-list and then reused within the same
|
|
** transaction, a problem comes up. If the page is not journalled when
|
|
** it is moved to the free-list and it is also not journalled when it
|
|
** is extracted from the free-list and reused, then the original data
|
|
** may be lost. In the event of a rollback, it may not be possible
|
|
** to restore the database to its original configuration.
|
|
**
|
|
** The solution is the BtShared.pHasContent bitvec. Whenever a page is
|
|
** moved to become a free-list leaf page, the corresponding bit is
|
|
** set in the bitvec. Whenever a leaf page is extracted from the free-list,
|
|
** optimization 2 above is omitted if the corresponding bit is already
|
|
** set in BtShared.pHasContent. The contents of the bitvec are cleared
|
|
** at the end of every transaction.
|
|
*/
|
|
|
|
private static int btreeSetHasContent(BtShared pBt, Pgno pgno)
|
|
{
|
|
int rc = SQLITE_OK;
|
|
if (null == pBt.pHasContent)
|
|
{
|
|
Debug.Assert(pgno <= pBt.nPage);
|
|
pBt.pHasContent = sqlite3BitvecCreate(pBt.nPage);
|
|
//if ( null == pBt.pHasContent )
|
|
//{
|
|
// rc = SQLITE_NOMEM;
|
|
//}
|
|
}
|
|
if (rc == SQLITE_OK && pgno <= sqlite3BitvecSize(pBt.pHasContent))
|
|
{
|
|
rc = sqlite3BitvecSet(pBt.pHasContent, pgno);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Query the BtShared.pHasContent vector.
|
|
**
|
|
** This function is called when a free-list leaf page is removed from the
|
|
** free-list for reuse. It returns false if it is safe to retrieve the
|
|
** page from the pager layer with the 'no-content' flag set. True otherwise.
|
|
*/
|
|
|
|
private static bool btreeGetHasContent(BtShared pBt, Pgno pgno)
|
|
{
|
|
Bitvec p = pBt.pHasContent;
|
|
return (p != null && (pgno > sqlite3BitvecSize(p) || sqlite3BitvecTest(p, pgno) != 0));
|
|
}
|
|
|
|
/*
|
|
** Clear (destroy) the BtShared.pHasContent bitvec. This should be
|
|
** invoked at the conclusion of each write-transaction.
|
|
*/
|
|
|
|
private static void btreeClearHasContent(BtShared pBt)
|
|
{
|
|
sqlite3BitvecDestroy(ref pBt.pHasContent);
|
|
pBt.pHasContent = null;
|
|
}
|
|
|
|
/*
|
|
** Save the current cursor position in the variables BtCursor.nKey
|
|
** and BtCursor.pKey. The cursor's state is set to CURSOR_REQUIRESEEK.
|
|
**
|
|
** The caller must ensure that the cursor is valid (has eState==CURSOR_VALID)
|
|
** prior to calling this routine.
|
|
*/
|
|
|
|
private static int saveCursorPosition(BtCursor pCur)
|
|
{
|
|
int rc;
|
|
|
|
Debug.Assert(CURSOR_VALID == pCur.eState);
|
|
Debug.Assert(null == pCur.pKey);
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
|
|
rc = sqlite3BtreeKeySize(pCur, ref pCur.nKey);
|
|
Debug.Assert(rc == SQLITE_OK); /* KeySize() cannot fail */
|
|
|
|
/* If this is an intKey table, then the above call to BtreeKeySize()
|
|
** stores the integer key in pCur.nKey. In this case this value is
|
|
** all that is required. Otherwise, if pCur is not open on an intKey
|
|
** table, then malloc space for and store the pCur.nKey bytes of key
|
|
** data.
|
|
*/
|
|
if (0 == pCur.apPage[0].intKey)
|
|
{
|
|
byte[] pKey = sqlite3Malloc((int)pCur.nKey);
|
|
//if( pKey !=null){
|
|
rc = sqlite3BtreeKey(pCur, 0, (u32)pCur.nKey, pKey);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
pCur.pKey = pKey;
|
|
}
|
|
//else{
|
|
// sqlite3_free(ref pKey);
|
|
//}
|
|
//}else{
|
|
// rc = SQLITE_NOMEM;
|
|
//}
|
|
}
|
|
Debug.Assert(0 == pCur.apPage[0].intKey || null == pCur.pKey);
|
|
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
int i;
|
|
for (i = 0; i <= pCur.iPage; i++)
|
|
{
|
|
releasePage(pCur.apPage[i]);
|
|
pCur.apPage[i] = null;
|
|
}
|
|
pCur.iPage = -1;
|
|
pCur.eState = CURSOR_REQUIRESEEK;
|
|
}
|
|
|
|
invalidateOverflowCache(pCur);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Save the positions of all cursors (except pExcept) that are open on
|
|
** the table with root-page iRoot. Usually, this is called just before cursor
|
|
** pExcept is used to modify the table (BtreeDelete() or BtreeInsert()).
|
|
*/
|
|
|
|
private static int saveAllCursors(BtShared pBt, Pgno iRoot, BtCursor pExcept)
|
|
{
|
|
BtCursor p;
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(pExcept == null || pExcept.pBt == pBt);
|
|
for (p = pBt.pCursor; p != null; p = p.pNext)
|
|
{
|
|
if (p != pExcept && (0 == iRoot || p.pgnoRoot == iRoot) &&
|
|
p.eState == CURSOR_VALID)
|
|
{
|
|
int rc = saveCursorPosition(p);
|
|
if (SQLITE_OK != rc)
|
|
{
|
|
return rc;
|
|
}
|
|
}
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Clear the current cursor position.
|
|
*/
|
|
|
|
private static void sqlite3BtreeClearCursor(BtCursor pCur)
|
|
{
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
sqlite3_free(ref pCur.pKey);
|
|
pCur.eState = CURSOR_INVALID;
|
|
}
|
|
|
|
/*
|
|
** In this version of BtreeMoveto, pKey is a packed index record
|
|
** such as is generated by the OP_MakeRecord opcode. Unpack the
|
|
** record and then call BtreeMovetoUnpacked() to do the work.
|
|
*/
|
|
|
|
private static int btreeMoveto(
|
|
BtCursor pCur, /* Cursor open on the btree to be searched */
|
|
byte[] pKey, /* Packed key if the btree is an index */
|
|
i64 nKey, /* Integer key for tables. Size of pKey for indices */
|
|
int bias, /* Bias search to the high end */
|
|
ref int pRes /* Write search results here */
|
|
)
|
|
{
|
|
int rc; /* Status code */
|
|
UnpackedRecord pIdxKey; /* Unpacked index key */
|
|
UnpackedRecord aSpace = new UnpackedRecord();//char aSpace[150]; /* Temp space for pIdxKey - to avoid a malloc */
|
|
|
|
if (pKey != null)
|
|
{
|
|
Debug.Assert(nKey == (i64)(int)nKey);
|
|
pIdxKey = sqlite3VdbeRecordUnpack(pCur.pKeyInfo, (int)nKey, pKey,
|
|
aSpace, 16);//sizeof( aSpace ) );
|
|
//if ( pIdxKey == null )
|
|
// return SQLITE_NOMEM;
|
|
}
|
|
else
|
|
{
|
|
pIdxKey = null;
|
|
}
|
|
rc = sqlite3BtreeMovetoUnpacked(pCur, pIdxKey, nKey, bias != 0 ? 1 : 0, ref pRes);
|
|
|
|
if (pKey != null)
|
|
{
|
|
sqlite3VdbeDeleteUnpackedRecord(pIdxKey);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Restore the cursor to the position it was in (or as close to as possible)
|
|
** when saveCursorPosition() was called. Note that this call deletes the
|
|
** saved position info stored by saveCursorPosition(), so there can be
|
|
** at most one effective restoreCursorPosition() call after each
|
|
** saveCursorPosition().
|
|
*/
|
|
|
|
private static int btreeRestoreCursorPosition(BtCursor pCur)
|
|
{
|
|
int rc;
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState >= CURSOR_REQUIRESEEK);
|
|
if (pCur.eState == CURSOR_FAULT)
|
|
{
|
|
return pCur.skipNext;
|
|
}
|
|
pCur.eState = CURSOR_INVALID;
|
|
rc = btreeMoveto(pCur, pCur.pKey, pCur.nKey, 0, ref pCur.skipNext);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
//sqlite3_free(ref pCur.pKey);
|
|
pCur.pKey = null;
|
|
Debug.Assert(pCur.eState == CURSOR_VALID || pCur.eState == CURSOR_INVALID);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
//#define restoreCursorPosition(p) \
|
|
// (p.eState>=CURSOR_REQUIRESEEK ? \
|
|
// btreeRestoreCursorPosition(p) : \
|
|
// SQLITE_OK)
|
|
private static int restoreCursorPosition(BtCursor pCur)
|
|
{
|
|
if (pCur.eState >= CURSOR_REQUIRESEEK)
|
|
return btreeRestoreCursorPosition(pCur);
|
|
else
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Determine whether or not a cursor has moved from the position it
|
|
** was last placed at. Cursors can move when the row they are pointing
|
|
** at is deleted out from under them.
|
|
**
|
|
** This routine returns an error code if something goes wrong. The
|
|
** integer pHasMoved is set to one if the cursor has moved and 0 if not.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCursorHasMoved(BtCursor pCur, ref int pHasMoved)
|
|
{
|
|
int rc;
|
|
|
|
rc = restoreCursorPosition(pCur);
|
|
if (rc != 0)
|
|
{
|
|
pHasMoved = 1;
|
|
return rc;
|
|
}
|
|
if (pCur.eState != CURSOR_VALID || pCur.skipNext != 0)
|
|
{
|
|
pHasMoved = 1;
|
|
}
|
|
else
|
|
{
|
|
pHasMoved = 0;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
/*
|
|
** Given a page number of a regular database page, return the page
|
|
** number for the pointer-map page that contains the entry for the
|
|
** input page number.
|
|
**
|
|
** Return 0 (not a valid page) for pgno==1 since there is
|
|
** no pointer map associated with page 1. The integrity_check logic
|
|
** requires that ptrmapPageno(*,1)!=1.
|
|
*/
|
|
|
|
private static Pgno ptrmapPageno(BtShared pBt, Pgno pgno)
|
|
{
|
|
int nPagesPerMapPage;
|
|
Pgno iPtrMap, ret;
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
if (pgno < 2)
|
|
return 0;
|
|
nPagesPerMapPage = (int)(pBt.usableSize / 5 + 1);
|
|
iPtrMap = (Pgno)((pgno - 2) / nPagesPerMapPage);
|
|
ret = (Pgno)(iPtrMap * nPagesPerMapPage) + 2;
|
|
if (ret == PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
ret++;
|
|
}
|
|
return ret;
|
|
}
|
|
|
|
/*
|
|
** Write an entry into the pointer map.
|
|
**
|
|
** This routine updates the pointer map entry for page number 'key'
|
|
** so that it maps to type 'eType' and parent page number 'pgno'.
|
|
**
|
|
** If pRC is initially non-zero (non-SQLITE_OK) then this routine is
|
|
** a no-op. If an error occurs, the appropriate error code is written
|
|
** into pRC.
|
|
*/
|
|
|
|
private static void ptrmapPut(BtShared pBt, Pgno key, u8 eType, Pgno parent, ref int pRC)
|
|
{
|
|
PgHdr pDbPage = new PgHdr(); /* The pointer map page */
|
|
u8[] pPtrmap; /* The pointer map data */
|
|
Pgno iPtrmap; /* The pointer map page number */
|
|
int offset; /* Offset in pointer map page */
|
|
int rc; /* Return code from subfunctions */
|
|
|
|
if (pRC != 0)
|
|
return;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
/* The master-journal page number must never be used as a pointer map page */
|
|
Debug.Assert(false == PTRMAP_ISPAGE(pBt, PENDING_BYTE_PAGE(pBt)));
|
|
|
|
Debug.Assert(pBt.autoVacuum);
|
|
if (key == 0)
|
|
{
|
|
pRC = SQLITE_CORRUPT_BKPT();
|
|
return;
|
|
}
|
|
iPtrmap = PTRMAP_PAGENO(pBt, key);
|
|
rc = sqlite3PagerGet(pBt.pPager, iPtrmap, ref pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
pRC = rc;
|
|
return;
|
|
}
|
|
offset = (int)PTRMAP_PTROFFSET(iPtrmap, key);
|
|
if (offset < 0)
|
|
{
|
|
pRC = SQLITE_CORRUPT_BKPT();
|
|
goto ptrmap_exit;
|
|
}
|
|
Debug.Assert(offset <= (int)pBt.usableSize - 5);
|
|
pPtrmap = sqlite3PagerGetData(pDbPage);
|
|
|
|
if (eType != pPtrmap[offset] || sqlite3Get4byte(pPtrmap, offset + 1) != parent)
|
|
{
|
|
TRACE("PTRMAP_UPDATE: %d->(%d,%d)\n", key, eType, parent);
|
|
pRC = rc = sqlite3PagerWrite(pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
pPtrmap[offset] = eType;
|
|
sqlite3Put4byte(pPtrmap, offset + 1, parent);
|
|
}
|
|
}
|
|
|
|
ptrmap_exit:
|
|
sqlite3PagerUnref(pDbPage);
|
|
}
|
|
|
|
/*
|
|
** Read an entry from the pointer map.
|
|
**
|
|
** This routine retrieves the pointer map entry for page 'key', writing
|
|
** the type and parent page number to pEType and pPgno respectively.
|
|
** An error code is returned if something goes wrong, otherwise SQLITE_OK.
|
|
*/
|
|
|
|
private static int ptrmapGet(BtShared pBt, Pgno key, ref u8 pEType, ref Pgno pPgno)
|
|
{
|
|
PgHdr pDbPage = new PgHdr();/* The pointer map page */
|
|
int iPtrmap; /* Pointer map page index */
|
|
u8[] pPtrmap; /* Pointer map page data */
|
|
int offset; /* Offset of entry in pointer map */
|
|
int rc;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
|
|
iPtrmap = (int)PTRMAP_PAGENO(pBt, key);
|
|
rc = sqlite3PagerGet(pBt.pPager, (u32)iPtrmap, ref pDbPage);
|
|
if (rc != 0)
|
|
{
|
|
return rc;
|
|
}
|
|
pPtrmap = sqlite3PagerGetData(pDbPage);
|
|
|
|
offset = (int)PTRMAP_PTROFFSET((u32)iPtrmap, key);
|
|
if (offset < 0)
|
|
{
|
|
sqlite3PagerUnref(pDbPage);
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
Debug.Assert(offset <= (int)pBt.usableSize - 5);
|
|
// Under C# pEType will always exist. No need to test; //
|
|
//Debug.Assert( pEType != 0 );
|
|
pEType = pPtrmap[offset];
|
|
// Under C# pPgno will always exist. No need to test; //
|
|
//if ( pPgno != 0 )
|
|
pPgno = sqlite3Get4byte(pPtrmap, offset + 1);
|
|
|
|
sqlite3PagerUnref(pDbPage);
|
|
if (pEType < 1 || pEType > 5)
|
|
return SQLITE_CORRUPT_BKPT();
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
#else //* if defined SQLITE_OMIT_AUTOVACUUM */
|
|
//#define ptrmapPut(w,x,y,z,rc)
|
|
//#define ptrmapGet(w,x,y,z) SQLITE_OK
|
|
//#define ptrmapPutOvflPtr(x, y, rc)
|
|
#endif
|
|
|
|
/*
|
|
** Given a btree page and a cell index (0 means the first cell on
|
|
** the page, 1 means the second cell, and so forth) return a pointer
|
|
** to the cell content.
|
|
**
|
|
** This routine works only for pages that do not contain overflow cells.
|
|
*/
|
|
|
|
//#define findCell(P,I) \
|
|
// ((P).aData + ((P).maskPage & get2byte((P).aData[(P).cellOffset+2*(I)])))
|
|
private static int findCell(MemPage pPage, int iCell)
|
|
{
|
|
return get2byte(pPage.aData, pPage.cellOffset + 2 * (iCell));
|
|
}
|
|
|
|
//#define findCellv2(D,M,O,I) (D+(M&get2byte(D+(O+2*(I)))))
|
|
private static u8[] findCellv2(u8[] pPage, u16 iCell, u16 O, int I)
|
|
{
|
|
Debugger.Break();
|
|
return pPage;
|
|
}
|
|
|
|
/*
|
|
** This a more complex version of findCell() that works for
|
|
** pages that do contain overflow cells.
|
|
*/
|
|
|
|
private static int findOverflowCell(MemPage pPage, int iCell)
|
|
{
|
|
int i;
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
for (i = pPage.nOverflow - 1; i >= 0; i--)
|
|
{
|
|
int k;
|
|
_OvflCell pOvfl;
|
|
pOvfl = pPage.aOvfl[i];
|
|
k = pOvfl.idx;
|
|
if (k <= iCell)
|
|
{
|
|
if (k == iCell)
|
|
{
|
|
//return pOvfl.pCell;
|
|
return -i - 1; // Negative Offset means overflow cells
|
|
}
|
|
iCell--;
|
|
}
|
|
}
|
|
return findCell(pPage, iCell);
|
|
}
|
|
|
|
/*
|
|
** Parse a cell content block and fill in the CellInfo structure. There
|
|
** are two versions of this function. btreeParseCell() takes a
|
|
** cell index as the second argument and btreeParseCellPtr()
|
|
** takes a pointer to the body of the cell as its second argument.
|
|
**
|
|
** Within this file, the parseCell() macro can be called instead of
|
|
** btreeParseCellPtr(). Using some compilers, this will be faster.
|
|
*/
|
|
|
|
//OVERLOADS
|
|
private static void btreeParseCellPtr(
|
|
MemPage pPage, /* Page containing the cell */
|
|
int iCell, /* Pointer to the cell text. */
|
|
ref CellInfo pInfo /* Fill in this structure */
|
|
)
|
|
{
|
|
btreeParseCellPtr(pPage, pPage.aData, iCell, ref pInfo);
|
|
}
|
|
|
|
private static void btreeParseCellPtr(
|
|
MemPage pPage, /* Page containing the cell */
|
|
byte[] pCell, /* The actual data */
|
|
ref CellInfo pInfo /* Fill in this structure */
|
|
)
|
|
{
|
|
btreeParseCellPtr(pPage, pCell, 0, ref pInfo);
|
|
}
|
|
|
|
private static void btreeParseCellPtr(
|
|
MemPage pPage, /* Page containing the cell */
|
|
u8[] pCell, /* Pointer to the cell text. */
|
|
int iCell, /* Pointer to the cell text. */
|
|
ref CellInfo pInfo /* Fill in this structure */
|
|
)
|
|
{
|
|
u16 n; /* Number bytes in cell content header */
|
|
u32 nPayload = 0; /* Number of bytes of cell payload */
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
|
|
if (pInfo.pCell != pCell)
|
|
pInfo.pCell = pCell;
|
|
pInfo.iCell = iCell;
|
|
Debug.Assert(pPage.leaf == 0 || pPage.leaf == 1);
|
|
n = pPage.childPtrSize;
|
|
Debug.Assert(n == 4 - 4 * pPage.leaf);
|
|
if (pPage.intKey != 0)
|
|
{
|
|
if (pPage.hasData != 0)
|
|
{
|
|
n += (u16)getVarint32(pCell, iCell + n, out nPayload);
|
|
}
|
|
else
|
|
{
|
|
nPayload = 0;
|
|
}
|
|
n += (u16)getVarint(pCell, iCell + n, out pInfo.nKey);
|
|
pInfo.nData = nPayload;
|
|
}
|
|
else
|
|
{
|
|
pInfo.nData = 0;
|
|
n += (u16)getVarint32(pCell, iCell + n, out nPayload);
|
|
pInfo.nKey = nPayload;
|
|
}
|
|
pInfo.nPayload = nPayload;
|
|
pInfo.nHeader = n;
|
|
testcase(nPayload == pPage.maxLocal);
|
|
testcase(nPayload == pPage.maxLocal + 1);
|
|
if (likely(nPayload <= pPage.maxLocal))
|
|
{
|
|
/* This is the (easy) common case where the entire payload fits
|
|
** on the local page. No overflow is required.
|
|
*/
|
|
if ((pInfo.nSize = (u16)(n + nPayload)) < 4)
|
|
pInfo.nSize = 4;
|
|
pInfo.nLocal = (u16)nPayload;
|
|
pInfo.iOverflow = 0;
|
|
}
|
|
else
|
|
{
|
|
/* If the payload will not fit completely on the local page, we have
|
|
** to decide how much to store locally and how much to spill onto
|
|
** overflow pages. The strategy is to minimize the amount of unused
|
|
** space on overflow pages while keeping the amount of local storage
|
|
** in between minLocal and maxLocal.
|
|
**
|
|
** Warning: changing the way overflow payload is distributed in any
|
|
** way will result in an incompatible file format.
|
|
*/
|
|
int minLocal; /* Minimum amount of payload held locally */
|
|
int maxLocal; /* Maximum amount of payload held locally */
|
|
int surplus; /* Overflow payload available for local storage */
|
|
|
|
minLocal = pPage.minLocal;
|
|
maxLocal = pPage.maxLocal;
|
|
surplus = (int)(minLocal + (nPayload - minLocal) % (pPage.pBt.usableSize - 4));
|
|
testcase(surplus == maxLocal);
|
|
testcase(surplus == maxLocal + 1);
|
|
if (surplus <= maxLocal)
|
|
{
|
|
pInfo.nLocal = (u16)surplus;
|
|
}
|
|
else
|
|
{
|
|
pInfo.nLocal = (u16)minLocal;
|
|
}
|
|
pInfo.iOverflow = (u16)(pInfo.nLocal + n);
|
|
pInfo.nSize = (u16)(pInfo.iOverflow + 4);
|
|
}
|
|
}
|
|
|
|
//#define parseCell(pPage, iCell, pInfo) \
|
|
// btreeParseCellPtr((pPage), findCell((pPage), (iCell)), (pInfo))
|
|
private static void parseCell(MemPage pPage, int iCell, ref CellInfo pInfo)
|
|
{
|
|
btreeParseCellPtr(pPage, findCell(pPage, iCell), ref pInfo);
|
|
}
|
|
|
|
private static void btreeParseCell(
|
|
MemPage pPage, /* Page containing the cell */
|
|
int iCell, /* The cell index. First cell is 0 */
|
|
ref CellInfo pInfo /* Fill in this structure */
|
|
)
|
|
{
|
|
parseCell(pPage, iCell, ref pInfo);
|
|
}
|
|
|
|
/*
|
|
** Compute the total number of bytes that a Cell needs in the cell
|
|
** data area of the btree-page. The return number includes the cell
|
|
** data header and the local payload, but not any overflow page or
|
|
** the space used by the cell pointer.
|
|
*/
|
|
|
|
// Alternative form for C#
|
|
private static u16 cellSizePtr(MemPage pPage, int iCell)
|
|
{
|
|
CellInfo info = new CellInfo();
|
|
byte[] pCell = new byte[13];
|
|
// Minimum Size = (2 bytes of Header or (4) Child Pointer) + (maximum of) 9 bytes data
|
|
if (iCell < 0)// Overflow Cell
|
|
Buffer.BlockCopy(pPage.aOvfl[-(iCell + 1)].pCell, 0, pCell, 0, pCell.Length < pPage.aOvfl[-(iCell + 1)].pCell.Length ? pCell.Length : pPage.aOvfl[-(iCell + 1)].pCell.Length);
|
|
else if (iCell >= pPage.aData.Length + 1 - pCell.Length)
|
|
Buffer.BlockCopy(pPage.aData, iCell, pCell, 0, pPage.aData.Length - iCell);
|
|
else
|
|
Buffer.BlockCopy(pPage.aData, iCell, pCell, 0, pCell.Length);
|
|
btreeParseCellPtr(pPage, pCell, ref info);
|
|
return info.nSize;
|
|
}
|
|
|
|
// Alternative form for C#
|
|
private static u16 cellSizePtr(MemPage pPage, byte[] pCell, int offset)
|
|
{
|
|
CellInfo info = new CellInfo();
|
|
info.pCell = sqlite3Malloc(pCell.Length);
|
|
Buffer.BlockCopy(pCell, offset, info.pCell, 0, pCell.Length - offset);
|
|
btreeParseCellPtr(pPage, info.pCell, ref info);
|
|
return info.nSize;
|
|
}
|
|
|
|
private static u16 cellSizePtr(MemPage pPage, u8[] pCell)
|
|
{
|
|
int _pIter = pPage.childPtrSize; //u8 pIter = &pCell[pPage.childPtrSize];
|
|
u32 nSize = 0;
|
|
|
|
#if SQLITE_DEBUG || DEBUG
|
|
/* The value returned by this function should always be the same as
|
|
** the (CellInfo.nSize) value found by doing a full parse of the
|
|
** cell. If SQLITE_DEBUG is defined, an Debug.Assert() at the bottom of
|
|
** this function verifies that this invariant is not violated. */
|
|
CellInfo debuginfo = new CellInfo();
|
|
btreeParseCellPtr(pPage, pCell, ref debuginfo);
|
|
#else
|
|
CellInfo debuginfo = new CellInfo();
|
|
#endif
|
|
|
|
if (pPage.intKey != 0)
|
|
{
|
|
int pEnd;
|
|
if (pPage.hasData != 0)
|
|
{
|
|
_pIter += getVarint32(pCell, out nSize);// pIter += getVarint32( pIter, out nSize );
|
|
}
|
|
else
|
|
{
|
|
nSize = 0;
|
|
}
|
|
|
|
/* pIter now points at the 64-bit integer key value, a variable length
|
|
** integer. The following block moves pIter to point at the first byte
|
|
** past the end of the key value. */
|
|
pEnd = _pIter + 9;//pEnd = &pIter[9];
|
|
while (((pCell[_pIter++]) & 0x80) != 0 && _pIter < pEnd)
|
|
;//while( (pIter++)&0x80 && pIter<pEnd );
|
|
}
|
|
else
|
|
{
|
|
_pIter += getVarint32(pCell, _pIter, out nSize); //pIter += getVarint32( pIter, out nSize );
|
|
}
|
|
|
|
testcase(nSize == pPage.maxLocal);
|
|
testcase(nSize == pPage.maxLocal + 1);
|
|
if (nSize > pPage.maxLocal)
|
|
{
|
|
int minLocal = pPage.minLocal;
|
|
nSize = (u32)(minLocal + (nSize - minLocal) % (pPage.pBt.usableSize - 4));
|
|
testcase(nSize == pPage.maxLocal);
|
|
testcase(nSize == pPage.maxLocal + 1);
|
|
if (nSize > pPage.maxLocal)
|
|
{
|
|
nSize = (u32)minLocal;
|
|
}
|
|
nSize += 4;
|
|
}
|
|
nSize += (uint)_pIter;//nSize += (u32)(pIter - pCell);
|
|
|
|
/* The minimum size of any cell is 4 bytes. */
|
|
if (nSize < 4)
|
|
{
|
|
nSize = 4;
|
|
}
|
|
|
|
Debug.Assert(nSize == debuginfo.nSize);
|
|
return (u16)nSize;
|
|
}
|
|
|
|
#if SQLITE_DEBUG
|
|
/* This variation on cellSizePtr() is used inside of assert() statements
|
|
** only. */
|
|
|
|
private static u16 cellSize(MemPage pPage, int iCell)
|
|
{
|
|
return cellSizePtr(pPage, findCell(pPage, iCell));
|
|
}
|
|
|
|
#else
|
|
static int cellSize(MemPage pPage, int iCell) { return -1; }
|
|
#endif
|
|
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
/*
|
|
** If the cell pCell, part of page pPage contains a pointer
|
|
** to an overflow page, insert an entry into the pointer-map
|
|
** for the overflow page.
|
|
*/
|
|
|
|
private static void ptrmapPutOvflPtr(MemPage pPage, int pCell, ref int pRC)
|
|
{
|
|
if (pRC != 0)
|
|
return;
|
|
CellInfo info = new CellInfo();
|
|
Debug.Assert(pCell != 0);
|
|
btreeParseCellPtr(pPage, pCell, ref info);
|
|
Debug.Assert((info.nData + (pPage.intKey != 0 ? 0 : info.nKey)) == info.nPayload);
|
|
if (info.iOverflow != 0)
|
|
{
|
|
Pgno ovfl = sqlite3Get4byte(pPage.aData, pCell, info.iOverflow);
|
|
ptrmapPut(pPage.pBt, ovfl, PTRMAP_OVERFLOW1, pPage.pgno, ref pRC);
|
|
}
|
|
}
|
|
|
|
private static void ptrmapPutOvflPtr(MemPage pPage, u8[] pCell, ref int pRC)
|
|
{
|
|
if (pRC != 0)
|
|
return;
|
|
CellInfo info = new CellInfo();
|
|
Debug.Assert(pCell != null);
|
|
btreeParseCellPtr(pPage, pCell, ref info);
|
|
Debug.Assert((info.nData + (pPage.intKey != 0 ? 0 : info.nKey)) == info.nPayload);
|
|
if (info.iOverflow != 0)
|
|
{
|
|
Pgno ovfl = sqlite3Get4byte(pCell, info.iOverflow);
|
|
ptrmapPut(pPage.pBt, ovfl, PTRMAP_OVERFLOW1, pPage.pgno, ref pRC);
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
** Defragment the page given. All Cells are moved to the
|
|
** end of the page and all free space is collected into one
|
|
** big FreeBlk that occurs in between the header and cell
|
|
** pointer array and the cell content area.
|
|
*/
|
|
|
|
private static int defragmentPage(MemPage pPage)
|
|
{
|
|
int i; /* Loop counter */
|
|
int pc; /* Address of a i-th cell */
|
|
int addr; /* Offset of first byte after cell pointer array */
|
|
int hdr; /* Offset to the page header */
|
|
int size; /* Size of a cell */
|
|
int usableSize; /* Number of usable bytes on a page */
|
|
int cellOffset; /* Offset to the cell pointer array */
|
|
int cbrk; /* Offset to the cell content area */
|
|
int nCell; /* Number of cells on the page */
|
|
byte[] data; /* The page data */
|
|
byte[] temp; /* Temp area for cell content */
|
|
int iCellFirst; /* First allowable cell index */
|
|
int iCellLast; /* Last possible cell index */
|
|
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
Debug.Assert(pPage.pBt != null);
|
|
Debug.Assert(pPage.pBt.usableSize <= SQLITE_MAX_PAGE_SIZE);
|
|
Debug.Assert(pPage.nOverflow == 0);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
temp = sqlite3PagerTempSpace(pPage.pBt.pPager);
|
|
data = pPage.aData;
|
|
hdr = pPage.hdrOffset;
|
|
cellOffset = pPage.cellOffset;
|
|
nCell = pPage.nCell;
|
|
Debug.Assert(nCell == get2byte(data, hdr + 3));
|
|
usableSize = (int)pPage.pBt.usableSize;
|
|
cbrk = get2byte(data, hdr + 5);
|
|
Buffer.BlockCopy(data, cbrk, temp, cbrk, usableSize - cbrk);//memcpy( temp[cbrk], ref data[cbrk], usableSize - cbrk );
|
|
cbrk = usableSize;
|
|
iCellFirst = cellOffset + 2 * nCell;
|
|
iCellLast = usableSize - 4;
|
|
for (i = 0; i < nCell; i++)
|
|
{
|
|
int pAddr; /* The i-th cell pointer */
|
|
pAddr = cellOffset + i * 2; // &data[cellOffset + i * 2];
|
|
pc = get2byte(data, pAddr);
|
|
testcase(pc == iCellFirst);
|
|
testcase(pc == iCellLast);
|
|
#if !(SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
|
|
/* These conditions have already been verified in btreeInitPage()
|
|
** if SQLITE_ENABLE_OVERSIZE_CELL_CHECK is defined
|
|
*/
|
|
if (pc < iCellFirst || pc > iCellLast)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
#endif
|
|
Debug.Assert(pc >= iCellFirst && pc <= iCellLast);
|
|
size = cellSizePtr(pPage, temp, pc);
|
|
cbrk -= size;
|
|
#if (SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
|
|
if ( cbrk < iCellFirst || pc + size > usableSize )
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
#else
|
|
if (cbrk < iCellFirst || pc + size > usableSize)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
#endif
|
|
Debug.Assert(cbrk + size <= usableSize && cbrk >= iCellFirst);
|
|
testcase(cbrk + size == usableSize);
|
|
testcase(pc + size == usableSize);
|
|
Buffer.BlockCopy(temp, pc, data, cbrk, size);//memcpy(data[cbrk], ref temp[pc], size);
|
|
put2byte(data, pAddr, cbrk);
|
|
}
|
|
Debug.Assert(cbrk >= iCellFirst);
|
|
put2byte(data, hdr + 5, cbrk);
|
|
data[hdr + 1] = 0;
|
|
data[hdr + 2] = 0;
|
|
data[hdr + 7] = 0;
|
|
addr = cellOffset + 2 * nCell;
|
|
Array.Clear(data, addr, cbrk - addr); //memset(data[iCellFirst], 0, cbrk-iCellFirst);
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
if (cbrk - iCellFirst != pPage.nFree)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Allocate nByte bytes of space from within the B-Tree page passed
|
|
** as the first argument. Write into pIdx the index into pPage.aData[]
|
|
** of the first byte of allocated space. Return either SQLITE_OK or
|
|
** an error code (usually SQLITE_CORRUPT).
|
|
**
|
|
** The caller guarantees that there is sufficient space to make the
|
|
** allocation. This routine might need to defragment in order to bring
|
|
** all the space together, however. This routine will avoid using
|
|
** the first two bytes past the cell pointer area since presumably this
|
|
** allocation is being made in order to insert a new cell, so we will
|
|
** also end up needing a new cell pointer.
|
|
*/
|
|
|
|
private static int allocateSpace(MemPage pPage, int nByte, ref int pIdx)
|
|
{
|
|
int hdr = pPage.hdrOffset; /* Local cache of pPage.hdrOffset */
|
|
u8[] data = pPage.aData; /* Local cache of pPage.aData */
|
|
int nFrag; /* Number of fragmented bytes on pPage */
|
|
int top; /* First byte of cell content area */
|
|
int gap; /* First byte of gap between cell pointers and cell content */
|
|
int rc; /* Integer return code */
|
|
u32 usableSize; /* Usable size of the page */
|
|
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
Debug.Assert(pPage.pBt != null);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(nByte >= 0); /* Minimum cell size is 4 */
|
|
Debug.Assert(pPage.nFree >= nByte);
|
|
Debug.Assert(pPage.nOverflow == 0);
|
|
usableSize = pPage.pBt.usableSize;
|
|
Debug.Assert(nByte < usableSize - 8);
|
|
|
|
nFrag = data[hdr + 7];
|
|
Debug.Assert(pPage.cellOffset == hdr + 12 - 4 * pPage.leaf);
|
|
gap = pPage.cellOffset + 2 * pPage.nCell;
|
|
top = get2byteNotZero(data, hdr + 5);
|
|
if (gap > top)
|
|
return SQLITE_CORRUPT_BKPT();
|
|
testcase(gap + 2 == top);
|
|
testcase(gap + 1 == top);
|
|
testcase(gap == top);
|
|
|
|
if (nFrag >= 60)
|
|
{
|
|
/* Always defragment highly fragmented pages */
|
|
rc = defragmentPage(pPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
top = get2byteNotZero(data, hdr + 5);
|
|
}
|
|
else if (gap + 2 <= top)
|
|
{
|
|
/* Search the freelist looking for a free slot big enough to satisfy
|
|
** the request. The allocation is made from the first free slot in
|
|
** the list that is large enough to accomadate it.
|
|
*/
|
|
int pc, addr;
|
|
for (addr = hdr + 1; (pc = get2byte(data, addr)) > 0; addr = pc)
|
|
{
|
|
int size; /* Size of free slot */
|
|
if (pc > usableSize - 4 || pc < addr + 4)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
size = get2byte(data, pc + 2);
|
|
if (size >= nByte)
|
|
{
|
|
int x = size - nByte;
|
|
testcase(x == 4);
|
|
testcase(x == 3);
|
|
if (x < 4)
|
|
{
|
|
/* Remove the slot from the free-list. Update the number of
|
|
** fragmented bytes within the page. */
|
|
data[addr + 0] = data[pc + 0];
|
|
data[addr + 1] = data[pc + 1]; //memcpy( data[addr], ref data[pc], 2 );
|
|
data[hdr + 7] = (u8)(nFrag + x);
|
|
}
|
|
else if (size + pc > usableSize)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
else
|
|
{
|
|
/* The slot remains on the free-list. Reduce its size to account
|
|
** for the portion used by the new allocation. */
|
|
put2byte(data, pc + 2, x);
|
|
}
|
|
pIdx = pc + x;
|
|
return SQLITE_OK;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Check to make sure there is enough space in the gap to satisfy
|
|
** the allocation. If not, defragment.
|
|
*/
|
|
testcase(gap + 2 + nByte == top);
|
|
if (gap + 2 + nByte > top)
|
|
{
|
|
rc = defragmentPage(pPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
top = get2byteNotZero(data, hdr + 5);
|
|
Debug.Assert(gap + nByte <= top);
|
|
}
|
|
|
|
/* Allocate memory from the gap in between the cell pointer array
|
|
** and the cell content area. The btreeInitPage() call has already
|
|
** validated the freelist. Given that the freelist is valid, there
|
|
** is no way that the allocation can extend off the end of the page.
|
|
** The Debug.Assert() below verifies the previous sentence.
|
|
*/
|
|
top -= nByte;
|
|
put2byte(data, hdr + 5, top);
|
|
Debug.Assert(top + nByte <= (int)pPage.pBt.usableSize);
|
|
pIdx = top;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Return a section of the pPage.aData to the freelist.
|
|
** The first byte of the new free block is pPage.aDisk[start]
|
|
** and the size of the block is "size" bytes.
|
|
**
|
|
** Most of the effort here is involved in coalesing adjacent
|
|
** free blocks into a single big free block.
|
|
*/
|
|
|
|
private static int freeSpace(MemPage pPage, u32 start, int size)
|
|
{
|
|
return freeSpace(pPage, (int)start, size);
|
|
}
|
|
|
|
private static int freeSpace(MemPage pPage, int start, int size)
|
|
{
|
|
int addr, pbegin, hdr;
|
|
int iLast; /* Largest possible freeblock offset */
|
|
byte[] data = pPage.aData;
|
|
|
|
Debug.Assert(pPage.pBt != null);
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
Debug.Assert(start >= pPage.hdrOffset + 6 + pPage.childPtrSize);
|
|
Debug.Assert((start + size) <= (int)pPage.pBt.usableSize);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(size >= 0); /* Minimum cell size is 4 */
|
|
|
|
if (pPage.pBt.secureDelete)
|
|
{
|
|
/* Overwrite deleted information with zeros when the secure_delete
|
|
** option is enabled */
|
|
Array.Clear(data, start, size);// memset(&data[start], 0, size);
|
|
}
|
|
|
|
/* Add the space back into the linked list of freeblocks. Note that
|
|
** even though the freeblock list was checked by btreeInitPage(),
|
|
** btreeInitPage() did not detect overlapping cells or
|
|
** freeblocks that overlapped cells. Nor does it detect when the
|
|
** cell content area exceeds the value in the page header. If these
|
|
** situations arise, then subsequent insert operations might corrupt
|
|
** the freelist. So we do need to check for corruption while scanning
|
|
** the freelist.
|
|
*/
|
|
hdr = pPage.hdrOffset;
|
|
addr = hdr + 1;
|
|
iLast = (int)pPage.pBt.usableSize - 4;
|
|
Debug.Assert(start <= iLast);
|
|
while ((pbegin = get2byte(data, addr)) < start && pbegin > 0)
|
|
{
|
|
if (pbegin < addr + 4)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
addr = pbegin;
|
|
}
|
|
if (pbegin > iLast)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
Debug.Assert(pbegin > addr || pbegin == 0);
|
|
put2byte(data, addr, start);
|
|
put2byte(data, start, pbegin);
|
|
put2byte(data, start + 2, size);
|
|
pPage.nFree = (u16)(pPage.nFree + size);
|
|
|
|
/* Coalesce adjacent free blocks */
|
|
addr = hdr + 1;
|
|
while ((pbegin = get2byte(data, addr)) > 0)
|
|
{
|
|
int pnext, psize, x;
|
|
Debug.Assert(pbegin > addr);
|
|
Debug.Assert(pbegin <= (int)pPage.pBt.usableSize - 4);
|
|
pnext = get2byte(data, pbegin);
|
|
psize = get2byte(data, pbegin + 2);
|
|
if (pbegin + psize + 3 >= pnext && pnext > 0)
|
|
{
|
|
int frag = pnext - (pbegin + psize);
|
|
if ((frag < 0) || (frag > (int)data[hdr + 7]))
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
data[hdr + 7] -= (u8)frag;
|
|
x = get2byte(data, pnext);
|
|
put2byte(data, pbegin, x);
|
|
x = pnext + get2byte(data, pnext + 2) - pbegin;
|
|
put2byte(data, pbegin + 2, x);
|
|
}
|
|
else
|
|
{
|
|
addr = pbegin;
|
|
}
|
|
}
|
|
|
|
/* If the cell content area begins with a freeblock, remove it. */
|
|
if (data[hdr + 1] == data[hdr + 5] && data[hdr + 2] == data[hdr + 6])
|
|
{
|
|
int top;
|
|
pbegin = get2byte(data, hdr + 1);
|
|
put2byte(data, hdr + 1, get2byte(data, pbegin)); //memcpy( data[hdr + 1], ref data[pbegin], 2 );
|
|
top = get2byte(data, hdr + 5) + get2byte(data, pbegin + 2);
|
|
put2byte(data, hdr + 5, top);
|
|
}
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Decode the flags byte (the first byte of the header) for a page
|
|
** and initialize fields of the MemPage structure accordingly.
|
|
**
|
|
** Only the following combinations are supported. Anything different
|
|
** indicates a corrupt database files:
|
|
**
|
|
** PTF_ZERODATA
|
|
** PTF_ZERODATA | PTF_LEAF
|
|
** PTF_LEAFDATA | PTF_INTKEY
|
|
** PTF_LEAFDATA | PTF_INTKEY | PTF_LEAF
|
|
*/
|
|
|
|
private static int decodeFlags(MemPage pPage, int flagByte)
|
|
{
|
|
BtShared pBt; /* A copy of pPage.pBt */
|
|
|
|
Debug.Assert(pPage.hdrOffset == (pPage.pgno == 1 ? 100 : 0));
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
pPage.leaf = (u8)(flagByte >> 3);
|
|
Debug.Assert(PTF_LEAF == 1 << 3);
|
|
flagByte &= ~PTF_LEAF;
|
|
pPage.childPtrSize = (u8)(4 - 4 * pPage.leaf);
|
|
pBt = pPage.pBt;
|
|
if (flagByte == (PTF_LEAFDATA | PTF_INTKEY))
|
|
{
|
|
pPage.intKey = 1;
|
|
pPage.hasData = pPage.leaf;
|
|
pPage.maxLocal = pBt.maxLeaf;
|
|
pPage.minLocal = pBt.minLeaf;
|
|
}
|
|
else if (flagByte == PTF_ZERODATA)
|
|
{
|
|
pPage.intKey = 0;
|
|
pPage.hasData = 0;
|
|
pPage.maxLocal = pBt.maxLocal;
|
|
pPage.minLocal = pBt.minLocal;
|
|
}
|
|
else
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Initialize the auxiliary information for a disk block.
|
|
**
|
|
** Return SQLITE_OK on success. If we see that the page does
|
|
** not contain a well-formed database page, then return
|
|
** SQLITE_CORRUPT. Note that a return of SQLITE_OK does not
|
|
** guarantee that the page is well-formed. It only shows that
|
|
** we failed to detect any corruption.
|
|
*/
|
|
|
|
private static int btreeInitPage(MemPage pPage)
|
|
{
|
|
Debug.Assert(pPage.pBt != null);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(pPage.pgno == sqlite3PagerPagenumber(pPage.pDbPage));
|
|
Debug.Assert(pPage == sqlite3PagerGetExtra(pPage.pDbPage));
|
|
Debug.Assert(pPage.aData == sqlite3PagerGetData(pPage.pDbPage));
|
|
|
|
if (0 == pPage.isInit)
|
|
{
|
|
u16 pc; /* Address of a freeblock within pPage.aData[] */
|
|
u8 hdr; /* Offset to beginning of page header */
|
|
u8[] data; /* Equal to pPage.aData */
|
|
BtShared pBt; /* The main btree structure */
|
|
int usableSize; /* Amount of usable space on each page */
|
|
u16 cellOffset; /* Offset from start of page to first cell pointer */
|
|
int nFree; /* Number of unused bytes on the page */
|
|
int top; /* First byte of the cell content area */
|
|
int iCellFirst; /* First allowable cell or freeblock offset */
|
|
int iCellLast; /* Last possible cell or freeblock offset */
|
|
|
|
pBt = pPage.pBt;
|
|
|
|
hdr = pPage.hdrOffset;
|
|
data = pPage.aData;
|
|
if (decodeFlags(pPage, data[hdr]) != 0)
|
|
return SQLITE_CORRUPT_BKPT();
|
|
Debug.Assert(pBt.pageSize >= 512 && pBt.pageSize <= 65536);
|
|
pPage.maskPage = (u16)(pBt.pageSize - 1);
|
|
pPage.nOverflow = 0;
|
|
usableSize = (int)pBt.usableSize;
|
|
pPage.cellOffset = (cellOffset = (u16)(hdr + 12 - 4 * pPage.leaf));
|
|
top = get2byteNotZero(data, hdr + 5);
|
|
pPage.nCell = (u16)(get2byte(data, hdr + 3));
|
|
if (pPage.nCell > MX_CELL(pBt))
|
|
{
|
|
/* To many cells for a single page. The page must be corrupt */
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
testcase(pPage.nCell == MX_CELL(pBt));
|
|
|
|
/* A malformed database page might cause us to read past the end
|
|
** of page when parsing a cell.
|
|
**
|
|
** The following block of code checks early to see if a cell extends
|
|
** past the end of a page boundary and causes SQLITE_CORRUPT to be
|
|
** returned if it does.
|
|
*/
|
|
iCellFirst = cellOffset + 2 * pPage.nCell;
|
|
iCellLast = usableSize - 4;
|
|
#if (SQLITE_ENABLE_OVERSIZE_CELL_CHECK)
|
|
{
|
|
int i; /* Index into the cell pointer array */
|
|
int sz; /* Size of a cell */
|
|
|
|
if ( 0 == pPage.leaf )
|
|
iCellLast--;
|
|
for ( i = 0; i < pPage.nCell; i++ )
|
|
{
|
|
pc = (u16)get2byte( data, cellOffset + i * 2 );
|
|
testcase( pc == iCellFirst );
|
|
testcase( pc == iCellLast );
|
|
if ( pc < iCellFirst || pc > iCellLast )
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
sz = cellSizePtr( pPage, data, pc );
|
|
testcase( pc + sz == usableSize );
|
|
if ( pc + sz > usableSize )
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
}
|
|
if ( 0 == pPage.leaf )
|
|
iCellLast++;
|
|
}
|
|
#endif
|
|
|
|
/* Compute the total free space on the page */
|
|
pc = (u16)get2byte(data, hdr + 1);
|
|
nFree = (u16)(data[hdr + 7] + top);
|
|
while (pc > 0)
|
|
{
|
|
u16 next, size;
|
|
if (pc < iCellFirst || pc > iCellLast)
|
|
{
|
|
/* Start of free block is off the page */
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
next = (u16)get2byte(data, pc);
|
|
size = (u16)get2byte(data, pc + 2);
|
|
if ((next > 0 && next <= pc + size + 3) || pc + size > usableSize)
|
|
{
|
|
/* Free blocks must be in ascending order. And the last byte of
|
|
** the free-block must lie on the database page. */
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
nFree = (u16)(nFree + size);
|
|
pc = next;
|
|
}
|
|
|
|
/* At this point, nFree contains the sum of the offset to the start
|
|
** of the cell-content area plus the number of free bytes within
|
|
** the cell-content area. If this is greater than the usable-size
|
|
** of the page, then the page must be corrupted. This check also
|
|
** serves to verify that the offset to the start of the cell-content
|
|
** area, according to the page header, lies within the page.
|
|
*/
|
|
if (nFree > usableSize)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
pPage.nFree = (u16)(nFree - iCellFirst);
|
|
pPage.isInit = 1;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Set up a raw page so that it looks like a database page holding
|
|
** no entries.
|
|
*/
|
|
|
|
private static void zeroPage(MemPage pPage, int flags)
|
|
{
|
|
byte[] data = pPage.aData;
|
|
BtShared pBt = pPage.pBt;
|
|
u8 hdr = pPage.hdrOffset;
|
|
u16 first;
|
|
|
|
Debug.Assert(sqlite3PagerPagenumber(pPage.pDbPage) == pPage.pgno);
|
|
Debug.Assert(sqlite3PagerGetExtra(pPage.pDbPage) == pPage);
|
|
Debug.Assert(sqlite3PagerGetData(pPage.pDbPage) == data);
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
if (pBt.secureDelete)
|
|
{
|
|
Array.Clear(data, hdr, (int)(pBt.usableSize - hdr));//memset(&data[hdr], 0, pBt->usableSize - hdr);
|
|
}
|
|
|
|
data[hdr] = (u8)flags;
|
|
first = (u16)(hdr + 8 + 4 * ((flags & PTF_LEAF) == 0 ? 1 : 0));
|
|
Array.Clear(data, hdr + 1, 4);//memset(data[hdr+1], 0, 4);
|
|
data[hdr + 7] = 0;
|
|
put2byte(data, hdr + 5, pBt.usableSize);
|
|
pPage.nFree = (u16)(pBt.usableSize - first);
|
|
decodeFlags(pPage, flags);
|
|
pPage.hdrOffset = hdr;
|
|
pPage.cellOffset = first;
|
|
pPage.nOverflow = 0;
|
|
Debug.Assert(pBt.pageSize >= 512 && pBt.pageSize <= 65536);
|
|
pPage.maskPage = (u16)(pBt.pageSize - 1);
|
|
pPage.nCell = 0;
|
|
pPage.isInit = 1;
|
|
}
|
|
|
|
/*
|
|
** Convert a DbPage obtained from the pager into a MemPage used by
|
|
** the btree layer.
|
|
*/
|
|
|
|
private static MemPage btreePageFromDbPage(DbPage pDbPage, Pgno pgno, BtShared pBt)
|
|
{
|
|
MemPage pPage = (MemPage)sqlite3PagerGetExtra(pDbPage);
|
|
pPage.aData = sqlite3PagerGetData(pDbPage);
|
|
pPage.pDbPage = pDbPage;
|
|
pPage.pBt = pBt;
|
|
pPage.pgno = pgno;
|
|
pPage.hdrOffset = (u8)(pPage.pgno == 1 ? 100 : 0);
|
|
return pPage;
|
|
}
|
|
|
|
/*
|
|
** Get a page from the pager. Initialize the MemPage.pBt and
|
|
** MemPage.aData elements if needed.
|
|
**
|
|
** If the noContent flag is set, it means that we do not care about
|
|
** the content of the page at this time. So do not go to the disk
|
|
** to fetch the content. Just fill in the content with zeros for now.
|
|
** If in the future we call sqlite3PagerWrite() on this page, that
|
|
** means we have started to be concerned about content and the disk
|
|
** read should occur at that point.
|
|
*/
|
|
|
|
private static int btreeGetPage(
|
|
BtShared pBt, /* The btree */
|
|
Pgno pgno, /* Number of the page to fetch */
|
|
ref MemPage ppPage, /* Return the page in this parameter */
|
|
int noContent /* Do not load page content if true */
|
|
)
|
|
{
|
|
int rc;
|
|
DbPage pDbPage = null;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
rc = sqlite3PagerAcquire(pBt.pPager, pgno, ref pDbPage, (u8)noContent);
|
|
if (rc != 0)
|
|
return rc;
|
|
ppPage = btreePageFromDbPage(pDbPage, pgno, pBt);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Retrieve a page from the pager cache. If the requested page is not
|
|
** already in the pager cache return NULL. Initialize the MemPage.pBt and
|
|
** MemPage.aData elements if needed.
|
|
*/
|
|
|
|
private static MemPage btreePageLookup(BtShared pBt, Pgno pgno)
|
|
{
|
|
DbPage pDbPage;
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
pDbPage = sqlite3PagerLookup(pBt.pPager, pgno);
|
|
if (pDbPage)
|
|
{
|
|
return btreePageFromDbPage(pDbPage, pgno, pBt);
|
|
}
|
|
return null;
|
|
}
|
|
|
|
/*
|
|
** Return the size of the database file in pages. If there is any kind of
|
|
** error, return ((unsigned int)-1).
|
|
*/
|
|
|
|
private static Pgno btreePagecount(BtShared pBt)
|
|
{
|
|
return pBt.nPage;
|
|
}
|
|
|
|
private static Pgno sqlite3BtreeLastPage(Btree p)
|
|
{
|
|
Debug.Assert(sqlite3BtreeHoldsMutex(p));
|
|
Debug.Assert(((p.pBt.nPage) & 0x8000000) == 0);
|
|
return (Pgno)btreePagecount(p.pBt);
|
|
}
|
|
|
|
/*
|
|
** Get a page from the pager and initialize it. This routine is just a
|
|
** convenience wrapper around separate calls to btreeGetPage() and
|
|
** btreeInitPage().
|
|
**
|
|
** If an error occurs, then the value ppPage is set to is undefined. It
|
|
** may remain unchanged, or it may be set to an invalid value.
|
|
*/
|
|
|
|
private static int getAndInitPage(
|
|
BtShared pBt, /* The database file */
|
|
Pgno pgno, /* Number of the page to get */
|
|
ref MemPage ppPage /* Write the page pointer here */
|
|
)
|
|
{
|
|
int rc;
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
|
|
if (pgno > btreePagecount(pBt))
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
}
|
|
else
|
|
{
|
|
rc = btreeGetPage(pBt, pgno, ref ppPage, 0);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = btreeInitPage(ppPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(ppPage);
|
|
}
|
|
}
|
|
}
|
|
|
|
testcase(pgno == 0);
|
|
Debug.Assert(pgno != 0 || rc == SQLITE_CORRUPT);
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Release a MemPage. This should be called once for each prior
|
|
** call to btreeGetPage.
|
|
*/
|
|
|
|
private static void releasePage(MemPage pPage)
|
|
{
|
|
if (pPage != null)
|
|
{
|
|
Debug.Assert(pPage.aData != null);
|
|
Debug.Assert(pPage.pBt != null);
|
|
//TODO -- find out why corrupt9 & diskfull fail on this tests
|
|
//Debug.Assert( sqlite3PagerGetExtra( pPage.pDbPage ) == pPage );
|
|
//Debug.Assert( sqlite3PagerGetData( pPage.pDbPage ) == pPage.aData );
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
sqlite3PagerUnref(pPage.pDbPage);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** During a rollback, when the pager reloads information into the cache
|
|
** so that the cache is restored to its original state at the start of
|
|
** the transaction, for each page restored this routine is called.
|
|
**
|
|
** This routine needs to reset the extra data section at the end of the
|
|
** page to agree with the restored data.
|
|
*/
|
|
|
|
private static void pageReinit(DbPage pData)
|
|
{
|
|
MemPage pPage;
|
|
pPage = sqlite3PagerGetExtra(pData);
|
|
Debug.Assert(sqlite3PagerPageRefcount(pData) > 0);
|
|
if (pPage.isInit != 0)
|
|
{
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
pPage.isInit = 0;
|
|
if (sqlite3PagerPageRefcount(pData) > 1)
|
|
{
|
|
/* pPage might not be a btree page; it might be an overflow page
|
|
** or ptrmap page or a free page. In those cases, the following
|
|
** call to btreeInitPage() will likely return SQLITE_CORRUPT.
|
|
** But no harm is done by this. And it is very important that
|
|
** btreeInitPage() be called on every btree page so we make
|
|
** the call for every page that comes in for re-initing. */
|
|
btreeInitPage(pPage);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Invoke the busy handler for a btree.
|
|
*/
|
|
|
|
private static int btreeInvokeBusyHandler(object pArg)
|
|
{
|
|
BtShared pBt = (BtShared)pArg;
|
|
Debug.Assert(pBt.db != null);
|
|
Debug.Assert(sqlite3_mutex_held(pBt.db.mutex));
|
|
return sqlite3InvokeBusyHandler(pBt.db.busyHandler);
|
|
}
|
|
|
|
/*
|
|
** Open a database file.
|
|
**
|
|
** zFilename is the name of the database file. If zFilename is NULL
|
|
** then an ephemeral database is created. The ephemeral database might
|
|
** be exclusively in memory, or it might use a disk-based memory cache.
|
|
** Either way, the ephemeral database will be automatically deleted
|
|
** when sqlite3BtreeClose() is called.
|
|
**
|
|
** If zFilename is ":memory:" then an in-memory database is created
|
|
** that is automatically destroyed when it is closed.
|
|
**
|
|
** The "flags" parameter is a bitmask that might contain bits
|
|
** BTREE_OMIT_JOURNAL and/or BTREE_NO_READLOCK. The BTREE_NO_READLOCK
|
|
** bit is also set if the SQLITE_NoReadlock flags is set in db->flags.
|
|
** These flags are passed through into sqlite3PagerOpen() and must
|
|
** be the same values as PAGER_OMIT_JOURNAL and PAGER_NO_READLOCK.
|
|
**
|
|
** If the database is already opened in the same database connection
|
|
** and we are in shared cache mode, then the open will fail with an
|
|
** SQLITE_CONSTRAINT error. We cannot allow two or more BtShared
|
|
** objects in the same database connection since doing so will lead
|
|
** to problems with locking.
|
|
*/
|
|
|
|
private static int sqlite3BtreeOpen(
|
|
sqlite3_vfs pVfs, /* VFS to use for this b-tree */
|
|
string zFilename, /* Name of the file containing the BTree database */
|
|
sqlite3 db, /* Associated database handle */
|
|
ref Btree ppBtree, /* Pointer to new Btree object written here */
|
|
int flags, /* Options */
|
|
int vfsFlags /* Flags passed through to sqlite3_vfs.xOpen() */
|
|
)
|
|
{
|
|
BtShared pBt = null; /* Shared part of btree structure */
|
|
Btree p; /* Handle to return */
|
|
sqlite3_mutex mutexOpen = null; /* Prevents a race condition. Ticket #3537 */
|
|
int rc = SQLITE_OK; /* Result code from this function */
|
|
u8 nReserve; /* Byte of unused space on each page */
|
|
byte[] zDbHeader = new byte[100]; /* Database header content */
|
|
|
|
/* True if opening an ephemeral, temporary database */
|
|
bool isTempDb = String.IsNullOrEmpty(zFilename);//zFilename==0 || zFilename[0]==0;
|
|
|
|
/* Set the variable isMemdb to true for an in-memory database, or
|
|
** false for a file-based database.
|
|
*/
|
|
#if SQLITE_OMIT_MEMORYDB
|
|
bool isMemdb = false;
|
|
#else
|
|
bool isMemdb = (zFilename == ":memory:")
|
|
|| (isTempDb && sqlite3TempInMemory(db));
|
|
|
|
#endif
|
|
|
|
Debug.Assert(db != null);
|
|
Debug.Assert(pVfs != null);
|
|
Debug.Assert(sqlite3_mutex_held(db.mutex));
|
|
Debug.Assert((flags & 0xff) == flags); /* flags fit in 8 bits */
|
|
|
|
/* Only a BTREE_SINGLE database can be BTREE_UNORDERED */
|
|
Debug.Assert((flags & BTREE_UNORDERED) == 0 || (flags & BTREE_SINGLE) != 0);
|
|
|
|
/* A BTREE_SINGLE database is always a temporary and/or ephemeral */
|
|
Debug.Assert((flags & BTREE_SINGLE) == 0 || isTempDb);
|
|
|
|
if ((db.flags & SQLITE_NoReadlock) != 0)
|
|
{
|
|
flags |= BTREE_NO_READLOCK;
|
|
}
|
|
if (isMemdb)
|
|
{
|
|
flags |= BTREE_MEMORY;
|
|
}
|
|
if ((vfsFlags & SQLITE_OPEN_MAIN_DB) != 0 && (isMemdb || isTempDb))
|
|
{
|
|
vfsFlags = (vfsFlags & ~SQLITE_OPEN_MAIN_DB) | SQLITE_OPEN_TEMP_DB;
|
|
}
|
|
|
|
p = new Btree();//sqlite3MallocZero(sizeof(Btree));
|
|
//if( !p ){
|
|
// return SQLITE_NOMEM;
|
|
//}
|
|
p.inTrans = TRANS_NONE;
|
|
p.db = db;
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
p.lock.pBtree = p;
|
|
p.lock.iTable = 1;
|
|
#endif
|
|
|
|
#if !(SQLITE_OMIT_SHARED_CACHE) && !(SQLITE_OMIT_DISKIO)
|
|
/*
|
|
** If this Btree is a candidate for shared cache, try to find an
|
|
** existing BtShared object that we can share with
|
|
*/
|
|
if( !isMemdb && !isTempDb ){
|
|
if( vfsFlags & SQLITE_OPEN_SHAREDCACHE ){
|
|
int nFullPathname = pVfs.mxPathname+1;
|
|
string zFullPathname = sqlite3Malloc(nFullPathname);
|
|
sqlite3_mutex *mutexShared;
|
|
p.sharable = 1;
|
|
if( !zFullPathname ){
|
|
p = null;//sqlite3_free(ref p);
|
|
return SQLITE_NOMEM;
|
|
}
|
|
sqlite3OsFullPathname(pVfs, zFilename, nFullPathname, zFullPathname);
|
|
mutexOpen = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_OPEN);
|
|
sqlite3_mutex_enter(mutexOpen);
|
|
mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
|
|
sqlite3_mutex_enter(mutexShared);
|
|
for(pBt=GLOBAL(BtShared*,sqlite3SharedCacheList); pBt; pBt=pBt.pNext){
|
|
Debug.Assert( pBt.nRef>0 );
|
|
if( 0==strcmp(zFullPathname, sqlite3PagerFilename(pBt.pPager))
|
|
&& sqlite3PagerVfs(pBt.pPager)==pVfs ){
|
|
int iDb;
|
|
for(iDb=db.nDb-1; iDb>=0; iDb--){
|
|
Btree pExisting = db.aDb[iDb].pBt;
|
|
if( pExisting && pExisting.pBt==pBt ){
|
|
sqlite3_mutex_leave(mutexShared);
|
|
sqlite3_mutex_leave(mutexOpen);
|
|
zFullPathname = null;//sqlite3_free(ref zFullPathname);
|
|
p=null;//sqlite3_free(ref p);
|
|
return SQLITE_CONSTRAINT;
|
|
}
|
|
}
|
|
p.pBt = pBt;
|
|
pBt.nRef++;
|
|
break;
|
|
}
|
|
}
|
|
sqlite3_mutex_leave(mutexShared);
|
|
zFullPathname=null;//sqlite3_free(ref zFullPathname);
|
|
}
|
|
#if SQLITE_DEBUG
|
|
else{
|
|
/* In debug mode, we mark all persistent databases as sharable
|
|
** even when they are not. This exercises the locking code and
|
|
** gives more opportunity for asserts(sqlite3_mutex_held())
|
|
** statements to find locking problems.
|
|
*/
|
|
p.sharable = 1;
|
|
}
|
|
#endif
|
|
}
|
|
#endif
|
|
if (pBt == null)
|
|
{
|
|
/*
|
|
** The following asserts make sure that structures used by the btree are
|
|
** the right size. This is to guard against size changes that result
|
|
** when compiling on a different architecture.
|
|
*/
|
|
Debug.Assert(sizeof(i64) == 8 || sizeof(i64) == 4);
|
|
Debug.Assert(sizeof(u64) == 8 || sizeof(u64) == 4);
|
|
Debug.Assert(sizeof(u32) == 4);
|
|
Debug.Assert(sizeof(u16) == 2);
|
|
Debug.Assert(sizeof(Pgno) == 4);
|
|
|
|
pBt = new BtShared();//sqlite3MallocZero( sizeof(pBt) );
|
|
//if( pBt==null ){
|
|
// rc = SQLITE_NOMEM;
|
|
// goto btree_open_out;
|
|
//}
|
|
rc = sqlite3PagerOpen(pVfs, out pBt.pPager, zFilename,
|
|
EXTRA_SIZE, flags, vfsFlags, pageReinit);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = sqlite3PagerReadFileheader(pBt.pPager, zDbHeader.Length, zDbHeader);
|
|
}
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto btree_open_out;
|
|
}
|
|
pBt.openFlags = (u8)flags;
|
|
pBt.db = db;
|
|
sqlite3PagerSetBusyhandler(pBt.pPager, btreeInvokeBusyHandler, pBt);
|
|
p.pBt = pBt;
|
|
|
|
pBt.pCursor = null;
|
|
pBt.pPage1 = null;
|
|
pBt.readOnly = sqlite3PagerIsreadonly(pBt.pPager);
|
|
#if SQLITE_SECURE_DELETE
|
|
pBt.secureDelete = true;
|
|
#endif
|
|
pBt.pageSize = (u32)((zDbHeader[16] << 8) | (zDbHeader[17] << 16));
|
|
if (pBt.pageSize < 512 || pBt.pageSize > SQLITE_MAX_PAGE_SIZE
|
|
|| ((pBt.pageSize - 1) & pBt.pageSize) != 0)
|
|
{
|
|
pBt.pageSize = 0;
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
/* If the magic name ":memory:" will create an in-memory database, then
|
|
** leave the autoVacuum mode at 0 (do not auto-vacuum), even if
|
|
** SQLITE_DEFAULT_AUTOVACUUM is true. On the other hand, if
|
|
** SQLITE_OMIT_MEMORYDB has been defined, then ":memory:" is just a
|
|
** regular file-name. In this case the auto-vacuum applies as per normal.
|
|
*/
|
|
if (zFilename != "" && !isMemdb)
|
|
{
|
|
pBt.autoVacuum = (SQLITE_DEFAULT_AUTOVACUUM != 0);
|
|
pBt.incrVacuum = (SQLITE_DEFAULT_AUTOVACUUM == 2);
|
|
}
|
|
#endif
|
|
nReserve = 0;
|
|
}
|
|
else
|
|
{
|
|
nReserve = zDbHeader[20];
|
|
pBt.pageSizeFixed = true;
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
pBt.autoVacuum = sqlite3Get4byte(zDbHeader, 36 + 4 * 4) != 0;
|
|
pBt.incrVacuum = sqlite3Get4byte(zDbHeader, 36 + 7 * 4) != 0;
|
|
#endif
|
|
}
|
|
rc = sqlite3PagerSetPagesize(pBt.pPager, ref pBt.pageSize, nReserve);
|
|
if (rc != 0)
|
|
goto btree_open_out;
|
|
pBt.usableSize = (u16)(pBt.pageSize - nReserve);
|
|
Debug.Assert((pBt.pageSize & 7) == 0); /* 8-byte alignment of pageSize */
|
|
|
|
#if !(SQLITE_OMIT_SHARED_CACHE) && !(SQLITE_OMIT_DISKIO)
|
|
/* Add the new BtShared object to the linked list sharable BtShareds.
|
|
*/
|
|
if( p.sharable ){
|
|
sqlite3_mutex *mutexShared;
|
|
pBt.nRef = 1;
|
|
mutexShared = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
|
|
if( SQLITE_THREADSAFE && sqlite3GlobalConfig.bCoreMutex ){
|
|
pBt.mutex = sqlite3MutexAlloc(SQLITE_MUTEX_FAST);
|
|
if( pBt.mutex==null ){
|
|
rc = SQLITE_NOMEM;
|
|
db.mallocFailed = 0;
|
|
goto btree_open_out;
|
|
}
|
|
}
|
|
sqlite3_mutex_enter(mutexShared);
|
|
pBt.pNext = GLOBAL(BtShared*,sqlite3SharedCacheList);
|
|
GLOBAL(BtShared*,sqlite3SharedCacheList) = pBt;
|
|
sqlite3_mutex_leave(mutexShared);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
#if !(SQLITE_OMIT_SHARED_CACHE) && !(SQLITE_OMIT_DISKIO)
|
|
/* If the new Btree uses a sharable pBtShared, then link the new
|
|
** Btree into the list of all sharable Btrees for the same connection.
|
|
** The list is kept in ascending order by pBt address.
|
|
*/
|
|
if( p.sharable ){
|
|
int i;
|
|
Btree pSib;
|
|
for(i=0; i<db.nDb; i++){
|
|
if( (pSib = db.aDb[i].pBt)!=null && pSib.sharable ){
|
|
while( pSib.pPrev ){ pSib = pSib.pPrev; }
|
|
if( p.pBt<pSib.pBt ){
|
|
p.pNext = pSib;
|
|
p.pPrev = 0;
|
|
pSib.pPrev = p;
|
|
}else{
|
|
while( pSib.pNext && pSib.pNext.pBt<p.pBt ){
|
|
pSib = pSib.pNext;
|
|
}
|
|
p.pNext = pSib.pNext;
|
|
p.pPrev = pSib;
|
|
if( p.pNext ){
|
|
p.pNext.pPrev = p;
|
|
}
|
|
pSib.pNext = p;
|
|
}
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
ppBtree = p;
|
|
|
|
btree_open_out:
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
if (pBt != null && pBt.pPager != null)
|
|
{
|
|
sqlite3PagerClose(pBt.pPager);
|
|
}
|
|
pBt = null; // sqlite3_free(ref pBt);
|
|
p = null; // sqlite3_free(ref p);
|
|
ppBtree = null;
|
|
}
|
|
else
|
|
{
|
|
/* If the B-Tree was successfully opened, set the pager-cache size to the
|
|
** default value. Except, when opening on an existing shared pager-cache,
|
|
** do not change the pager-cache size.
|
|
*/
|
|
if (sqlite3BtreeSchema(p, 0, null) == null)
|
|
{
|
|
sqlite3PagerSetCachesize(p.pBt.pPager, SQLITE_DEFAULT_CACHE_SIZE);
|
|
}
|
|
}
|
|
if (mutexOpen != null)
|
|
{
|
|
Debug.Assert(sqlite3_mutex_held(mutexOpen));
|
|
sqlite3_mutex_leave(mutexOpen);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Decrement the BtShared.nRef counter. When it reaches zero,
|
|
** remove the BtShared structure from the sharing list. Return
|
|
** true if the BtShared.nRef counter reaches zero and return
|
|
** false if it is still positive.
|
|
*/
|
|
|
|
private static bool removeFromSharingList(BtShared pBt)
|
|
{
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
sqlite3_mutex pMaster;
|
|
BtShared pList;
|
|
bool removed = false;
|
|
|
|
Debug.Assert( sqlite3_mutex_notheld(pBt.mutex) );
|
|
pMaster = sqlite3MutexAlloc(SQLITE_MUTEX_STATIC_MASTER);
|
|
sqlite3_mutex_enter(pMaster);
|
|
pBt.nRef--;
|
|
if( pBt.nRef<=0 ){
|
|
if( GLOBAL(BtShared*,sqlite3SharedCacheList)==pBt ){
|
|
GLOBAL(BtShared*,sqlite3SharedCacheList) = pBt.pNext;
|
|
}else{
|
|
pList = GLOBAL(BtShared*,sqlite3SharedCacheList);
|
|
while( ALWAYS(pList) && pList.pNext!=pBt ){
|
|
pList=pList.pNext;
|
|
}
|
|
if( ALWAYS(pList) ){
|
|
pList.pNext = pBt.pNext;
|
|
}
|
|
}
|
|
if( SQLITE_THREADSAFE ){
|
|
sqlite3_mutex_free(pBt.mutex);
|
|
}
|
|
removed = true;
|
|
}
|
|
sqlite3_mutex_leave(pMaster);
|
|
return removed;
|
|
#else
|
|
return true;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
** Make sure pBt.pTmpSpace points to an allocation of
|
|
** MX_CELL_SIZE(pBt) bytes.
|
|
*/
|
|
|
|
private static void allocateTempSpace(BtShared pBt)
|
|
{
|
|
if (null == pBt.pTmpSpace)
|
|
{
|
|
pBt.pTmpSpace = sqlite3Malloc(pBt.pageSize);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Free the pBt.pTmpSpace allocation
|
|
*/
|
|
|
|
private static void freeTempSpace(BtShared pBt)
|
|
{
|
|
sqlite3PageFree(ref pBt.pTmpSpace);
|
|
}
|
|
|
|
/*
|
|
** Close an open database and invalidate all cursors.
|
|
*/
|
|
|
|
private static int sqlite3BtreeClose(ref Btree p)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
BtCursor pCur;
|
|
|
|
/* Close all cursors opened via this handle. */
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
sqlite3BtreeEnter(p);
|
|
pCur = pBt.pCursor;
|
|
while (pCur != null)
|
|
{
|
|
BtCursor pTmp = pCur;
|
|
pCur = pCur.pNext;
|
|
if (pTmp.pBtree == p)
|
|
{
|
|
sqlite3BtreeCloseCursor(pTmp);
|
|
}
|
|
}
|
|
|
|
/* Rollback any active transaction and free the handle structure.
|
|
** The call to sqlite3BtreeRollback() drops any table-locks held by
|
|
** this handle.
|
|
*/
|
|
sqlite3BtreeRollback(p);
|
|
sqlite3BtreeLeave(p);
|
|
|
|
/* If there are still other outstanding references to the shared-btree
|
|
** structure, return now. The remainder of this procedure cleans
|
|
** up the shared-btree.
|
|
*/
|
|
Debug.Assert(p.wantToLock == 0 && !p.locked);
|
|
if (!p.sharable || removeFromSharingList(pBt))
|
|
{
|
|
/* The pBt is no longer on the sharing list, so we can access
|
|
** it without having to hold the mutex.
|
|
**
|
|
** Clean out and delete the BtShared object.
|
|
*/
|
|
Debug.Assert(null == pBt.pCursor);
|
|
sqlite3PagerClose(pBt.pPager);
|
|
if (pBt.xFreeSchema != null && pBt.pSchema != null)
|
|
{
|
|
pBt.xFreeSchema(pBt.pSchema);
|
|
}
|
|
pBt.pSchema = null;// sqlite3DbFree(0, pBt->pSchema);
|
|
//freeTempSpace(pBt);
|
|
pBt = null; //sqlite3_free(ref pBt);
|
|
}
|
|
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
Debug.Assert( p.wantToLock==null );
|
|
Debug.Assert( p.locked==null );
|
|
if( p.pPrev ) p.pPrev.pNext = p.pNext;
|
|
if( p.pNext ) p.pNext.pPrev = p.pPrev;
|
|
#endif
|
|
|
|
//sqlite3_free(ref p);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Change the limit on the number of pages allowed in the cache.
|
|
**
|
|
** The maximum number of cache pages is set to the absolute
|
|
** value of mxPage. If mxPage is negative, the pager will
|
|
** operate asynchronously - it will not stop to do fsync()s
|
|
** to insure data is written to the disk surface before
|
|
** continuing. Transactions still work if synchronous is off,
|
|
** and the database cannot be corrupted if this program
|
|
** crashes. But if the operating system crashes or there is
|
|
** an abrupt power failure when synchronous is off, the database
|
|
** could be left in an inconsistent and unrecoverable state.
|
|
** Synchronous is on by default so database corruption is not
|
|
** normally a worry.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSetCacheSize(Btree p, int mxPage)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
sqlite3BtreeEnter(p);
|
|
sqlite3PagerSetCachesize(pBt.pPager, mxPage);
|
|
sqlite3BtreeLeave(p);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Change the way data is synced to disk in order to increase or decrease
|
|
** how well the database resists damage due to OS crashes and power
|
|
** failures. Level 1 is the same as asynchronous (no syncs() occur and
|
|
** there is a high probability of damage) Level 2 is the default. There
|
|
** is a very low but non-zero probability of damage. Level 3 reduces the
|
|
** probability of damage to near zero but with a write performance reduction.
|
|
*/
|
|
#if !SQLITE_OMIT_PAGER_PRAGMAS
|
|
|
|
private static int sqlite3BtreeSetSafetyLevel(
|
|
Btree p, /* The btree to set the safety level on */
|
|
int level, /* PRAGMA synchronous. 1=OFF, 2=NORMAL, 3=FULL */
|
|
int fullSync, /* PRAGMA fullfsync. */
|
|
int ckptFullSync /* PRAGMA checkpoint_fullfync */
|
|
)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
Debug.Assert(level >= 1 && level <= 3);
|
|
sqlite3BtreeEnter(p);
|
|
sqlite3PagerSetSafetyLevel(pBt.pPager, level, fullSync, ckptFullSync);
|
|
sqlite3BtreeLeave(p);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
** Return TRUE if the given btree is set to safety level 1. In other
|
|
** words, return TRUE if no sync() occurs on the disk files.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSyncDisabled(Btree p)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
int rc;
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(pBt != null && pBt.pPager != null);
|
|
rc = sqlite3PagerNosync(pBt.pPager) ? 1 : 0;
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Change the default pages size and the number of reserved bytes per page.
|
|
** Or, if the page size has already been fixed, return SQLITE_READONLY
|
|
** without changing anything.
|
|
**
|
|
** The page size must be a power of 2 between 512 and 65536. If the page
|
|
** size supplied does not meet this constraint then the page size is not
|
|
** changed.
|
|
**
|
|
** Page sizes are constrained to be a power of two so that the region
|
|
** of the database file used for locking (beginning at PENDING_BYTE,
|
|
** the first byte past the 1GB boundary, 0x40000000) needs to occur
|
|
** at the beginning of a page.
|
|
**
|
|
** If parameter nReserve is less than zero, then the number of reserved
|
|
** bytes per page is left unchanged.
|
|
**
|
|
** If iFix!=0 then the pageSizeFixed flag is set so that the page size
|
|
** and autovacuum mode can no longer be changed.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSetPageSize(Btree p, int pageSize, int nReserve, int iFix)
|
|
{
|
|
int rc = SQLITE_OK;
|
|
BtShared pBt = p.pBt;
|
|
Debug.Assert(nReserve >= -1 && nReserve <= 255);
|
|
sqlite3BtreeEnter(p);
|
|
if (pBt.pageSizeFixed)
|
|
{
|
|
sqlite3BtreeLeave(p);
|
|
return SQLITE_READONLY;
|
|
}
|
|
if (nReserve < 0)
|
|
{
|
|
nReserve = (int)(pBt.pageSize - pBt.usableSize);
|
|
}
|
|
Debug.Assert(nReserve >= 0 && nReserve <= 255);
|
|
if (pageSize >= 512 && pageSize <= SQLITE_MAX_PAGE_SIZE &&
|
|
((pageSize - 1) & pageSize) == 0)
|
|
{
|
|
Debug.Assert((pageSize & 7) == 0);
|
|
Debug.Assert(null == pBt.pPage1 && null == pBt.pCursor);
|
|
pBt.pageSize = (u32)pageSize;
|
|
// freeTempSpace(pBt);
|
|
}
|
|
rc = sqlite3PagerSetPagesize(pBt.pPager, ref pBt.pageSize, nReserve);
|
|
pBt.usableSize = (u16)(pBt.pageSize - nReserve);
|
|
if (iFix != 0)
|
|
pBt.pageSizeFixed = true;
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Return the currently defined page size
|
|
*/
|
|
|
|
private static int sqlite3BtreeGetPageSize(Btree p)
|
|
{
|
|
return (int)p.pBt.pageSize;
|
|
}
|
|
|
|
#if !(SQLITE_OMIT_PAGER_PRAGMAS) || !(SQLITE_OMIT_VACUUM)
|
|
/*
|
|
** Return the number of bytes of space at the end of every page that
|
|
** are intentually left unused. This is the "reserved" space that is
|
|
** sometimes used by extensions.
|
|
*/
|
|
|
|
private static int sqlite3BtreeGetReserve(Btree p)
|
|
{
|
|
int n;
|
|
sqlite3BtreeEnter(p);
|
|
n = (int)(p.pBt.pageSize - p.pBt.usableSize);
|
|
sqlite3BtreeLeave(p);
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
** Set the maximum page count for a database if mxPage is positive.
|
|
** No changes are made if mxPage is 0 or negative.
|
|
** Regardless of the value of mxPage, return the maximum page count.
|
|
*/
|
|
|
|
private static Pgno sqlite3BtreeMaxPageCount(Btree p, int mxPage)
|
|
{
|
|
Pgno n;
|
|
sqlite3BtreeEnter(p);
|
|
n = sqlite3PagerMaxPageCount(p.pBt.pPager, mxPage);
|
|
sqlite3BtreeLeave(p);
|
|
return n;
|
|
}
|
|
|
|
/*
|
|
** Set the secureDelete flag if newFlag is 0 or 1. If newFlag is -1,
|
|
** then make no changes. Always return the value of the secureDelete
|
|
** setting after the change.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSecureDelete(Btree p, int newFlag)
|
|
{
|
|
int b;
|
|
if (p == null)
|
|
return 0;
|
|
sqlite3BtreeEnter(p);
|
|
if (newFlag >= 0)
|
|
{
|
|
p.pBt.secureDelete = (newFlag != 0);
|
|
}
|
|
b = p.pBt.secureDelete ? 1 : 0;
|
|
sqlite3BtreeLeave(p);
|
|
return b;
|
|
}
|
|
|
|
#endif //* !(SQLITE_OMIT_PAGER_PRAGMAS) || !(SQLITE_OMIT_VACUUM) */
|
|
|
|
/*
|
|
** Change the 'auto-vacuum' property of the database. If the 'autoVacuum'
|
|
** parameter is non-zero, then auto-vacuum mode is enabled. If zero, it
|
|
** is disabled. The default value for the auto-vacuum property is
|
|
** determined by the SQLITE_DEFAULT_AUTOVACUUM macro.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSetAutoVacuum(Btree p, int autoVacuum)
|
|
{
|
|
#if SQLITE_OMIT_AUTOVACUUM
|
|
return SQLITE_READONLY;
|
|
#else
|
|
BtShared pBt = p.pBt;
|
|
int rc = SQLITE_OK;
|
|
u8 av = (u8)autoVacuum;
|
|
|
|
sqlite3BtreeEnter(p);
|
|
if (pBt.pageSizeFixed && (av != 0) != pBt.autoVacuum)
|
|
{
|
|
rc = SQLITE_READONLY;
|
|
}
|
|
else
|
|
{
|
|
pBt.autoVacuum = av != 0;
|
|
pBt.incrVacuum = av == 2;
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
** Return the value of the 'auto-vacuum' property. If auto-vacuum is
|
|
** enabled 1 is returned. Otherwise 0.
|
|
*/
|
|
|
|
private static int sqlite3BtreeGetAutoVacuum(Btree p)
|
|
{
|
|
#if SQLITE_OMIT_AUTOVACUUM
|
|
return BTREE_AUTOVACUUM_NONE;
|
|
#else
|
|
int rc;
|
|
sqlite3BtreeEnter(p);
|
|
rc = (
|
|
(!p.pBt.autoVacuum) ? BTREE_AUTOVACUUM_NONE :
|
|
(!p.pBt.incrVacuum) ? BTREE_AUTOVACUUM_FULL :
|
|
BTREE_AUTOVACUUM_INCR
|
|
);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
#endif
|
|
}
|
|
|
|
/*
|
|
** Get a reference to pPage1 of the database file. This will
|
|
** also acquire a readlock on that file.
|
|
**
|
|
** SQLITE_OK is returned on success. If the file is not a
|
|
** well-formed database file, then SQLITE_CORRUPT is returned.
|
|
** SQLITE_BUSY is returned if the database is locked. SQLITE_NOMEM
|
|
** is returned if we run out of memory.
|
|
*/
|
|
|
|
private static int lockBtree(BtShared pBt)
|
|
{
|
|
int rc; /* Result code from subfunctions */
|
|
MemPage pPage1 = null; /* Page 1 of the database file */
|
|
Pgno nPage; /* Number of pages in the database */
|
|
Pgno nPageFile = 0; /* Number of pages in the database file */
|
|
////Pgno nPageHeader; /* Number of pages in the database according to hdr */
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(pBt.pPage1 == null);
|
|
rc = sqlite3PagerSharedLock(pBt.pPager);
|
|
if (rc != SQLITE_OK)
|
|
return rc;
|
|
rc = btreeGetPage(pBt, 1, ref pPage1, 0);
|
|
if (rc != SQLITE_OK)
|
|
return rc;
|
|
|
|
/* Do some checking to help insure the file we opened really is
|
|
** a valid database file.
|
|
*/
|
|
nPage = sqlite3Get4byte(pPage1.aData, 28);//get4byte(28+(u8*)pPage1->aData);
|
|
sqlite3PagerPagecount(pBt.pPager, out nPageFile);
|
|
if (nPage == 0 || memcmp(pPage1.aData, 24, pPage1.aData, 92, 4) != 0)//memcmp(24 + (u8*)pPage1.aData, 92 + (u8*)pPage1.aData, 4) != 0)
|
|
{
|
|
nPage = nPageFile;
|
|
}
|
|
if (nPage > 0)
|
|
{
|
|
u32 pageSize;
|
|
u32 usableSize;
|
|
u8[] page1 = pPage1.aData;
|
|
rc = SQLITE_NOTADB;
|
|
if (memcmp(page1, zMagicHeader, 16) != 0)
|
|
{
|
|
goto page1_init_failed;
|
|
}
|
|
|
|
#if SQLITE_OMIT_WAL
|
|
if (page1[18] > 1)
|
|
{
|
|
pBt.readOnly = true;
|
|
}
|
|
if (page1[19] > 1)
|
|
{
|
|
pBt.pSchema.file_format = page1[19];
|
|
goto page1_init_failed;
|
|
}
|
|
#else
|
|
if( page1[18]>2 ){
|
|
pBt.readOnly = true;
|
|
}
|
|
if( page1[19]>2 ){
|
|
goto page1_init_failed;
|
|
}
|
|
|
|
/* If the write version is set to 2, this database should be accessed
|
|
** in WAL mode. If the log is not already open, open it now. Then
|
|
** return SQLITE_OK and return without populating BtShared.pPage1.
|
|
** The caller detects this and calls this function again. This is
|
|
** required as the version of page 1 currently in the page1 buffer
|
|
** may not be the latest version - there may be a newer one in the log
|
|
** file.
|
|
*/
|
|
if( page1[19]==2 && pBt.doNotUseWAL==false ){
|
|
int isOpen = 0;
|
|
rc = sqlite3PagerOpenWal(pBt.pPager, ref isOpen);
|
|
if( rc!=SQLITE_OK ){
|
|
goto page1_init_failed;
|
|
}else if( isOpen==0 ){
|
|
releasePage(pPage1);
|
|
return SQLITE_OK;
|
|
}
|
|
rc = SQLITE_NOTADB;
|
|
}
|
|
#endif
|
|
|
|
/* The maximum embedded fraction must be exactly 25%. And the minimum
|
|
** embedded fraction must be 12.5% for both leaf-data and non-leaf-data.
|
|
** The original design allowed these amounts to vary, but as of
|
|
** version 3.6.0, we require them to be fixed.
|
|
*/
|
|
if (memcmp(page1, 21, "\x0040\x0020\x0020", 3) != 0)// "\100\040\040"
|
|
{
|
|
goto page1_init_failed;
|
|
}
|
|
pageSize = (u32)((page1[16] << 8) | (page1[17] << 16));
|
|
if (((pageSize - 1) & pageSize) != 0
|
|
|| pageSize > SQLITE_MAX_PAGE_SIZE
|
|
|| pageSize <= 256
|
|
)
|
|
{
|
|
goto page1_init_failed;
|
|
}
|
|
Debug.Assert((pageSize & 7) == 0);
|
|
usableSize = pageSize - page1[20];
|
|
if (pageSize != pBt.pageSize)
|
|
{
|
|
/* After reading the first page of the database assuming a page size
|
|
** of BtShared.pageSize, we have discovered that the page-size is
|
|
** actually pageSize. Unlock the database, leave pBt.pPage1 at
|
|
** zero and return SQLITE_OK. The caller will call this function
|
|
** again with the correct page-size.
|
|
*/
|
|
releasePage(pPage1);
|
|
pBt.usableSize = usableSize;
|
|
pBt.pageSize = pageSize;
|
|
// freeTempSpace(pBt);
|
|
rc = sqlite3PagerSetPagesize(pBt.pPager, ref pBt.pageSize,
|
|
(int)(pageSize - usableSize));
|
|
return rc;
|
|
}
|
|
if ((pBt.db.flags & SQLITE_RecoveryMode) == 0 && nPage > nPageFile)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto page1_init_failed;
|
|
}
|
|
if (usableSize < 480)
|
|
{
|
|
goto page1_init_failed;
|
|
}
|
|
pBt.pageSize = pageSize;
|
|
pBt.usableSize = usableSize;
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
pBt.autoVacuum = (sqlite3Get4byte(page1, 36 + 4 * 4) != 0);
|
|
pBt.incrVacuum = (sqlite3Get4byte(page1, 36 + 7 * 4) != 0);
|
|
#endif
|
|
}
|
|
|
|
/* maxLocal is the maximum amount of payload to store locally for
|
|
** a cell. Make sure it is small enough so that at least minFanout
|
|
** cells can will fit on one page. We assume a 10-byte page header.
|
|
** Besides the payload, the cell must store:
|
|
** 2-byte pointer to the cell
|
|
** 4-byte child pointer
|
|
** 9-byte nKey value
|
|
** 4-byte nData value
|
|
** 4-byte overflow page pointer
|
|
** So a cell consists of a 2-byte pointer, a header which is as much as
|
|
** 17 bytes long, 0 to N bytes of payload, and an optional 4 byte overflow
|
|
** page pointer.
|
|
*/
|
|
pBt.maxLocal = (u16)((pBt.usableSize - 12) * 64 / 255 - 23);
|
|
pBt.minLocal = (u16)((pBt.usableSize - 12) * 32 / 255 - 23);
|
|
pBt.maxLeaf = (u16)(pBt.usableSize - 35);
|
|
pBt.minLeaf = (u16)((pBt.usableSize - 12) * 32 / 255 - 23);
|
|
Debug.Assert(pBt.maxLeaf + 23 <= MX_CELL_SIZE(pBt));
|
|
pBt.pPage1 = pPage1;
|
|
pBt.nPage = nPage;
|
|
return SQLITE_OK;
|
|
|
|
page1_init_failed:
|
|
releasePage(pPage1);
|
|
pBt.pPage1 = null;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** If there are no outstanding cursors and we are not in the middle
|
|
** of a transaction but there is a read lock on the database, then
|
|
** this routine unrefs the first page of the database file which
|
|
** has the effect of releasing the read lock.
|
|
**
|
|
** If there is a transaction in progress, this routine is a no-op.
|
|
*/
|
|
|
|
private static void unlockBtreeIfUnused(BtShared pBt)
|
|
{
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(pBt.pCursor == null || pBt.inTransaction > TRANS_NONE);
|
|
if (pBt.inTransaction == TRANS_NONE && pBt.pPage1 != null)
|
|
{
|
|
Debug.Assert(pBt.pPage1.aData != null);
|
|
//Debug.Assert( sqlite3PagerRefcount( pBt.pPager ) == 1 );
|
|
releasePage(pBt.pPage1);
|
|
pBt.pPage1 = null;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** If pBt points to an empty file then convert that empty file
|
|
** into a new empty database by initializing the first page of
|
|
** the database.
|
|
*/
|
|
|
|
private static int newDatabase(BtShared pBt)
|
|
{
|
|
MemPage pP1;
|
|
byte[] data;
|
|
int rc;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
if (pBt.nPage > 0)
|
|
{
|
|
return SQLITE_OK;
|
|
}
|
|
pP1 = pBt.pPage1;
|
|
Debug.Assert(pP1 != null);
|
|
data = pP1.aData;
|
|
rc = sqlite3PagerWrite(pP1.pDbPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
Buffer.BlockCopy(zMagicHeader, 0, data, 0, 16);// memcpy(data, zMagicHeader, sizeof(zMagicHeader));
|
|
Debug.Assert(zMagicHeader.Length == 16);
|
|
data[16] = (u8)((pBt.pageSize >> 8) & 0xff);
|
|
data[17] = (u8)((pBt.pageSize >> 16) & 0xff);
|
|
data[18] = 1;
|
|
data[19] = 1;
|
|
Debug.Assert(pBt.usableSize <= pBt.pageSize && pBt.usableSize + 255 >= pBt.pageSize);
|
|
data[20] = (u8)(pBt.pageSize - pBt.usableSize);
|
|
data[21] = 64;
|
|
data[22] = 32;
|
|
data[23] = 32;
|
|
//memset(&data[24], 0, 100-24);
|
|
zeroPage(pP1, PTF_INTKEY | PTF_LEAF | PTF_LEAFDATA);
|
|
pBt.pageSizeFixed = true;
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
Debug.Assert(pBt.autoVacuum == true || pBt.autoVacuum == false);
|
|
Debug.Assert(pBt.incrVacuum == true || pBt.incrVacuum == false);
|
|
sqlite3Put4byte(data, 36 + 4 * 4, pBt.autoVacuum ? 1 : 0);
|
|
sqlite3Put4byte(data, 36 + 7 * 4, pBt.incrVacuum ? 1 : 0);
|
|
#endif
|
|
pBt.nPage = 1;
|
|
data[31] = 1;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Attempt to start a new transaction. A write-transaction
|
|
** is started if the second argument is nonzero, otherwise a read-
|
|
** transaction. If the second argument is 2 or more and exclusive
|
|
** transaction is started, meaning that no other process is allowed
|
|
** to access the database. A preexisting transaction may not be
|
|
** upgraded to exclusive by calling this routine a second time - the
|
|
** exclusivity flag only works for a new transaction.
|
|
**
|
|
** A write-transaction must be started before attempting any
|
|
** changes to the database. None of the following routines
|
|
** will work unless a transaction is started first:
|
|
**
|
|
** sqlite3BtreeCreateTable()
|
|
** sqlite3BtreeCreateIndex()
|
|
** sqlite3BtreeClearTable()
|
|
** sqlite3BtreeDropTable()
|
|
** sqlite3BtreeInsert()
|
|
** sqlite3BtreeDelete()
|
|
** sqlite3BtreeUpdateMeta()
|
|
**
|
|
** If an initial attempt to acquire the lock fails because of lock contention
|
|
** and the database was previously unlocked, then invoke the busy handler
|
|
** if there is one. But if there was previously a read-lock, do not
|
|
** invoke the busy handler - just return SQLITE_BUSY. SQLITE_BUSY is
|
|
** returned when there is already a read-lock in order to avoid a deadlock.
|
|
**
|
|
** Suppose there are two processes A and B. A has a read lock and B has
|
|
** a reserved lock. B tries to promote to exclusive but is blocked because
|
|
** of A's read lock. A tries to promote to reserved but is blocked by B.
|
|
** One or the other of the two processes must give way or there can be
|
|
** no progress. By returning SQLITE_BUSY and not invoking the busy callback
|
|
** when A already has a read lock, we encourage A to give up and let B
|
|
** proceed.
|
|
*/
|
|
|
|
private static int sqlite3BtreeBeginTrans(Btree p, int wrflag)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
int rc = SQLITE_OK;
|
|
|
|
sqlite3BtreeEnter(p);
|
|
btreeIntegrity(p);
|
|
|
|
/* If the btree is already in a write-transaction, or it
|
|
** is already in a read-transaction and a read-transaction
|
|
** is requested, this is a no-op.
|
|
*/
|
|
if (p.inTrans == TRANS_WRITE || (p.inTrans == TRANS_READ && 0 == wrflag))
|
|
{
|
|
goto trans_begun;
|
|
}
|
|
|
|
/* Write transactions are not possible on a read-only database */
|
|
if (pBt.readOnly && wrflag != 0)
|
|
{
|
|
rc = SQLITE_READONLY;
|
|
goto trans_begun;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
/* If another database handle has already opened a write transaction
|
|
** on this shared-btree structure and a second write transaction is
|
|
** requested, return SQLITE_LOCKED.
|
|
*/
|
|
if( (wrflag && pBt.inTransaction==TRANS_WRITE) || pBt.isPending ){
|
|
sqlite3 pBlock = pBt.pWriter.db;
|
|
}else if( wrflag>1 ){
|
|
BtLock pIter;
|
|
for(pIter=pBt.pLock; pIter; pIter=pIter.pNext){
|
|
if( pIter.pBtree!=p ){
|
|
pBlock = pIter.pBtree.db;
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
if( pBlock ){
|
|
sqlite3ConnectionBlocked(p.db, pBlock);
|
|
rc = SQLITE_LOCKED_SHAREDCACHE;
|
|
goto trans_begun;
|
|
}
|
|
#endif
|
|
|
|
/* Any read-only or read-write transaction implies a read-lock on
|
|
** page 1. So if some other shared-cache client already has a write-lock
|
|
** on page 1, the transaction cannot be opened. */
|
|
rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);
|
|
if (SQLITE_OK != rc)
|
|
goto trans_begun;
|
|
|
|
pBt.initiallyEmpty = pBt.nPage == 0;
|
|
do
|
|
{
|
|
/* Call lockBtree() until either pBt.pPage1 is populated or
|
|
** lockBtree() returns something other than SQLITE_OK. lockBtree()
|
|
** may return SQLITE_OK but leave pBt.pPage1 set to 0 if after
|
|
** reading page 1 it discovers that the page-size of the database
|
|
** file is not pBt.pageSize. In this case lockBtree() will update
|
|
** pBt.pageSize to the page-size of the file on disk.
|
|
*/
|
|
while (pBt.pPage1 == null && SQLITE_OK == (rc = lockBtree(pBt)))
|
|
;
|
|
|
|
if (rc == SQLITE_OK && wrflag != 0)
|
|
{
|
|
if (pBt.readOnly)
|
|
{
|
|
rc = SQLITE_READONLY;
|
|
}
|
|
else
|
|
{
|
|
rc = sqlite3PagerBegin(pBt.pPager, wrflag > 1, sqlite3TempInMemory(p.db) ? 1 : 0);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = newDatabase(pBt);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
unlockBtreeIfUnused(pBt);
|
|
}
|
|
} while ((rc & 0xFF) == SQLITE_BUSY && pBt.inTransaction == TRANS_NONE &&
|
|
btreeInvokeBusyHandler(pBt) != 0);
|
|
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
if (p.inTrans == TRANS_NONE)
|
|
{
|
|
pBt.nTransaction++;
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
if( p.sharable ){
|
|
Debug.Assert( p.lock.pBtree==p && p.lock.iTable==1 );
|
|
p.lock.eLock = READ_LOCK;
|
|
p.lock.pNext = pBt.pLock;
|
|
pBt.pLock = &p.lock;
|
|
}
|
|
#endif
|
|
}
|
|
p.inTrans = (wrflag != 0 ? TRANS_WRITE : TRANS_READ);
|
|
if (p.inTrans > pBt.inTransaction)
|
|
{
|
|
pBt.inTransaction = p.inTrans;
|
|
}
|
|
if (wrflag != 0)
|
|
{
|
|
MemPage pPage1 = pBt.pPage1;
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
Debug.Assert( !pBt.pWriter );
|
|
pBt.pWriter = p;
|
|
pBt.isExclusive = (u8)(wrflag>1);
|
|
#endif
|
|
/* If the db-size header field is incorrect (as it may be if an old
|
|
** client has been writing the database file), update it now. Doing
|
|
** this sooner rather than later means the database size can safely
|
|
** re-read the database size from page 1 if a savepoint or transaction
|
|
** rollback occurs within the transaction.
|
|
*/
|
|
if (pBt.nPage != sqlite3Get4byte(pPage1.aData, 28))
|
|
{
|
|
rc = sqlite3PagerWrite(pPage1.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
sqlite3Put4byte(pPage1.aData, (u32)28, pBt.nPage);
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
trans_begun:
|
|
if (rc == SQLITE_OK && wrflag != 0)
|
|
{
|
|
/* This call makes sure that the pager has the correct number of
|
|
** open savepoints. If the second parameter is greater than 0 and
|
|
** the sub-journal is not already open, then it will be opened here.
|
|
*/
|
|
rc = sqlite3PagerOpenSavepoint(pBt.pPager, p.db.nSavepoint);
|
|
}
|
|
|
|
btreeIntegrity(p);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
|
|
/*
|
|
** Set the pointer-map entries for all children of page pPage. Also, if
|
|
** pPage contains cells that point to overflow pages, set the pointer
|
|
** map entries for the overflow pages as well.
|
|
*/
|
|
|
|
private static int setChildPtrmaps(MemPage pPage)
|
|
{
|
|
int i; /* Counter variable */
|
|
int nCell; /* Number of cells in page pPage */
|
|
int rc; /* Return code */
|
|
BtShared pBt = pPage.pBt;
|
|
u8 isInitOrig = pPage.isInit;
|
|
Pgno pgno = pPage.pgno;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
rc = btreeInitPage(pPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto set_child_ptrmaps_out;
|
|
}
|
|
nCell = pPage.nCell;
|
|
|
|
for (i = 0; i < nCell; i++)
|
|
{
|
|
int pCell = findCell(pPage, i);
|
|
|
|
ptrmapPutOvflPtr(pPage, pCell, ref rc);
|
|
|
|
if (0 == pPage.leaf)
|
|
{
|
|
Pgno childPgno = sqlite3Get4byte(pPage.aData, pCell);
|
|
ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno, ref rc);
|
|
}
|
|
}
|
|
|
|
if (0 == pPage.leaf)
|
|
{
|
|
Pgno childPgno = sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8);
|
|
ptrmapPut(pBt, childPgno, PTRMAP_BTREE, pgno, ref rc);
|
|
}
|
|
|
|
set_child_ptrmaps_out:
|
|
pPage.isInit = isInitOrig;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Somewhere on pPage is a pointer to page iFrom. Modify this pointer so
|
|
** that it points to iTo. Parameter eType describes the type of pointer to
|
|
** be modified, as follows:
|
|
**
|
|
** PTRMAP_BTREE: pPage is a btree-page. The pointer points at a child
|
|
** page of pPage.
|
|
**
|
|
** PTRMAP_OVERFLOW1: pPage is a btree-page. The pointer points at an overflow
|
|
** page pointed to by one of the cells on pPage.
|
|
**
|
|
** PTRMAP_OVERFLOW2: pPage is an overflow-page. The pointer points at the next
|
|
** overflow page in the list.
|
|
*/
|
|
|
|
private static int modifyPagePointer(MemPage pPage, Pgno iFrom, Pgno iTo, u8 eType)
|
|
{
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
if (eType == PTRMAP_OVERFLOW2)
|
|
{
|
|
/* The pointer is always the first 4 bytes of the page in this case. */
|
|
if (sqlite3Get4byte(pPage.aData) != iFrom)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
sqlite3Put4byte(pPage.aData, iTo);
|
|
}
|
|
else
|
|
{
|
|
u8 isInitOrig = pPage.isInit;
|
|
int i;
|
|
int nCell;
|
|
|
|
btreeInitPage(pPage);
|
|
nCell = pPage.nCell;
|
|
|
|
for (i = 0; i < nCell; i++)
|
|
{
|
|
int pCell = findCell(pPage, i);
|
|
if (eType == PTRMAP_OVERFLOW1)
|
|
{
|
|
CellInfo info = new CellInfo();
|
|
btreeParseCellPtr(pPage, pCell, ref info);
|
|
if (info.iOverflow != 0)
|
|
{
|
|
if (iFrom == sqlite3Get4byte(pPage.aData, pCell, info.iOverflow))
|
|
{
|
|
sqlite3Put4byte(pPage.aData, pCell + info.iOverflow, (int)iTo);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (sqlite3Get4byte(pPage.aData, pCell) == iFrom)
|
|
{
|
|
sqlite3Put4byte(pPage.aData, pCell, (int)iTo);
|
|
break;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (i == nCell)
|
|
{
|
|
if (eType != PTRMAP_BTREE ||
|
|
sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8) != iFrom)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
sqlite3Put4byte(pPage.aData, pPage.hdrOffset + 8, iTo);
|
|
}
|
|
|
|
pPage.isInit = isInitOrig;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Move the open database page pDbPage to location iFreePage in the
|
|
** database. The pDbPage reference remains valid.
|
|
**
|
|
** The isCommit flag indicates that there is no need to remember that
|
|
** the journal needs to be sync()ed before database page pDbPage.pgno
|
|
** can be written to. The caller has already promised not to write to that
|
|
** page.
|
|
*/
|
|
|
|
private static int relocatePage(
|
|
BtShared pBt, /* Btree */
|
|
MemPage pDbPage, /* Open page to move */
|
|
u8 eType, /* Pointer map 'type' entry for pDbPage */
|
|
Pgno iPtrPage, /* Pointer map 'page-no' entry for pDbPage */
|
|
Pgno iFreePage, /* The location to move pDbPage to */
|
|
int isCommit /* isCommit flag passed to sqlite3PagerMovepage */
|
|
)
|
|
{
|
|
MemPage pPtrPage = new MemPage(); /* The page that contains a pointer to pDbPage */
|
|
Pgno iDbPage = pDbPage.pgno;
|
|
Pager pPager = pBt.pPager;
|
|
int rc;
|
|
|
|
Debug.Assert(eType == PTRMAP_OVERFLOW2 || eType == PTRMAP_OVERFLOW1 ||
|
|
eType == PTRMAP_BTREE || eType == PTRMAP_ROOTPAGE);
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(pDbPage.pBt == pBt);
|
|
|
|
/* Move page iDbPage from its current location to page number iFreePage */
|
|
TRACE("AUTOVACUUM: Moving %d to free page %d (ptr page %d type %d)\n",
|
|
iDbPage, iFreePage, iPtrPage, eType);
|
|
rc = sqlite3PagerMovepage(pPager, pDbPage.pDbPage, iFreePage, isCommit);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
pDbPage.pgno = iFreePage;
|
|
|
|
/* If pDbPage was a btree-page, then it may have child pages and/or cells
|
|
** that point to overflow pages. The pointer map entries for all these
|
|
** pages need to be changed.
|
|
**
|
|
** If pDbPage is an overflow page, then the first 4 bytes may store a
|
|
** pointer to a subsequent overflow page. If this is the case, then
|
|
** the pointer map needs to be updated for the subsequent overflow page.
|
|
*/
|
|
if (eType == PTRMAP_BTREE || eType == PTRMAP_ROOTPAGE)
|
|
{
|
|
rc = setChildPtrmaps(pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
Pgno nextOvfl = sqlite3Get4byte(pDbPage.aData);
|
|
if (nextOvfl != 0)
|
|
{
|
|
ptrmapPut(pBt, nextOvfl, PTRMAP_OVERFLOW2, iFreePage, ref rc);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Fix the database pointer on page iPtrPage that pointed at iDbPage so
|
|
** that it points at iFreePage. Also fix the pointer map entry for
|
|
** iPtrPage.
|
|
*/
|
|
if (eType != PTRMAP_ROOTPAGE)
|
|
{
|
|
rc = btreeGetPage(pBt, iPtrPage, ref pPtrPage, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = sqlite3PagerWrite(pPtrPage.pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(pPtrPage);
|
|
return rc;
|
|
}
|
|
rc = modifyPagePointer(pPtrPage, iDbPage, iFreePage, eType);
|
|
releasePage(pPtrPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
ptrmapPut(pBt, iFreePage, eType, iPtrPage, ref rc);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/* Forward declaration required by incrVacuumStep(). */
|
|
//static int allocateBtreePage(BtShared *, MemPage **, Pgno *, Pgno, u8);
|
|
|
|
/*
|
|
** Perform a single step of an incremental-vacuum. If successful,
|
|
** return SQLITE_OK. If there is no work to do (and therefore no
|
|
** point in calling this function again), return SQLITE_DONE.
|
|
**
|
|
** More specificly, this function attempts to re-organize the
|
|
** database so that the last page of the file currently in use
|
|
** is no longer in use.
|
|
**
|
|
** If the nFin parameter is non-zero, this function assumes
|
|
** that the caller will keep calling incrVacuumStep() until
|
|
** it returns SQLITE_DONE or an error, and that nFin is the
|
|
** number of pages the database file will contain after this
|
|
** process is complete. If nFin is zero, it is assumed that
|
|
** incrVacuumStep() will be called a finite amount of times
|
|
** which may or may not empty the freelist. A full autovacuum
|
|
** has nFin>0. A "PRAGMA incremental_vacuum" has nFin==null.
|
|
*/
|
|
|
|
private static int incrVacuumStep(BtShared pBt, Pgno nFin, Pgno iLastPg)
|
|
{
|
|
Pgno nFreeList; /* Number of pages still on the free-list */
|
|
int rc;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(iLastPg > nFin);
|
|
|
|
if (!PTRMAP_ISPAGE(pBt, iLastPg) && iLastPg != PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
u8 eType = 0;
|
|
Pgno iPtrPage = 0;
|
|
|
|
nFreeList = sqlite3Get4byte(pBt.pPage1.aData, 36);
|
|
if (nFreeList == 0)
|
|
{
|
|
return SQLITE_DONE;
|
|
}
|
|
|
|
rc = ptrmapGet(pBt, iLastPg, ref eType, ref iPtrPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
if (eType == PTRMAP_ROOTPAGE)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
|
|
if (eType == PTRMAP_FREEPAGE)
|
|
{
|
|
if (nFin == 0)
|
|
{
|
|
/* Remove the page from the files free-list. This is not required
|
|
** if nFin is non-zero. In that case, the free-list will be
|
|
** truncated to zero after this function returns, so it doesn't
|
|
** matter if it still contains some garbage entries.
|
|
*/
|
|
Pgno iFreePg = 0;
|
|
MemPage pFreePg = new MemPage();
|
|
rc = allocateBtreePage(pBt, ref pFreePg, ref iFreePg, iLastPg, 1);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
Debug.Assert(iFreePg == iLastPg);
|
|
releasePage(pFreePg);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
Pgno iFreePg = 0; /* Index of free page to move pLastPg to */
|
|
MemPage pLastPg = new MemPage();
|
|
|
|
rc = btreeGetPage(pBt, iLastPg, ref pLastPg, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
|
|
/* If nFin is zero, this loop runs exactly once and page pLastPg
|
|
** is swapped with the first free page pulled off the free list.
|
|
**
|
|
** On the other hand, if nFin is greater than zero, then keep
|
|
** looping until a free-page located within the first nFin pages
|
|
** of the file is found.
|
|
*/
|
|
do
|
|
{
|
|
MemPage pFreePg = new MemPage();
|
|
rc = allocateBtreePage(pBt, ref pFreePg, ref iFreePg, 0, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(pLastPg);
|
|
return rc;
|
|
}
|
|
releasePage(pFreePg);
|
|
} while (nFin != 0 && iFreePg > nFin);
|
|
Debug.Assert(iFreePg < iLastPg);
|
|
|
|
rc = sqlite3PagerWrite(pLastPg.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = relocatePage(pBt, pLastPg, eType, iPtrPage, iFreePg, (nFin != 0) ? 1 : 0);
|
|
}
|
|
releasePage(pLastPg);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
}
|
|
}
|
|
|
|
if (nFin == 0)
|
|
{
|
|
iLastPg--;
|
|
while (iLastPg == PENDING_BYTE_PAGE(pBt) || PTRMAP_ISPAGE(pBt, iLastPg))
|
|
{
|
|
if (PTRMAP_ISPAGE(pBt, iLastPg))
|
|
{
|
|
MemPage pPg = new MemPage();
|
|
rc = btreeGetPage(pBt, iLastPg, ref pPg, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = sqlite3PagerWrite(pPg.pDbPage);
|
|
releasePage(pPg);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
}
|
|
iLastPg--;
|
|
}
|
|
sqlite3PagerTruncateImage(pBt.pPager, iLastPg);
|
|
pBt.nPage = iLastPg;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** A write-transaction must be opened before calling this function.
|
|
** It performs a single unit of work towards an incremental vacuum.
|
|
**
|
|
** If the incremental vacuum is finished after this function has run,
|
|
** SQLITE_DONE is returned. If it is not finished, but no error occurred,
|
|
** SQLITE_OK is returned. Otherwise an SQLite error code.
|
|
*/
|
|
|
|
private static int sqlite3BtreeIncrVacuum(Btree p)
|
|
{
|
|
int rc;
|
|
BtShared pBt = p.pBt;
|
|
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(pBt.inTransaction == TRANS_WRITE && p.inTrans == TRANS_WRITE);
|
|
if (!pBt.autoVacuum)
|
|
{
|
|
rc = SQLITE_DONE;
|
|
}
|
|
else
|
|
{
|
|
invalidateAllOverflowCache(pBt);
|
|
rc = incrVacuumStep(pBt, 0, btreePagecount(pBt));
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = sqlite3PagerWrite(pBt.pPage1.pDbPage);
|
|
sqlite3Put4byte(pBt.pPage1.aData, (u32)28, pBt.nPage);//put4byte(&pBt->pPage1->aData[28], pBt->nPage);
|
|
}
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This routine is called prior to sqlite3PagerCommit when a transaction
|
|
** is commited for an auto-vacuum database.
|
|
**
|
|
** If SQLITE_OK is returned, then pnTrunc is set to the number of pages
|
|
** the database file should be truncated to during the commit process.
|
|
** i.e. the database has been reorganized so that only the first pnTrunc
|
|
** pages are in use.
|
|
*/
|
|
|
|
private static int autoVacuumCommit(BtShared pBt)
|
|
{
|
|
int rc = SQLITE_OK;
|
|
Pager pPager = pBt.pPager;
|
|
// VVA_ONLY( int nRef = sqlite3PagerRefcount(pPager) );
|
|
#if !NDEBUG || DEBUG
|
|
int nRef = sqlite3PagerRefcount(pPager);
|
|
#else
|
|
int nRef=0;
|
|
#endif
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
invalidateAllOverflowCache(pBt);
|
|
Debug.Assert(pBt.autoVacuum);
|
|
if (!pBt.incrVacuum)
|
|
{
|
|
Pgno nFin; /* Number of pages in database after autovacuuming */
|
|
Pgno nFree; /* Number of pages on the freelist initially */
|
|
Pgno nPtrmap; /* Number of PtrMap pages to be freed */
|
|
Pgno iFree; /* The next page to be freed */
|
|
int nEntry; /* Number of entries on one ptrmap page */
|
|
Pgno nOrig; /* Database size before freeing */
|
|
|
|
nOrig = btreePagecount(pBt);
|
|
if (PTRMAP_ISPAGE(pBt, nOrig) || nOrig == PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
/* It is not possible to create a database for which the final page
|
|
** is either a pointer-map page or the pending-byte page. If one
|
|
** is encountered, this indicates corruption.
|
|
*/
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
|
|
nFree = sqlite3Get4byte(pBt.pPage1.aData, 36);
|
|
nEntry = (int)pBt.usableSize / 5;
|
|
nPtrmap = (Pgno)((nFree - nOrig + PTRMAP_PAGENO(pBt, nOrig) + (Pgno)nEntry) / nEntry);
|
|
nFin = nOrig - nFree - nPtrmap;
|
|
if (nOrig > PENDING_BYTE_PAGE(pBt) && nFin < PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
nFin--;
|
|
}
|
|
while (PTRMAP_ISPAGE(pBt, nFin) || nFin == PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
nFin--;
|
|
}
|
|
if (nFin > nOrig)
|
|
return SQLITE_CORRUPT_BKPT();
|
|
|
|
for (iFree = nOrig; iFree > nFin && rc == SQLITE_OK; iFree--)
|
|
{
|
|
rc = incrVacuumStep(pBt, nFin, iFree);
|
|
}
|
|
if ((rc == SQLITE_DONE || rc == SQLITE_OK) && nFree > 0)
|
|
{
|
|
rc = sqlite3PagerWrite(pBt.pPage1.pDbPage);
|
|
sqlite3Put4byte(pBt.pPage1.aData, 32, 0);
|
|
sqlite3Put4byte(pBt.pPage1.aData, 36, 0);
|
|
sqlite3Put4byte(pBt.pPage1.aData, (u32)28, nFin);
|
|
sqlite3PagerTruncateImage(pBt.pPager, nFin);
|
|
pBt.nPage = nFin;
|
|
}
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
sqlite3PagerRollback(pPager);
|
|
}
|
|
}
|
|
|
|
Debug.Assert(nRef == sqlite3PagerRefcount(pPager));
|
|
return rc;
|
|
}
|
|
|
|
#else //* ifndef SQLITE_OMIT_AUTOVACUUM */
|
|
//# define setChildPtrmaps(x) SQLITE_OK
|
|
#endif
|
|
|
|
/*
|
|
** This routine does the first phase of a two-phase commit. This routine
|
|
** causes a rollback journal to be created (if it does not already exist)
|
|
** and populated with enough information so that if a power loss occurs
|
|
** the database can be restored to its original state by playing back
|
|
** the journal. Then the contents of the journal are flushed out to
|
|
** the disk. After the journal is safely on oxide, the changes to the
|
|
** database are written into the database file and flushed to oxide.
|
|
** At the end of this call, the rollback journal still exists on the
|
|
** disk and we are still holding all locks, so the transaction has not
|
|
** committed. See sqlite3BtreeCommitPhaseTwo() for the second phase of the
|
|
** commit process.
|
|
**
|
|
** This call is a no-op if no write-transaction is currently active on pBt.
|
|
**
|
|
** Otherwise, sync the database file for the btree pBt. zMaster points to
|
|
** the name of a master journal file that should be written into the
|
|
** individual journal file, or is NULL, indicating no master journal file
|
|
** (single database transaction).
|
|
**
|
|
** When this is called, the master journal should already have been
|
|
** created, populated with this journal pointer and synced to disk.
|
|
**
|
|
** Once this is routine has returned, the only thing required to commit
|
|
** the write-transaction for this database file is to delete the journal.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCommitPhaseOne(Btree p, string zMaster)
|
|
{
|
|
int rc = SQLITE_OK;
|
|
if (p.inTrans == TRANS_WRITE)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
sqlite3BtreeEnter(p);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pBt.autoVacuum)
|
|
{
|
|
rc = autoVacuumCommit(pBt);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
}
|
|
#endif
|
|
rc = sqlite3PagerCommitPhaseOne(pBt.pPager, zMaster, false);
|
|
sqlite3BtreeLeave(p);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is called from both BtreeCommitPhaseTwo() and BtreeRollback()
|
|
** at the conclusion of a transaction.
|
|
*/
|
|
|
|
private static void btreeEndTransaction(Btree p)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
Debug.Assert(sqlite3BtreeHoldsMutex(p));
|
|
|
|
btreeClearHasContent(pBt);
|
|
if (p.inTrans > TRANS_NONE && p.db.activeVdbeCnt > 1)
|
|
{
|
|
/* If there are other active statements that belong to this database
|
|
** handle, downgrade to a read-only transaction. The other statements
|
|
** may still be reading from the database. */
|
|
|
|
downgradeAllSharedCacheTableLocks(p);
|
|
p.inTrans = TRANS_READ;
|
|
}
|
|
else
|
|
{
|
|
/* If the handle had any kind of transaction open, decrement the
|
|
** transaction count of the shared btree. If the transaction count
|
|
** reaches 0, set the shared state to TRANS_NONE. The unlockBtreeIfUnused()
|
|
** call below will unlock the pager. */
|
|
if (p.inTrans != TRANS_NONE)
|
|
{
|
|
clearAllSharedCacheTableLocks(p);
|
|
pBt.nTransaction--;
|
|
if (0 == pBt.nTransaction)
|
|
{
|
|
pBt.inTransaction = TRANS_NONE;
|
|
}
|
|
}
|
|
|
|
/* Set the current transaction state to TRANS_NONE and unlock the
|
|
** pager if this call closed the only read or write transaction. */
|
|
p.inTrans = TRANS_NONE;
|
|
unlockBtreeIfUnused(pBt);
|
|
}
|
|
|
|
btreeIntegrity(p);
|
|
}
|
|
|
|
/*
|
|
** Commit the transaction currently in progress.
|
|
**
|
|
** This routine implements the second phase of a 2-phase commit. The
|
|
** sqlite3BtreeCommitPhaseOne() routine does the first phase and should
|
|
** be invoked prior to calling this routine. The sqlite3BtreeCommitPhaseOne()
|
|
** routine did all the work of writing information out to disk and flushing the
|
|
** contents so that they are written onto the disk platter. All this
|
|
** routine has to do is delete or truncate or zero the header in the
|
|
** the rollback journal (which causes the transaction to commit) and
|
|
** drop locks.
|
|
**
|
|
** Normally, if an error occurs while the pager layer is attempting to
|
|
** finalize the underlying journal file, this function returns an error and
|
|
** the upper layer will attempt a rollback. However, if the second argument
|
|
** is non-zero then this b-tree transaction is part of a multi-file
|
|
** transaction. In this case, the transaction has already been committed
|
|
** (by deleting a master journal file) and the caller will ignore this
|
|
** functions return code. So, even if an error occurs in the pager layer,
|
|
** reset the b-tree objects internal state to indicate that the write
|
|
** transaction has been closed. This is quite safe, as the pager will have
|
|
** transitioned to the error state.
|
|
**
|
|
** This will release the write lock on the database file. If there
|
|
** are no active cursors, it also releases the read lock.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCommitPhaseTwo(Btree p, int bCleanup)
|
|
{
|
|
if (p.inTrans == TRANS_NONE)
|
|
return SQLITE_OK;
|
|
sqlite3BtreeEnter(p);
|
|
btreeIntegrity(p);
|
|
|
|
/* If the handle has a write-transaction open, commit the shared-btrees
|
|
** transaction and set the shared state to TRANS_READ.
|
|
*/
|
|
if (p.inTrans == TRANS_WRITE)
|
|
{
|
|
int rc;
|
|
BtShared pBt = p.pBt;
|
|
Debug.Assert(pBt.inTransaction == TRANS_WRITE);
|
|
Debug.Assert(pBt.nTransaction > 0);
|
|
rc = sqlite3PagerCommitPhaseTwo(pBt.pPager);
|
|
if (rc != SQLITE_OK && bCleanup == 0)
|
|
{
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
pBt.inTransaction = TRANS_READ;
|
|
}
|
|
|
|
btreeEndTransaction(p);
|
|
sqlite3BtreeLeave(p);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Do both phases of a commit.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCommit(Btree p)
|
|
{
|
|
int rc;
|
|
sqlite3BtreeEnter(p);
|
|
rc = sqlite3BtreeCommitPhaseOne(p, null);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = sqlite3BtreeCommitPhaseTwo(p, 0);
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
#if !NDEBUG || DEBUG
|
|
/*
|
|
** Return the number of write-cursors open on this handle. This is for use
|
|
** in Debug.Assert() expressions, so it is only compiled if NDEBUG is not
|
|
** defined.
|
|
**
|
|
** For the purposes of this routine, a write-cursor is any cursor that
|
|
** is capable of writing to the databse. That means the cursor was
|
|
** originally opened for writing and the cursor has not be disabled
|
|
** by having its state changed to CURSOR_FAULT.
|
|
*/
|
|
|
|
private static int countWriteCursors(BtShared pBt)
|
|
{
|
|
BtCursor pCur;
|
|
int r = 0;
|
|
for (pCur = pBt.pCursor; pCur != null; pCur = pCur.pNext)
|
|
{
|
|
if (pCur.wrFlag != 0 && pCur.eState != CURSOR_FAULT)
|
|
r++;
|
|
}
|
|
return r;
|
|
}
|
|
|
|
#else
|
|
static int countWriteCursors(BtShared pBt) { return -1; }
|
|
#endif
|
|
|
|
/*
|
|
** This routine sets the state to CURSOR_FAULT and the error
|
|
** code to errCode for every cursor on BtShared that pBtree
|
|
** references.
|
|
**
|
|
** Every cursor is tripped, including cursors that belong
|
|
** to other database connections that happen to be sharing
|
|
** the cache with pBtree.
|
|
**
|
|
** This routine gets called when a rollback occurs.
|
|
** All cursors using the same cache must be tripped
|
|
** to prevent them from trying to use the btree after
|
|
** the rollback. The rollback may have deleted tables
|
|
** or moved root pages, so it is not sufficient to
|
|
** save the state of the cursor. The cursor must be
|
|
** invalidated.
|
|
*/
|
|
|
|
private static void sqlite3BtreeTripAllCursors(Btree pBtree, int errCode)
|
|
{
|
|
BtCursor p;
|
|
sqlite3BtreeEnter(pBtree);
|
|
for (p = pBtree.pBt.pCursor; p != null; p = p.pNext)
|
|
{
|
|
int i;
|
|
sqlite3BtreeClearCursor(p);
|
|
p.eState = CURSOR_FAULT;
|
|
p.skipNext = errCode;
|
|
for (i = 0; i <= p.iPage; i++)
|
|
{
|
|
releasePage(p.apPage[i]);
|
|
p.apPage[i] = null;
|
|
}
|
|
}
|
|
sqlite3BtreeLeave(pBtree);
|
|
}
|
|
|
|
/*
|
|
** Rollback the transaction in progress. All cursors will be
|
|
** invalided by this operation. Any attempt to use a cursor
|
|
** that was open at the beginning of this operation will result
|
|
** in an error.
|
|
**
|
|
** This will release the write lock on the database file. If there
|
|
** are no active cursors, it also releases the read lock.
|
|
*/
|
|
|
|
private static int sqlite3BtreeRollback(Btree p)
|
|
{
|
|
int rc;
|
|
BtShared pBt = p.pBt;
|
|
MemPage pPage1 = new MemPage();
|
|
|
|
sqlite3BtreeEnter(p);
|
|
rc = saveAllCursors(pBt, 0, null);
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
if( rc!=SQLITE_OK ){
|
|
/* This is a horrible situation. An IO or malloc() error occurred whilst
|
|
** trying to save cursor positions. If this is an automatic rollback (as
|
|
** the result of a constraint, malloc() failure or IO error) then
|
|
** the cache may be internally inconsistent (not contain valid trees) so
|
|
** we cannot simply return the error to the caller. Instead, abort
|
|
** all queries that may be using any of the cursors that failed to save.
|
|
*/
|
|
sqlite3BtreeTripAllCursors(p, rc);
|
|
}
|
|
#endif
|
|
btreeIntegrity(p);
|
|
|
|
if (p.inTrans == TRANS_WRITE)
|
|
{
|
|
int rc2;
|
|
|
|
Debug.Assert(TRANS_WRITE == pBt.inTransaction);
|
|
rc2 = sqlite3PagerRollback(pBt.pPager);
|
|
if (rc2 != SQLITE_OK)
|
|
{
|
|
rc = rc2;
|
|
}
|
|
|
|
/* The rollback may have destroyed the pPage1.aData value. So
|
|
** call btreeGetPage() on page 1 again to make
|
|
** sure pPage1.aData is set correctly. */
|
|
if (btreeGetPage(pBt, 1, ref pPage1, 0) == SQLITE_OK)
|
|
{
|
|
Pgno nPage = sqlite3Get4byte(pPage1.aData, 28);
|
|
testcase(nPage == 0);
|
|
if (nPage == 0)
|
|
sqlite3PagerPagecount(pBt.pPager, out nPage);
|
|
testcase(pBt.nPage != nPage);
|
|
pBt.nPage = nPage;
|
|
releasePage(pPage1);
|
|
}
|
|
Debug.Assert(countWriteCursors(pBt) == 0);
|
|
pBt.inTransaction = TRANS_READ;
|
|
}
|
|
|
|
btreeEndTransaction(p);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Start a statement subtransaction. The subtransaction can can be rolled
|
|
** back independently of the main transaction. You must start a transaction
|
|
** before starting a subtransaction. The subtransaction is ended automatically
|
|
** if the main transaction commits or rolls back.
|
|
**
|
|
** Statement subtransactions are used around individual SQL statements
|
|
** that are contained within a BEGIN...COMMIT block. If a constraint
|
|
** error occurs within the statement, the effect of that one statement
|
|
** can be rolled back without having to rollback the entire transaction.
|
|
**
|
|
** A statement sub-transaction is implemented as an anonymous savepoint. The
|
|
** value passed as the second parameter is the total number of savepoints,
|
|
** including the new anonymous savepoint, open on the B-Tree. i.e. if there
|
|
** are no active savepoints and no other statement-transactions open,
|
|
** iStatement is 1. This anonymous savepoint can be released or rolled back
|
|
** using the sqlite3BtreeSavepoint() function.
|
|
*/
|
|
|
|
private static int sqlite3BtreeBeginStmt(Btree p, int iStatement)
|
|
{
|
|
int rc;
|
|
BtShared pBt = p.pBt;
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(p.inTrans == TRANS_WRITE);
|
|
Debug.Assert(!pBt.readOnly);
|
|
Debug.Assert(iStatement > 0);
|
|
Debug.Assert(iStatement > p.db.nSavepoint);
|
|
Debug.Assert(pBt.inTransaction == TRANS_WRITE);
|
|
/* At the pager level, a statement transaction is a savepoint with
|
|
** an index greater than all savepoints created explicitly using
|
|
** SQL statements. It is illegal to open, release or rollback any
|
|
** such savepoints while the statement transaction savepoint is active.
|
|
*/
|
|
rc = sqlite3PagerOpenSavepoint(pBt.pPager, iStatement);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** The second argument to this function, op, is always SAVEPOINT_ROLLBACK
|
|
** or SAVEPOINT_RELEASE. This function either releases or rolls back the
|
|
** savepoint identified by parameter iSavepoint, depending on the value
|
|
** of op.
|
|
**
|
|
** Normally, iSavepoint is greater than or equal to zero. However, if op is
|
|
** SAVEPOINT_ROLLBACK, then iSavepoint may also be -1. In this case the
|
|
** contents of the entire transaction are rolled back. This is different
|
|
** from a normal transaction rollback, as no locks are released and the
|
|
** transaction remains open.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSavepoint(Btree p, int op, int iSavepoint)
|
|
{
|
|
int rc = SQLITE_OK;
|
|
if (p != null && p.inTrans == TRANS_WRITE)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
Debug.Assert(op == SAVEPOINT_RELEASE || op == SAVEPOINT_ROLLBACK);
|
|
Debug.Assert(iSavepoint >= 0 || (iSavepoint == -1 && op == SAVEPOINT_ROLLBACK));
|
|
sqlite3BtreeEnter(p);
|
|
rc = sqlite3PagerSavepoint(pBt.pPager, op, iSavepoint);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
if (iSavepoint < 0 && pBt.initiallyEmpty)
|
|
pBt.nPage = 0;
|
|
rc = newDatabase(pBt);
|
|
pBt.nPage = sqlite3Get4byte(pBt.pPage1.aData, 28);
|
|
/* The database size was written into the offset 28 of the header
|
|
** when the transaction started, so we know that the value at offset
|
|
** 28 is nonzero. */
|
|
Debug.Assert(pBt.nPage > 0);
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Create a new cursor for the BTree whose root is on the page
|
|
** iTable. If a read-only cursor is requested, it is assumed that
|
|
** the caller already has at least a read-only transaction open
|
|
** on the database already. If a write-cursor is requested, then
|
|
** the caller is assumed to have an open write transaction.
|
|
**
|
|
** If wrFlag==null, then the cursor can only be used for reading.
|
|
** If wrFlag==1, then the cursor can be used for reading or for
|
|
** writing if other conditions for writing are also met. These
|
|
** are the conditions that must be met in order for writing to
|
|
** be allowed:
|
|
**
|
|
** 1: The cursor must have been opened with wrFlag==1
|
|
**
|
|
** 2: Other database connections that share the same pager cache
|
|
** but which are not in the READ_UNCOMMITTED state may not have
|
|
** cursors open with wrFlag==null on the same table. Otherwise
|
|
** the changes made by this write cursor would be visible to
|
|
** the read cursors in the other database connection.
|
|
**
|
|
** 3: The database must be writable (not on read-only media)
|
|
**
|
|
** 4: There must be an active transaction.
|
|
**
|
|
** No checking is done to make sure that page iTable really is the
|
|
** root page of a b-tree. If it is not, then the cursor acquired
|
|
** will not work correctly.
|
|
**
|
|
** It is assumed that the sqlite3BtreeCursorZero() has been called
|
|
** on pCur to initialize the memory space prior to invoking this routine.
|
|
*/
|
|
|
|
private static int btreeCursor(
|
|
Btree p, /* The btree */
|
|
int iTable, /* Root page of table to open */
|
|
int wrFlag, /* 1 to write. 0 read-only */
|
|
KeyInfo pKeyInfo, /* First arg to comparison function */
|
|
BtCursor pCur /* Space for new cursor */
|
|
)
|
|
{
|
|
BtShared pBt = p.pBt; /* Shared b-tree handle */
|
|
|
|
Debug.Assert(sqlite3BtreeHoldsMutex(p));
|
|
Debug.Assert(wrFlag == 0 || wrFlag == 1);
|
|
|
|
/* The following Debug.Assert statements verify that if this is a sharable
|
|
** b-tree database, the connection is holding the required table locks,
|
|
** and that no other connection has any open cursor that conflicts with
|
|
** this lock. */
|
|
Debug.Assert(hasSharedCacheTableLock(p, (u32)iTable, pKeyInfo != null ? 1 : 0, wrFlag + 1));
|
|
Debug.Assert(wrFlag == 0 || !hasReadConflicts(p, (u32)iTable));
|
|
|
|
/* Assert that the caller has opened the required transaction. */
|
|
Debug.Assert(p.inTrans > TRANS_NONE);
|
|
Debug.Assert(wrFlag == 0 || p.inTrans == TRANS_WRITE);
|
|
Debug.Assert(pBt.pPage1 != null && pBt.pPage1.aData != null);
|
|
|
|
if (NEVER(wrFlag != 0 && pBt.readOnly))
|
|
{
|
|
return SQLITE_READONLY;
|
|
}
|
|
if (iTable == 1 && btreePagecount(pBt) == 0)
|
|
{
|
|
return SQLITE_EMPTY;
|
|
}
|
|
|
|
/* Now that no other errors can occur, finish filling in the BtCursor
|
|
** variables and link the cursor into the BtShared list. */
|
|
pCur.pgnoRoot = (Pgno)iTable;
|
|
pCur.iPage = -1;
|
|
pCur.pKeyInfo = pKeyInfo;
|
|
pCur.pBtree = p;
|
|
pCur.pBt = pBt;
|
|
pCur.wrFlag = (u8)wrFlag;
|
|
pCur.pNext = pBt.pCursor;
|
|
if (pCur.pNext != null)
|
|
{
|
|
pCur.pNext.pPrev = pCur;
|
|
}
|
|
pBt.pCursor = pCur;
|
|
pCur.eState = CURSOR_INVALID;
|
|
pCur.cachedRowid = 0;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
private static int sqlite3BtreeCursor(
|
|
Btree p, /* The btree */
|
|
int iTable, /* Root page of table to open */
|
|
int wrFlag, /* 1 to write. 0 read-only */
|
|
KeyInfo pKeyInfo, /* First arg to xCompare() */
|
|
BtCursor pCur /* Write new cursor here */
|
|
)
|
|
{
|
|
int rc;
|
|
sqlite3BtreeEnter(p);
|
|
rc = btreeCursor(p, iTable, wrFlag, pKeyInfo, pCur);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Return the size of a BtCursor object in bytes.
|
|
**
|
|
** This interfaces is needed so that users of cursors can preallocate
|
|
** sufficient storage to hold a cursor. The BtCursor object is opaque
|
|
** to users so they cannot do the sizeof() themselves - they must call
|
|
** this routine.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCursorSize()
|
|
{
|
|
return -1; // Not Used -- return ROUND8(sizeof(BtCursor));
|
|
}
|
|
|
|
/*
|
|
** Initialize memory that will be converted into a BtCursor object.
|
|
**
|
|
** The simple approach here would be to memset() the entire object
|
|
** to zero. But it turns out that the apPage[] and aiIdx[] arrays
|
|
** do not need to be zeroed and they are large, so we can save a lot
|
|
** of run-time by skipping the initialization of those elements.
|
|
*/
|
|
|
|
private static void sqlite3BtreeCursorZero(BtCursor p)
|
|
{
|
|
p.Clear(); // memset( p, 0, offsetof( BtCursor, iPage ) );
|
|
}
|
|
|
|
/*
|
|
** Set the cached rowid value of every cursor in the same database file
|
|
** as pCur and having the same root page number as pCur. The value is
|
|
** set to iRowid.
|
|
**
|
|
** Only positive rowid values are considered valid for this cache.
|
|
** The cache is initialized to zero, indicating an invalid cache.
|
|
** A btree will work fine with zero or negative rowids. We just cannot
|
|
** cache zero or negative rowids, which means tables that use zero or
|
|
** negative rowids might run a little slower. But in practice, zero
|
|
** or negative rowids are very uncommon so this should not be a problem.
|
|
*/
|
|
|
|
private static void sqlite3BtreeSetCachedRowid(BtCursor pCur, sqlite3_int64 iRowid)
|
|
{
|
|
BtCursor p;
|
|
for (p = pCur.pBt.pCursor; p != null; p = p.pNext)
|
|
{
|
|
if (p.pgnoRoot == pCur.pgnoRoot)
|
|
p.cachedRowid = iRowid;
|
|
}
|
|
Debug.Assert(pCur.cachedRowid == iRowid);
|
|
}
|
|
|
|
/*
|
|
** Return the cached rowid for the given cursor. A negative or zero
|
|
** return value indicates that the rowid cache is invalid and should be
|
|
** ignored. If the rowid cache has never before been set, then a
|
|
** zero is returned.
|
|
*/
|
|
|
|
private static sqlite3_int64 sqlite3BtreeGetCachedRowid(BtCursor pCur)
|
|
{
|
|
return pCur.cachedRowid;
|
|
}
|
|
|
|
/*
|
|
** Close a cursor. The read lock on the database file is released
|
|
** when the last cursor is closed.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCloseCursor(BtCursor pCur)
|
|
{
|
|
Btree pBtree = pCur.pBtree;
|
|
if (pBtree != null)
|
|
{
|
|
int i;
|
|
BtShared pBt = pCur.pBt;
|
|
sqlite3BtreeEnter(pBtree);
|
|
sqlite3BtreeClearCursor(pCur);
|
|
if (pCur.pPrev != null)
|
|
{
|
|
pCur.pPrev.pNext = pCur.pNext;
|
|
}
|
|
else
|
|
{
|
|
pBt.pCursor = pCur.pNext;
|
|
}
|
|
if (pCur.pNext != null)
|
|
{
|
|
pCur.pNext.pPrev = pCur.pPrev;
|
|
}
|
|
for (i = 0; i <= pCur.iPage; i++)
|
|
{
|
|
releasePage(pCur.apPage[i]);
|
|
}
|
|
unlockBtreeIfUnused(pBt);
|
|
invalidateOverflowCache(pCur);
|
|
/* sqlite3_free(ref pCur); */
|
|
sqlite3BtreeLeave(pBtree);
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Make sure the BtCursor* given in the argument has a valid
|
|
** BtCursor.info structure. If it is not already valid, call
|
|
** btreeParseCell() to fill it in.
|
|
**
|
|
** BtCursor.info is a cache of the information in the current cell.
|
|
** Using this cache reduces the number of calls to btreeParseCell().
|
|
**
|
|
** 2007-06-25: There is a bug in some versions of MSVC that cause the
|
|
** compiler to crash when getCellInfo() is implemented as a macro.
|
|
** But there is a measureable speed advantage to using the macro on gcc
|
|
** (when less compiler optimizations like -Os or -O0 are used and the
|
|
** compiler is not doing agressive inlining.) So we use a real function
|
|
** for MSVC and a macro for everything else. Ticket #2457.
|
|
*/
|
|
#if !NDEBUG
|
|
|
|
private static void assertCellInfo(BtCursor pCur)
|
|
{
|
|
CellInfo info;
|
|
int iPage = pCur.iPage;
|
|
info = new CellInfo();//memset(info, 0, sizeof(info));
|
|
btreeParseCell(pCur.apPage[iPage], pCur.aiIdx[iPage], ref info);
|
|
Debug.Assert(info.GetHashCode() == pCur.info.GetHashCode() || info.Equals(pCur.info));//memcmp(info, pCur.info, sizeof(info))==0 );
|
|
}
|
|
|
|
#else
|
|
// #define assertCellInfo(x)
|
|
static void assertCellInfo(BtCursor pCur) { }
|
|
#endif
|
|
#if _MSC_VER
|
|
/* Use a real function in MSVC to work around bugs in that compiler. */
|
|
|
|
private static void getCellInfo(BtCursor pCur)
|
|
{
|
|
if (pCur.info.nSize == 0)
|
|
{
|
|
int iPage = pCur.iPage;
|
|
btreeParseCell(pCur.apPage[iPage], pCur.aiIdx[iPage], ref pCur.info);
|
|
pCur.validNKey = true;
|
|
}
|
|
else
|
|
{
|
|
assertCellInfo(pCur);
|
|
}
|
|
}
|
|
|
|
#else //* if not _MSC_VER */
|
|
/* Use a macro in all other compilers so that the function is inlined */
|
|
//#define getCellInfo(pCur) \
|
|
// if( pCur.info.nSize==null ){ \
|
|
// int iPage = pCur.iPage; \
|
|
// btreeParseCell(pCur.apPage[iPage],pCur.aiIdx[iPage],&pCur.info); \
|
|
// pCur.validNKey = true; \
|
|
// }else{ \
|
|
// assertCellInfo(pCur); \
|
|
// }
|
|
#endif //* _MSC_VER */
|
|
|
|
#if !NDEBUG //* The next routine used only within Debug.Assert() statements */
|
|
/*
|
|
** Return true if the given BtCursor is valid. A valid cursor is one
|
|
** that is currently pointing to a row in a (non-empty) table.
|
|
** This is a verification routine is used only within Debug.Assert() statements.
|
|
*/
|
|
|
|
private static bool sqlite3BtreeCursorIsValid(BtCursor pCur)
|
|
{
|
|
return pCur != null && pCur.eState == CURSOR_VALID;
|
|
}
|
|
|
|
#else
|
|
static bool sqlite3BtreeCursorIsValid(BtCursor pCur) { return true; }
|
|
#endif //* NDEBUG */
|
|
|
|
/*
|
|
** Set pSize to the size of the buffer needed to hold the value of
|
|
** the key for the current entry. If the cursor is not pointing
|
|
** to a valid entry, pSize is set to 0.
|
|
**
|
|
** For a table with the INTKEY flag set, this routine returns the key
|
|
** itself, not the number of bytes in the key.
|
|
**
|
|
** The caller must position the cursor prior to invoking this routine.
|
|
**
|
|
** This routine cannot fail. It always returns SQLITE_OK.
|
|
*/
|
|
|
|
private static int sqlite3BtreeKeySize(BtCursor pCur, ref i64 pSize)
|
|
{
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_INVALID || pCur.eState == CURSOR_VALID);
|
|
if (pCur.eState != CURSOR_VALID)
|
|
{
|
|
pSize = 0;
|
|
}
|
|
else
|
|
{
|
|
getCellInfo(pCur);
|
|
pSize = pCur.info.nKey;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Set pSize to the number of bytes of data in the entry the
|
|
** cursor currently points to.
|
|
**
|
|
** The caller must guarantee that the cursor is pointing to a non-NULL
|
|
** valid entry. In other words, the calling procedure must guarantee
|
|
** that the cursor has Cursor.eState==CURSOR_VALID.
|
|
**
|
|
** Failure is not possible. This function always returns SQLITE_OK.
|
|
** It might just as well be a procedure (returning void) but we continue
|
|
** to return an integer result code for historical reasons.
|
|
*/
|
|
|
|
private static int sqlite3BtreeDataSize(BtCursor pCur, ref u32 pSize)
|
|
{
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
getCellInfo(pCur);
|
|
pSize = pCur.info.nData;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Given the page number of an overflow page in the database (parameter
|
|
** ovfl), this function finds the page number of the next page in the
|
|
** linked list of overflow pages. If possible, it uses the auto-vacuum
|
|
** pointer-map data instead of reading the content of page ovfl to do so.
|
|
**
|
|
** If an error occurs an SQLite error code is returned. Otherwise:
|
|
**
|
|
** The page number of the next overflow page in the linked list is
|
|
** written to pPgnoNext. If page ovfl is the last page in its linked
|
|
** list, pPgnoNext is set to zero.
|
|
**
|
|
** If ppPage is not NULL, and a reference to the MemPage object corresponding
|
|
** to page number pOvfl was obtained, then ppPage is set to point to that
|
|
** reference. It is the responsibility of the caller to call releasePage()
|
|
** on ppPage to free the reference. In no reference was obtained (because
|
|
** the pointer-map was used to obtain the value for pPgnoNext), then
|
|
** ppPage is set to zero.
|
|
*/
|
|
|
|
private static int getOverflowPage(
|
|
BtShared pBt, /* The database file */
|
|
Pgno ovfl, /* Current overflow page number */
|
|
out MemPage ppPage, /* OUT: MemPage handle (may be NULL) */
|
|
out Pgno pPgnoNext /* OUT: Next overflow page number */
|
|
)
|
|
{
|
|
Pgno next = 0;
|
|
MemPage pPage = null;
|
|
ppPage = null;
|
|
int rc = SQLITE_OK;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
// Debug.Assert( pPgnoNext);
|
|
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
/* Try to find the next page in the overflow list using the
|
|
** autovacuum pointer-map pages. Guess that the next page in
|
|
** the overflow list is page number (ovfl+1). If that guess turns
|
|
** out to be wrong, fall back to loading the data of page
|
|
** number ovfl to determine the next page number.
|
|
*/
|
|
if (pBt.autoVacuum)
|
|
{
|
|
Pgno pgno = 0;
|
|
Pgno iGuess = ovfl + 1;
|
|
u8 eType = 0;
|
|
|
|
while (PTRMAP_ISPAGE(pBt, iGuess) || iGuess == PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
iGuess++;
|
|
}
|
|
|
|
if (iGuess <= btreePagecount(pBt))
|
|
{
|
|
rc = ptrmapGet(pBt, iGuess, ref eType, ref pgno);
|
|
if (rc == SQLITE_OK && eType == PTRMAP_OVERFLOW2 && pgno == ovfl)
|
|
{
|
|
next = iGuess;
|
|
rc = SQLITE_DONE;
|
|
}
|
|
}
|
|
}
|
|
#endif
|
|
|
|
Debug.Assert(next == 0 || rc == SQLITE_DONE);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = btreeGetPage(pBt, ovfl, ref pPage, 0);
|
|
Debug.Assert(rc == SQLITE_OK || pPage == null);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
next = sqlite3Get4byte(pPage.aData);
|
|
}
|
|
}
|
|
|
|
pPgnoNext = next;
|
|
if (ppPage != null)
|
|
{
|
|
ppPage = pPage;
|
|
}
|
|
else
|
|
{
|
|
releasePage(pPage);
|
|
}
|
|
return (rc == SQLITE_DONE ? SQLITE_OK : rc);
|
|
}
|
|
|
|
/*
|
|
** Copy data from a buffer to a page, or from a page to a buffer.
|
|
**
|
|
** pPayload is a pointer to data stored on database page pDbPage.
|
|
** If argument eOp is false, then nByte bytes of data are copied
|
|
** from pPayload to the buffer pointed at by pBuf. If eOp is true,
|
|
** then sqlite3PagerWrite() is called on pDbPage and nByte bytes
|
|
** of data are copied from the buffer pBuf to pPayload.
|
|
**
|
|
** SQLITE_OK is returned on success, otherwise an error code.
|
|
*/
|
|
|
|
private static int copyPayload(
|
|
byte[] pPayload, /* Pointer to page data */
|
|
u32 payloadOffset, /* Offset into page data */
|
|
byte[] pBuf, /* Pointer to buffer */
|
|
u32 pBufOffset, /* Offset into buffer */
|
|
u32 nByte, /* Number of bytes to copy */
|
|
int eOp, /* 0 . copy from page, 1 . copy to page */
|
|
DbPage pDbPage /* Page containing pPayload */
|
|
)
|
|
{
|
|
if (eOp != 0)
|
|
{
|
|
/* Copy data from buffer to page (a write operation) */
|
|
int rc = sqlite3PagerWrite(pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
Buffer.BlockCopy(pBuf, (int)pBufOffset, pPayload, (int)payloadOffset, (int)nByte);// memcpy( pPayload, pBuf, nByte );
|
|
}
|
|
else
|
|
{
|
|
/* Copy data from page to buffer (a read operation) */
|
|
Buffer.BlockCopy(pPayload, (int)payloadOffset, pBuf, (int)pBufOffset, (int)nByte);//memcpy(pBuf, pPayload, nByte);
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
//static int copyPayload(
|
|
// byte[] pPayload, /* Pointer to page data */
|
|
// byte[] pBuf, /* Pointer to buffer */
|
|
// int nByte, /* Number of bytes to copy */
|
|
// int eOp, /* 0 -> copy from page, 1 -> copy to page */
|
|
// DbPage pDbPage /* Page containing pPayload */
|
|
//){
|
|
// if( eOp!=0 ){
|
|
// /* Copy data from buffer to page (a write operation) */
|
|
// int rc = sqlite3PagerWrite(pDbPage);
|
|
// if( rc!=SQLITE_OK ){
|
|
// return rc;
|
|
// }
|
|
// memcpy(pPayload, pBuf, nByte);
|
|
// }else{
|
|
// /* Copy data from page to buffer (a read operation) */
|
|
// memcpy(pBuf, pPayload, nByte);
|
|
// }
|
|
// return SQLITE_OK;
|
|
//}
|
|
|
|
/*
|
|
** This function is used to read or overwrite payload information
|
|
** for the entry that the pCur cursor is pointing to. If the eOp
|
|
** parameter is 0, this is a read operation (data copied into
|
|
** buffer pBuf). If it is non-zero, a write (data copied from
|
|
** buffer pBuf).
|
|
**
|
|
** A total of "amt" bytes are read or written beginning at "offset".
|
|
** Data is read to or from the buffer pBuf.
|
|
**
|
|
** The content being read or written might appear on the main page
|
|
** or be scattered out on multiple overflow pages.
|
|
**
|
|
** If the BtCursor.isIncrblobHandle flag is set, and the current
|
|
** cursor entry uses one or more overflow pages, this function
|
|
** allocates space for and lazily popluates the overflow page-list
|
|
** cache array (BtCursor.aOverflow). Subsequent calls use this
|
|
** cache to make seeking to the supplied offset more efficient.
|
|
**
|
|
** Once an overflow page-list cache has been allocated, it may be
|
|
** invalidated if some other cursor writes to the same table, or if
|
|
** the cursor is moved to a different row. Additionally, in auto-vacuum
|
|
** mode, the following events may invalidate an overflow page-list cache.
|
|
**
|
|
** * An incremental vacuum,
|
|
** * A commit in auto_vacuum="full" mode,
|
|
** * Creating a table (may require moving an overflow page).
|
|
*/
|
|
|
|
private static int accessPayload(
|
|
BtCursor pCur, /* Cursor pointing to entry to read from */
|
|
u32 offset, /* Begin reading this far into payload */
|
|
u32 amt, /* Read this many bytes */
|
|
byte[] pBuf, /* Write the bytes into this buffer */
|
|
int eOp /* zero to read. non-zero to write. */
|
|
)
|
|
{
|
|
u32 pBufOffset = 0;
|
|
byte[] aPayload;
|
|
int rc = SQLITE_OK;
|
|
u32 nKey;
|
|
int iIdx = 0;
|
|
MemPage pPage = pCur.apPage[pCur.iPage]; /* Btree page of current entry */
|
|
BtShared pBt = pCur.pBt; /* Btree this cursor belongs to */
|
|
|
|
Debug.Assert(pPage != null);
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] < pPage.nCell);
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
|
|
getCellInfo(pCur);
|
|
aPayload = pCur.info.pCell; //pCur.info.pCell + pCur.info.nHeader;
|
|
nKey = (u32)(pPage.intKey != 0 ? 0 : (int)pCur.info.nKey);
|
|
|
|
if (NEVER(offset + amt > nKey + pCur.info.nData)
|
|
|| pCur.info.nLocal > pBt.usableSize//&aPayload[pCur.info.nLocal] > &pPage.aData[pBt.usableSize]
|
|
)
|
|
{
|
|
/* Trying to read or write past the end of the data is an error */
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
|
|
/* Check if data must be read/written to/from the btree page itself. */
|
|
if (offset < pCur.info.nLocal)
|
|
{
|
|
int a = (int)amt;
|
|
if (a + offset > pCur.info.nLocal)
|
|
{
|
|
a = (int)(pCur.info.nLocal - offset);
|
|
}
|
|
rc = copyPayload(aPayload, (u32)(offset + pCur.info.iCell + pCur.info.nHeader), pBuf, pBufOffset, (u32)a, eOp, pPage.pDbPage);
|
|
offset = 0;
|
|
pBufOffset += (u32)a; //pBuf += a;
|
|
amt -= (u32)a;
|
|
}
|
|
else
|
|
{
|
|
offset -= pCur.info.nLocal;
|
|
}
|
|
|
|
if (rc == SQLITE_OK && amt > 0)
|
|
{
|
|
u32 ovflSize = (u32)(pBt.usableSize - 4); /* Bytes content per ovfl page */
|
|
Pgno nextPage;
|
|
|
|
nextPage = sqlite3Get4byte(aPayload, pCur.info.nLocal + pCur.info.iCell + pCur.info.nHeader);
|
|
|
|
#if !SQLITE_OMIT_INCRBLOB
|
|
/* If the isIncrblobHandle flag is set and the BtCursor.aOverflow[]
|
|
** has not been allocated, allocate it now. The array is sized at
|
|
** one entry for each overflow page in the overflow chain. The
|
|
** page number of the first overflow page is stored in aOverflow[0],
|
|
** etc. A value of 0 in the aOverflow[] array means "not yet known"
|
|
** (the cache is lazily populated).
|
|
*/
|
|
if( pCur.isIncrblobHandle && !pCur.aOverflow ){
|
|
int nOvfl = (pCur.info.nPayload-pCur.info.nLocal+ovflSize-1)/ovflSize;
|
|
pCur.aOverflow = (Pgno *)sqlite3MallocZero(sizeof(Pgno)*nOvfl);
|
|
/* nOvfl is always positive. If it were zero, fetchPayload would have
|
|
** been used instead of this routine. */
|
|
if( ALWAYS(nOvfl) && !pCur.aOverflow ){
|
|
rc = SQLITE_NOMEM;
|
|
}
|
|
}
|
|
|
|
/* If the overflow page-list cache has been allocated and the
|
|
** entry for the first required overflow page is valid, skip
|
|
** directly to it.
|
|
*/
|
|
if( pCur.aOverflow && pCur.aOverflow[offset/ovflSize] ){
|
|
iIdx = (offset/ovflSize);
|
|
nextPage = pCur.aOverflow[iIdx];
|
|
offset = (offset%ovflSize);
|
|
}
|
|
#endif
|
|
|
|
for (; rc == SQLITE_OK && amt > 0 && nextPage != 0; iIdx++)
|
|
{
|
|
#if !SQLITE_OMIT_INCRBLOB
|
|
/* If required, populate the overflow page-list cache. */
|
|
if( pCur.aOverflow ){
|
|
Debug.Assert(!pCur.aOverflow[iIdx] || pCur.aOverflow[iIdx]==nextPage);
|
|
pCur.aOverflow[iIdx] = nextPage;
|
|
}
|
|
#endif
|
|
|
|
MemPage MemPageDummy = null;
|
|
if (offset >= ovflSize)
|
|
{
|
|
/* The only reason to read this page is to obtain the page
|
|
** number for the next page in the overflow chain. The page
|
|
** data is not required. So first try to lookup the overflow
|
|
** page-list cache, if any, then fall back to the getOverflowPage()
|
|
** function.
|
|
*/
|
|
#if !SQLITE_OMIT_INCRBLOB
|
|
if( pCur.aOverflow && pCur.aOverflow[iIdx+1] ){
|
|
nextPage = pCur.aOverflow[iIdx+1];
|
|
} else
|
|
#endif
|
|
rc = getOverflowPage(pBt, nextPage, out MemPageDummy, out nextPage);
|
|
offset -= ovflSize;
|
|
}
|
|
else
|
|
{
|
|
/* Need to read this page properly. It contains some of the
|
|
** range of data that is being read (eOp==null) or written (eOp!=null).
|
|
*/
|
|
PgHdr pDbPage = new PgHdr();
|
|
int a = (int)amt;
|
|
rc = sqlite3PagerGet(pBt.pPager, nextPage, ref pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
aPayload = sqlite3PagerGetData(pDbPage);
|
|
nextPage = sqlite3Get4byte(aPayload);
|
|
if (a + offset > ovflSize)
|
|
{
|
|
a = (int)(ovflSize - offset);
|
|
}
|
|
rc = copyPayload(aPayload, offset + 4, pBuf, pBufOffset, (u32)a, eOp, pDbPage);
|
|
sqlite3PagerUnref(pDbPage);
|
|
offset = 0;
|
|
amt -= (u32)a;
|
|
pBufOffset += (u32)a;//pBuf += a;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
if (rc == SQLITE_OK && amt > 0)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Read part of the key associated with cursor pCur. Exactly
|
|
** "amt" bytes will be transfered into pBuf[]. The transfer
|
|
** begins at "offset".
|
|
**
|
|
** The caller must ensure that pCur is pointing to a valid row
|
|
** in the table.
|
|
**
|
|
** Return SQLITE_OK on success or an error code if anything goes
|
|
** wrong. An error is returned if "offset+amt" is larger than
|
|
** the available payload.
|
|
*/
|
|
|
|
private static int sqlite3BtreeKey(BtCursor pCur, u32 offset, u32 amt, byte[] pBuf)
|
|
{
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
Debug.Assert(pCur.iPage >= 0 && pCur.apPage[pCur.iPage] != null);
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] < pCur.apPage[pCur.iPage].nCell);
|
|
return accessPayload(pCur, offset, amt, pBuf, 0);
|
|
}
|
|
|
|
/*
|
|
** Read part of the data associated with cursor pCur. Exactly
|
|
** "amt" bytes will be transfered into pBuf[]. The transfer
|
|
** begins at "offset".
|
|
**
|
|
** Return SQLITE_OK on success or an error code if anything goes
|
|
** wrong. An error is returned if "offset+amt" is larger than
|
|
** the available payload.
|
|
*/
|
|
|
|
private static int sqlite3BtreeData(BtCursor pCur, u32 offset, u32 amt, byte[] pBuf)
|
|
{
|
|
int rc;
|
|
|
|
#if !SQLITE_OMIT_INCRBLOB
|
|
if ( pCur.eState==CURSOR_INVALID ){
|
|
return SQLITE_ABORT;
|
|
}
|
|
#endif
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
rc = restoreCursorPosition(pCur);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
Debug.Assert(pCur.iPage >= 0 && pCur.apPage[pCur.iPage] != null);
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] < pCur.apPage[pCur.iPage].nCell);
|
|
rc = accessPayload(pCur, offset, amt, pBuf, 0);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Return a pointer to payload information from the entry that the
|
|
** pCur cursor is pointing to. The pointer is to the beginning of
|
|
** the key if skipKey==null and it points to the beginning of data if
|
|
** skipKey==1. The number of bytes of available key/data is written
|
|
** into pAmt. If pAmt==null, then the value returned will not be
|
|
** a valid pointer.
|
|
**
|
|
** This routine is an optimization. It is common for the entire key
|
|
** and data to fit on the local page and for there to be no overflow
|
|
** pages. When that is so, this routine can be used to access the
|
|
** key and data without making a copy. If the key and/or data spills
|
|
** onto overflow pages, then accessPayload() must be used to reassemble
|
|
** the key/data and copy it into a preallocated buffer.
|
|
**
|
|
** The pointer returned by this routine looks directly into the cached
|
|
** page of the database. The data might change or move the next time
|
|
** any btree routine is called.
|
|
*/
|
|
|
|
private static byte[] fetchPayload(
|
|
BtCursor pCur, /* Cursor pointing to entry to read from */
|
|
ref int pAmt, /* Write the number of available bytes here */
|
|
ref int outOffset, /* Offset into Buffer */
|
|
bool skipKey /* read beginning at data if this is true */
|
|
)
|
|
{
|
|
byte[] aPayload;
|
|
MemPage pPage;
|
|
u32 nKey;
|
|
u32 nLocal;
|
|
|
|
Debug.Assert(pCur != null && pCur.iPage >= 0 && pCur.apPage[pCur.iPage] != null);
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
outOffset = -1;
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] < pPage.nCell);
|
|
if (NEVER(pCur.info.nSize == 0))
|
|
{
|
|
btreeParseCell(pCur.apPage[pCur.iPage], pCur.aiIdx[pCur.iPage],
|
|
ref pCur.info);
|
|
}
|
|
//aPayload = pCur.info.pCell;
|
|
//aPayload += pCur.info.nHeader;
|
|
aPayload = sqlite3Malloc(pCur.info.nSize - pCur.info.nHeader);
|
|
if (pPage.intKey != 0)
|
|
{
|
|
nKey = 0;
|
|
}
|
|
else
|
|
{
|
|
nKey = (u32)pCur.info.nKey;
|
|
}
|
|
if (skipKey)
|
|
{
|
|
//aPayload += nKey;
|
|
outOffset = (int)(pCur.info.iCell + pCur.info.nHeader + nKey);
|
|
Buffer.BlockCopy(pCur.info.pCell, outOffset, aPayload, 0, (int)(pCur.info.nSize - pCur.info.nHeader - nKey));
|
|
nLocal = pCur.info.nLocal - nKey;
|
|
}
|
|
else
|
|
{
|
|
outOffset = (int)(pCur.info.iCell + pCur.info.nHeader);
|
|
Buffer.BlockCopy(pCur.info.pCell, outOffset, aPayload, 0, pCur.info.nSize - pCur.info.nHeader);
|
|
nLocal = pCur.info.nLocal;
|
|
Debug.Assert(nLocal <= nKey);
|
|
}
|
|
pAmt = (int)nLocal;
|
|
return aPayload;
|
|
}
|
|
|
|
/*
|
|
** For the entry that cursor pCur is point to, return as
|
|
** many bytes of the key or data as are available on the local
|
|
** b-tree page. Write the number of available bytes into pAmt.
|
|
**
|
|
** The pointer returned is ephemeral. The key/data may move
|
|
** or be destroyed on the next call to any Btree routine,
|
|
** including calls from other threads against the same cache.
|
|
** Hence, a mutex on the BtShared should be held prior to calling
|
|
** this routine.
|
|
**
|
|
** These routines is used to get quick access to key and data
|
|
** in the common case where no overflow pages are used.
|
|
*/
|
|
|
|
private static byte[] sqlite3BtreeKeyFetch(BtCursor pCur, ref int pAmt, ref int outOffset)
|
|
{
|
|
byte[] p = null;
|
|
Debug.Assert(sqlite3_mutex_held(pCur.pBtree.db.mutex));
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
if (ALWAYS(pCur.eState == CURSOR_VALID))
|
|
{
|
|
p = fetchPayload(pCur, ref pAmt, ref outOffset, false);
|
|
}
|
|
return p;
|
|
}
|
|
|
|
private static byte[] sqlite3BtreeDataFetch(BtCursor pCur, ref int pAmt, ref int outOffset)
|
|
{
|
|
byte[] p = null;
|
|
Debug.Assert(sqlite3_mutex_held(pCur.pBtree.db.mutex));
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
if (ALWAYS(pCur.eState == CURSOR_VALID))
|
|
{
|
|
p = fetchPayload(pCur, ref pAmt, ref outOffset, true);
|
|
}
|
|
return p;
|
|
}
|
|
|
|
/*
|
|
** Move the cursor down to a new child page. The newPgno argument is the
|
|
** page number of the child page to move to.
|
|
**
|
|
** This function returns SQLITE_CORRUPT if the page-header flags field of
|
|
** the new child page does not match the flags field of the parent (i.e.
|
|
** if an intkey page appears to be the parent of a non-intkey page, or
|
|
** vice-versa).
|
|
*/
|
|
|
|
private static int moveToChild(BtCursor pCur, u32 newPgno)
|
|
{
|
|
int rc;
|
|
int i = pCur.iPage;
|
|
MemPage pNewPage = new MemPage();
|
|
BtShared pBt = pCur.pBt;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
Debug.Assert(pCur.iPage < BTCURSOR_MAX_DEPTH);
|
|
if (pCur.iPage >= (BTCURSOR_MAX_DEPTH - 1))
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
rc = getAndInitPage(pBt, newPgno, ref pNewPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
pCur.apPage[i + 1] = pNewPage;
|
|
pCur.aiIdx[i + 1] = 0;
|
|
pCur.iPage++;
|
|
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
if (pNewPage.nCell < 1 || pNewPage.intKey != pCur.apPage[i].intKey)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
#if !NDEBUG
|
|
/*
|
|
** Page pParent is an internal (non-leaf) tree page. This function
|
|
** asserts that page number iChild is the left-child if the iIdx'th
|
|
** cell in page pParent. Or, if iIdx is equal to the total number of
|
|
** cells in pParent, that page number iChild is the right-child of
|
|
** the page.
|
|
*/
|
|
|
|
private static void assertParentIndex(MemPage pParent, int iIdx, Pgno iChild)
|
|
{
|
|
Debug.Assert(iIdx <= pParent.nCell);
|
|
if (iIdx == pParent.nCell)
|
|
{
|
|
Debug.Assert(sqlite3Get4byte(pParent.aData, pParent.hdrOffset + 8) == iChild);
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(sqlite3Get4byte(pParent.aData, findCell(pParent, iIdx)) == iChild);
|
|
}
|
|
}
|
|
|
|
#else
|
|
//# define assertParentIndex(x,y,z)
|
|
static void assertParentIndex(MemPage pParent, int iIdx, Pgno iChild) { }
|
|
#endif
|
|
|
|
/*
|
|
** Move the cursor up to the parent page.
|
|
**
|
|
** pCur.idx is set to the cell index that contains the pointer
|
|
** to the page we are coming from. If we are coming from the
|
|
** right-most child page then pCur.idx is set to one more than
|
|
** the largest cell index.
|
|
*/
|
|
|
|
private static void moveToParent(BtCursor pCur)
|
|
{
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
Debug.Assert(pCur.iPage > 0);
|
|
Debug.Assert(pCur.apPage[pCur.iPage] != null);
|
|
assertParentIndex(
|
|
pCur.apPage[pCur.iPage - 1],
|
|
pCur.aiIdx[pCur.iPage - 1],
|
|
pCur.apPage[pCur.iPage].pgno
|
|
);
|
|
releasePage(pCur.apPage[pCur.iPage]);
|
|
pCur.iPage--;
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
}
|
|
|
|
/*
|
|
** Move the cursor to point to the root page of its b-tree structure.
|
|
**
|
|
** If the table has a virtual root page, then the cursor is moved to point
|
|
** to the virtual root page instead of the actual root page. A table has a
|
|
** virtual root page when the actual root page contains no cells and a
|
|
** single child page. This can only happen with the table rooted at page 1.
|
|
**
|
|
** If the b-tree structure is empty, the cursor state is set to
|
|
** CURSOR_INVALID. Otherwise, the cursor is set to point to the first
|
|
** cell located on the root (or virtual root) page and the cursor state
|
|
** is set to CURSOR_VALID.
|
|
**
|
|
** If this function returns successfully, it may be assumed that the
|
|
** page-header flags indicate that the [virtual] root-page is the expected
|
|
** kind of b-tree page (i.e. if when opening the cursor the caller did not
|
|
** specify a KeyInfo structure the flags byte is set to 0x05 or 0x0D,
|
|
** indicating a table b-tree, or if the caller did specify a KeyInfo
|
|
** structure the flags byte is set to 0x02 or 0x0A, indicating an index
|
|
** b-tree).
|
|
*/
|
|
|
|
private static int moveToRoot(BtCursor pCur)
|
|
{
|
|
MemPage pRoot;
|
|
int rc = SQLITE_OK;
|
|
Btree p = pCur.pBtree;
|
|
BtShared pBt = p.pBt;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(CURSOR_INVALID < CURSOR_REQUIRESEEK);
|
|
Debug.Assert(CURSOR_VALID < CURSOR_REQUIRESEEK);
|
|
Debug.Assert(CURSOR_FAULT > CURSOR_REQUIRESEEK);
|
|
if (pCur.eState >= CURSOR_REQUIRESEEK)
|
|
{
|
|
if (pCur.eState == CURSOR_FAULT)
|
|
{
|
|
Debug.Assert(pCur.skipNext != SQLITE_OK);
|
|
return pCur.skipNext;
|
|
}
|
|
sqlite3BtreeClearCursor(pCur);
|
|
}
|
|
|
|
if (pCur.iPage >= 0)
|
|
{
|
|
int i;
|
|
for (i = 1; i <= pCur.iPage; i++)
|
|
{
|
|
releasePage(pCur.apPage[i]);
|
|
}
|
|
pCur.iPage = 0;
|
|
}
|
|
else
|
|
{
|
|
rc = getAndInitPage(pBt, pCur.pgnoRoot, ref pCur.apPage[0]);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
pCur.eState = CURSOR_INVALID;
|
|
return rc;
|
|
}
|
|
pCur.iPage = 0;
|
|
|
|
/* If pCur.pKeyInfo is not NULL, then the caller that opened this cursor
|
|
** expected to open it on an index b-tree. Otherwise, if pKeyInfo is
|
|
** NULL, the caller expects a table b-tree. If this is not the case,
|
|
** return an SQLITE_CORRUPT error. */
|
|
Debug.Assert(pCur.apPage[0].intKey == 1 || pCur.apPage[0].intKey == 0);
|
|
if ((pCur.pKeyInfo == null) != (pCur.apPage[0].intKey != 0))
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
}
|
|
|
|
/* Assert that the root page is of the correct type. This must be the
|
|
** case as the call to this function that loaded the root-page (either
|
|
** this call or a previous invocation) would have detected corruption
|
|
** if the assumption were not true, and it is not possible for the flags
|
|
** byte to have been modified while this cursor is holding a reference
|
|
** to the page. */
|
|
pRoot = pCur.apPage[0];
|
|
Debug.Assert(pRoot.pgno == pCur.pgnoRoot);
|
|
Debug.Assert(pRoot.isInit != 0 && (pCur.pKeyInfo == null) == (pRoot.intKey != 0));
|
|
|
|
pCur.aiIdx[0] = 0;
|
|
pCur.info.nSize = 0;
|
|
pCur.atLast = 0;
|
|
pCur.validNKey = false;
|
|
|
|
if (pRoot.nCell == 0 && 0 == pRoot.leaf)
|
|
{
|
|
Pgno subpage;
|
|
if (pRoot.pgno != 1)
|
|
return SQLITE_CORRUPT_BKPT();
|
|
subpage = sqlite3Get4byte(pRoot.aData, pRoot.hdrOffset + 8);
|
|
pCur.eState = CURSOR_VALID;
|
|
rc = moveToChild(pCur, subpage);
|
|
}
|
|
else
|
|
{
|
|
pCur.eState = ((pRoot.nCell > 0) ? CURSOR_VALID : CURSOR_INVALID);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Move the cursor down to the left-most leaf entry beneath the
|
|
** entry to which it is currently pointing.
|
|
**
|
|
** The left-most leaf is the one with the smallest key - the first
|
|
** in ascending order.
|
|
*/
|
|
|
|
private static int moveToLeftmost(BtCursor pCur)
|
|
{
|
|
Pgno pgno;
|
|
int rc = SQLITE_OK;
|
|
MemPage pPage;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
while (rc == SQLITE_OK && 0 == (pPage = pCur.apPage[pCur.iPage]).leaf)
|
|
{
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] < pPage.nCell);
|
|
pgno = sqlite3Get4byte(pPage.aData, findCell(pPage, pCur.aiIdx[pCur.iPage]));
|
|
rc = moveToChild(pCur, pgno);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Move the cursor down to the right-most leaf entry beneath the
|
|
** page to which it is currently pointing. Notice the difference
|
|
** between moveToLeftmost() and moveToRightmost(). moveToLeftmost()
|
|
** finds the left-most entry beneath the *entry* whereas moveToRightmost()
|
|
** finds the right-most entry beneath the page*.
|
|
**
|
|
** The right-most entry is the one with the largest key - the last
|
|
** key in ascending order.
|
|
*/
|
|
|
|
private static int moveToRightmost(BtCursor pCur)
|
|
{
|
|
Pgno pgno;
|
|
int rc = SQLITE_OK;
|
|
MemPage pPage = null;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
while (rc == SQLITE_OK && 0 == (pPage = pCur.apPage[pCur.iPage]).leaf)
|
|
{
|
|
pgno = sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8);
|
|
pCur.aiIdx[pCur.iPage] = pPage.nCell;
|
|
rc = moveToChild(pCur, pgno);
|
|
}
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
pCur.aiIdx[pCur.iPage] = (u16)(pPage.nCell - 1);
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/* Move the cursor to the first entry in the table. Return SQLITE_OK
|
|
** on success. Set pRes to 0 if the cursor actually points to something
|
|
** or set pRes to 1 if the table is empty.
|
|
*/
|
|
|
|
private static int sqlite3BtreeFirst(BtCursor pCur, ref int pRes)
|
|
{
|
|
int rc;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(sqlite3_mutex_held(pCur.pBtree.db.mutex));
|
|
rc = moveToRoot(pCur);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
if (pCur.eState == CURSOR_INVALID)
|
|
{
|
|
Debug.Assert(pCur.apPage[pCur.iPage].nCell == 0);
|
|
pRes = 1;
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(pCur.apPage[pCur.iPage].nCell > 0);
|
|
pRes = 0;
|
|
rc = moveToLeftmost(pCur);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/* Move the cursor to the last entry in the table. Return SQLITE_OK
|
|
** on success. Set pRes to 0 if the cursor actually points to something
|
|
** or set pRes to 1 if the table is empty.
|
|
*/
|
|
|
|
private static int sqlite3BtreeLast(BtCursor pCur, ref int pRes)
|
|
{
|
|
int rc;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(sqlite3_mutex_held(pCur.pBtree.db.mutex));
|
|
|
|
/* If the cursor already points to the last entry, this is a no-op. */
|
|
if (CURSOR_VALID == pCur.eState && pCur.atLast != 0)
|
|
{
|
|
#if SQLITE_DEBUG
|
|
/* This block serves to Debug.Assert() that the cursor really does point
|
|
** to the last entry in the b-tree. */
|
|
int ii;
|
|
for (ii = 0; ii < pCur.iPage; ii++)
|
|
{
|
|
Debug.Assert(pCur.aiIdx[ii] == pCur.apPage[ii].nCell);
|
|
}
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] == pCur.apPage[pCur.iPage].nCell - 1);
|
|
Debug.Assert(pCur.apPage[pCur.iPage].leaf != 0);
|
|
#endif
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
rc = moveToRoot(pCur);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
if (CURSOR_INVALID == pCur.eState)
|
|
{
|
|
Debug.Assert(pCur.apPage[pCur.iPage].nCell == 0);
|
|
pRes = 1;
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(pCur.eState == CURSOR_VALID);
|
|
pRes = 0;
|
|
rc = moveToRightmost(pCur);
|
|
pCur.atLast = (u8)(rc == SQLITE_OK ? 1 : 0);
|
|
}
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/* Move the cursor so that it points to an entry near the key
|
|
** specified by pIdxKey or intKey. Return a success code.
|
|
**
|
|
** For INTKEY tables, the intKey parameter is used. pIdxKey
|
|
** must be NULL. For index tables, pIdxKey is used and intKey
|
|
** is ignored.
|
|
**
|
|
** If an exact match is not found, then the cursor is always
|
|
** left pointing at a leaf page which would hold the entry if it
|
|
** were present. The cursor might point to an entry that comes
|
|
** before or after the key.
|
|
**
|
|
** An integer is written into pRes which is the result of
|
|
** comparing the key with the entry to which the cursor is
|
|
** pointing. The meaning of the integer written into
|
|
** pRes is as follows:
|
|
**
|
|
** pRes<0 The cursor is left pointing at an entry that
|
|
** is smaller than intKey/pIdxKey or if the table is empty
|
|
** and the cursor is therefore left point to nothing.
|
|
**
|
|
** pRes==null The cursor is left pointing at an entry that
|
|
** exactly matches intKey/pIdxKey.
|
|
**
|
|
** pRes>0 The cursor is left pointing at an entry that
|
|
** is larger than intKey/pIdxKey.
|
|
**
|
|
*/
|
|
|
|
private static int sqlite3BtreeMovetoUnpacked(
|
|
BtCursor pCur, /* The cursor to be moved */
|
|
UnpackedRecord pIdxKey, /* Unpacked index key */
|
|
i64 intKey, /* The table key */
|
|
int biasRight, /* If true, bias the search to the high end */
|
|
ref int pRes /* Write search results here */
|
|
)
|
|
{
|
|
int rc;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(sqlite3_mutex_held(pCur.pBtree.db.mutex));
|
|
// Not needed in C# // Debug.Assert( pRes != 0 );
|
|
Debug.Assert((pIdxKey == null) == (pCur.pKeyInfo == null));
|
|
|
|
/* If the cursor is already positioned at the point we are trying
|
|
** to move to, then just return without doing any work */
|
|
if (pCur.eState == CURSOR_VALID && pCur.validNKey
|
|
&& pCur.apPage[0].intKey != 0
|
|
)
|
|
{
|
|
if (pCur.info.nKey == intKey)
|
|
{
|
|
pRes = 0;
|
|
return SQLITE_OK;
|
|
}
|
|
if (pCur.atLast != 0 && pCur.info.nKey < intKey)
|
|
{
|
|
pRes = -1;
|
|
return SQLITE_OK;
|
|
}
|
|
}
|
|
|
|
rc = moveToRoot(pCur);
|
|
if (rc != 0)
|
|
{
|
|
return rc;
|
|
}
|
|
Debug.Assert(pCur.apPage[pCur.iPage] != null);
|
|
Debug.Assert(pCur.apPage[pCur.iPage].isInit != 0);
|
|
Debug.Assert(pCur.apPage[pCur.iPage].nCell > 0 || pCur.eState == CURSOR_INVALID);
|
|
if (pCur.eState == CURSOR_INVALID)
|
|
{
|
|
pRes = -1;
|
|
Debug.Assert(pCur.apPage[pCur.iPage].nCell == 0);
|
|
return SQLITE_OK;
|
|
}
|
|
Debug.Assert(pCur.apPage[0].intKey != 0 || pIdxKey != null);
|
|
for (; ; )
|
|
{
|
|
int lwr, upr, idx;
|
|
Pgno chldPg;
|
|
MemPage pPage = pCur.apPage[pCur.iPage];
|
|
int c;
|
|
|
|
/* pPage.nCell must be greater than zero. If this is the root-page
|
|
** the cursor would have been INVALID above and this for(;;) loop
|
|
** not run. If this is not the root-page, then the moveToChild() routine
|
|
** would have already detected db corruption. Similarly, pPage must
|
|
** be the right kind (index or table) of b-tree page. Otherwise
|
|
** a moveToChild() or moveToRoot() call would have detected corruption. */
|
|
Debug.Assert(pPage.nCell > 0);
|
|
Debug.Assert(pPage.intKey == ((pIdxKey == null) ? 1 : 0));
|
|
lwr = 0;
|
|
upr = pPage.nCell - 1;
|
|
if (biasRight != 0)
|
|
{
|
|
pCur.aiIdx[pCur.iPage] = (u16)(idx = upr);
|
|
}
|
|
else
|
|
{
|
|
pCur.aiIdx[pCur.iPage] = (u16)(idx = (upr + lwr) / 2);
|
|
}
|
|
for (; ; )
|
|
{
|
|
int pCell; /* Pointer to current cell in pPage */
|
|
|
|
Debug.Assert(idx == pCur.aiIdx[pCur.iPage]);
|
|
pCur.info.nSize = 0;
|
|
pCell = findCell(pPage, idx) + pPage.childPtrSize;
|
|
if (pPage.intKey != 0)
|
|
{
|
|
i64 nCellKey = 0;
|
|
if (pPage.hasData != 0)
|
|
{
|
|
u32 Dummy0 = 0;
|
|
pCell += getVarint32(pPage.aData, pCell, out Dummy0);
|
|
}
|
|
getVarint(pPage.aData, pCell, out nCellKey);
|
|
if (nCellKey == intKey)
|
|
{
|
|
c = 0;
|
|
}
|
|
else if (nCellKey < intKey)
|
|
{
|
|
c = -1;
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(nCellKey > intKey);
|
|
c = +1;
|
|
}
|
|
pCur.validNKey = true;
|
|
pCur.info.nKey = nCellKey;
|
|
}
|
|
else
|
|
{
|
|
/* The maximum supported page-size is 65536 bytes. This means that
|
|
** the maximum number of record bytes stored on an index B-Tree
|
|
** page is less than 16384 bytes and may be stored as a 2-byte
|
|
** varint. This information is used to attempt to avoid parsing
|
|
** the entire cell by checking for the cases where the record is
|
|
** stored entirely within the b-tree page by inspecting the first
|
|
** 2 bytes of the cell.
|
|
*/
|
|
int nCell = pPage.aData[pCell + 0]; //pCell[0];
|
|
if (0 == (nCell & 0x80) && nCell <= pPage.maxLocal)
|
|
{
|
|
/* This branch runs if the record-size field of the cell is a
|
|
** single byte varint and the record fits entirely on the main
|
|
** b-tree page. */
|
|
c = sqlite3VdbeRecordCompare(nCell, pPage.aData, pCell + 1, pIdxKey); //c = sqlite3VdbeRecordCompare( nCell, (void*)&pCell[1], pIdxKey );
|
|
}
|
|
else if (0 == (pPage.aData[pCell + 1] & 0x80)//!(pCell[1] & 0x80)
|
|
&& (nCell = ((nCell & 0x7f) << 7) + pPage.aData[pCell + 1]) <= pPage.maxLocal//pCell[1])<=pPage.maxLocal
|
|
)
|
|
{
|
|
/* The record-size field is a 2 byte varint and the record
|
|
** fits entirely on the main b-tree page. */
|
|
c = sqlite3VdbeRecordCompare(nCell, pPage.aData, pCell + 2, pIdxKey); //c = sqlite3VdbeRecordCompare( nCell, (void*)&pCell[2], pIdxKey );
|
|
}
|
|
else
|
|
{
|
|
/* The record flows over onto one or more overflow pages. In
|
|
** this case the whole cell needs to be parsed, a buffer allocated
|
|
** and accessPayload() used to retrieve the record into the
|
|
** buffer before VdbeRecordCompare() can be called. */
|
|
u8[] pCellKey;
|
|
u8[] pCellBody = new u8[pPage.aData.Length - pCell + pPage.childPtrSize];
|
|
Buffer.BlockCopy(pPage.aData, pCell - pPage.childPtrSize, pCellBody, 0, pCellBody.Length);// u8 * const pCellBody = pCell - pPage->childPtrSize;
|
|
btreeParseCellPtr(pPage, pCellBody, ref pCur.info);
|
|
nCell = (int)pCur.info.nKey;
|
|
pCellKey = sqlite3Malloc(nCell);
|
|
//if ( pCellKey == null )
|
|
//{
|
|
// rc = SQLITE_NOMEM;
|
|
// goto moveto_finish;
|
|
//}
|
|
rc = accessPayload(pCur, 0, (u32)nCell, pCellKey, 0);
|
|
if (rc != 0)
|
|
{
|
|
pCellKey = null;// sqlite3_free(ref pCellKey );
|
|
goto moveto_finish;
|
|
}
|
|
c = sqlite3VdbeRecordCompare(nCell, pCellKey, pIdxKey);
|
|
pCellKey = null;// sqlite3_free(ref pCellKey );
|
|
}
|
|
}
|
|
if (c == 0)
|
|
{
|
|
if (pPage.intKey != 0 && 0 == pPage.leaf)
|
|
{
|
|
lwr = idx;
|
|
upr = lwr - 1;
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
pRes = 0;
|
|
rc = SQLITE_OK;
|
|
goto moveto_finish;
|
|
}
|
|
}
|
|
if (c < 0)
|
|
{
|
|
lwr = idx + 1;
|
|
}
|
|
else
|
|
{
|
|
upr = idx - 1;
|
|
}
|
|
if (lwr > upr)
|
|
{
|
|
break;
|
|
}
|
|
pCur.aiIdx[pCur.iPage] = (u16)(idx = (lwr + upr) / 2);
|
|
}
|
|
Debug.Assert(lwr == upr + 1);
|
|
Debug.Assert(pPage.isInit != 0);
|
|
if (pPage.leaf != 0)
|
|
{
|
|
chldPg = 0;
|
|
}
|
|
else if (lwr >= pPage.nCell)
|
|
{
|
|
chldPg = sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8);
|
|
}
|
|
else
|
|
{
|
|
chldPg = sqlite3Get4byte(pPage.aData, findCell(pPage, lwr));
|
|
}
|
|
if (chldPg == 0)
|
|
{
|
|
Debug.Assert(pCur.aiIdx[pCur.iPage] < pCur.apPage[pCur.iPage].nCell);
|
|
pRes = c;
|
|
rc = SQLITE_OK;
|
|
goto moveto_finish;
|
|
}
|
|
pCur.aiIdx[pCur.iPage] = (u16)lwr;
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
rc = moveToChild(pCur, chldPg);
|
|
if (rc != 0)
|
|
goto moveto_finish;
|
|
}
|
|
moveto_finish:
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Return TRUE if the cursor is not pointing at an entry of the table.
|
|
**
|
|
** TRUE will be returned after a call to sqlite3BtreeNext() moves
|
|
** past the last entry in the table or sqlite3BtreePrev() moves past
|
|
** the first entry. TRUE is also returned if the table is empty.
|
|
*/
|
|
|
|
private static bool sqlite3BtreeEof(BtCursor pCur)
|
|
{
|
|
/* TODO: What if the cursor is in CURSOR_REQUIRESEEK but all table entries
|
|
** have been deleted? This API will need to change to return an error code
|
|
** as well as the boolean result value.
|
|
*/
|
|
return (CURSOR_VALID != pCur.eState);
|
|
}
|
|
|
|
/*
|
|
** Advance the cursor to the next entry in the database. If
|
|
** successful then set pRes=0. If the cursor
|
|
** was already pointing to the last entry in the database before
|
|
** this routine was called, then set pRes=1.
|
|
*/
|
|
|
|
private static int sqlite3BtreeNext(BtCursor pCur, ref int pRes)
|
|
{
|
|
int rc;
|
|
int idx;
|
|
MemPage pPage;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
rc = restoreCursorPosition(pCur);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
// Not needed in C# // Debug.Assert( pRes != 0 );
|
|
if (CURSOR_INVALID == pCur.eState)
|
|
{
|
|
pRes = 1;
|
|
return SQLITE_OK;
|
|
}
|
|
if (pCur.skipNext > 0)
|
|
{
|
|
pCur.skipNext = 0;
|
|
pRes = 0;
|
|
return SQLITE_OK;
|
|
}
|
|
pCur.skipNext = 0;
|
|
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
idx = ++pCur.aiIdx[pCur.iPage];
|
|
Debug.Assert(pPage.isInit != 0);
|
|
Debug.Assert(idx <= pPage.nCell);
|
|
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
if (idx >= pPage.nCell)
|
|
{
|
|
if (0 == pPage.leaf)
|
|
{
|
|
rc = moveToChild(pCur, sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8));
|
|
if (rc != 0)
|
|
return rc;
|
|
rc = moveToLeftmost(pCur);
|
|
pRes = 0;
|
|
return rc;
|
|
}
|
|
do
|
|
{
|
|
if (pCur.iPage == 0)
|
|
{
|
|
pRes = 1;
|
|
pCur.eState = CURSOR_INVALID;
|
|
return SQLITE_OK;
|
|
}
|
|
moveToParent(pCur);
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
} while (pCur.aiIdx[pCur.iPage] >= pPage.nCell);
|
|
pRes = 0;
|
|
if (pPage.intKey != 0)
|
|
{
|
|
rc = sqlite3BtreeNext(pCur, ref pRes);
|
|
}
|
|
else
|
|
{
|
|
rc = SQLITE_OK;
|
|
}
|
|
return rc;
|
|
}
|
|
pRes = 0;
|
|
if (pPage.leaf != 0)
|
|
{
|
|
return SQLITE_OK;
|
|
}
|
|
rc = moveToLeftmost(pCur);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Step the cursor to the back to the previous entry in the database. If
|
|
** successful then set pRes=0. If the cursor
|
|
** was already pointing to the first entry in the database before
|
|
** this routine was called, then set pRes=1.
|
|
*/
|
|
|
|
private static int sqlite3BtreePrevious(BtCursor pCur, ref int pRes)
|
|
{
|
|
int rc;
|
|
MemPage pPage;
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
rc = restoreCursorPosition(pCur);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
pCur.atLast = 0;
|
|
if (CURSOR_INVALID == pCur.eState)
|
|
{
|
|
pRes = 1;
|
|
return SQLITE_OK;
|
|
}
|
|
if (pCur.skipNext < 0)
|
|
{
|
|
pCur.skipNext = 0;
|
|
pRes = 0;
|
|
return SQLITE_OK;
|
|
}
|
|
pCur.skipNext = 0;
|
|
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
Debug.Assert(pPage.isInit != 0);
|
|
if (0 == pPage.leaf)
|
|
{
|
|
int idx = pCur.aiIdx[pCur.iPage];
|
|
rc = moveToChild(pCur, sqlite3Get4byte(pPage.aData, findCell(pPage, idx)));
|
|
if (rc != 0)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = moveToRightmost(pCur);
|
|
}
|
|
else
|
|
{
|
|
while (pCur.aiIdx[pCur.iPage] == 0)
|
|
{
|
|
if (pCur.iPage == 0)
|
|
{
|
|
pCur.eState = CURSOR_INVALID;
|
|
pRes = 1;
|
|
return SQLITE_OK;
|
|
}
|
|
moveToParent(pCur);
|
|
}
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
|
|
pCur.aiIdx[pCur.iPage]--;
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
if (pPage.intKey != 0 && 0 == pPage.leaf)
|
|
{
|
|
rc = sqlite3BtreePrevious(pCur, ref pRes);
|
|
}
|
|
else
|
|
{
|
|
rc = SQLITE_OK;
|
|
}
|
|
}
|
|
pRes = 0;
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Allocate a new page from the database file.
|
|
**
|
|
** The new page is marked as dirty. (In other words, sqlite3PagerWrite()
|
|
** has already been called on the new page.) The new page has also
|
|
** been referenced and the calling routine is responsible for calling
|
|
** sqlite3PagerUnref() on the new page when it is done.
|
|
**
|
|
** SQLITE_OK is returned on success. Any other return value indicates
|
|
** an error. ppPage and pPgno are undefined in the event of an error.
|
|
** Do not invoke sqlite3PagerUnref() on ppPage if an error is returned.
|
|
**
|
|
** If the "nearby" parameter is not 0, then a (feeble) effort is made to
|
|
** locate a page close to the page number "nearby". This can be used in an
|
|
** attempt to keep related pages close to each other in the database file,
|
|
** which in turn can make database access faster.
|
|
**
|
|
** If the "exact" parameter is not 0, and the page-number nearby exists
|
|
** anywhere on the free-list, then it is guarenteed to be returned. This
|
|
** is only used by auto-vacuum databases when allocating a new table.
|
|
*/
|
|
|
|
private static int allocateBtreePage(
|
|
BtShared pBt,
|
|
ref MemPage ppPage,
|
|
ref Pgno pPgno,
|
|
Pgno nearby,
|
|
u8 exact
|
|
)
|
|
{
|
|
MemPage pPage1;
|
|
int rc;
|
|
u32 n; /* Number of pages on the freelist */
|
|
u32 k; /* Number of leaves on the trunk of the freelist */
|
|
MemPage pTrunk = null;
|
|
MemPage pPrevTrunk = null;
|
|
Pgno mxPage; /* Total size of the database file */
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
pPage1 = pBt.pPage1;
|
|
mxPage = btreePagecount(pBt);
|
|
n = sqlite3Get4byte(pPage1.aData, 36);
|
|
testcase(n == mxPage - 1);
|
|
if (n >= mxPage)
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
if (n > 0)
|
|
{
|
|
/* There are pages on the freelist. Reuse one of those pages. */
|
|
Pgno iTrunk;
|
|
u8 searchList = 0; /* If the free-list must be searched for 'nearby' */
|
|
|
|
/* If the 'exact' parameter was true and a query of the pointer-map
|
|
** shows that the page 'nearby' is somewhere on the free-list, then
|
|
** the entire-list will be searched for that page.
|
|
*/
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (exact != 0 && nearby <= mxPage)
|
|
{
|
|
u8 eType = 0;
|
|
Debug.Assert(nearby > 0);
|
|
Debug.Assert(pBt.autoVacuum);
|
|
u32 Dummy0 = 0;
|
|
rc = ptrmapGet(pBt, nearby, ref eType, ref Dummy0);
|
|
if (rc != 0)
|
|
return rc;
|
|
if (eType == PTRMAP_FREEPAGE)
|
|
{
|
|
searchList = 1;
|
|
}
|
|
pPgno = nearby;
|
|
}
|
|
#endif
|
|
|
|
/* Decrement the free-list count by 1. Set iTrunk to the index of the
|
|
** first free-list trunk page. iPrevTrunk is initially 1.
|
|
*/
|
|
rc = sqlite3PagerWrite(pPage1.pDbPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
sqlite3Put4byte(pPage1.aData, (u32)36, n - 1);
|
|
|
|
/* The code within this loop is run only once if the 'searchList' variable
|
|
** is not true. Otherwise, it runs once for each trunk-page on the
|
|
** free-list until the page 'nearby' is located.
|
|
*/
|
|
do
|
|
{
|
|
pPrevTrunk = pTrunk;
|
|
if (pPrevTrunk != null)
|
|
{
|
|
iTrunk = sqlite3Get4byte(pPrevTrunk.aData, 0);
|
|
}
|
|
else
|
|
{
|
|
iTrunk = sqlite3Get4byte(pPage1.aData, 32);
|
|
}
|
|
testcase(iTrunk == mxPage);
|
|
if (iTrunk > mxPage)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
}
|
|
else
|
|
{
|
|
rc = btreeGetPage(pBt, iTrunk, ref pTrunk, 0);
|
|
}
|
|
if (rc != 0)
|
|
{
|
|
pTrunk = null;
|
|
goto end_allocate_page;
|
|
}
|
|
|
|
k = sqlite3Get4byte(pTrunk.aData, 4); /* # of leaves on this trunk page */
|
|
if (k == 0 && 0 == searchList)
|
|
{
|
|
/* The trunk has no leaves and the list is not being searched.
|
|
** So extract the trunk page itself and use it as the newly
|
|
** allocated page */
|
|
Debug.Assert(pPrevTrunk == null);
|
|
rc = sqlite3PagerWrite(pTrunk.pDbPage);
|
|
if (rc != 0)
|
|
{
|
|
goto end_allocate_page;
|
|
}
|
|
pPgno = iTrunk;
|
|
Buffer.BlockCopy(pTrunk.aData, 0, pPage1.aData, 32, 4);//memcpy( pPage1.aData[32], ref pTrunk.aData[0], 4 );
|
|
ppPage = pTrunk;
|
|
pTrunk = null;
|
|
TRACE("ALLOCATE: %d trunk - %d free pages left\n", pPgno, n - 1);
|
|
}
|
|
else if (k > (u32)(pBt.usableSize / 4 - 2))
|
|
{
|
|
/* Value of k is out of range. Database corruption */
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto end_allocate_page;
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
}
|
|
else if (searchList != 0 && nearby == iTrunk)
|
|
{
|
|
/* The list is being searched and this trunk page is the page
|
|
** to allocate, regardless of whether it has leaves.
|
|
*/
|
|
Debug.Assert(pPgno == iTrunk);
|
|
ppPage = pTrunk;
|
|
searchList = 0;
|
|
rc = sqlite3PagerWrite(pTrunk.pDbPage);
|
|
if (rc != 0)
|
|
{
|
|
goto end_allocate_page;
|
|
}
|
|
if (k == 0)
|
|
{
|
|
if (null == pPrevTrunk)
|
|
{
|
|
//memcpy(pPage1.aData[32], pTrunk.aData[0], 4);
|
|
pPage1.aData[32 + 0] = pTrunk.aData[0 + 0];
|
|
pPage1.aData[32 + 1] = pTrunk.aData[0 + 1];
|
|
pPage1.aData[32 + 2] = pTrunk.aData[0 + 2];
|
|
pPage1.aData[32 + 3] = pTrunk.aData[0 + 3];
|
|
}
|
|
else
|
|
{
|
|
rc = sqlite3PagerWrite(pPrevTrunk.pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto end_allocate_page;
|
|
}
|
|
//memcpy(pPrevTrunk.aData[0], pTrunk.aData[0], 4);
|
|
pPrevTrunk.aData[0 + 0] = pTrunk.aData[0 + 0];
|
|
pPrevTrunk.aData[0 + 1] = pTrunk.aData[0 + 1];
|
|
pPrevTrunk.aData[0 + 2] = pTrunk.aData[0 + 2];
|
|
pPrevTrunk.aData[0 + 3] = pTrunk.aData[0 + 3];
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The trunk page is required by the caller but it contains
|
|
** pointers to free-list leaves. The first leaf becomes a trunk
|
|
** page in this case.
|
|
*/
|
|
MemPage pNewTrunk = new MemPage();
|
|
Pgno iNewTrunk = sqlite3Get4byte(pTrunk.aData, 8);
|
|
if (iNewTrunk > mxPage)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto end_allocate_page;
|
|
}
|
|
testcase(iNewTrunk == mxPage);
|
|
rc = btreeGetPage(pBt, iNewTrunk, ref pNewTrunk, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto end_allocate_page;
|
|
}
|
|
rc = sqlite3PagerWrite(pNewTrunk.pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(pNewTrunk);
|
|
goto end_allocate_page;
|
|
}
|
|
//memcpy(pNewTrunk.aData[0], pTrunk.aData[0], 4);
|
|
pNewTrunk.aData[0 + 0] = pTrunk.aData[0 + 0];
|
|
pNewTrunk.aData[0 + 1] = pTrunk.aData[0 + 1];
|
|
pNewTrunk.aData[0 + 2] = pTrunk.aData[0 + 2];
|
|
pNewTrunk.aData[0 + 3] = pTrunk.aData[0 + 3];
|
|
sqlite3Put4byte(pNewTrunk.aData, (u32)4, (u32)(k - 1));
|
|
Buffer.BlockCopy(pTrunk.aData, 12, pNewTrunk.aData, 8, (int)(k - 1) * 4);//memcpy( pNewTrunk.aData[8], ref pTrunk.aData[12], ( k - 1 ) * 4 );
|
|
releasePage(pNewTrunk);
|
|
if (null == pPrevTrunk)
|
|
{
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage1.pDbPage));
|
|
sqlite3Put4byte(pPage1.aData, (u32)32, iNewTrunk);
|
|
}
|
|
else
|
|
{
|
|
rc = sqlite3PagerWrite(pPrevTrunk.pDbPage);
|
|
if (rc != 0)
|
|
{
|
|
goto end_allocate_page;
|
|
}
|
|
sqlite3Put4byte(pPrevTrunk.aData, (u32)0, iNewTrunk);
|
|
}
|
|
}
|
|
pTrunk = null;
|
|
TRACE("ALLOCATE: %d trunk - %d free pages left\n", pPgno, n - 1);
|
|
#endif
|
|
}
|
|
else if (k > 0)
|
|
{
|
|
/* Extract a leaf from the trunk */
|
|
u32 closest;
|
|
Pgno iPage;
|
|
byte[] aData = pTrunk.aData;
|
|
if (nearby > 0)
|
|
{
|
|
u32 i;
|
|
int dist;
|
|
closest = 0;
|
|
dist = sqlite3AbsInt32((int)(sqlite3Get4byte(aData, 8) - nearby));
|
|
for (i = 1; i < k; i++)
|
|
{
|
|
int d2 = sqlite3AbsInt32((int)(sqlite3Get4byte(aData, 8 + i * 4) - nearby));
|
|
if (d2 < dist)
|
|
{
|
|
closest = i;
|
|
dist = d2;
|
|
}
|
|
}
|
|
}
|
|
else
|
|
{
|
|
closest = 0;
|
|
}
|
|
|
|
iPage = sqlite3Get4byte(aData, 8 + closest * 4);
|
|
testcase(iPage == mxPage);
|
|
if (iPage > mxPage)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto end_allocate_page;
|
|
}
|
|
testcase(iPage == mxPage);
|
|
if (0 == searchList || iPage == nearby)
|
|
{
|
|
int noContent;
|
|
pPgno = iPage;
|
|
TRACE("ALLOCATE: %d was leaf %d of %d on trunk %d" +
|
|
": %d more free pages\n",
|
|
pPgno, closest + 1, k, pTrunk.pgno, n - 1);
|
|
rc = sqlite3PagerWrite(pTrunk.pDbPage);
|
|
if (rc != 0)
|
|
goto end_allocate_page;
|
|
if (closest < k - 1)
|
|
{
|
|
Buffer.BlockCopy(aData, (int)(4 + k * 4), aData, 8 + (int)closest * 4, 4);//memcpy( aData[8 + closest * 4], ref aData[4 + k * 4], 4 );
|
|
}
|
|
sqlite3Put4byte(aData, (u32)4, (k - 1));// sqlite3Put4byte( aData, 4, k - 1 );
|
|
noContent = !btreeGetHasContent(pBt, pPgno) ? 1 : 0;
|
|
rc = btreeGetPage(pBt, pPgno, ref ppPage, noContent);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = sqlite3PagerWrite((ppPage).pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(ppPage);
|
|
}
|
|
}
|
|
searchList = 0;
|
|
}
|
|
}
|
|
releasePage(pPrevTrunk);
|
|
pPrevTrunk = null;
|
|
} while (searchList != 0);
|
|
}
|
|
else
|
|
{
|
|
/* There are no pages on the freelist, so create a new page at the
|
|
** end of the file */
|
|
rc = sqlite3PagerWrite(pBt.pPage1.pDbPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
pBt.nPage++;
|
|
if (pBt.nPage == PENDING_BYTE_PAGE(pBt))
|
|
pBt.nPage++;
|
|
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pBt.autoVacuum && PTRMAP_ISPAGE(pBt, pBt.nPage))
|
|
{
|
|
/* If pPgno refers to a pointer-map page, allocate two new pages
|
|
** at the end of the file instead of one. The first allocated page
|
|
** becomes a new pointer-map page, the second is used by the caller.
|
|
*/
|
|
MemPage pPg = null;
|
|
TRACE("ALLOCATE: %d from end of file (pointer-map page)\n", pPgno);
|
|
Debug.Assert(pBt.nPage != PENDING_BYTE_PAGE(pBt));
|
|
rc = btreeGetPage(pBt, pBt.nPage, ref pPg, 1);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = sqlite3PagerWrite(pPg.pDbPage);
|
|
releasePage(pPg);
|
|
}
|
|
if (rc != 0)
|
|
return rc;
|
|
pBt.nPage++;
|
|
if (pBt.nPage == PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
pBt.nPage++;
|
|
}
|
|
}
|
|
#endif
|
|
sqlite3Put4byte(pBt.pPage1.aData, (u32)28, pBt.nPage);
|
|
pPgno = pBt.nPage;
|
|
|
|
Debug.Assert(pPgno != PENDING_BYTE_PAGE(pBt));
|
|
rc = btreeGetPage(pBt, pPgno, ref ppPage, 1);
|
|
if (rc != 0)
|
|
return rc;
|
|
rc = sqlite3PagerWrite((ppPage).pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(ppPage);
|
|
}
|
|
TRACE("ALLOCATE: %d from end of file\n", pPgno);
|
|
}
|
|
|
|
Debug.Assert(pPgno != PENDING_BYTE_PAGE(pBt));
|
|
|
|
end_allocate_page:
|
|
releasePage(pTrunk);
|
|
releasePage(pPrevTrunk);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
if (sqlite3PagerPageRefcount((ppPage).pDbPage) > 1)
|
|
{
|
|
releasePage(ppPage);
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
(ppPage).isInit = 0;
|
|
}
|
|
else
|
|
{
|
|
ppPage = null;
|
|
}
|
|
Debug.Assert(rc != SQLITE_OK || sqlite3PagerIswriteable((ppPage).pDbPage));
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is used to add page iPage to the database file free-list.
|
|
** It is assumed that the page is not already a part of the free-list.
|
|
**
|
|
** The value passed as the second argument to this function is optional.
|
|
** If the caller happens to have a pointer to the MemPage object
|
|
** corresponding to page iPage handy, it may pass it as the second value.
|
|
** Otherwise, it may pass NULL.
|
|
**
|
|
** If a pointer to a MemPage object is passed as the second argument,
|
|
** its reference count is not altered by this function.
|
|
*/
|
|
|
|
private static int freePage2(BtShared pBt, MemPage pMemPage, Pgno iPage)
|
|
{
|
|
MemPage pTrunk = null; /* Free-list trunk page */
|
|
Pgno iTrunk = 0; /* Page number of free-list trunk page */
|
|
MemPage pPage1 = pBt.pPage1; /* Local reference to page 1 */
|
|
MemPage pPage; /* Page being freed. May be NULL. */
|
|
int rc; /* Return Code */
|
|
int nFree; /* Initial number of pages on free-list */
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(iPage > 1);
|
|
Debug.Assert(null == pMemPage || pMemPage.pgno == iPage);
|
|
|
|
if (pMemPage != null)
|
|
{
|
|
pPage = pMemPage;
|
|
sqlite3PagerRef(pPage.pDbPage);
|
|
}
|
|
else
|
|
{
|
|
pPage = btreePageLookup(pBt, iPage);
|
|
}
|
|
|
|
/* Increment the free page count on pPage1 */
|
|
rc = sqlite3PagerWrite(pPage1.pDbPage);
|
|
if (rc != 0)
|
|
goto freepage_out;
|
|
nFree = (int)sqlite3Get4byte(pPage1.aData, 36);
|
|
sqlite3Put4byte(pPage1.aData, 36, nFree + 1);
|
|
|
|
if (pBt.secureDelete)
|
|
{
|
|
/* If the secure_delete option is enabled, then
|
|
** always fully overwrite deleted information with zeros.
|
|
*/
|
|
if ((null == pPage && ((rc = btreeGetPage(pBt, iPage, ref pPage, 0)) != 0))
|
|
|| ((rc = sqlite3PagerWrite(pPage.pDbPage)) != 0)
|
|
)
|
|
{
|
|
goto freepage_out;
|
|
}
|
|
Array.Clear(pPage.aData, 0, (int)pPage.pBt.pageSize);//memset(pPage->aData, 0, pPage->pBt->pageSize);
|
|
}
|
|
|
|
/* If the database supports auto-vacuum, write an entry in the pointer-map
|
|
** to indicate that the page is free.
|
|
*/
|
|
#if !SQLITE_OMIT_AUTOVACUUM // if ( ISAUTOVACUUM )
|
|
if (pBt.autoVacuum)
|
|
#else
|
|
if (false)
|
|
#endif
|
|
{
|
|
ptrmapPut(pBt, iPage, PTRMAP_FREEPAGE, 0, ref rc);
|
|
if (rc != 0)
|
|
goto freepage_out;
|
|
}
|
|
|
|
/* Now manipulate the actual database free-list structure. There are two
|
|
** possibilities. If the free-list is currently empty, or if the first
|
|
** trunk page in the free-list is full, then this page will become a
|
|
** new free-list trunk page. Otherwise, it will become a leaf of the
|
|
** first trunk page in the current free-list. This block tests if it
|
|
** is possible to add the page as a new free-list leaf.
|
|
*/
|
|
if (nFree != 0)
|
|
{
|
|
u32 nLeaf; /* Initial number of leaf cells on trunk page */
|
|
|
|
iTrunk = sqlite3Get4byte(pPage1.aData, 32);
|
|
rc = btreeGetPage(pBt, iTrunk, ref pTrunk, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto freepage_out;
|
|
}
|
|
|
|
nLeaf = sqlite3Get4byte(pTrunk.aData, 4);
|
|
Debug.Assert(pBt.usableSize > 32);
|
|
if (nLeaf > (u32)pBt.usableSize / 4 - 2)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto freepage_out;
|
|
}
|
|
if (nLeaf < (u32)pBt.usableSize / 4 - 8)
|
|
{
|
|
/* In this case there is room on the trunk page to insert the page
|
|
** being freed as a new leaf.
|
|
**
|
|
** Note that the trunk page is not really full until it contains
|
|
** usableSize/4 - 2 entries, not usableSize/4 - 8 entries as we have
|
|
** coded. But due to a coding error in versions of SQLite prior to
|
|
** 3.6.0, databases with freelist trunk pages holding more than
|
|
** usableSize/4 - 8 entries will be reported as corrupt. In order
|
|
** to maintain backwards compatibility with older versions of SQLite,
|
|
** we will continue to restrict the number of entries to usableSize/4 - 8
|
|
** for now. At some point in the future (once everyone has upgraded
|
|
** to 3.6.0 or later) we should consider fixing the conditional above
|
|
** to read "usableSize/4-2" instead of "usableSize/4-8".
|
|
*/
|
|
rc = sqlite3PagerWrite(pTrunk.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
sqlite3Put4byte(pTrunk.aData, (u32)4, nLeaf + 1);
|
|
sqlite3Put4byte(pTrunk.aData, (u32)8 + nLeaf * 4, iPage);
|
|
if (pPage != null && !pBt.secureDelete)
|
|
{
|
|
sqlite3PagerDontWrite(pPage.pDbPage);
|
|
}
|
|
rc = btreeSetHasContent(pBt, iPage);
|
|
}
|
|
TRACE("FREE-PAGE: %d leaf on trunk page %d\n", iPage, pTrunk.pgno);
|
|
goto freepage_out;
|
|
}
|
|
}
|
|
|
|
/* If control flows to this point, then it was not possible to add the
|
|
** the page being freed as a leaf page of the first trunk in the free-list.
|
|
** Possibly because the free-list is empty, or possibly because the
|
|
** first trunk in the free-list is full. Either way, the page being freed
|
|
** will become the new first trunk page in the free-list.
|
|
*/
|
|
if (pPage == null && SQLITE_OK != (rc = btreeGetPage(pBt, iPage, ref pPage, 0)))
|
|
{
|
|
goto freepage_out;
|
|
}
|
|
rc = sqlite3PagerWrite(pPage.pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto freepage_out;
|
|
}
|
|
sqlite3Put4byte(pPage.aData, iTrunk);
|
|
sqlite3Put4byte(pPage.aData, 4, 0);
|
|
sqlite3Put4byte(pPage1.aData, (u32)32, iPage);
|
|
TRACE("FREE-PAGE: %d new trunk page replacing %d\n", pPage.pgno, iTrunk);
|
|
|
|
freepage_out:
|
|
if (pPage != null)
|
|
{
|
|
pPage.isInit = 0;
|
|
}
|
|
releasePage(pPage);
|
|
releasePage(pTrunk);
|
|
return rc;
|
|
}
|
|
|
|
private static void freePage(MemPage pPage, ref int pRC)
|
|
{
|
|
if ((pRC) == SQLITE_OK)
|
|
{
|
|
pRC = freePage2(pPage.pBt, pPage, pPage.pgno);
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Free any overflow pages associated with the given Cell.
|
|
*/
|
|
|
|
private static int clearCell(MemPage pPage, int pCell)
|
|
{
|
|
BtShared pBt = pPage.pBt;
|
|
CellInfo info = new CellInfo();
|
|
Pgno ovflPgno;
|
|
int rc;
|
|
int nOvfl;
|
|
u32 ovflPageSize;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
btreeParseCellPtr(pPage, pCell, ref info);
|
|
if (info.iOverflow == 0)
|
|
{
|
|
return SQLITE_OK; /* No overflow pages. Return without doing anything */
|
|
}
|
|
ovflPgno = sqlite3Get4byte(pPage.aData, pCell, info.iOverflow);
|
|
Debug.Assert(pBt.usableSize > 4);
|
|
ovflPageSize = (u16)(pBt.usableSize - 4);
|
|
nOvfl = (int)((info.nPayload - info.nLocal + ovflPageSize - 1) / ovflPageSize);
|
|
Debug.Assert(ovflPgno == 0 || nOvfl > 0);
|
|
while (nOvfl-- != 0)
|
|
{
|
|
Pgno iNext = 0;
|
|
MemPage pOvfl = null;
|
|
if (ovflPgno < 2 || ovflPgno > btreePagecount(pBt))
|
|
{
|
|
/* 0 is not a legal page number and page 1 cannot be an
|
|
** overflow page. Therefore if ovflPgno<2 or past the end of the
|
|
** file the database must be corrupt. */
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
if (nOvfl != 0)
|
|
{
|
|
rc = getOverflowPage(pBt, ovflPgno, out pOvfl, out iNext);
|
|
if (rc != 0)
|
|
return rc;
|
|
}
|
|
|
|
if ((pOvfl != null || ((pOvfl = btreePageLookup(pBt, ovflPgno)) != null))
|
|
&& sqlite3PagerPageRefcount(pOvfl.pDbPage) != 1
|
|
)
|
|
{
|
|
/* There is no reason any cursor should have an outstanding reference
|
|
** to an overflow page belonging to a cell that is being deleted/updated.
|
|
** So if there exists more than one reference to this page, then it
|
|
** must not really be an overflow page and the database must be corrupt.
|
|
** It is helpful to detect this before calling freePage2(), as
|
|
** freePage2() may zero the page contents if secure-delete mode is
|
|
** enabled. If this 'overflow' page happens to be a page that the
|
|
** caller is iterating through or using in some other way, this
|
|
** can be problematic.
|
|
*/
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
}
|
|
else
|
|
{
|
|
rc = freePage2(pBt, pOvfl, ovflPgno);
|
|
}
|
|
if (pOvfl != null)
|
|
{
|
|
sqlite3PagerUnref(pOvfl.pDbPage);
|
|
}
|
|
if (rc != 0)
|
|
return rc;
|
|
ovflPgno = iNext;
|
|
}
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Create the byte sequence used to represent a cell on page pPage
|
|
** and write that byte sequence into pCell[]. Overflow pages are
|
|
** allocated and filled in as necessary. The calling procedure
|
|
** is responsible for making sure sufficient space has been allocated
|
|
** for pCell[].
|
|
**
|
|
** Note that pCell does not necessary need to point to the pPage.aData
|
|
** area. pCell might point to some temporary storage. The cell will
|
|
** be constructed in this temporary area then copied into pPage.aData
|
|
** later.
|
|
*/
|
|
|
|
private static int fillInCell(
|
|
MemPage pPage, /* The page that contains the cell */
|
|
byte[] pCell, /* Complete text of the cell */
|
|
byte[] pKey, i64 nKey, /* The key */
|
|
byte[] pData, int nData, /* The data */
|
|
int nZero, /* Extra zero bytes to append to pData */
|
|
ref int pnSize /* Write cell size here */
|
|
)
|
|
{
|
|
int nPayload;
|
|
u8[] pSrc;
|
|
int pSrcIndex = 0;
|
|
int nSrc, n, rc;
|
|
int spaceLeft;
|
|
MemPage pOvfl = null;
|
|
MemPage pToRelease = null;
|
|
byte[] pPrior;
|
|
int pPriorIndex = 0;
|
|
byte[] pPayload;
|
|
int pPayloadIndex = 0;
|
|
BtShared pBt = pPage.pBt;
|
|
Pgno pgnoOvfl = 0;
|
|
int nHeader;
|
|
CellInfo info = new CellInfo();
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
|
|
/* pPage is not necessarily writeable since pCell might be auxiliary
|
|
** buffer space that is separate from the pPage buffer area */
|
|
// TODO -- Determine if the following Assert is needed under c#
|
|
//Debug.Assert( pCell < pPage.aData || pCell >= &pPage.aData[pBt.pageSize]
|
|
// || sqlite3PagerIswriteable(pPage.pDbPage) );
|
|
|
|
/* Fill in the header. */
|
|
nHeader = 0;
|
|
if (0 == pPage.leaf)
|
|
{
|
|
nHeader += 4;
|
|
}
|
|
if (pPage.hasData != 0)
|
|
{
|
|
nHeader += (int)putVarint(pCell, nHeader, (int)(nData + nZero)); //putVarint( pCell[nHeader], nData + nZero );
|
|
}
|
|
else
|
|
{
|
|
nData = nZero = 0;
|
|
}
|
|
nHeader += putVarint(pCell, nHeader, (u64)nKey); //putVarint( pCell[nHeader], *(u64*)&nKey );
|
|
btreeParseCellPtr(pPage, pCell, ref info);
|
|
Debug.Assert(info.nHeader == nHeader);
|
|
Debug.Assert(info.nKey == nKey);
|
|
Debug.Assert(info.nData == (u32)(nData + nZero));
|
|
|
|
/* Fill in the payload */
|
|
nPayload = nData + nZero;
|
|
if (pPage.intKey != 0)
|
|
{
|
|
pSrc = pData;
|
|
nSrc = nData;
|
|
nData = 0;
|
|
}
|
|
else
|
|
{
|
|
if (NEVER(nKey > 0x7fffffff || pKey == null))
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
nPayload += (int)nKey;
|
|
pSrc = pKey;
|
|
nSrc = (int)nKey;
|
|
}
|
|
pnSize = info.nSize;
|
|
spaceLeft = info.nLocal;
|
|
// pPayload = &pCell[nHeader];
|
|
pPayload = pCell;
|
|
pPayloadIndex = nHeader;
|
|
// pPrior = &pCell[info.iOverflow];
|
|
pPrior = pCell;
|
|
pPriorIndex = info.iOverflow;
|
|
|
|
while (nPayload > 0)
|
|
{
|
|
if (spaceLeft == 0)
|
|
{
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
Pgno pgnoPtrmap = pgnoOvfl; /* Overflow page pointer-map entry page */
|
|
if (pBt.autoVacuum)
|
|
{
|
|
do
|
|
{
|
|
pgnoOvfl++;
|
|
} while (
|
|
PTRMAP_ISPAGE(pBt, pgnoOvfl) || pgnoOvfl == PENDING_BYTE_PAGE(pBt)
|
|
);
|
|
}
|
|
#endif
|
|
rc = allocateBtreePage(pBt, ref pOvfl, ref pgnoOvfl, pgnoOvfl, 0);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
/* If the database supports auto-vacuum, and the second or subsequent
|
|
** overflow page is being allocated, add an entry to the pointer-map
|
|
** for that page now.
|
|
**
|
|
** If this is the first overflow page, then write a partial entry
|
|
** to the pointer-map. If we write nothing to this pointer-map slot,
|
|
** then the optimistic overflow chain processing in clearCell()
|
|
** may misinterpret the uninitialised values and delete the
|
|
** wrong pages from the database.
|
|
*/
|
|
if (pBt.autoVacuum && rc == SQLITE_OK)
|
|
{
|
|
u8 eType = (u8)(pgnoPtrmap != 0 ? PTRMAP_OVERFLOW2 : PTRMAP_OVERFLOW1);
|
|
ptrmapPut(pBt, pgnoOvfl, eType, pgnoPtrmap, ref rc);
|
|
if (rc != 0)
|
|
{
|
|
releasePage(pOvfl);
|
|
}
|
|
}
|
|
#endif
|
|
if (rc != 0)
|
|
{
|
|
releasePage(pToRelease);
|
|
return rc;
|
|
}
|
|
|
|
/* If pToRelease is not zero than pPrior points into the data area
|
|
** of pToRelease. Make sure pToRelease is still writeable. */
|
|
Debug.Assert(pToRelease == null || sqlite3PagerIswriteable(pToRelease.pDbPage));
|
|
|
|
/* If pPrior is part of the data area of pPage, then make sure pPage
|
|
** is still writeable */
|
|
// TODO -- Determine if the following Assert is needed under c#
|
|
//Debug.Assert( pPrior < pPage.aData || pPrior >= &pPage.aData[pBt.pageSize]
|
|
// || sqlite3PagerIswriteable(pPage.pDbPage) );
|
|
|
|
sqlite3Put4byte(pPrior, pPriorIndex, pgnoOvfl);
|
|
releasePage(pToRelease);
|
|
pToRelease = pOvfl;
|
|
pPrior = pOvfl.aData;
|
|
pPriorIndex = 0;
|
|
sqlite3Put4byte(pPrior, 0);
|
|
pPayload = pOvfl.aData;
|
|
pPayloadIndex = 4; //&pOvfl.aData[4];
|
|
spaceLeft = (int)pBt.usableSize - 4;
|
|
}
|
|
n = nPayload;
|
|
if (n > spaceLeft)
|
|
n = spaceLeft;
|
|
|
|
/* If pToRelease is not zero than pPayload points into the data area
|
|
** of pToRelease. Make sure pToRelease is still writeable. */
|
|
Debug.Assert(pToRelease == null || sqlite3PagerIswriteable(pToRelease.pDbPage));
|
|
|
|
/* If pPayload is part of the data area of pPage, then make sure pPage
|
|
** is still writeable */
|
|
// TODO -- Determine if the following Assert is needed under c#
|
|
//Debug.Assert( pPayload < pPage.aData || pPayload >= &pPage.aData[pBt.pageSize]
|
|
// || sqlite3PagerIswriteable(pPage.pDbPage) );
|
|
|
|
if (nSrc > 0)
|
|
{
|
|
if (n > nSrc)
|
|
n = nSrc;
|
|
Debug.Assert(pSrc != null);
|
|
Buffer.BlockCopy(pSrc, pSrcIndex, pPayload, pPayloadIndex, n);//memcpy(pPayload, pSrc, n);
|
|
}
|
|
else
|
|
{
|
|
byte[] pZeroBlob = sqlite3Malloc(n); // memset(pPayload, 0, n);
|
|
Buffer.BlockCopy(pZeroBlob, 0, pPayload, pPayloadIndex, n);
|
|
}
|
|
nPayload -= n;
|
|
pPayloadIndex += n;// pPayload += n;
|
|
pSrcIndex += n;// pSrc += n;
|
|
nSrc -= n;
|
|
spaceLeft -= n;
|
|
if (nSrc == 0)
|
|
{
|
|
nSrc = nData;
|
|
pSrc = pData;
|
|
}
|
|
}
|
|
releasePage(pToRelease);
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** Remove the i-th cell from pPage. This routine effects pPage only.
|
|
** The cell content is not freed or deallocated. It is assumed that
|
|
** the cell content has been copied someplace else. This routine just
|
|
** removes the reference to the cell from pPage.
|
|
**
|
|
** "sz" must be the number of bytes in the cell.
|
|
*/
|
|
|
|
private static void dropCell(MemPage pPage, int idx, int sz, ref int pRC)
|
|
{
|
|
u32 pc; /* Offset to cell content of cell being deleted */
|
|
u8[] data; /* pPage.aData */
|
|
int ptr; /* Used to move bytes around within data[] */
|
|
int endPtr; /* End of loop */
|
|
int rc; /* The return code */
|
|
int hdr; /* Beginning of the header. 0 most pages. 100 page 1 */
|
|
|
|
if (pRC != 0)
|
|
return;
|
|
|
|
Debug.Assert(idx >= 0 && idx < pPage.nCell);
|
|
#if SQLITE_DEBUG
|
|
Debug.Assert(sz == cellSize(pPage, idx));
|
|
#endif
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
data = pPage.aData;
|
|
ptr = pPage.cellOffset + 2 * idx; //ptr = &data[pPage.cellOffset + 2 * idx];
|
|
pc = (u32)get2byte(data, ptr);
|
|
hdr = pPage.hdrOffset;
|
|
testcase(pc == get2byte(data, hdr + 5));
|
|
testcase(pc + sz == pPage.pBt.usableSize);
|
|
if (pc < (u32)get2byte(data, hdr + 5) || pc + sz > pPage.pBt.usableSize)
|
|
{
|
|
pRC = SQLITE_CORRUPT_BKPT();
|
|
return;
|
|
}
|
|
rc = freeSpace(pPage, pc, sz);
|
|
if (rc != 0)
|
|
{
|
|
pRC = rc;
|
|
return;
|
|
}
|
|
//endPtr = &data[pPage->cellOffset + 2*pPage->nCell - 2];
|
|
//assert( (SQLITE_PTR_TO_INT(ptr)&1)==0 ); /* ptr is always 2-byte aligned */
|
|
//while( ptr<endPtr ){
|
|
// *(u16*)ptr = *(u16*)&ptr[2];
|
|
// ptr += 2;
|
|
Buffer.BlockCopy(data, ptr + 2, data, ptr, (pPage.nCell - 1 - idx) * 2);
|
|
pPage.nCell--;
|
|
data[pPage.hdrOffset + 3] = (byte)(pPage.nCell >> 8);
|
|
data[pPage.hdrOffset + 4] = (byte)(pPage.nCell); //put2byte( data, hdr + 3, pPage.nCell );
|
|
pPage.nFree += 2;
|
|
}
|
|
|
|
/*
|
|
** Insert a new cell on pPage at cell index "i". pCell points to the
|
|
** content of the cell.
|
|
**
|
|
** If the cell content will fit on the page, then put it there. If it
|
|
** will not fit, then make a copy of the cell content into pTemp if
|
|
** pTemp is not null. Regardless of pTemp, allocate a new entry
|
|
** in pPage.aOvfl[] and make it point to the cell content (either
|
|
** in pTemp or the original pCell) and also record its index.
|
|
** Allocating a new entry in pPage.aCell[] implies that
|
|
** pPage.nOverflow is incremented.
|
|
**
|
|
** If nSkip is non-zero, then do not copy the first nSkip bytes of the
|
|
** cell. The caller will overwrite them after this function returns. If
|
|
** nSkip is non-zero, then pCell may not point to an invalid memory location
|
|
** (but pCell+nSkip is always valid).
|
|
*/
|
|
|
|
private static void insertCell(
|
|
MemPage pPage, /* Page into which we are copying */
|
|
int i, /* New cell becomes the i-th cell of the page */
|
|
u8[] pCell, /* Content of the new cell */
|
|
int sz, /* Bytes of content in pCell */
|
|
u8[] pTemp, /* Temp storage space for pCell, if needed */
|
|
Pgno iChild, /* If non-zero, replace first 4 bytes with this value */
|
|
ref int pRC /* Read and write return code from here */
|
|
)
|
|
{
|
|
int idx = 0; /* Where to write new cell content in data[] */
|
|
int j; /* Loop counter */
|
|
int end; /* First byte past the last cell pointer in data[] */
|
|
int ins; /* Index in data[] where new cell pointer is inserted */
|
|
int cellOffset; /* Address of first cell pointer in data[] */
|
|
u8[] data; /* The content of the whole page */
|
|
u8 ptr; /* Used for moving information around in data[] */
|
|
u8 endPtr; /* End of the loop */
|
|
|
|
int nSkip = (iChild != 0 ? 4 : 0);
|
|
|
|
if (pRC != 0)
|
|
return;
|
|
|
|
Debug.Assert(i >= 0 && i <= pPage.nCell + pPage.nOverflow);
|
|
Debug.Assert(pPage.nCell <= MX_CELL(pPage.pBt) && MX_CELL(pPage.pBt) <= 10921);
|
|
Debug.Assert(pPage.nOverflow <= ArraySize(pPage.aOvfl));
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
/* The cell should normally be sized correctly. However, when moving a
|
|
** malformed cell from a leaf page to an interior page, if the cell size
|
|
** wanted to be less than 4 but got rounded up to 4 on the leaf, then size
|
|
** might be less than 8 (leaf-size + pointer) on the interior node. Hence
|
|
** the term after the || in the following assert(). */
|
|
Debug.Assert(sz == cellSizePtr(pPage, pCell) || (sz == 8 && iChild > 0));
|
|
if (pPage.nOverflow != 0 || sz + 2 > pPage.nFree)
|
|
{
|
|
if (pTemp != null)
|
|
{
|
|
Buffer.BlockCopy(pCell, nSkip, pTemp, nSkip, sz - nSkip);//memcpy(pTemp+nSkip, pCell+nSkip, sz-nSkip);
|
|
pCell = pTemp;
|
|
}
|
|
if (iChild != 0)
|
|
{
|
|
sqlite3Put4byte(pCell, iChild);
|
|
}
|
|
j = pPage.nOverflow++;
|
|
Debug.Assert(j < pPage.aOvfl.Length);//(int)(sizeof(pPage.aOvfl)/sizeof(pPage.aOvfl[0])) );
|
|
pPage.aOvfl[j].pCell = pCell;
|
|
pPage.aOvfl[j].idx = (u16)i;
|
|
}
|
|
else
|
|
{
|
|
int rc = sqlite3PagerWrite(pPage.pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
pRC = rc;
|
|
return;
|
|
}
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
data = pPage.aData;
|
|
cellOffset = pPage.cellOffset;
|
|
end = cellOffset + 2 * pPage.nCell;
|
|
ins = cellOffset + 2 * i;
|
|
rc = allocateSpace(pPage, sz, ref idx);
|
|
if (rc != 0)
|
|
{
|
|
pRC = rc;
|
|
return;
|
|
}
|
|
/* The allocateSpace() routine guarantees the following two properties
|
|
** if it returns success */
|
|
Debug.Assert(idx >= end + 2);
|
|
Debug.Assert(idx + sz <= (int)pPage.pBt.usableSize);
|
|
pPage.nCell++;
|
|
pPage.nFree -= (u16)(2 + sz);
|
|
Buffer.BlockCopy(pCell, nSkip, data, idx + nSkip, sz - nSkip); //memcpy( data[idx + nSkip], pCell + nSkip, sz - nSkip );
|
|
if (iChild != 0)
|
|
{
|
|
sqlite3Put4byte(data, idx, iChild);
|
|
}
|
|
//ptr = &data[end];
|
|
//endPtr = &data[ins];
|
|
//assert( ( SQLITE_PTR_TO_INT( ptr ) & 1 ) == 0 ); /* ptr is always 2-byte aligned */
|
|
//while ( ptr > endPtr )
|
|
//{
|
|
// *(u16*)ptr = *(u16*)&ptr[-2];
|
|
// ptr -= 2;
|
|
//}
|
|
for (j = end; j > ins; j -= 2)
|
|
{
|
|
data[j + 0] = data[j - 2];
|
|
data[j + 1] = data[j - 1];
|
|
}
|
|
put2byte(data, ins, idx);
|
|
put2byte(data, pPage.hdrOffset + 3, pPage.nCell);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pPage.pBt.autoVacuum)
|
|
{
|
|
/* The cell may contain a pointer to an overflow page. If so, write
|
|
** the entry for the overflow page into the pointer map.
|
|
*/
|
|
ptrmapPutOvflPtr(pPage, pCell, ref pRC);
|
|
}
|
|
#endif
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Add a list of cells to a page. The page should be initially empty.
|
|
** The cells are guaranteed to fit on the page.
|
|
*/
|
|
|
|
private static void assemblePage(
|
|
MemPage pPage, /* The page to be assemblied */
|
|
int nCell, /* The number of cells to add to this page */
|
|
u8[] apCell, /* Pointer to a single the cell bodies */
|
|
int[] aSize /* Sizes of the cells bodie*/
|
|
)
|
|
{
|
|
int i; /* Loop counter */
|
|
int pCellptr; /* Address of next cell pointer */
|
|
int cellbody; /* Address of next cell body */
|
|
byte[] data = pPage.aData; /* Pointer to data for pPage */
|
|
int hdr = pPage.hdrOffset; /* Offset of header on pPage */
|
|
int nUsable = (int)pPage.pBt.usableSize; /* Usable size of page */
|
|
|
|
Debug.Assert(pPage.nOverflow == 0);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(nCell >= 0 && nCell <= (int)MX_CELL(pPage.pBt)
|
|
&& (int)MX_CELL(pPage.pBt) <= 10921);
|
|
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
|
|
/* Check that the page has just been zeroed by zeroPage() */
|
|
Debug.Assert(pPage.nCell == 0);
|
|
Debug.Assert(get2byteNotZero(data, hdr + 5) == nUsable);
|
|
|
|
pCellptr = pPage.cellOffset + nCell * 2; //data[pPage.cellOffset + nCell * 2];
|
|
cellbody = nUsable;
|
|
for (i = nCell - 1; i >= 0; i--)
|
|
{
|
|
u16 sz = (u16)aSize[i];
|
|
pCellptr -= 2;
|
|
cellbody -= sz;
|
|
put2byte(data, pCellptr, cellbody);
|
|
Buffer.BlockCopy(apCell, 0, data, cellbody, sz);// memcpy(&data[cellbody], apCell[i], sz);
|
|
}
|
|
put2byte(data, hdr + 3, nCell);
|
|
put2byte(data, hdr + 5, cellbody);
|
|
pPage.nFree -= (u16)(nCell * 2 + nUsable - cellbody);
|
|
pPage.nCell = (u16)nCell;
|
|
}
|
|
|
|
private static void assemblePage(
|
|
MemPage pPage, /* The page to be assemblied */
|
|
int nCell, /* The number of cells to add to this page */
|
|
u8[][] apCell, /* Pointers to cell bodies */
|
|
u16[] aSize, /* Sizes of the cells */
|
|
int offset /* Offset into the cell bodies, for c# */
|
|
)
|
|
{
|
|
int i; /* Loop counter */
|
|
int pCellptr; /* Address of next cell pointer */
|
|
int cellbody; /* Address of next cell body */
|
|
byte[] data = pPage.aData; /* Pointer to data for pPage */
|
|
int hdr = pPage.hdrOffset; /* Offset of header on pPage */
|
|
int nUsable = (int)pPage.pBt.usableSize; /* Usable size of page */
|
|
|
|
Debug.Assert(pPage.nOverflow == 0);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(nCell >= 0 && nCell <= MX_CELL(pPage.pBt) && MX_CELL(pPage.pBt) <= 5460);
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
|
|
/* Check that the page has just been zeroed by zeroPage() */
|
|
Debug.Assert(pPage.nCell == 0);
|
|
Debug.Assert(get2byte(data, hdr + 5) == nUsable);
|
|
|
|
pCellptr = pPage.cellOffset + nCell * 2; //data[pPage.cellOffset + nCell * 2];
|
|
cellbody = nUsable;
|
|
for (i = nCell - 1; i >= 0; i--)
|
|
{
|
|
pCellptr -= 2;
|
|
cellbody -= aSize[i + offset];
|
|
put2byte(data, pCellptr, cellbody);
|
|
Buffer.BlockCopy(apCell[offset + i], 0, data, cellbody, aSize[i + offset]);// memcpy(&data[cellbody], apCell[i], aSize[i]);
|
|
}
|
|
put2byte(data, hdr + 3, nCell);
|
|
put2byte(data, hdr + 5, cellbody);
|
|
pPage.nFree -= (u16)(nCell * 2 + nUsable - cellbody);
|
|
pPage.nCell = (u16)nCell;
|
|
}
|
|
|
|
private static void assemblePage(
|
|
MemPage pPage, /* The page to be assemblied */
|
|
int nCell, /* The number of cells to add to this page */
|
|
u8[] apCell, /* Pointers to cell bodies */
|
|
u16[] aSize /* Sizes of the cells */
|
|
)
|
|
{
|
|
int i; /* Loop counter */
|
|
int pCellptr; /* Address of next cell pointer */
|
|
int cellbody; /* Address of next cell body */
|
|
u8[] data = pPage.aData; /* Pointer to data for pPage */
|
|
int hdr = pPage.hdrOffset; /* Offset of header on pPage */
|
|
int nUsable = (int)pPage.pBt.usableSize; /* Usable size of page */
|
|
|
|
Debug.Assert(pPage.nOverflow == 0);
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(nCell >= 0 && nCell <= MX_CELL(pPage.pBt) && MX_CELL(pPage.pBt) <= 5460);
|
|
Debug.Assert(sqlite3PagerIswriteable(pPage.pDbPage));
|
|
|
|
/* Check that the page has just been zeroed by zeroPage() */
|
|
Debug.Assert(pPage.nCell == 0);
|
|
Debug.Assert(get2byte(data, hdr + 5) == nUsable);
|
|
|
|
pCellptr = pPage.cellOffset + nCell * 2; //&data[pPage.cellOffset + nCell * 2];
|
|
cellbody = nUsable;
|
|
for (i = nCell - 1; i >= 0; i--)
|
|
{
|
|
pCellptr -= 2;
|
|
cellbody -= aSize[i];
|
|
put2byte(data, pCellptr, cellbody);
|
|
Buffer.BlockCopy(apCell, 0, data, cellbody, aSize[i]);//memcpy( data[cellbody], apCell[i], aSize[i] );
|
|
}
|
|
put2byte(data, hdr + 3, nCell);
|
|
put2byte(data, hdr + 5, cellbody);
|
|
pPage.nFree -= (u16)(nCell * 2 + nUsable - cellbody);
|
|
pPage.nCell = (u16)nCell;
|
|
}
|
|
|
|
/*
|
|
** The following parameters determine how many adjacent pages get involved
|
|
** in a balancing operation. NN is the number of neighbors on either side
|
|
** of the page that participate in the balancing operation. NB is the
|
|
** total number of pages that participate, including the target page and
|
|
** NN neighbors on either side.
|
|
**
|
|
** The minimum value of NN is 1 (of course). Increasing NN above 1
|
|
** (to 2 or 3) gives a modest improvement in SELECT and DELETE performance
|
|
** in exchange for a larger degradation in INSERT and UPDATE performance.
|
|
** The value of NN appears to give the best results overall.
|
|
*/
|
|
private static int NN = 1; /* Number of neighbors on either side of pPage */
|
|
private static int NB = (NN * 2 + 1); /* Total pages involved in the balance */
|
|
|
|
#if !SQLITE_OMIT_QUICKBALANCE
|
|
/*
|
|
** This version of balance() handles the common special case where
|
|
** a new entry is being inserted on the extreme right-end of the
|
|
** tree, in other words, when the new entry will become the largest
|
|
** entry in the tree.
|
|
**
|
|
** Instead of trying to balance the 3 right-most leaf pages, just add
|
|
** a new page to the right-hand side and put the one new entry in
|
|
** that page. This leaves the right side of the tree somewhat
|
|
** unbalanced. But odds are that we will be inserting new entries
|
|
** at the end soon afterwards so the nearly empty page will quickly
|
|
** fill up. On average.
|
|
**
|
|
** pPage is the leaf page which is the right-most page in the tree.
|
|
** pParent is its parent. pPage must have a single overflow entry
|
|
** which is also the right-most entry on the page.
|
|
**
|
|
** The pSpace buffer is used to store a temporary copy of the divider
|
|
** cell that will be inserted into pParent. Such a cell consists of a 4
|
|
** byte page number followed by a variable length integer. In other
|
|
** words, at most 13 bytes. Hence the pSpace buffer must be at
|
|
** least 13 bytes in size.
|
|
*/
|
|
|
|
private static int balance_quick(MemPage pParent, MemPage pPage, u8[] pSpace)
|
|
{
|
|
BtShared pBt = pPage.pBt; /* B-Tree Database */
|
|
MemPage pNew = new MemPage();/* Newly allocated page */
|
|
int rc; /* Return Code */
|
|
Pgno pgnoNew = 0; /* Page number of pNew */
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pPage.pBt.mutex));
|
|
Debug.Assert(sqlite3PagerIswriteable(pParent.pDbPage));
|
|
Debug.Assert(pPage.nOverflow == 1);
|
|
|
|
/* This error condition is now caught prior to reaching this function */
|
|
if (pPage.nCell <= 0)
|
|
return SQLITE_CORRUPT_BKPT();
|
|
|
|
/* Allocate a new page. This page will become the right-sibling of
|
|
** pPage. Make the parent page writable, so that the new divider cell
|
|
** may be inserted. If both these operations are successful, proceed.
|
|
*/
|
|
rc = allocateBtreePage(pBt, ref pNew, ref pgnoNew, 0, 0);
|
|
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
int pOut = 4;//u8 pOut = &pSpace[4];
|
|
u8[] pCell = pPage.aOvfl[0].pCell;
|
|
int[] szCell = new int[1];
|
|
szCell[0] = cellSizePtr(pPage, pCell);
|
|
int pStop;
|
|
|
|
Debug.Assert(sqlite3PagerIswriteable(pNew.pDbPage));
|
|
Debug.Assert(pPage.aData[0] == (PTF_INTKEY | PTF_LEAFDATA | PTF_LEAF));
|
|
zeroPage(pNew, PTF_INTKEY | PTF_LEAFDATA | PTF_LEAF);
|
|
assemblePage(pNew, 1, pCell, szCell);
|
|
|
|
/* If this is an auto-vacuum database, update the pointer map
|
|
** with entries for the new page, and any pointer from the
|
|
** cell on the page to an overflow page. If either of these
|
|
** operations fails, the return code is set, but the contents
|
|
** of the parent page are still manipulated by thh code below.
|
|
** That is Ok, at this point the parent page is guaranteed to
|
|
** be marked as dirty. Returning an error code will cause a
|
|
** rollback, undoing any changes made to the parent page.
|
|
*/
|
|
#if !SQLITE_OMIT_AUTOVACUUM // if ( ISAUTOVACUUM )
|
|
if (pBt.autoVacuum)
|
|
#else
|
|
if (false)
|
|
#endif
|
|
{
|
|
ptrmapPut(pBt, pgnoNew, PTRMAP_BTREE, pParent.pgno, ref rc);
|
|
if (szCell[0] > pNew.minLocal)
|
|
{
|
|
ptrmapPutOvflPtr(pNew, pCell, ref rc);
|
|
}
|
|
}
|
|
|
|
/* Create a divider cell to insert into pParent. The divider cell
|
|
** consists of a 4-byte page number (the page number of pPage) and
|
|
** a variable length key value (which must be the same value as the
|
|
** largest key on pPage).
|
|
**
|
|
** To find the largest key value on pPage, first find the right-most
|
|
** cell on pPage. The first two fields of this cell are the
|
|
** record-length (a variable length integer at most 32-bits in size)
|
|
** and the key value (a variable length integer, may have any value).
|
|
** The first of the while(...) loops below skips over the record-length
|
|
** field. The second while(...) loop copies the key value from the
|
|
** cell on pPage into the pSpace buffer.
|
|
*/
|
|
int iCell = findCell(pPage, pPage.nCell - 1); //pCell = findCell( pPage, pPage.nCell - 1 );
|
|
pCell = pPage.aData;
|
|
int _pCell = iCell;
|
|
pStop = _pCell + 9; //pStop = &pCell[9];
|
|
while (((pCell[_pCell++]) & 0x80) != 0 && _pCell < pStop)
|
|
; //while ( ( *( pCell++ ) & 0x80 ) && pCell < pStop ) ;
|
|
pStop = _pCell + 9;//pStop = &pCell[9];
|
|
while (((pSpace[pOut++] = pCell[_pCell++]) & 0x80) != 0 && _pCell < pStop)
|
|
; //while ( ( ( *( pOut++ ) = *( pCell++ ) ) & 0x80 ) && pCell < pStop ) ;
|
|
|
|
/* Insert the new divider cell into pParent. */
|
|
insertCell(pParent, pParent.nCell, pSpace, pOut, //(int)(pOut-pSpace),
|
|
null, pPage.pgno, ref rc);
|
|
|
|
/* Set the right-child pointer of pParent to point to the new page. */
|
|
sqlite3Put4byte(pParent.aData, pParent.hdrOffset + 8, pgnoNew);
|
|
|
|
/* Release the reference to the new page. */
|
|
releasePage(pNew);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_QUICKBALANCE */
|
|
|
|
#if FALSE
|
|
/*
|
|
** This function does not contribute anything to the operation of SQLite.
|
|
** it is sometimes activated temporarily while debugging code responsible
|
|
** for setting pointer-map entries.
|
|
*/
|
|
static int ptrmapCheckPages(MemPage **apPage, int nPage){
|
|
int i, j;
|
|
for(i=0; i<nPage; i++){
|
|
Pgno n;
|
|
u8 e;
|
|
MemPage pPage = apPage[i];
|
|
BtShared pBt = pPage.pBt;
|
|
Debug.Assert( pPage.isInit!=0 );
|
|
|
|
for(j=0; j<pPage.nCell; j++){
|
|
CellInfo info;
|
|
u8 *z;
|
|
|
|
z = findCell(pPage, j);
|
|
btreeParseCellPtr(pPage, z, info);
|
|
if( info.iOverflow ){
|
|
Pgno ovfl = sqlite3Get4byte(z[info.iOverflow]);
|
|
ptrmapGet(pBt, ovfl, ref e, ref n);
|
|
Debug.Assert( n==pPage.pgno && e==PTRMAP_OVERFLOW1 );
|
|
}
|
|
if( 0==pPage.leaf ){
|
|
Pgno child = sqlite3Get4byte(z);
|
|
ptrmapGet(pBt, child, ref e, ref n);
|
|
Debug.Assert( n==pPage.pgno && e==PTRMAP_BTREE );
|
|
}
|
|
}
|
|
if( 0==pPage.leaf ){
|
|
Pgno child = sqlite3Get4byte(pPage.aData,pPage.hdrOffset+8]);
|
|
ptrmapGet(pBt, child, ref e, ref n);
|
|
Debug.Assert( n==pPage.pgno && e==PTRMAP_BTREE );
|
|
}
|
|
}
|
|
return 1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
** This function is used to copy the contents of the b-tree node stored
|
|
** on page pFrom to page pTo. If page pFrom was not a leaf page, then
|
|
** the pointer-map entries for each child page are updated so that the
|
|
** parent page stored in the pointer map is page pTo. If pFrom contained
|
|
** any cells with overflow page pointers, then the corresponding pointer
|
|
** map entries are also updated so that the parent page is page pTo.
|
|
**
|
|
** If pFrom is currently carrying any overflow cells (entries in the
|
|
** MemPage.aOvfl[] array), they are not copied to pTo.
|
|
**
|
|
** Before returning, page pTo is reinitialized using btreeInitPage().
|
|
**
|
|
** The performance of this function is not critical. It is only used by
|
|
** the balance_shallower() and balance_deeper() procedures, neither of
|
|
** which are called often under normal circumstances.
|
|
*/
|
|
|
|
private static void copyNodeContent(MemPage pFrom, MemPage pTo, ref int pRC)
|
|
{
|
|
if ((pRC) == SQLITE_OK)
|
|
{
|
|
BtShared pBt = pFrom.pBt;
|
|
u8[] aFrom = pFrom.aData;
|
|
u8[] aTo = pTo.aData;
|
|
int iFromHdr = pFrom.hdrOffset;
|
|
int iToHdr = ((pTo.pgno == 1) ? 100 : 0);
|
|
int rc;
|
|
int iData;
|
|
|
|
Debug.Assert(pFrom.isInit != 0);
|
|
Debug.Assert(pFrom.nFree >= iToHdr);
|
|
Debug.Assert(get2byte(aFrom, iFromHdr + 5) <= (int)pBt.usableSize);
|
|
|
|
/* Copy the b-tree node content from page pFrom to page pTo. */
|
|
iData = get2byte(aFrom, iFromHdr + 5);
|
|
Buffer.BlockCopy(aFrom, iData, aTo, iData, (int)pBt.usableSize - iData);//memcpy(aTo[iData], ref aFrom[iData], pBt.usableSize-iData);
|
|
Buffer.BlockCopy(aFrom, iFromHdr, aTo, iToHdr, pFrom.cellOffset + 2 * pFrom.nCell);//memcpy(aTo[iToHdr], ref aFrom[iFromHdr], pFrom.cellOffset + 2*pFrom.nCell);
|
|
|
|
/* Reinitialize page pTo so that the contents of the MemPage structure
|
|
** match the new data. The initialization of pTo can actually fail under
|
|
** fairly obscure circumstances, even though it is a copy of initialized
|
|
** page pFrom.
|
|
*/
|
|
pTo.isInit = 0;
|
|
rc = btreeInitPage(pTo);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
pRC = rc;
|
|
return;
|
|
}
|
|
|
|
/* If this is an auto-vacuum database, update the pointer-map entries
|
|
** for any b-tree or overflow pages that pTo now contains the pointers to.
|
|
*/
|
|
#if !SQLITE_OMIT_AUTOVACUUM // if ( ISAUTOVACUUM )
|
|
if (pBt.autoVacuum)
|
|
#else
|
|
if (false)
|
|
#endif
|
|
{
|
|
pRC = setChildPtrmaps(pTo);
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
** This routine redistributes cells on the iParentIdx'th child of pParent
|
|
** (hereafter "the page") and up to 2 siblings so that all pages have about the
|
|
** same amount of free space. Usually a single sibling on either side of the
|
|
** page are used in the balancing, though both siblings might come from one
|
|
** side if the page is the first or last child of its parent. If the page
|
|
** has fewer than 2 siblings (something which can only happen if the page
|
|
** is a root page or a child of a root page) then all available siblings
|
|
** participate in the balancing.
|
|
**
|
|
** The number of siblings of the page might be increased or decreased by
|
|
** one or two in an effort to keep pages nearly full but not over full.
|
|
**
|
|
** Note that when this routine is called, some of the cells on the page
|
|
** might not actually be stored in MemPage.aData[]. This can happen
|
|
** if the page is overfull. This routine ensures that all cells allocated
|
|
** to the page and its siblings fit into MemPage.aData[] before returning.
|
|
**
|
|
** In the course of balancing the page and its siblings, cells may be
|
|
** inserted into or removed from the parent page (pParent). Doing so
|
|
** may cause the parent page to become overfull or underfull. If this
|
|
** happens, it is the responsibility of the caller to invoke the correct
|
|
** balancing routine to fix this problem (see the balance() routine).
|
|
**
|
|
** If this routine fails for any reason, it might leave the database
|
|
** in a corrupted state. So if this routine fails, the database should
|
|
** be rolled back.
|
|
**
|
|
** The third argument to this function, aOvflSpace, is a pointer to a
|
|
** buffer big enough to hold one page. If while inserting cells into the parent
|
|
** page (pParent) the parent page becomes overfull, this buffer is
|
|
** used to store the parent's overflow cells. Because this function inserts
|
|
** a maximum of four divider cells into the parent page, and the maximum
|
|
** size of a cell stored within an internal node is always less than 1/4
|
|
** of the page-size, the aOvflSpace[] buffer is guaranteed to be large
|
|
** enough for all overflow cells.
|
|
**
|
|
** If aOvflSpace is set to a null pointer, this function returns
|
|
** SQLITE_NOMEM.
|
|
*/
|
|
|
|
// under C#; Try to reuse Memory
|
|
|
|
private static int balance_nonroot(
|
|
MemPage pParent, /* Parent page of siblings being balanced */
|
|
int iParentIdx, /* Index of "the page" in pParent */
|
|
u8[] aOvflSpace, /* page-size bytes of space for parent ovfl */
|
|
int isRoot /* True if pParent is a root-page */
|
|
)
|
|
{
|
|
MemPage[] apOld = new MemPage[NB]; /* pPage and up to two siblings */
|
|
MemPage[] apCopy = new MemPage[NB]; /* Private copies of apOld[] pages */
|
|
MemPage[] apNew = new MemPage[NB + 2];/* pPage and up to NB siblings after balancing */
|
|
int[] apDiv = new int[NB - 1]; /* Divider cells in pParent */
|
|
int[] cntNew = new int[NB + 2]; /* Index in aCell[] of cell after i-th page */
|
|
int[] szNew = new int[NB + 2]; /* Combined size of cells place on i-th page */
|
|
u16[] szCell = new u16[1]; /* Local size of all cells in apCell[] */
|
|
BtShared pBt; /* The whole database */
|
|
int nCell = 0; /* Number of cells in apCell[] */
|
|
int nMaxCells = 0; /* Allocated size of apCell, szCell, aFrom. */
|
|
int nNew = 0; /* Number of pages in apNew[] */
|
|
int nOld; /* Number of pages in apOld[] */
|
|
int i, j, k; /* Loop counters */
|
|
int nxDiv; /* Next divider slot in pParent.aCell[] */
|
|
int rc = SQLITE_OK; /* The return code */
|
|
u16 leafCorrection; /* 4 if pPage is a leaf. 0 if not */
|
|
int leafData; /* True if pPage is a leaf of a LEAFDATA tree */
|
|
int usableSpace; /* Bytes in pPage beyond the header */
|
|
int pageFlags; /* Value of pPage.aData[0] */
|
|
int subtotal; /* Subtotal of bytes in cells on one page */
|
|
//int iSpace1 = 0; /* First unused byte of aSpace1[] */
|
|
int iOvflSpace = 0; /* First unused byte of aOvflSpace[] */
|
|
int szScratch; /* Size of scratch memory requested */
|
|
int pRight; /* Location in parent of right-sibling pointer */
|
|
u8[][] apCell = null; /* All cells begin balanced */
|
|
//u16[] szCell; /* Local size of all cells in apCell[] */
|
|
//u8[] aSpace1; /* Space for copies of dividers cells */
|
|
Pgno pgno; /* Temp var to store a page number in */
|
|
|
|
pBt = pParent.pBt;
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
Debug.Assert(sqlite3PagerIswriteable(pParent.pDbPage));
|
|
|
|
#if FALSE
|
|
TRACE("BALANCE: begin page %d child of %d\n", pPage.pgno, pParent.pgno);
|
|
#endif
|
|
|
|
/* At this point pParent may have at most one overflow cell. And if
|
|
** this overflow cell is present, it must be the cell with
|
|
** index iParentIdx. This scenario comes about when this function
|
|
** is called (indirectly) from sqlite3BtreeDelete().
|
|
*/
|
|
Debug.Assert(pParent.nOverflow == 0 || pParent.nOverflow == 1);
|
|
Debug.Assert(pParent.nOverflow == 0 || pParent.aOvfl[0].idx == iParentIdx);
|
|
|
|
//if( !aOvflSpace ){
|
|
// return SQLITE_NOMEM;
|
|
//}
|
|
|
|
/* Find the sibling pages to balance. Also locate the cells in pParent
|
|
** that divide the siblings. An attempt is made to find NN siblings on
|
|
** either side of pPage. More siblings are taken from one side, however,
|
|
** if there are fewer than NN siblings on the other side. If pParent
|
|
** has NB or fewer children then all children of pParent are taken.
|
|
**
|
|
** This loop also drops the divider cells from the parent page. This
|
|
** way, the remainder of the function does not have to deal with any
|
|
** overflow cells in the parent page, since if any existed they will
|
|
** have already been removed.
|
|
*/
|
|
i = pParent.nOverflow + pParent.nCell;
|
|
if (i < 2)
|
|
{
|
|
nxDiv = 0;
|
|
nOld = i + 1;
|
|
}
|
|
else
|
|
{
|
|
nOld = 3;
|
|
if (iParentIdx == 0)
|
|
{
|
|
nxDiv = 0;
|
|
}
|
|
else if (iParentIdx == i)
|
|
{
|
|
nxDiv = i - 2;
|
|
}
|
|
else
|
|
{
|
|
nxDiv = iParentIdx - 1;
|
|
}
|
|
i = 2;
|
|
}
|
|
if ((i + nxDiv - pParent.nOverflow) == pParent.nCell)
|
|
{
|
|
pRight = pParent.hdrOffset + 8; //&pParent.aData[pParent.hdrOffset + 8];
|
|
}
|
|
else
|
|
{
|
|
pRight = findCell(pParent, i + nxDiv - pParent.nOverflow);
|
|
}
|
|
pgno = sqlite3Get4byte(pParent.aData, pRight);
|
|
while (true)
|
|
{
|
|
rc = getAndInitPage(pBt, pgno, ref apOld[i]);
|
|
if (rc != 0)
|
|
{
|
|
//memset(apOld, 0, (i+1)*sizeof(MemPage*));
|
|
goto balance_cleanup;
|
|
}
|
|
nMaxCells += 1 + apOld[i].nCell + apOld[i].nOverflow;
|
|
if ((i--) == 0)
|
|
break;
|
|
|
|
if (i + nxDiv == pParent.aOvfl[0].idx && pParent.nOverflow != 0)
|
|
{
|
|
apDiv[i] = 0;// = pParent.aOvfl[0].pCell;
|
|
pgno = sqlite3Get4byte(pParent.aOvfl[0].pCell, apDiv[i]);
|
|
szNew[i] = cellSizePtr(pParent, apDiv[i]);
|
|
pParent.nOverflow = 0;
|
|
}
|
|
else
|
|
{
|
|
apDiv[i] = findCell(pParent, i + nxDiv - pParent.nOverflow);
|
|
pgno = sqlite3Get4byte(pParent.aData, apDiv[i]);
|
|
szNew[i] = cellSizePtr(pParent, apDiv[i]);
|
|
|
|
/* Drop the cell from the parent page. apDiv[i] still points to
|
|
** the cell within the parent, even though it has been dropped.
|
|
** This is safe because dropping a cell only overwrites the first
|
|
** four bytes of it, and this function does not need the first
|
|
** four bytes of the divider cell. So the pointer is safe to use
|
|
** later on.
|
|
**
|
|
** Unless SQLite is compiled in secure-delete mode. In this case,
|
|
** the dropCell() routine will overwrite the entire cell with zeroes.
|
|
** In this case, temporarily copy the cell into the aOvflSpace[]
|
|
** buffer. It will be copied out again as soon as the aSpace[] buffer
|
|
** is allocated. */
|
|
//if (pBt.secureDelete)
|
|
//{
|
|
// int iOff = (int)(apDiv[i]) - (int)(pParent.aData); //SQLITE_PTR_TO_INT(apDiv[i]) - SQLITE_PTR_TO_INT(pParent.aData);
|
|
// if( (iOff+szNew[i])>(int)pBt->usableSize )
|
|
// {
|
|
// rc = SQLITE_CORRUPT_BKPT();
|
|
// Array.Clear(apOld[0].aData,0,apOld[0].aData.Length); //memset(apOld, 0, (i + 1) * sizeof(MemPage*));
|
|
// goto balance_cleanup;
|
|
// }
|
|
// else
|
|
// {
|
|
// memcpy(&aOvflSpace[iOff], apDiv[i], szNew[i]);
|
|
// apDiv[i] = &aOvflSpace[apDiv[i] - pParent.aData];
|
|
// }
|
|
//}
|
|
dropCell(pParent, i + nxDiv - pParent.nOverflow, szNew[i], ref rc);
|
|
}
|
|
}
|
|
|
|
/* Make nMaxCells a multiple of 4 in order to preserve 8-byte
|
|
** alignment */
|
|
nMaxCells = (nMaxCells + 3) & ~3;
|
|
|
|
/*
|
|
** Allocate space for memory structures
|
|
*/
|
|
//k = pBt.pageSize + ROUND8(sizeof(MemPage));
|
|
//szScratch =
|
|
// nMaxCells*sizeof(u8*) /* apCell */
|
|
// + nMaxCells*sizeof(u16) /* szCell */
|
|
// + pBt.pageSize /* aSpace1 */
|
|
// + k*nOld; /* Page copies (apCopy) */
|
|
apCell = sqlite3ScratchMalloc(apCell, nMaxCells);
|
|
//if( apCell==null ){
|
|
// rc = SQLITE_NOMEM;
|
|
// goto balance_cleanup;
|
|
//}
|
|
if (szCell.Length < nMaxCells)
|
|
Array.Resize(ref szCell, nMaxCells); //(u16*)&apCell[nMaxCells];
|
|
//aSpace1 = new byte[pBt.pageSize * (nMaxCells)];// aSpace1 = (u8*)&szCell[nMaxCells];
|
|
//Debug.Assert( EIGHT_BYTE_ALIGNMENT(aSpace1) );
|
|
|
|
/*
|
|
** Load pointers to all cells on sibling pages and the divider cells
|
|
** into the local apCell[] array. Make copies of the divider cells
|
|
** into space obtained from aSpace1[] and remove the the divider Cells
|
|
** from pParent.
|
|
**
|
|
** If the siblings are on leaf pages, then the child pointers of the
|
|
** divider cells are stripped from the cells before they are copied
|
|
** into aSpace1[]. In this way, all cells in apCell[] are without
|
|
** child pointers. If siblings are not leaves, then all cell in
|
|
** apCell[] include child pointers. Either way, all cells in apCell[]
|
|
** are alike.
|
|
**
|
|
** leafCorrection: 4 if pPage is a leaf. 0 if pPage is not a leaf.
|
|
** leafData: 1 if pPage holds key+data and pParent holds only keys.
|
|
*/
|
|
leafCorrection = (u16)(apOld[0].leaf * 4);
|
|
leafData = apOld[0].hasData;
|
|
for (i = 0; i < nOld; i++)
|
|
{
|
|
int limit;
|
|
|
|
/* Before doing anything else, take a copy of the i'th original sibling
|
|
** The rest of this function will use data from the copies rather
|
|
** that the original pages since the original pages will be in the
|
|
** process of being overwritten. */
|
|
//MemPage pOld = apCopy[i] = (MemPage*)&aSpace1[pBt.pageSize + k*i];
|
|
//memcpy(pOld, apOld[i], sizeof(MemPage));
|
|
//pOld.aData = (void*)&pOld[1];
|
|
//memcpy(pOld.aData, apOld[i].aData, pBt.pageSize);
|
|
MemPage pOld = apCopy[i] = apOld[i].Copy();
|
|
|
|
limit = pOld.nCell + pOld.nOverflow;
|
|
if (pOld.nOverflow > 0 || true)
|
|
{
|
|
for (j = 0; j < limit; j++)
|
|
{
|
|
Debug.Assert(nCell < nMaxCells);
|
|
//apCell[nCell] = findOverflowCell( pOld, j );
|
|
//szCell[nCell] = cellSizePtr( pOld, apCell, nCell );
|
|
int iFOFC = findOverflowCell(pOld, j);
|
|
szCell[nCell] = cellSizePtr(pOld, iFOFC);
|
|
// Copy the Data Locally
|
|
if (apCell[nCell] == null)
|
|
apCell[nCell] = new u8[szCell[nCell]];
|
|
else if (apCell[nCell].Length < szCell[nCell])
|
|
Array.Resize(ref apCell[nCell], szCell[nCell]);
|
|
if (iFOFC < 0) // Overflow Cell
|
|
Buffer.BlockCopy(pOld.aOvfl[-(iFOFC + 1)].pCell, 0, apCell[nCell], 0, szCell[nCell]);
|
|
else
|
|
Buffer.BlockCopy(pOld.aData, iFOFC, apCell[nCell], 0, szCell[nCell]);
|
|
nCell++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
u8[] aData = pOld.aData;
|
|
u16 maskPage = pOld.maskPage;
|
|
u16 cellOffset = pOld.cellOffset;
|
|
for (j = 0; j < limit; j++)
|
|
{
|
|
Debugger.Break();
|
|
Debug.Assert(nCell < nMaxCells);
|
|
apCell[nCell] = findCellv2(aData, maskPage, cellOffset, j);
|
|
szCell[nCell] = cellSizePtr(pOld, apCell[nCell]);
|
|
nCell++;
|
|
}
|
|
}
|
|
if (i < nOld - 1 && 0 == leafData)
|
|
{
|
|
u16 sz = (u16)szNew[i];
|
|
byte[] pTemp = sqlite3Malloc(sz + leafCorrection);
|
|
Debug.Assert(nCell < nMaxCells);
|
|
szCell[nCell] = sz;
|
|
//pTemp = &aSpace1[iSpace1];
|
|
//iSpace1 += sz;
|
|
Debug.Assert(sz <= pBt.maxLocal + 23);
|
|
//Debug.Assert(iSpace1 <= (int)pBt.pageSize);
|
|
Buffer.BlockCopy(pParent.aData, apDiv[i], pTemp, 0, sz);//memcpy( pTemp, apDiv[i], sz );
|
|
if (apCell[nCell] == null || apCell[nCell].Length < sz)
|
|
Array.Resize(ref apCell[nCell], sz);
|
|
Buffer.BlockCopy(pTemp, leafCorrection, apCell[nCell], 0, sz);//apCell[nCell] = pTemp + leafCorrection;
|
|
Debug.Assert(leafCorrection == 0 || leafCorrection == 4);
|
|
szCell[nCell] = (u16)(szCell[nCell] - leafCorrection);
|
|
if (0 == pOld.leaf)
|
|
{
|
|
Debug.Assert(leafCorrection == 0);
|
|
Debug.Assert(pOld.hdrOffset == 0);
|
|
/* The right pointer of the child page pOld becomes the left
|
|
** pointer of the divider cell */
|
|
Buffer.BlockCopy(pOld.aData, 8, apCell[nCell], 0, 4);//memcpy( apCell[nCell], ref pOld.aData[8], 4 );
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(leafCorrection == 4);
|
|
if (szCell[nCell] < 4)
|
|
{
|
|
/* Do not allow any cells smaller than 4 bytes. */
|
|
szCell[nCell] = 4;
|
|
}
|
|
}
|
|
nCell++;
|
|
}
|
|
}
|
|
|
|
/*
|
|
** Figure out the number of pages needed to hold all nCell cells.
|
|
** Store this number in "k". Also compute szNew[] which is the total
|
|
** size of all cells on the i-th page and cntNew[] which is the index
|
|
** in apCell[] of the cell that divides page i from page i+1.
|
|
** cntNew[k] should equal nCell.
|
|
**
|
|
** Values computed by this block:
|
|
**
|
|
** k: The total number of sibling pages
|
|
** szNew[i]: Spaced used on the i-th sibling page.
|
|
** cntNew[i]: Index in apCell[] and szCell[] for the first cell to
|
|
** the right of the i-th sibling page.
|
|
** usableSpace: Number of bytes of space available on each sibling.
|
|
**
|
|
*/
|
|
usableSpace = (int)pBt.usableSize - 12 + leafCorrection;
|
|
for (subtotal = k = i = 0; i < nCell; i++)
|
|
{
|
|
Debug.Assert(i < nMaxCells);
|
|
subtotal += szCell[i] + 2;
|
|
if (subtotal > usableSpace)
|
|
{
|
|
szNew[k] = subtotal - szCell[i];
|
|
cntNew[k] = i;
|
|
if (leafData != 0)
|
|
{
|
|
i--;
|
|
}
|
|
subtotal = 0;
|
|
k++;
|
|
if (k > NB + 1)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto balance_cleanup;
|
|
}
|
|
}
|
|
}
|
|
szNew[k] = subtotal;
|
|
cntNew[k] = nCell;
|
|
k++;
|
|
|
|
/*
|
|
** The packing computed by the previous block is biased toward the siblings
|
|
** on the left side. The left siblings are always nearly full, while the
|
|
** right-most sibling might be nearly empty. This block of code attempts
|
|
** to adjust the packing of siblings to get a better balance.
|
|
**
|
|
** This adjustment is more than an optimization. The packing above might
|
|
** be so out of balance as to be illegal. For example, the right-most
|
|
** sibling might be completely empty. This adjustment is not optional.
|
|
*/
|
|
for (i = k - 1; i > 0; i--)
|
|
{
|
|
int szRight = szNew[i]; /* Size of sibling on the right */
|
|
int szLeft = szNew[i - 1]; /* Size of sibling on the left */
|
|
int r; /* Index of right-most cell in left sibling */
|
|
int d; /* Index of first cell to the left of right sibling */
|
|
|
|
r = cntNew[i - 1] - 1;
|
|
d = r + 1 - leafData;
|
|
Debug.Assert(d < nMaxCells);
|
|
Debug.Assert(r < nMaxCells);
|
|
while (szRight == 0 || szRight + szCell[d] + 2 <= szLeft - (szCell[r] + 2))
|
|
{
|
|
szRight += szCell[d] + 2;
|
|
szLeft -= szCell[r] + 2;
|
|
cntNew[i - 1]--;
|
|
r = cntNew[i - 1] - 1;
|
|
d = r + 1 - leafData;
|
|
}
|
|
szNew[i] = szRight;
|
|
szNew[i - 1] = szLeft;
|
|
}
|
|
|
|
/* Either we found one or more cells (cntnew[0])>0) or pPage is
|
|
** a virtual root page. A virtual root page is when the real root
|
|
** page is page 1 and we are the only child of that page.
|
|
*/
|
|
Debug.Assert(cntNew[0] > 0 || (pParent.pgno == 1 && pParent.nCell == 0));
|
|
|
|
TRACE("BALANCE: old: %d %d %d ",
|
|
apOld[0].pgno,
|
|
nOld >= 2 ? apOld[1].pgno : 0,
|
|
nOld >= 3 ? apOld[2].pgno : 0
|
|
);
|
|
|
|
/*
|
|
** Allocate k new pages. Reuse old pages where possible.
|
|
*/
|
|
if (apOld[0].pgno <= 1)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
goto balance_cleanup;
|
|
}
|
|
pageFlags = apOld[0].aData[0];
|
|
for (i = 0; i < k; i++)
|
|
{
|
|
MemPage pNew = new MemPage();
|
|
if (i < nOld)
|
|
{
|
|
pNew = apNew[i] = apOld[i];
|
|
apOld[i] = null;
|
|
rc = sqlite3PagerWrite(pNew.pDbPage);
|
|
nNew++;
|
|
if (rc != 0)
|
|
goto balance_cleanup;
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(i > 0);
|
|
rc = allocateBtreePage(pBt, ref pNew, ref pgno, pgno, 0);
|
|
if (rc != 0)
|
|
goto balance_cleanup;
|
|
apNew[i] = pNew;
|
|
nNew++;
|
|
|
|
/* Set the pointer-map entry for the new sibling page. */
|
|
#if !SQLITE_OMIT_AUTOVACUUM // if ( ISAUTOVACUUM )
|
|
if (pBt.autoVacuum)
|
|
#else
|
|
if (false)
|
|
#endif
|
|
{
|
|
ptrmapPut(pBt, pNew.pgno, PTRMAP_BTREE, pParent.pgno, ref rc);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
goto balance_cleanup;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Free any old pages that were not reused as new pages.
|
|
*/
|
|
while (i < nOld)
|
|
{
|
|
freePage(apOld[i], ref rc);
|
|
if (rc != 0)
|
|
goto balance_cleanup;
|
|
releasePage(apOld[i]);
|
|
apOld[i] = null;
|
|
i++;
|
|
}
|
|
|
|
/*
|
|
** Put the new pages in accending order. This helps to
|
|
** keep entries in the disk file in order so that a scan
|
|
** of the table is a linear scan through the file. That
|
|
** in turn helps the operating system to deliver pages
|
|
** from the disk more rapidly.
|
|
**
|
|
** An O(n^2) insertion sort algorithm is used, but since
|
|
** n is never more than NB (a small constant), that should
|
|
** not be a problem.
|
|
**
|
|
** When NB==3, this one optimization makes the database
|
|
** about 25% faster for large insertions and deletions.
|
|
*/
|
|
for (i = 0; i < k - 1; i++)
|
|
{
|
|
int minV = (int)apNew[i].pgno;
|
|
int minI = i;
|
|
for (j = i + 1; j < k; j++)
|
|
{
|
|
if (apNew[j].pgno < (u32)minV)
|
|
{
|
|
minI = j;
|
|
minV = (int)apNew[j].pgno;
|
|
}
|
|
}
|
|
if (minI > i)
|
|
{
|
|
MemPage pT;
|
|
pT = apNew[i];
|
|
apNew[i] = apNew[minI];
|
|
apNew[minI] = pT;
|
|
}
|
|
}
|
|
TRACE("new: %d(%d) %d(%d) %d(%d) %d(%d) %d(%d)\n",
|
|
apNew[0].pgno, szNew[0],
|
|
nNew >= 2 ? apNew[1].pgno : 0, nNew >= 2 ? szNew[1] : 0,
|
|
nNew >= 3 ? apNew[2].pgno : 0, nNew >= 3 ? szNew[2] : 0,
|
|
nNew >= 4 ? apNew[3].pgno : 0, nNew >= 4 ? szNew[3] : 0,
|
|
nNew >= 5 ? apNew[4].pgno : 0, nNew >= 5 ? szNew[4] : 0);
|
|
|
|
Debug.Assert(sqlite3PagerIswriteable(pParent.pDbPage));
|
|
sqlite3Put4byte(pParent.aData, pRight, apNew[nNew - 1].pgno);
|
|
|
|
/*
|
|
** Evenly distribute the data in apCell[] across the new pages.
|
|
** Insert divider cells into pParent as necessary.
|
|
*/
|
|
j = 0;
|
|
for (i = 0; i < nNew; i++)
|
|
{
|
|
/* Assemble the new sibling page. */
|
|
MemPage pNew = apNew[i];
|
|
Debug.Assert(j < nMaxCells);
|
|
zeroPage(pNew, pageFlags);
|
|
assemblePage(pNew, cntNew[i] - j, apCell, szCell, j);
|
|
Debug.Assert(pNew.nCell > 0 || (nNew == 1 && cntNew[0] == 0));
|
|
Debug.Assert(pNew.nOverflow == 0);
|
|
|
|
j = cntNew[i];
|
|
|
|
/* If the sibling page assembled above was not the right-most sibling,
|
|
** insert a divider cell into the parent page.
|
|
*/
|
|
Debug.Assert(i < nNew - 1 || j == nCell);
|
|
if (j < nCell)
|
|
{
|
|
u8[] pCell;
|
|
u8[] pTemp;
|
|
int sz;
|
|
|
|
Debug.Assert(j < nMaxCells);
|
|
pCell = apCell[j];
|
|
sz = szCell[j] + leafCorrection;
|
|
pTemp = sqlite3Malloc(sz);//&aOvflSpace[iOvflSpace];
|
|
if (0 == pNew.leaf)
|
|
{
|
|
Buffer.BlockCopy(pCell, 0, pNew.aData, 8, 4);//memcpy( pNew.aData[8], pCell, 4 );
|
|
}
|
|
else if (leafData != 0)
|
|
{
|
|
/* If the tree is a leaf-data tree, and the siblings are leaves,
|
|
** then there is no divider cell in apCell[]. Instead, the divider
|
|
** cell consists of the integer key for the right-most cell of
|
|
** the sibling-page assembled above only.
|
|
*/
|
|
CellInfo info = new CellInfo();
|
|
j--;
|
|
btreeParseCellPtr(pNew, apCell[j], ref info);
|
|
pCell = pTemp;
|
|
sz = 4 + putVarint(pCell, 4, (u64)info.nKey);
|
|
pTemp = null;
|
|
}
|
|
else
|
|
{
|
|
//------------ pCell -= 4;
|
|
byte[] _pCell_4 = sqlite3Malloc(pCell.Length + 4);
|
|
Buffer.BlockCopy(pCell, 0, _pCell_4, 4, pCell.Length);
|
|
pCell = _pCell_4;
|
|
//
|
|
/* Obscure case for non-leaf-data trees: If the cell at pCell was
|
|
** previously stored on a leaf node, and its reported size was 4
|
|
** bytes, then it may actually be smaller than this
|
|
** (see btreeParseCellPtr(), 4 bytes is the minimum size of
|
|
** any cell). But it is important to pass the correct size to
|
|
** insertCell(), so reparse the cell now.
|
|
**
|
|
** Note that this can never happen in an SQLite data file, as all
|
|
** cells are at least 4 bytes. It only happens in b-trees used
|
|
** to evaluate "IN (SELECT ...)" and similar clauses.
|
|
*/
|
|
if (szCell[j] == 4)
|
|
{
|
|
Debug.Assert(leafCorrection == 4);
|
|
sz = cellSizePtr(pParent, pCell);
|
|
}
|
|
}
|
|
iOvflSpace += sz;
|
|
Debug.Assert(sz <= pBt.maxLocal + 23);
|
|
Debug.Assert(iOvflSpace <= (int)pBt.pageSize);
|
|
insertCell(pParent, nxDiv, pCell, sz, pTemp, pNew.pgno, ref rc);
|
|
if (rc != SQLITE_OK)
|
|
goto balance_cleanup;
|
|
Debug.Assert(sqlite3PagerIswriteable(pParent.pDbPage));
|
|
|
|
j++;
|
|
nxDiv++;
|
|
}
|
|
}
|
|
Debug.Assert(j == nCell);
|
|
Debug.Assert(nOld > 0);
|
|
Debug.Assert(nNew > 0);
|
|
if ((pageFlags & PTF_LEAF) == 0)
|
|
{
|
|
Buffer.BlockCopy(apCopy[nOld - 1].aData, 8, apNew[nNew - 1].aData, 8, 4); //u8* zChild = &apCopy[nOld - 1].aData[8];
|
|
//memcpy( apNew[nNew - 1].aData[8], zChild, 4 );
|
|
}
|
|
|
|
if (isRoot != 0 && pParent.nCell == 0 && pParent.hdrOffset <= apNew[0].nFree)
|
|
{
|
|
/* The root page of the b-tree now contains no cells. The only sibling
|
|
** page is the right-child of the parent. Copy the contents of the
|
|
** child page into the parent, decreasing the overall height of the
|
|
** b-tree structure by one. This is described as the "balance-shallower"
|
|
** sub-algorithm in some documentation.
|
|
**
|
|
** If this is an auto-vacuum database, the call to copyNodeContent()
|
|
** sets all pointer-map entries corresponding to database image pages
|
|
** for which the pointer is stored within the content being copied.
|
|
**
|
|
** The second Debug.Assert below verifies that the child page is defragmented
|
|
** (it must be, as it was just reconstructed using assemblePage()). This
|
|
** is important if the parent page happens to be page 1 of the database
|
|
** image. */
|
|
Debug.Assert(nNew == 1);
|
|
Debug.Assert(apNew[0].nFree ==
|
|
(get2byte(apNew[0].aData, 5) - apNew[0].cellOffset - apNew[0].nCell * 2)
|
|
);
|
|
copyNodeContent(apNew[0], pParent, ref rc);
|
|
freePage(apNew[0], ref rc);
|
|
}
|
|
else
|
|
#if !SQLITE_OMIT_AUTOVACUUM // if ( ISAUTOVACUUM )
|
|
if (pBt.autoVacuum)
|
|
#else
|
|
if (false)
|
|
#endif
|
|
{
|
|
/* Fix the pointer-map entries for all the cells that were shifted around.
|
|
** There are several different types of pointer-map entries that need to
|
|
** be dealt with by this routine. Some of these have been set already, but
|
|
** many have not. The following is a summary:
|
|
**
|
|
** 1) The entries associated with new sibling pages that were not
|
|
** siblings when this function was called. These have already
|
|
** been set. We don't need to worry about old siblings that were
|
|
** moved to the free-list - the freePage() code has taken care
|
|
** of those.
|
|
**
|
|
** 2) The pointer-map entries associated with the first overflow
|
|
** page in any overflow chains used by new divider cells. These
|
|
** have also already been taken care of by the insertCell() code.
|
|
**
|
|
** 3) If the sibling pages are not leaves, then the child pages of
|
|
** cells stored on the sibling pages may need to be updated.
|
|
**
|
|
** 4) If the sibling pages are not internal intkey nodes, then any
|
|
** overflow pages used by these cells may need to be updated
|
|
** (internal intkey nodes never contain pointers to overflow pages).
|
|
**
|
|
** 5) If the sibling pages are not leaves, then the pointer-map
|
|
** entries for the right-child pages of each sibling may need
|
|
** to be updated.
|
|
**
|
|
** Cases 1 and 2 are dealt with above by other code. The next
|
|
** block deals with cases 3 and 4 and the one after that, case 5. Since
|
|
** setting a pointer map entry is a relatively expensive operation, this
|
|
** code only sets pointer map entries for child or overflow pages that have
|
|
** actually moved between pages. */
|
|
MemPage pNew = apNew[0];
|
|
MemPage pOld = apCopy[0];
|
|
int nOverflow = pOld.nOverflow;
|
|
int iNextOld = pOld.nCell + nOverflow;
|
|
int iOverflow = (nOverflow != 0 ? pOld.aOvfl[0].idx : -1);
|
|
j = 0; /* Current 'old' sibling page */
|
|
k = 0; /* Current 'new' sibling page */
|
|
for (i = 0; i < nCell; i++)
|
|
{
|
|
int isDivider = 0;
|
|
while (i == iNextOld)
|
|
{
|
|
/* Cell i is the cell immediately following the last cell on old
|
|
** sibling page j. If the siblings are not leaf pages of an
|
|
** intkey b-tree, then cell i was a divider cell. */
|
|
pOld = apCopy[++j];
|
|
iNextOld = i + (0 == leafData ? 1 : 0) + pOld.nCell + pOld.nOverflow;
|
|
if (pOld.nOverflow != 0)
|
|
{
|
|
nOverflow = pOld.nOverflow;
|
|
iOverflow = i + (0 == leafData ? 1 : 0) + pOld.aOvfl[0].idx;
|
|
}
|
|
isDivider = 0 == leafData ? 1 : 0;
|
|
}
|
|
|
|
Debug.Assert(nOverflow > 0 || iOverflow < i);
|
|
Debug.Assert(nOverflow < 2 || pOld.aOvfl[0].idx == pOld.aOvfl[1].idx - 1);
|
|
Debug.Assert(nOverflow < 3 || pOld.aOvfl[1].idx == pOld.aOvfl[2].idx - 1);
|
|
if (i == iOverflow)
|
|
{
|
|
isDivider = 1;
|
|
if ((--nOverflow) > 0)
|
|
{
|
|
iOverflow++;
|
|
}
|
|
}
|
|
|
|
if (i == cntNew[k])
|
|
{
|
|
/* Cell i is the cell immediately following the last cell on new
|
|
** sibling page k. If the siblings are not leaf pages of an
|
|
** intkey b-tree, then cell i is a divider cell. */
|
|
pNew = apNew[++k];
|
|
if (0 == leafData)
|
|
continue;
|
|
}
|
|
Debug.Assert(j < nOld);
|
|
Debug.Assert(k < nNew);
|
|
|
|
/* If the cell was originally divider cell (and is not now) or
|
|
** an overflow cell, or if the cell was located on a different sibling
|
|
** page before the balancing, then the pointer map entries associated
|
|
** with any child or overflow pages need to be updated. */
|
|
if (isDivider != 0 || pOld.pgno != pNew.pgno)
|
|
{
|
|
if (0 == leafCorrection)
|
|
{
|
|
ptrmapPut(pBt, sqlite3Get4byte(apCell[i]), PTRMAP_BTREE, pNew.pgno, ref rc);
|
|
}
|
|
if (szCell[i] > pNew.minLocal)
|
|
{
|
|
ptrmapPutOvflPtr(pNew, apCell[i], ref rc);
|
|
}
|
|
}
|
|
}
|
|
|
|
if (0 == leafCorrection)
|
|
{
|
|
for (i = 0; i < nNew; i++)
|
|
{
|
|
u32 key = sqlite3Get4byte(apNew[i].aData, 8);
|
|
ptrmapPut(pBt, key, PTRMAP_BTREE, apNew[i].pgno, ref rc);
|
|
}
|
|
}
|
|
|
|
#if FALSE
|
|
/* The ptrmapCheckPages() contains Debug.Assert() statements that verify that
|
|
** all pointer map pages are set correctly. This is helpful while
|
|
** debugging. This is usually disabled because a corrupt database may
|
|
** cause an Debug.Assert() statement to fail. */
|
|
ptrmapCheckPages(apNew, nNew);
|
|
ptrmapCheckPages(pParent, 1);
|
|
#endif
|
|
}
|
|
|
|
Debug.Assert(pParent.isInit != 0);
|
|
TRACE("BALANCE: finished: old=%d new=%d cells=%d\n",
|
|
nOld, nNew, nCell);
|
|
|
|
/*
|
|
** Cleanup before returning.
|
|
*/
|
|
balance_cleanup:
|
|
sqlite3ScratchFree(apCell);
|
|
for (i = 0; i < nOld; i++)
|
|
{
|
|
releasePage(apOld[i]);
|
|
}
|
|
for (i = 0; i < nNew; i++)
|
|
{
|
|
releasePage(apNew[i]);
|
|
}
|
|
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function is called when the root page of a b-tree structure is
|
|
** overfull (has one or more overflow pages).
|
|
**
|
|
** A new child page is allocated and the contents of the current root
|
|
** page, including overflow cells, are copied into the child. The root
|
|
** page is then overwritten to make it an empty page with the right-child
|
|
** pointer pointing to the new page.
|
|
**
|
|
** Before returning, all pointer-map entries corresponding to pages
|
|
** that the new child-page now contains pointers to are updated. The
|
|
** entry corresponding to the new right-child pointer of the root
|
|
** page is also updated.
|
|
**
|
|
** If successful, ppChild is set to contain a reference to the child
|
|
** page and SQLITE_OK is returned. In this case the caller is required
|
|
** to call releasePage() on ppChild exactly once. If an error occurs,
|
|
** an error code is returned and ppChild is set to 0.
|
|
*/
|
|
|
|
private static int balance_deeper(MemPage pRoot, ref MemPage ppChild)
|
|
{
|
|
int rc; /* Return value from subprocedures */
|
|
MemPage pChild = null; /* Pointer to a new child page */
|
|
Pgno pgnoChild = 0; /* Page number of the new child page */
|
|
BtShared pBt = pRoot.pBt; /* The BTree */
|
|
|
|
Debug.Assert(pRoot.nOverflow > 0);
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
|
|
/* Make pRoot, the root page of the b-tree, writable. Allocate a new
|
|
** page that will become the new right-child of pPage. Copy the contents
|
|
** of the node stored on pRoot into the new child page.
|
|
*/
|
|
rc = sqlite3PagerWrite(pRoot.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = allocateBtreePage(pBt, ref pChild, ref pgnoChild, pRoot.pgno, 0);
|
|
copyNodeContent(pRoot, pChild, ref rc);
|
|
#if !SQLITE_OMIT_AUTOVACUUM // if ( ISAUTOVACUUM )
|
|
if (pBt.autoVacuum)
|
|
#else
|
|
if (false)
|
|
#endif
|
|
{
|
|
ptrmapPut(pBt, pgnoChild, PTRMAP_BTREE, pRoot.pgno, ref rc);
|
|
}
|
|
}
|
|
if (rc != 0)
|
|
{
|
|
ppChild = null;
|
|
releasePage(pChild);
|
|
return rc;
|
|
}
|
|
Debug.Assert(sqlite3PagerIswriteable(pChild.pDbPage));
|
|
Debug.Assert(sqlite3PagerIswriteable(pRoot.pDbPage));
|
|
Debug.Assert(pChild.nCell == pRoot.nCell);
|
|
|
|
TRACE("BALANCE: copy root %d into %d\n", pRoot.pgno, pChild.pgno);
|
|
|
|
/* Copy the overflow cells from pRoot to pChild */
|
|
Array.Copy(pRoot.aOvfl, pChild.aOvfl, pRoot.nOverflow);//memcpy(pChild.aOvfl, pRoot.aOvfl, pRoot.nOverflow*sizeof(pRoot.aOvfl[0]));
|
|
pChild.nOverflow = pRoot.nOverflow;
|
|
|
|
/* Zero the contents of pRoot. Then install pChild as the right-child. */
|
|
zeroPage(pRoot, pChild.aData[0] & ~PTF_LEAF);
|
|
sqlite3Put4byte(pRoot.aData, pRoot.hdrOffset + 8, pgnoChild);
|
|
|
|
ppChild = pChild;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
/*
|
|
** The page that pCur currently points to has just been modified in
|
|
** some way. This function figures out if this modification means the
|
|
** tree needs to be balanced, and if so calls the appropriate balancing
|
|
** routine. Balancing routines are:
|
|
**
|
|
** balance_quick()
|
|
** balance_deeper()
|
|
** balance_nonroot()
|
|
*/
|
|
private static u8[] aBalanceQuickSpace = new u8[13];
|
|
|
|
private static int balance(BtCursor pCur)
|
|
{
|
|
int rc = SQLITE_OK;
|
|
int nMin = (int)pCur.pBt.usableSize * 2 / 3;
|
|
|
|
//u8[] pFree = null;
|
|
|
|
#if !NDEBUG || SQLITE_COVERAGE_TEST || DEBUG
|
|
int balance_quick_called = 0;//TESTONLY( int balance_quick_called = 0 );
|
|
int balance_deeper_called = 0;//TESTONLY( int balance_deeper_called = 0 );
|
|
#else
|
|
int balance_quick_called = 0;
|
|
int balance_deeper_called = 0;
|
|
#endif
|
|
|
|
do
|
|
{
|
|
int iPage = pCur.iPage;
|
|
MemPage pPage = pCur.apPage[iPage];
|
|
|
|
if (iPage == 0)
|
|
{
|
|
if (pPage.nOverflow != 0)
|
|
{
|
|
/* The root page of the b-tree is overfull. In this case call the
|
|
** balance_deeper() function to create a new child for the root-page
|
|
** and copy the current contents of the root-page to it. The
|
|
** next iteration of the do-loop will balance the child page.
|
|
*/
|
|
Debug.Assert((balance_deeper_called++) == 0);
|
|
rc = balance_deeper(pPage, ref pCur.apPage[1]);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
pCur.iPage = 1;
|
|
pCur.aiIdx[0] = 0;
|
|
pCur.aiIdx[1] = 0;
|
|
Debug.Assert(pCur.apPage[1].nOverflow != 0);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
break;
|
|
}
|
|
}
|
|
else if (pPage.nOverflow == 0 && pPage.nFree <= nMin)
|
|
{
|
|
break;
|
|
}
|
|
else
|
|
{
|
|
MemPage pParent = pCur.apPage[iPage - 1];
|
|
int iIdx = pCur.aiIdx[iPage - 1];
|
|
|
|
rc = sqlite3PagerWrite(pParent.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
#if !SQLITE_OMIT_QUICKBALANCE
|
|
if (pPage.hasData != 0
|
|
&& pPage.nOverflow == 1
|
|
&& pPage.aOvfl[0].idx == pPage.nCell
|
|
&& pParent.pgno != 1
|
|
&& pParent.nCell == iIdx
|
|
)
|
|
{
|
|
/* Call balance_quick() to create a new sibling of pPage on which
|
|
** to store the overflow cell. balance_quick() inserts a new cell
|
|
** into pParent, which may cause pParent overflow. If this
|
|
** happens, the next interation of the do-loop will balance pParent
|
|
** use either balance_nonroot() or balance_deeper(). Until this
|
|
** happens, the overflow cell is stored in the aBalanceQuickSpace[]
|
|
** buffer.
|
|
**
|
|
** The purpose of the following Debug.Assert() is to check that only a
|
|
** single call to balance_quick() is made for each call to this
|
|
** function. If this were not verified, a subtle bug involving reuse
|
|
** of the aBalanceQuickSpace[] might sneak in.
|
|
*/
|
|
Debug.Assert((balance_quick_called++) == 0);
|
|
rc = balance_quick(pParent, pPage, aBalanceQuickSpace);
|
|
}
|
|
else
|
|
#endif
|
|
{
|
|
/* In this case, call balance_nonroot() to redistribute cells
|
|
** between pPage and up to 2 of its sibling pages. This involves
|
|
** modifying the contents of pParent, which may cause pParent to
|
|
** become overfull or underfull. The next iteration of the do-loop
|
|
** will balance the parent page to correct this.
|
|
**
|
|
** If the parent page becomes overfull, the overflow cell or cells
|
|
** are stored in the pSpace buffer allocated immediately below.
|
|
** A subsequent iteration of the do-loop will deal with this by
|
|
** calling balance_nonroot() (balance_deeper() may be called first,
|
|
** but it doesn't deal with overflow cells - just moves them to a
|
|
** different page). Once this subsequent call to balance_nonroot()
|
|
** has completed, it is safe to release the pSpace buffer used by
|
|
** the previous call, as the overflow cell data will have been
|
|
** copied either into the body of a database page or into the new
|
|
** pSpace buffer passed to the latter call to balance_nonroot().
|
|
*/
|
|
////u8[] pSpace = new u8[pCur.pBt.pageSize];// u8 pSpace = sqlite3PageMalloc( pCur.pBt.pageSize );
|
|
rc = balance_nonroot(pParent, iIdx, null, iPage == 1 ? 1 : 0);
|
|
//if (pFree != null)
|
|
//{
|
|
// /* If pFree is not NULL, it points to the pSpace buffer used
|
|
// ** by a previous call to balance_nonroot(). Its contents are
|
|
// ** now stored either on real database pages or within the
|
|
// ** new pSpace buffer, so it may be safely freed here. */
|
|
// sqlite3PageFree(ref pFree);
|
|
//}
|
|
|
|
/* The pSpace buffer will be freed after the next call to
|
|
** balance_nonroot(), or just before this function returns, whichever
|
|
** comes first. */
|
|
//pFree = pSpace;
|
|
}
|
|
}
|
|
|
|
pPage.nOverflow = 0;
|
|
|
|
/* The next iteration of the do-loop balances the parent page. */
|
|
releasePage(pPage);
|
|
pCur.iPage--;
|
|
}
|
|
} while (rc == SQLITE_OK);
|
|
|
|
//if (pFree != null)
|
|
//{
|
|
// sqlite3PageFree(ref pFree);
|
|
//}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Insert a new record into the BTree. The key is given by (pKey,nKey)
|
|
** and the data is given by (pData,nData). The cursor is used only to
|
|
** define what table the record should be inserted into. The cursor
|
|
** is left pointing at a random location.
|
|
**
|
|
** For an INTKEY table, only the nKey value of the key is used. pKey is
|
|
** ignored. For a ZERODATA table, the pData and nData are both ignored.
|
|
**
|
|
** If the seekResult parameter is non-zero, then a successful call to
|
|
** MovetoUnpacked() to seek cursor pCur to (pKey, nKey) has already
|
|
** been performed. seekResult is the search result returned (a negative
|
|
** number if pCur points at an entry that is smaller than (pKey, nKey), or
|
|
** a positive value if pCur points at an etry that is larger than
|
|
** (pKey, nKey)).
|
|
**
|
|
** If the seekResult parameter is non-zero, then the caller guarantees that
|
|
** cursor pCur is pointing at the existing copy of a row that is to be
|
|
** overwritten. If the seekResult parameter is 0, then cursor pCur may
|
|
** point to any entry or to no entry at all and so this function has to seek
|
|
** the cursor before the new key can be inserted.
|
|
*/
|
|
|
|
private static int sqlite3BtreeInsert(
|
|
BtCursor pCur, /* Insert data into the table of this cursor */
|
|
byte[] pKey, i64 nKey, /* The key of the new record */
|
|
byte[] pData, int nData, /* The data of the new record */
|
|
int nZero, /* Number of extra 0 bytes to append to data */
|
|
int appendBias, /* True if this is likely an append */
|
|
int seekResult /* Result of prior MovetoUnpacked() call */
|
|
)
|
|
{
|
|
int rc;
|
|
int loc = seekResult; /* -1: before desired location +1: after */
|
|
int szNew = 0;
|
|
int idx;
|
|
MemPage pPage;
|
|
Btree p = pCur.pBtree;
|
|
BtShared pBt = p.pBt;
|
|
int oldCell;
|
|
byte[] newCell = null;
|
|
|
|
if (pCur.eState == CURSOR_FAULT)
|
|
{
|
|
Debug.Assert(pCur.skipNext != SQLITE_OK);
|
|
return pCur.skipNext;
|
|
}
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pCur.wrFlag != 0 && pBt.inTransaction == TRANS_WRITE && !pBt.readOnly);
|
|
Debug.Assert(hasSharedCacheTableLock(p, pCur.pgnoRoot, pCur.pKeyInfo != null ? 1 : 0, 2));
|
|
|
|
/* Assert that the caller has been consistent. If this cursor was opened
|
|
** expecting an index b-tree, then the caller should be inserting blob
|
|
** keys with no associated data. If the cursor was opened expecting an
|
|
** intkey table, the caller should be inserting integer keys with a
|
|
** blob of associated data. */
|
|
Debug.Assert((pKey == null) == (pCur.pKeyInfo == null));
|
|
|
|
/* If this is an insert into a table b-tree, invalidate any incrblob
|
|
** cursors open on the row being replaced (assuming this is a replace
|
|
** operation - if it is not, the following is a no-op). */
|
|
if (pCur.pKeyInfo == null)
|
|
{
|
|
invalidateIncrblobCursors(p, nKey, 0);
|
|
}
|
|
|
|
/* Save the positions of any other cursors open on this table.
|
|
**
|
|
** In some cases, the call to btreeMoveto() below is a no-op. For
|
|
** example, when inserting data into a table with auto-generated integer
|
|
** keys, the VDBE layer invokes sqlite3BtreeLast() to figure out the
|
|
** integer key to use. It then calls this function to actually insert the
|
|
** data into the intkey B-Tree. In this case btreeMoveto() recognizes
|
|
** that the cursor is already where it needs to be and returns without
|
|
** doing any work. To avoid thwarting these optimizations, it is important
|
|
** not to clear the cursor here.
|
|
*/
|
|
rc = saveAllCursors(pBt, pCur.pgnoRoot, pCur);
|
|
if (rc != 0)
|
|
return rc;
|
|
if (0 == loc)
|
|
{
|
|
rc = btreeMoveto(pCur, pKey, nKey, appendBias, ref loc);
|
|
if (rc != 0)
|
|
return rc;
|
|
}
|
|
Debug.Assert(pCur.eState == CURSOR_VALID || (pCur.eState == CURSOR_INVALID && loc != 0));
|
|
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
Debug.Assert(pPage.intKey != 0 || nKey >= 0);
|
|
Debug.Assert(pPage.leaf != 0 || 0 == pPage.intKey);
|
|
|
|
TRACE("INSERT: table=%d nkey=%lld ndata=%d page=%d %s\n",
|
|
pCur.pgnoRoot, nKey, nData, pPage.pgno,
|
|
loc == 0 ? "overwrite" : "new entry");
|
|
Debug.Assert(pPage.isInit != 0);
|
|
allocateTempSpace(pBt);
|
|
newCell = pBt.pTmpSpace;
|
|
//if (newCell == null) return SQLITE_NOMEM;
|
|
rc = fillInCell(pPage, newCell, pKey, nKey, pData, nData, nZero, ref szNew);
|
|
if (rc != 0)
|
|
goto end_insert;
|
|
Debug.Assert(szNew == cellSizePtr(pPage, newCell));
|
|
Debug.Assert(szNew <= MX_CELL_SIZE(pBt));
|
|
idx = pCur.aiIdx[pCur.iPage];
|
|
if (loc == 0)
|
|
{
|
|
u16 szOld;
|
|
Debug.Assert(idx < pPage.nCell);
|
|
rc = sqlite3PagerWrite(pPage.pDbPage);
|
|
if (rc != 0)
|
|
{
|
|
goto end_insert;
|
|
}
|
|
oldCell = findCell(pPage, idx);
|
|
if (0 == pPage.leaf)
|
|
{
|
|
//memcpy(newCell, oldCell, 4);
|
|
newCell[0] = pPage.aData[oldCell + 0];
|
|
newCell[1] = pPage.aData[oldCell + 1];
|
|
newCell[2] = pPage.aData[oldCell + 2];
|
|
newCell[3] = pPage.aData[oldCell + 3];
|
|
}
|
|
szOld = cellSizePtr(pPage, oldCell);
|
|
rc = clearCell(pPage, oldCell);
|
|
dropCell(pPage, idx, szOld, ref rc);
|
|
if (rc != 0)
|
|
goto end_insert;
|
|
}
|
|
else if (loc < 0 && pPage.nCell > 0)
|
|
{
|
|
Debug.Assert(pPage.leaf != 0);
|
|
idx = ++pCur.aiIdx[pCur.iPage];
|
|
}
|
|
else
|
|
{
|
|
Debug.Assert(pPage.leaf != 0);
|
|
}
|
|
insertCell(pPage, idx, newCell, szNew, null, 0, ref rc);
|
|
Debug.Assert(rc != SQLITE_OK || pPage.nCell > 0 || pPage.nOverflow > 0);
|
|
|
|
/* If no error has occured and pPage has an overflow cell, call balance()
|
|
** to redistribute the cells within the tree. Since balance() may move
|
|
** the cursor, zero the BtCursor.info.nSize and BtCursor.validNKey
|
|
** variables.
|
|
**
|
|
** Previous versions of SQLite called moveToRoot() to move the cursor
|
|
** back to the root page as balance() used to invalidate the contents
|
|
** of BtCursor.apPage[] and BtCursor.aiIdx[]. Instead of doing that,
|
|
** set the cursor state to "invalid". This makes common insert operations
|
|
** slightly faster.
|
|
**
|
|
** There is a subtle but important optimization here too. When inserting
|
|
** multiple records into an intkey b-tree using a single cursor (as can
|
|
** happen while processing an "INSERT INTO ... SELECT" statement), it
|
|
** is advantageous to leave the cursor pointing to the last entry in
|
|
** the b-tree if possible. If the cursor is left pointing to the last
|
|
** entry in the table, and the next row inserted has an integer key
|
|
** larger than the largest existing key, it is possible to insert the
|
|
** row without seeking the cursor. This can be a big performance boost.
|
|
*/
|
|
pCur.info.nSize = 0;
|
|
pCur.validNKey = false;
|
|
if (rc == SQLITE_OK && pPage.nOverflow != 0)
|
|
{
|
|
rc = balance(pCur);
|
|
|
|
/* Must make sure nOverflow is reset to zero even if the balance()
|
|
** fails. Internal data structure corruption will result otherwise.
|
|
** Also, set the cursor state to invalid. This stops saveCursorPosition()
|
|
** from trying to save the current position of the cursor. */
|
|
pCur.apPage[pCur.iPage].nOverflow = 0;
|
|
pCur.eState = CURSOR_INVALID;
|
|
}
|
|
Debug.Assert(pCur.apPage[pCur.iPage].nOverflow == 0);
|
|
|
|
end_insert:
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Delete the entry that the cursor is pointing to. The cursor
|
|
** is left pointing at a arbitrary location.
|
|
*/
|
|
|
|
private static int sqlite3BtreeDelete(BtCursor pCur)
|
|
{
|
|
Btree p = pCur.pBtree;
|
|
BtShared pBt = p.pBt;
|
|
int rc; /* Return code */
|
|
MemPage pPage; /* Page to delete cell from */
|
|
int pCell; /* Pointer to cell to delete */
|
|
int iCellIdx; /* Index of cell to delete */
|
|
int iCellDepth; /* Depth of node containing pCell */
|
|
|
|
Debug.Assert(cursorHoldsMutex(pCur));
|
|
Debug.Assert(pBt.inTransaction == TRANS_WRITE);
|
|
Debug.Assert(!pBt.readOnly);
|
|
Debug.Assert(pCur.wrFlag != 0);
|
|
Debug.Assert(hasSharedCacheTableLock(p, pCur.pgnoRoot, pCur.pKeyInfo != null ? 1 : 0, 2));
|
|
Debug.Assert(!hasReadConflicts(p, pCur.pgnoRoot));
|
|
|
|
if (NEVER(pCur.aiIdx[pCur.iPage] >= pCur.apPage[pCur.iPage].nCell)
|
|
|| NEVER(pCur.eState != CURSOR_VALID)
|
|
)
|
|
{
|
|
return SQLITE_ERROR; /* Something has gone awry. */
|
|
}
|
|
|
|
/* If this is a delete operation to remove a row from a table b-tree,
|
|
** invalidate any incrblob cursors open on the row being deleted. */
|
|
if (pCur.pKeyInfo == null)
|
|
{
|
|
invalidateIncrblobCursors(p, pCur.info.nKey, 0);
|
|
}
|
|
|
|
iCellDepth = pCur.iPage;
|
|
iCellIdx = pCur.aiIdx[iCellDepth];
|
|
pPage = pCur.apPage[iCellDepth];
|
|
pCell = findCell(pPage, iCellIdx);
|
|
|
|
/* If the page containing the entry to delete is not a leaf page, move
|
|
** the cursor to the largest entry in the tree that is smaller than
|
|
** the entry being deleted. This cell will replace the cell being deleted
|
|
** from the internal node. The 'previous' entry is used for this instead
|
|
** of the 'next' entry, as the previous entry is always a part of the
|
|
** sub-tree headed by the child page of the cell being deleted. This makes
|
|
** balancing the tree following the delete operation easier. */
|
|
if (0 == pPage.leaf)
|
|
{
|
|
int notUsed = 0;
|
|
rc = sqlite3BtreePrevious(pCur, ref notUsed);
|
|
if (rc != 0)
|
|
return rc;
|
|
}
|
|
|
|
/* Save the positions of any other cursors open on this table before
|
|
** making any modifications. Make the page containing the entry to be
|
|
** deleted writable. Then free any overflow pages associated with the
|
|
** entry and finally remove the cell itself from within the page.
|
|
*/
|
|
rc = saveAllCursors(pBt, pCur.pgnoRoot, pCur);
|
|
if (rc != 0)
|
|
return rc;
|
|
rc = sqlite3PagerWrite(pPage.pDbPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
rc = clearCell(pPage, pCell);
|
|
dropCell(pPage, iCellIdx, cellSizePtr(pPage, pCell), ref rc);
|
|
if (rc != 0)
|
|
return rc;
|
|
|
|
/* If the cell deleted was not located on a leaf page, then the cursor
|
|
** is currently pointing to the largest entry in the sub-tree headed
|
|
** by the child-page of the cell that was just deleted from an internal
|
|
** node. The cell from the leaf node needs to be moved to the internal
|
|
** node to replace the deleted cell. */
|
|
if (0 == pPage.leaf)
|
|
{
|
|
MemPage pLeaf = pCur.apPage[pCur.iPage];
|
|
int nCell;
|
|
Pgno n = pCur.apPage[iCellDepth + 1].pgno;
|
|
//byte[] pTmp;
|
|
|
|
pCell = findCell(pLeaf, pLeaf.nCell - 1);
|
|
nCell = cellSizePtr(pLeaf, pCell);
|
|
Debug.Assert(MX_CELL_SIZE(pBt) >= nCell);
|
|
|
|
//allocateTempSpace(pBt);
|
|
//pTmp = pBt.pTmpSpace;
|
|
|
|
rc = sqlite3PagerWrite(pLeaf.pDbPage);
|
|
byte[] pNext_4 = sqlite3Malloc(nCell + 4);
|
|
Buffer.BlockCopy(pLeaf.aData, pCell - 4, pNext_4, 0, nCell + 4);
|
|
insertCell(pPage, iCellIdx, pNext_4, nCell + 4, null, n, ref rc); //insertCell( pPage, iCellIdx, pCell - 4, nCell + 4, pTmp, n, ref rc );
|
|
dropCell(pLeaf, pLeaf.nCell - 1, nCell, ref rc);
|
|
if (rc != 0)
|
|
return rc;
|
|
}
|
|
|
|
/* Balance the tree. If the entry deleted was located on a leaf page,
|
|
** then the cursor still points to that page. In this case the first
|
|
** call to balance() repairs the tree, and the if(...) condition is
|
|
** never true.
|
|
**
|
|
** Otherwise, if the entry deleted was on an internal node page, then
|
|
** pCur is pointing to the leaf page from which a cell was removed to
|
|
** replace the cell deleted from the internal node. This is slightly
|
|
** tricky as the leaf node may be underfull, and the internal node may
|
|
** be either under or overfull. In this case run the balancing algorithm
|
|
** on the leaf node first. If the balance proceeds far enough up the
|
|
** tree that we can be sure that any problem in the internal node has
|
|
** been corrected, so be it. Otherwise, after balancing the leaf node,
|
|
** walk the cursor up the tree to the internal node and balance it as
|
|
** well. */
|
|
rc = balance(pCur);
|
|
if (rc == SQLITE_OK && pCur.iPage > iCellDepth)
|
|
{
|
|
while (pCur.iPage > iCellDepth)
|
|
{
|
|
releasePage(pCur.apPage[pCur.iPage--]);
|
|
}
|
|
rc = balance(pCur);
|
|
}
|
|
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
moveToRoot(pCur);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Create a new BTree table. Write into piTable the page
|
|
** number for the root page of the new table.
|
|
**
|
|
** The type of type is determined by the flags parameter. Only the
|
|
** following values of flags are currently in use. Other values for
|
|
** flags might not work:
|
|
**
|
|
** BTREE_INTKEY|BTREE_LEAFDATA Used for SQL tables with rowid keys
|
|
** BTREE_ZERODATA Used for SQL indices
|
|
*/
|
|
|
|
private static int btreeCreateTable(Btree p, ref int piTable, int createTabFlags)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
MemPage pRoot = new MemPage();
|
|
Pgno pgnoRoot = 0;
|
|
int rc;
|
|
int ptfFlags; /* Page-type flage for the root page of new table */
|
|
|
|
Debug.Assert(sqlite3BtreeHoldsMutex(p));
|
|
Debug.Assert(pBt.inTransaction == TRANS_WRITE);
|
|
Debug.Assert(!pBt.readOnly);
|
|
|
|
#if SQLITE_OMIT_AUTOVACUUM
|
|
rc = allocateBtreePage(pBt, ref pRoot, ref pgnoRoot, 1, 0);
|
|
if( rc !=0){
|
|
return rc;
|
|
}
|
|
#else
|
|
if (pBt.autoVacuum)
|
|
{
|
|
Pgno pgnoMove = 0; /* Move a page here to make room for the root-page */
|
|
MemPage pPageMove = new MemPage(); /* The page to move to. */
|
|
|
|
/* Creating a new table may probably require moving an existing database
|
|
** to make room for the new tables root page. In case this page turns
|
|
** out to be an overflow page, delete all overflow page-map caches
|
|
** held by open cursors.
|
|
*/
|
|
invalidateAllOverflowCache(pBt);
|
|
|
|
/* Read the value of meta[3] from the database to determine where the
|
|
** root page of the new table should go. meta[3] is the largest root-page
|
|
** created so far, so the new root-page is (meta[3]+1).
|
|
*/
|
|
sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, ref pgnoRoot);
|
|
pgnoRoot++;
|
|
|
|
/* The new root-page may not be allocated on a pointer-map page, or the
|
|
** PENDING_BYTE page.
|
|
*/
|
|
while (pgnoRoot == PTRMAP_PAGENO(pBt, pgnoRoot) ||
|
|
pgnoRoot == PENDING_BYTE_PAGE(pBt))
|
|
{
|
|
pgnoRoot++;
|
|
}
|
|
Debug.Assert(pgnoRoot >= 3);
|
|
|
|
/* Allocate a page. The page that currently resides at pgnoRoot will
|
|
** be moved to the allocated page (unless the allocated page happens
|
|
** to reside at pgnoRoot).
|
|
*/
|
|
rc = allocateBtreePage(pBt, ref pPageMove, ref pgnoMove, pgnoRoot, 1);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
|
|
if (pgnoMove != pgnoRoot)
|
|
{
|
|
/* pgnoRoot is the page that will be used for the root-page of
|
|
** the new table (assuming an error did not occur). But we were
|
|
** allocated pgnoMove. If required (i.e. if it was not allocated
|
|
** by extending the file), the current page at position pgnoMove
|
|
** is already journaled.
|
|
*/
|
|
u8 eType = 0;
|
|
Pgno iPtrPage = 0;
|
|
|
|
releasePage(pPageMove);
|
|
|
|
/* Move the page currently at pgnoRoot to pgnoMove. */
|
|
rc = btreeGetPage(pBt, pgnoRoot, ref pRoot, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = ptrmapGet(pBt, pgnoRoot, ref eType, ref iPtrPage);
|
|
if (eType == PTRMAP_ROOTPAGE || eType == PTRMAP_FREEPAGE)
|
|
{
|
|
rc = SQLITE_CORRUPT_BKPT();
|
|
}
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(pRoot);
|
|
return rc;
|
|
}
|
|
Debug.Assert(eType != PTRMAP_ROOTPAGE);
|
|
Debug.Assert(eType != PTRMAP_FREEPAGE);
|
|
rc = relocatePage(pBt, pRoot, eType, iPtrPage, pgnoMove, 0);
|
|
releasePage(pRoot);
|
|
|
|
/* Obtain the page at pgnoRoot */
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = btreeGetPage(pBt, pgnoRoot, ref pRoot, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = sqlite3PagerWrite(pRoot.pDbPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
releasePage(pRoot);
|
|
return rc;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
pRoot = pPageMove;
|
|
}
|
|
|
|
/* Update the pointer-map and meta-data with the new root-page number. */
|
|
ptrmapPut(pBt, pgnoRoot, PTRMAP_ROOTPAGE, 0, ref rc);
|
|
if (rc != 0)
|
|
{
|
|
releasePage(pRoot);
|
|
return rc;
|
|
}
|
|
|
|
/* When the new root page was allocated, page 1 was made writable in
|
|
** order either to increase the database filesize, or to decrement the
|
|
** freelist count. Hence, the sqlite3BtreeUpdateMeta() call cannot fail.
|
|
*/
|
|
Debug.Assert(sqlite3PagerIswriteable(pBt.pPage1.pDbPage));
|
|
rc = sqlite3BtreeUpdateMeta(p, 4, pgnoRoot);
|
|
if (NEVER(rc != 0))
|
|
{
|
|
releasePage(pRoot);
|
|
return rc;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
rc = allocateBtreePage(pBt, ref pRoot, ref pgnoRoot, 1, 0);
|
|
if (rc != 0)
|
|
return rc;
|
|
}
|
|
#endif
|
|
Debug.Assert(sqlite3PagerIswriteable(pRoot.pDbPage));
|
|
if ((createTabFlags & BTREE_INTKEY) != 0)
|
|
{
|
|
ptfFlags = PTF_INTKEY | PTF_LEAFDATA | PTF_LEAF;
|
|
}
|
|
else
|
|
{
|
|
ptfFlags = PTF_ZERODATA | PTF_LEAF;
|
|
}
|
|
zeroPage(pRoot, ptfFlags);
|
|
sqlite3PagerUnref(pRoot.pDbPage);
|
|
Debug.Assert((pBt.openFlags & BTREE_SINGLE) == 0 || pgnoRoot == 2);
|
|
piTable = (int)pgnoRoot;
|
|
return SQLITE_OK;
|
|
}
|
|
|
|
private static int sqlite3BtreeCreateTable(Btree p, ref int piTable, int flags)
|
|
{
|
|
int rc;
|
|
sqlite3BtreeEnter(p);
|
|
rc = btreeCreateTable(p, ref piTable, flags);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Erase the given database page and all its children. Return
|
|
** the page to the freelist.
|
|
*/
|
|
|
|
private static int clearDatabasePage(
|
|
BtShared pBt, /* The BTree that contains the table */
|
|
Pgno pgno, /* Page number to clear */
|
|
int freePageFlag, /* Deallocate page if true */
|
|
ref int pnChange /* Add number of Cells freed to this counter */
|
|
)
|
|
{
|
|
MemPage pPage = new MemPage();
|
|
int rc;
|
|
byte[] pCell;
|
|
int i;
|
|
|
|
Debug.Assert(sqlite3_mutex_held(pBt.mutex));
|
|
if (pgno > btreePagecount(pBt))
|
|
{
|
|
return SQLITE_CORRUPT_BKPT();
|
|
}
|
|
|
|
rc = getAndInitPage(pBt, pgno, ref pPage);
|
|
if (rc != 0)
|
|
return rc;
|
|
for (i = 0; i < pPage.nCell; i++)
|
|
{
|
|
int iCell = findCell(pPage, i);
|
|
pCell = pPage.aData; // pCell = findCell( pPage, i );
|
|
if (0 == pPage.leaf)
|
|
{
|
|
rc = clearDatabasePage(pBt, sqlite3Get4byte(pCell, iCell), 1, ref pnChange);
|
|
if (rc != 0)
|
|
goto cleardatabasepage_out;
|
|
}
|
|
rc = clearCell(pPage, iCell);
|
|
if (rc != 0)
|
|
goto cleardatabasepage_out;
|
|
}
|
|
if (0 == pPage.leaf)
|
|
{
|
|
rc = clearDatabasePage(pBt, sqlite3Get4byte(pPage.aData, 8), 1, ref pnChange);
|
|
if (rc != 0)
|
|
goto cleardatabasepage_out;
|
|
}
|
|
else //if (pnChange != 0)
|
|
{
|
|
//Debug.Assert(pPage.intKey != 0);
|
|
pnChange += pPage.nCell;
|
|
}
|
|
if (freePageFlag != 0)
|
|
{
|
|
freePage(pPage, ref rc);
|
|
}
|
|
else if ((rc = sqlite3PagerWrite(pPage.pDbPage)) == 0)
|
|
{
|
|
zeroPage(pPage, pPage.aData[0] | PTF_LEAF);
|
|
}
|
|
|
|
cleardatabasepage_out:
|
|
releasePage(pPage);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Delete all information from a single table in the database. iTable is
|
|
** the page number of the root of the table. After this routine returns,
|
|
** the root page is empty, but still exists.
|
|
**
|
|
** This routine will fail with SQLITE_LOCKED if there are any open
|
|
** read cursors on the table. Open write cursors are moved to the
|
|
** root of the table.
|
|
**
|
|
** If pnChange is not NULL, then table iTable must be an intkey table. The
|
|
** integer value pointed to by pnChange is incremented by the number of
|
|
** entries in the table.
|
|
*/
|
|
|
|
private static int sqlite3BtreeClearTable(Btree p, int iTable, ref int pnChange)
|
|
{
|
|
int rc;
|
|
BtShared pBt = p.pBt;
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(p.inTrans == TRANS_WRITE);
|
|
|
|
/* Invalidate all incrblob cursors open on table iTable (assuming iTable
|
|
** is the root of a table b-tree - if it is not, the following call is
|
|
** a no-op). */
|
|
invalidateIncrblobCursors(p, 0, 1);
|
|
|
|
rc = saveAllCursors(pBt, (Pgno)iTable, null);
|
|
if (SQLITE_OK == rc)
|
|
{
|
|
rc = clearDatabasePage(pBt, (Pgno)iTable, 0, ref pnChange);
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** Erase all information in a table and add the root of the table to
|
|
** the freelist. Except, the root of the principle table (the one on
|
|
** page 1) is never added to the freelist.
|
|
**
|
|
** This routine will fail with SQLITE_LOCKED if there are any open
|
|
** cursors on the table.
|
|
**
|
|
** If AUTOVACUUM is enabled and the page at iTable is not the last
|
|
** root page in the database file, then the last root page
|
|
** in the database file is moved into the slot formerly occupied by
|
|
** iTable and that last slot formerly occupied by the last root page
|
|
** is added to the freelist instead of iTable. In this say, all
|
|
** root pages are kept at the beginning of the database file, which
|
|
** is necessary for AUTOVACUUM to work right. piMoved is set to the
|
|
** page number that used to be the last root page in the file before
|
|
** the move. If no page gets moved, piMoved is set to 0.
|
|
** The last root page is recorded in meta[3] and the value of
|
|
** meta[3] is updated by this procedure.
|
|
*/
|
|
|
|
private static int btreeDropTable(Btree p, Pgno iTable, ref int piMoved)
|
|
{
|
|
int rc;
|
|
MemPage pPage = null;
|
|
BtShared pBt = p.pBt;
|
|
|
|
Debug.Assert(sqlite3BtreeHoldsMutex(p));
|
|
Debug.Assert(p.inTrans == TRANS_WRITE);
|
|
|
|
/* It is illegal to drop a table if any cursors are open on the
|
|
** database. This is because in auto-vacuum mode the backend may
|
|
** need to move another root-page to fill a gap left by the deleted
|
|
** root page. If an open cursor was using this page a problem would
|
|
** occur.
|
|
**
|
|
** This error is caught long before control reaches this point.
|
|
*/
|
|
if (NEVER(pBt.pCursor))
|
|
{
|
|
sqlite3ConnectionBlocked(p.db, pBt.pCursor.pBtree.db);
|
|
return SQLITE_LOCKED_SHAREDCACHE;
|
|
}
|
|
|
|
rc = btreeGetPage(pBt, (Pgno)iTable, ref pPage, 0);
|
|
if (rc != 0)
|
|
return rc;
|
|
int Dummy0 = 0;
|
|
rc = sqlite3BtreeClearTable(p, (int)iTable, ref Dummy0);
|
|
if (rc != 0)
|
|
{
|
|
releasePage(pPage);
|
|
return rc;
|
|
}
|
|
|
|
piMoved = 0;
|
|
|
|
if (iTable > 1)
|
|
{
|
|
#if SQLITE_OMIT_AUTOVACUUM
|
|
freePage(pPage, ref rc);
|
|
releasePage(pPage);
|
|
#else
|
|
if (pBt.autoVacuum)
|
|
{
|
|
Pgno maxRootPgno = 0;
|
|
sqlite3BtreeGetMeta(p, BTREE_LARGEST_ROOT_PAGE, ref maxRootPgno);
|
|
|
|
if (iTable == maxRootPgno)
|
|
{
|
|
/* If the table being dropped is the table with the largest root-page
|
|
** number in the database, put the root page on the free list.
|
|
*/
|
|
freePage(pPage, ref rc);
|
|
releasePage(pPage);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* The table being dropped does not have the largest root-page
|
|
** number in the database. So move the page that does into the
|
|
** gap left by the deleted root-page.
|
|
*/
|
|
MemPage pMove = new MemPage();
|
|
releasePage(pPage);
|
|
rc = btreeGetPage(pBt, maxRootPgno, ref pMove, 0);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
rc = relocatePage(pBt, pMove, PTRMAP_ROOTPAGE, 0, iTable, 0);
|
|
releasePage(pMove);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
pMove = null;
|
|
rc = btreeGetPage(pBt, maxRootPgno, ref pMove, 0);
|
|
freePage(pMove, ref rc);
|
|
releasePage(pMove);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
return rc;
|
|
}
|
|
piMoved = (int)maxRootPgno;
|
|
}
|
|
|
|
/* Set the new 'max-root-page' value in the database header. This
|
|
** is the old value less one, less one more if that happens to
|
|
** be a root-page number, less one again if that is the
|
|
** PENDING_BYTE_PAGE.
|
|
*/
|
|
maxRootPgno--;
|
|
while (maxRootPgno == PENDING_BYTE_PAGE(pBt)
|
|
|| PTRMAP_ISPAGE(pBt, maxRootPgno))
|
|
{
|
|
maxRootPgno--;
|
|
}
|
|
Debug.Assert(maxRootPgno != PENDING_BYTE_PAGE(pBt));
|
|
|
|
rc = sqlite3BtreeUpdateMeta(p, 4, maxRootPgno);
|
|
}
|
|
else
|
|
{
|
|
freePage(pPage, ref rc);
|
|
releasePage(pPage);
|
|
}
|
|
#endif
|
|
}
|
|
else
|
|
{
|
|
/* If sqlite3BtreeDropTable was called on page 1.
|
|
** This really never should happen except in a corrupt
|
|
** database.
|
|
*/
|
|
zeroPage(pPage, PTF_INTKEY | PTF_LEAF);
|
|
releasePage(pPage);
|
|
}
|
|
return rc;
|
|
}
|
|
|
|
private static int sqlite3BtreeDropTable(Btree p, int iTable, ref int piMoved)
|
|
{
|
|
int rc;
|
|
sqlite3BtreeEnter(p);
|
|
rc = btreeDropTable(p, (u32)iTable, ref piMoved);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
/*
|
|
** This function may only be called if the b-tree connection already
|
|
** has a read or write transaction open on the database.
|
|
**
|
|
** Read the meta-information out of a database file. Meta[0]
|
|
** is the number of free pages currently in the database. Meta[1]
|
|
** through meta[15] are available for use by higher layers. Meta[0]
|
|
** is read-only, the others are read/write.
|
|
**
|
|
** The schema layer numbers meta values differently. At the schema
|
|
** layer (and the SetCookie and ReadCookie opcodes) the number of
|
|
** free pages is not visible. So Cookie[0] is the same as Meta[1].
|
|
*/
|
|
|
|
private static void sqlite3BtreeGetMeta(Btree p, int idx, ref u32 pMeta)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(p.inTrans > TRANS_NONE);
|
|
Debug.Assert(SQLITE_OK == querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK));
|
|
Debug.Assert(pBt.pPage1 != null);
|
|
Debug.Assert(idx >= 0 && idx <= 15);
|
|
|
|
pMeta = sqlite3Get4byte(pBt.pPage1.aData, 36 + idx * 4);
|
|
|
|
/* If auto-vacuum is disabled in this build and this is an auto-vacuum
|
|
** database, mark the database as read-only. */
|
|
#if SQLITE_OMIT_AUTOVACUUM
|
|
if( idx==BTREE_LARGEST_ROOT_PAGE && pMeta>0 ) pBt.readOnly = 1;
|
|
#endif
|
|
|
|
sqlite3BtreeLeave(p);
|
|
}
|
|
|
|
/*
|
|
** Write meta-information back into the database. Meta[0] is
|
|
** read-only and may not be written.
|
|
*/
|
|
|
|
private static int sqlite3BtreeUpdateMeta(Btree p, int idx, u32 iMeta)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
byte[] pP1;
|
|
int rc;
|
|
Debug.Assert(idx >= 1 && idx <= 15);
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(p.inTrans == TRANS_WRITE);
|
|
Debug.Assert(pBt.pPage1 != null);
|
|
pP1 = pBt.pPage1.aData;
|
|
rc = sqlite3PagerWrite(pBt.pPage1.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
sqlite3Put4byte(pP1, 36 + idx * 4, iMeta);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (idx == BTREE_INCR_VACUUM)
|
|
{
|
|
Debug.Assert(pBt.autoVacuum || iMeta == 0);
|
|
Debug.Assert(iMeta == 0 || iMeta == 1);
|
|
pBt.incrVacuum = iMeta != 0;
|
|
}
|
|
#endif
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_BTREECOUNT
|
|
/*
|
|
** The first argument, pCur, is a cursor opened on some b-tree. Count the
|
|
** number of entries in the b-tree and write the result to pnEntry.
|
|
**
|
|
** SQLITE_OK is returned if the operation is successfully executed.
|
|
** Otherwise, if an error is encountered (i.e. an IO error or database
|
|
** corruption) an SQLite error code is returned.
|
|
*/
|
|
|
|
private static int sqlite3BtreeCount(BtCursor pCur, ref i64 pnEntry)
|
|
{
|
|
i64 nEntry = 0; /* Value to return in pnEntry */
|
|
int rc; /* Return code */
|
|
rc = moveToRoot(pCur);
|
|
|
|
/* Unless an error occurs, the following loop runs one iteration for each
|
|
** page in the B-Tree structure (not including overflow pages).
|
|
*/
|
|
while (rc == SQLITE_OK)
|
|
{
|
|
int iIdx; /* Index of child node in parent */
|
|
MemPage pPage; /* Current page of the b-tree */
|
|
|
|
/* If this is a leaf page or the tree is not an int-key tree, then
|
|
** this page contains countable entries. Increment the entry counter
|
|
** accordingly.
|
|
*/
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
if (pPage.leaf != 0 || 0 == pPage.intKey)
|
|
{
|
|
nEntry += pPage.nCell;
|
|
}
|
|
|
|
/* pPage is a leaf node. This loop navigates the cursor so that it
|
|
** points to the first interior cell that it points to the parent of
|
|
** the next page in the tree that has not yet been visited. The
|
|
** pCur.aiIdx[pCur.iPage] value is set to the index of the parent cell
|
|
** of the page, or to the number of cells in the page if the next page
|
|
** to visit is the right-child of its parent.
|
|
**
|
|
** If all pages in the tree have been visited, return SQLITE_OK to the
|
|
** caller.
|
|
*/
|
|
if (pPage.leaf != 0)
|
|
{
|
|
do
|
|
{
|
|
if (pCur.iPage == 0)
|
|
{
|
|
/* All pages of the b-tree have been visited. Return successfully. */
|
|
pnEntry = nEntry;
|
|
return SQLITE_OK;
|
|
}
|
|
moveToParent(pCur);
|
|
} while (pCur.aiIdx[pCur.iPage] >= pCur.apPage[pCur.iPage].nCell);
|
|
|
|
pCur.aiIdx[pCur.iPage]++;
|
|
pPage = pCur.apPage[pCur.iPage];
|
|
}
|
|
|
|
/* Descend to the child node of the cell that the cursor currently
|
|
** points at. This is the right-child if (iIdx==pPage.nCell).
|
|
*/
|
|
iIdx = pCur.aiIdx[pCur.iPage];
|
|
if (iIdx == pPage.nCell)
|
|
{
|
|
rc = moveToChild(pCur, sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8));
|
|
}
|
|
else
|
|
{
|
|
rc = moveToChild(pCur, sqlite3Get4byte(pPage.aData, findCell(pPage, iIdx)));
|
|
}
|
|
}
|
|
|
|
/* An error has occurred. Return an error code. */
|
|
return rc;
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
** Return the pager associated with a BTree. This routine is used for
|
|
** testing and debugging only.
|
|
*/
|
|
|
|
private static Pager sqlite3BtreePager(Btree p)
|
|
{
|
|
return p.pBt.pPager;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_INTEGRITY_CHECK
|
|
/*
|
|
** Append a message to the error message string.
|
|
*/
|
|
|
|
private static void checkAppendMsg(
|
|
IntegrityCk pCheck,
|
|
string zMsg1,
|
|
string zFormat,
|
|
params object[] ap
|
|
)
|
|
{
|
|
if (0 == pCheck.mxErr)
|
|
return;
|
|
//va_list ap;
|
|
lock (lock_va_list)
|
|
{
|
|
pCheck.mxErr--;
|
|
pCheck.nErr++;
|
|
va_start(ap, zFormat);
|
|
if (pCheck.errMsg.zText.Length != 0)
|
|
{
|
|
sqlite3StrAccumAppend(pCheck.errMsg, "\n", 1);
|
|
}
|
|
if (zMsg1.Length > 0)
|
|
{
|
|
sqlite3StrAccumAppend(pCheck.errMsg, zMsg1.ToString(), -1);
|
|
}
|
|
sqlite3VXPrintf(pCheck.errMsg, 1, zFormat, ap);
|
|
va_end(ref ap);
|
|
}
|
|
}
|
|
|
|
private static void checkAppendMsg(
|
|
IntegrityCk pCheck,
|
|
StringBuilder zMsg1,
|
|
string zFormat,
|
|
params object[] ap
|
|
)
|
|
{
|
|
if (0 == pCheck.mxErr)
|
|
return;
|
|
//va_list ap;
|
|
lock (lock_va_list)
|
|
{
|
|
pCheck.mxErr--;
|
|
pCheck.nErr++;
|
|
va_start(ap, zFormat);
|
|
if (pCheck.errMsg.zText.Length != 0)
|
|
{
|
|
sqlite3StrAccumAppend(pCheck.errMsg, "\n", 1);
|
|
}
|
|
if (zMsg1.Length > 0)
|
|
{
|
|
sqlite3StrAccumAppend(pCheck.errMsg, zMsg1.ToString(), -1);
|
|
}
|
|
sqlite3VXPrintf(pCheck.errMsg, 1, zFormat, ap);
|
|
va_end(ref ap);
|
|
}
|
|
//if( pCheck.errMsg.mallocFailed ){
|
|
// pCheck.mallocFailed = 1;
|
|
//}
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_INTEGRITY_CHECK */
|
|
|
|
#if !SQLITE_OMIT_INTEGRITY_CHECK
|
|
/*
|
|
** Add 1 to the reference count for page iPage. If this is the second
|
|
** reference to the page, add an error message to pCheck.zErrMsg.
|
|
** Return 1 if there are 2 ore more references to the page and 0 if
|
|
** if this is the first reference to the page.
|
|
**
|
|
** Also check that the page number is in bounds.
|
|
*/
|
|
|
|
private static int checkRef(IntegrityCk pCheck, Pgno iPage, string zContext)
|
|
{
|
|
if (iPage == 0)
|
|
return 1;
|
|
if (iPage > pCheck.nPage)
|
|
{
|
|
checkAppendMsg(pCheck, zContext, "invalid page number %d", iPage);
|
|
return 1;
|
|
}
|
|
if (pCheck.anRef[iPage] == 1)
|
|
{
|
|
checkAppendMsg(pCheck, zContext, "2nd reference to page %d", iPage);
|
|
return 1;
|
|
}
|
|
return ((pCheck.anRef[iPage]++) > 1) ? 1 : 0;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
/*
|
|
** Check that the entry in the pointer-map for page iChild maps to
|
|
** page iParent, pointer type ptrType. If not, append an error message
|
|
** to pCheck.
|
|
*/
|
|
|
|
private static void checkPtrmap(
|
|
IntegrityCk pCheck, /* Integrity check context */
|
|
Pgno iChild, /* Child page number */
|
|
u8 eType, /* Expected pointer map type */
|
|
Pgno iParent, /* Expected pointer map parent page number */
|
|
string zContext /* Context description (used for error msg) */
|
|
)
|
|
{
|
|
int rc;
|
|
u8 ePtrmapType = 0;
|
|
Pgno iPtrmapParent = 0;
|
|
|
|
rc = ptrmapGet(pCheck.pBt, iChild, ref ePtrmapType, ref iPtrmapParent);
|
|
if (rc != SQLITE_OK)
|
|
{
|
|
//if( rc==SQLITE_NOMEM || rc==SQLITE_IOERR_NOMEM ) pCheck.mallocFailed = 1;
|
|
checkAppendMsg(pCheck, zContext, "Failed to read ptrmap key=%d", iChild);
|
|
return;
|
|
}
|
|
|
|
if (ePtrmapType != eType || iPtrmapParent != iParent)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"Bad ptr map entry key=%d expected=(%d,%d) got=(%d,%d)",
|
|
iChild, eType, iParent, ePtrmapType, iPtrmapParent);
|
|
}
|
|
}
|
|
|
|
#endif
|
|
|
|
/*
|
|
** Check the integrity of the freelist or of an overflow page list.
|
|
** Verify that the number of pages on the list is N.
|
|
*/
|
|
|
|
private static void checkList(
|
|
IntegrityCk pCheck, /* Integrity checking context */
|
|
int isFreeList, /* True for a freelist. False for overflow page list */
|
|
int iPage, /* Page number for first page in the list */
|
|
int N, /* Expected number of pages in the list */
|
|
string zContext /* Context for error messages */
|
|
)
|
|
{
|
|
int i;
|
|
int expected = N;
|
|
int iFirst = iPage;
|
|
while (N-- > 0 && pCheck.mxErr != 0)
|
|
{
|
|
PgHdr pOvflPage = new PgHdr();
|
|
byte[] pOvflData;
|
|
if (iPage < 1)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"%d of %d pages missing from overflow list starting at %d",
|
|
N + 1, expected, iFirst);
|
|
break;
|
|
}
|
|
if (checkRef(pCheck, (u32)iPage, zContext) != 0)
|
|
break;
|
|
if (sqlite3PagerGet(pCheck.pPager, (Pgno)iPage, ref pOvflPage) != 0)
|
|
{
|
|
checkAppendMsg(pCheck, zContext, "failed to get page %d", iPage);
|
|
break;
|
|
}
|
|
pOvflData = sqlite3PagerGetData(pOvflPage);
|
|
if (isFreeList != 0)
|
|
{
|
|
int n = (int)sqlite3Get4byte(pOvflData, 4);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pCheck.pBt.autoVacuum)
|
|
{
|
|
checkPtrmap(pCheck, (u32)iPage, PTRMAP_FREEPAGE, 0, zContext);
|
|
}
|
|
#endif
|
|
if (n > (int)pCheck.pBt.usableSize / 4 - 2)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"freelist leaf count too big on page %d", iPage);
|
|
N--;
|
|
}
|
|
else
|
|
{
|
|
for (i = 0; i < n; i++)
|
|
{
|
|
Pgno iFreePage = sqlite3Get4byte(pOvflData, 8 + i * 4);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pCheck.pBt.autoVacuum)
|
|
{
|
|
checkPtrmap(pCheck, iFreePage, PTRMAP_FREEPAGE, 0, zContext);
|
|
}
|
|
#endif
|
|
checkRef(pCheck, iFreePage, zContext);
|
|
}
|
|
N -= n;
|
|
}
|
|
}
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
else
|
|
{
|
|
/* If this database supports auto-vacuum and iPage is not the last
|
|
** page in this overflow list, check that the pointer-map entry for
|
|
** the following page matches iPage.
|
|
*/
|
|
if (pCheck.pBt.autoVacuum && N > 0)
|
|
{
|
|
i = (int)sqlite3Get4byte(pOvflData);
|
|
checkPtrmap(pCheck, (u32)i, PTRMAP_OVERFLOW2, (u32)iPage, zContext);
|
|
}
|
|
}
|
|
#endif
|
|
iPage = (int)sqlite3Get4byte(pOvflData);
|
|
sqlite3PagerUnref(pOvflPage);
|
|
}
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_INTEGRITY_CHECK */
|
|
|
|
#if !SQLITE_OMIT_INTEGRITY_CHECK
|
|
/*
|
|
** Do various sanity checks on a single page of a tree. Return
|
|
** the tree depth. Root pages return 0. Parents of root pages
|
|
** return 1, and so forth.
|
|
**
|
|
** These checks are done:
|
|
**
|
|
** 1. Make sure that cells and freeblocks do not overlap
|
|
** but combine to completely cover the page.
|
|
** NO 2. Make sure cell keys are in order.
|
|
** NO 3. Make sure no key is less than or equal to zLowerBound.
|
|
** NO 4. Make sure no key is greater than or equal to zUpperBound.
|
|
** 5. Check the integrity of overflow pages.
|
|
** 6. Recursively call checkTreePage on all children.
|
|
** 7. Verify that the depth of all children is the same.
|
|
** 8. Make sure this page is at least 33% full or else it is
|
|
** the root of the tree.
|
|
*/
|
|
|
|
private static i64 refNULL = 0; //Dummy for C# ref NULL
|
|
|
|
private static int checkTreePage(
|
|
IntegrityCk pCheck, /* Context for the sanity check */
|
|
int iPage, /* Page number of the page to check */
|
|
string zParentContext, /* Parent context */
|
|
ref i64 pnParentMinKey,
|
|
ref i64 pnParentMaxKey,
|
|
object _pnParentMinKey, /* C# Needed to determine if content passed*/
|
|
object _pnParentMaxKey /* C# Needed to determine if content passed*/
|
|
)
|
|
{
|
|
MemPage pPage = new MemPage();
|
|
int i, rc, depth, d2, pgno, cnt;
|
|
int hdr, cellStart;
|
|
int nCell;
|
|
u8[] data;
|
|
BtShared pBt;
|
|
int usableSize;
|
|
StringBuilder zContext = new StringBuilder(100);
|
|
byte[] hit = null;
|
|
i64 nMinKey = 0;
|
|
i64 nMaxKey = 0;
|
|
|
|
sqlite3_snprintf(200, zContext, "Page %d: ", iPage);
|
|
|
|
/* Check that the page exists
|
|
*/
|
|
pBt = pCheck.pBt;
|
|
usableSize = (int)pBt.usableSize;
|
|
if (iPage == 0)
|
|
return 0;
|
|
if (checkRef(pCheck, (u32)iPage, zParentContext) != 0)
|
|
return 0;
|
|
if ((rc = btreeGetPage(pBt, (Pgno)iPage, ref pPage, 0)) != 0)
|
|
{
|
|
checkAppendMsg(pCheck, zContext.ToString(),
|
|
"unable to get the page. error code=%d", rc);
|
|
return 0;
|
|
}
|
|
|
|
/* Clear MemPage.isInit to make sure the corruption detection code in
|
|
** btreeInitPage() is executed. */
|
|
pPage.isInit = 0;
|
|
if ((rc = btreeInitPage(pPage)) != 0)
|
|
{
|
|
Debug.Assert(rc == SQLITE_CORRUPT); /* The only possible error from InitPage */
|
|
checkAppendMsg(pCheck, zContext.ToString(),
|
|
"btreeInitPage() returns error code %d", rc);
|
|
releasePage(pPage);
|
|
return 0;
|
|
}
|
|
|
|
/* Check out all the cells.
|
|
*/
|
|
depth = 0;
|
|
for (i = 0; i < pPage.nCell && pCheck.mxErr != 0; i++)
|
|
{
|
|
u8[] pCell;
|
|
u32 sz;
|
|
CellInfo info = new CellInfo();
|
|
|
|
/* Check payload overflow pages
|
|
*/
|
|
sqlite3_snprintf(200, zContext,
|
|
"On tree page %d cell %d: ", iPage, i);
|
|
int iCell = findCell(pPage, i); //pCell = findCell( pPage, i );
|
|
pCell = pPage.aData;
|
|
btreeParseCellPtr(pPage, iCell, ref info); //btreeParseCellPtr( pPage, pCell, info );
|
|
sz = info.nData;
|
|
if (0 == pPage.intKey)
|
|
sz += (u32)info.nKey;
|
|
/* For intKey pages, check that the keys are in order.
|
|
*/
|
|
else if (i == 0)
|
|
nMinKey = nMaxKey = info.nKey;
|
|
else
|
|
{
|
|
if (info.nKey <= nMaxKey)
|
|
{
|
|
checkAppendMsg(pCheck, zContext.ToString(),
|
|
"Rowid %lld out of order (previous was %lld)", info.nKey, nMaxKey);
|
|
}
|
|
nMaxKey = info.nKey;
|
|
}
|
|
Debug.Assert(sz == info.nPayload);
|
|
if ((sz > info.nLocal)
|
|
//&& (pCell[info.iOverflow]<=&pPage.aData[pBt.usableSize])
|
|
)
|
|
{
|
|
int nPage = (int)(sz - info.nLocal + usableSize - 5) / (usableSize - 4);
|
|
Pgno pgnoOvfl = sqlite3Get4byte(pCell, iCell, info.iOverflow);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pBt.autoVacuum)
|
|
{
|
|
checkPtrmap(pCheck, pgnoOvfl, PTRMAP_OVERFLOW1, (u32)iPage, zContext.ToString());
|
|
}
|
|
#endif
|
|
checkList(pCheck, 0, (int)pgnoOvfl, nPage, zContext.ToString());
|
|
}
|
|
|
|
/* Check sanity of left child page.
|
|
*/
|
|
if (0 == pPage.leaf)
|
|
{
|
|
pgno = (int)sqlite3Get4byte(pCell, iCell); //sqlite3Get4byte( pCell );
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pBt.autoVacuum)
|
|
{
|
|
checkPtrmap(pCheck, (u32)pgno, PTRMAP_BTREE, (u32)iPage, zContext.ToString());
|
|
}
|
|
#endif
|
|
if (i == 0)
|
|
d2 = checkTreePage(pCheck, pgno, zContext.ToString(), ref nMinKey, ref refNULL, pCheck, null);
|
|
else
|
|
d2 = checkTreePage(pCheck, pgno, zContext.ToString(), ref nMinKey, ref nMaxKey, pCheck, pCheck);
|
|
|
|
if (i > 0 && d2 != depth)
|
|
{
|
|
checkAppendMsg(pCheck, zContext, "Child page depth differs");
|
|
}
|
|
depth = d2;
|
|
}
|
|
}
|
|
if (0 == pPage.leaf)
|
|
{
|
|
pgno = (int)sqlite3Get4byte(pPage.aData, pPage.hdrOffset + 8);
|
|
sqlite3_snprintf(200, zContext,
|
|
"On page %d at right child: ", iPage);
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pBt.autoVacuum)
|
|
{
|
|
checkPtrmap(pCheck, (u32)pgno, PTRMAP_BTREE, (u32)iPage, zContext.ToString());
|
|
}
|
|
#endif
|
|
// checkTreePage(pCheck, pgno, zContext, NULL, !pPage->nCell ? NULL : &nMaxKey);
|
|
if (0 == pPage.nCell)
|
|
checkTreePage(pCheck, pgno, zContext.ToString(), ref refNULL, ref refNULL, null, null);
|
|
else
|
|
checkTreePage(pCheck, pgno, zContext.ToString(), ref refNULL, ref nMaxKey, null, pCheck);
|
|
}
|
|
|
|
/* For intKey leaf pages, check that the min/max keys are in order
|
|
** with any left/parent/right pages.
|
|
*/
|
|
if (pPage.leaf != 0 && pPage.intKey != 0)
|
|
{
|
|
/* if we are a left child page */
|
|
if (_pnParentMinKey != null)
|
|
{
|
|
/* if we are the left most child page */
|
|
if (_pnParentMaxKey == null)
|
|
{
|
|
if (nMaxKey > pnParentMinKey)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"Rowid %lld out of order (max larger than parent min of %lld)",
|
|
nMaxKey, pnParentMinKey);
|
|
}
|
|
}
|
|
else
|
|
{
|
|
if (nMinKey <= pnParentMinKey)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"Rowid %lld out of order (min less than parent min of %lld)",
|
|
nMinKey, pnParentMinKey);
|
|
}
|
|
if (nMaxKey > pnParentMaxKey)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"Rowid %lld out of order (max larger than parent max of %lld)",
|
|
nMaxKey, pnParentMaxKey);
|
|
}
|
|
pnParentMinKey = nMaxKey;
|
|
}
|
|
/* else if we're a right child page */
|
|
}
|
|
else if (_pnParentMaxKey != null)
|
|
{
|
|
if (nMinKey <= pnParentMaxKey)
|
|
{
|
|
checkAppendMsg(pCheck, zContext,
|
|
"Rowid %lld out of order (min less than parent max of %lld)",
|
|
nMinKey, pnParentMaxKey);
|
|
}
|
|
}
|
|
}
|
|
|
|
/* Check for complete coverage of the page
|
|
*/
|
|
data = pPage.aData;
|
|
hdr = pPage.hdrOffset;
|
|
hit = sqlite3Malloc(pBt.pageSize);
|
|
//if( hit==null ){
|
|
// pCheck.mallocFailed = 1;
|
|
//}else
|
|
{
|
|
int contentOffset = get2byteNotZero(data, hdr + 5);
|
|
Debug.Assert(contentOffset <= usableSize); /* Enforced by btreeInitPage() */
|
|
Array.Clear(hit, contentOffset, usableSize - contentOffset);//memset(hit+contentOffset, 0, usableSize-contentOffset);
|
|
for (int iLoop = contentOffset - 1; iLoop >= 0; iLoop--)
|
|
hit[iLoop] = 1;//memset(hit, 1, contentOffset);
|
|
nCell = get2byte(data, hdr + 3);
|
|
cellStart = hdr + 12 - 4 * pPage.leaf;
|
|
for (i = 0; i < nCell; i++)
|
|
{
|
|
int pc = get2byte(data, cellStart + i * 2);
|
|
u32 size = 65536;
|
|
int j;
|
|
if (pc <= usableSize - 4)
|
|
{
|
|
size = cellSizePtr(pPage, data, pc);
|
|
}
|
|
if ((int)(pc + size - 1) >= usableSize)
|
|
{
|
|
checkAppendMsg(pCheck, "",
|
|
"Corruption detected in cell %d on page %d", i, iPage);
|
|
}
|
|
else
|
|
{
|
|
for (j = (int)(pc + size - 1); j >= pc; j--)
|
|
hit[j]++;
|
|
}
|
|
}
|
|
i = get2byte(data, hdr + 1);
|
|
while (i > 0)
|
|
{
|
|
int size, j;
|
|
Debug.Assert(i <= usableSize - 4); /* Enforced by btreeInitPage() */
|
|
size = get2byte(data, i + 2);
|
|
Debug.Assert(i + size <= usableSize); /* Enforced by btreeInitPage() */
|
|
for (j = i + size - 1; j >= i; j--)
|
|
hit[j]++;
|
|
j = get2byte(data, i);
|
|
Debug.Assert(j == 0 || j > i + size); /* Enforced by btreeInitPage() */
|
|
Debug.Assert(j <= usableSize - 4); /* Enforced by btreeInitPage() */
|
|
i = j;
|
|
}
|
|
for (i = cnt = 0; i < usableSize; i++)
|
|
{
|
|
if (hit[i] == 0)
|
|
{
|
|
cnt++;
|
|
}
|
|
else if (hit[i] > 1)
|
|
{
|
|
checkAppendMsg(pCheck, "",
|
|
"Multiple uses for byte %d of page %d", i, iPage);
|
|
break;
|
|
}
|
|
}
|
|
if (cnt != data[hdr + 7])
|
|
{
|
|
checkAppendMsg(pCheck, "",
|
|
"Fragmentation of %d bytes reported as %d on page %d",
|
|
cnt, data[hdr + 7], iPage);
|
|
}
|
|
}
|
|
sqlite3PageFree(ref hit);
|
|
releasePage(pPage);
|
|
return depth + 1;
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_INTEGRITY_CHECK */
|
|
|
|
#if !SQLITE_OMIT_INTEGRITY_CHECK
|
|
/*
|
|
** This routine does a complete check of the given BTree file. aRoot[] is
|
|
** an array of pages numbers were each page number is the root page of
|
|
** a table. nRoot is the number of entries in aRoot.
|
|
**
|
|
** A read-only or read-write transaction must be opened before calling
|
|
** this function.
|
|
**
|
|
** Write the number of error seen in pnErr. Except for some memory
|
|
** allocation errors, an error message held in memory obtained from
|
|
** malloc is returned if pnErr is non-zero. If pnErr==null then NULL is
|
|
** returned. If a memory allocation error occurs, NULL is returned.
|
|
*/
|
|
|
|
private static string sqlite3BtreeIntegrityCheck(
|
|
Btree p, /* The btree to be checked */
|
|
int[] aRoot, /* An array of root pages numbers for individual trees */
|
|
int nRoot, /* Number of entries in aRoot[] */
|
|
int mxErr, /* Stop reporting errors after this many */
|
|
ref int pnErr /* Write number of errors seen to this variable */
|
|
)
|
|
{
|
|
Pgno i;
|
|
int nRef;
|
|
IntegrityCk sCheck = new IntegrityCk();
|
|
BtShared pBt = p.pBt;
|
|
|
|
sqlite3BtreeEnter(p);
|
|
Debug.Assert(p.inTrans > TRANS_NONE && pBt.inTransaction > TRANS_NONE);
|
|
nRef = sqlite3PagerRefcount(pBt.pPager);
|
|
sCheck.pBt = pBt;
|
|
sCheck.pPager = pBt.pPager;
|
|
sCheck.nPage = btreePagecount(sCheck.pBt);
|
|
sCheck.mxErr = mxErr;
|
|
sCheck.nErr = 0;
|
|
//sCheck.mallocFailed = 0;
|
|
pnErr = 0;
|
|
if (sCheck.nPage == 0)
|
|
{
|
|
sqlite3BtreeLeave(p);
|
|
return "";
|
|
}
|
|
sCheck.anRef = sqlite3Malloc(sCheck.anRef, (int)sCheck.nPage + 1);
|
|
//if( !sCheck.anRef ){
|
|
// pnErr = 1;
|
|
// sqlite3BtreeLeave(p);
|
|
// return 0;
|
|
//}
|
|
// for (i = 0; i <= sCheck.nPage; i++) { sCheck.anRef[i] = 0; }
|
|
i = PENDING_BYTE_PAGE(pBt);
|
|
if (i <= sCheck.nPage)
|
|
{
|
|
sCheck.anRef[i] = 1;
|
|
}
|
|
sqlite3StrAccumInit(sCheck.errMsg, null, 1000, 20000);
|
|
//sCheck.errMsg.useMalloc = 2;
|
|
|
|
/* Check the integrity of the freelist
|
|
*/
|
|
checkList(sCheck, 1, (int)sqlite3Get4byte(pBt.pPage1.aData, 32),
|
|
(int)sqlite3Get4byte(pBt.pPage1.aData, 36), "Main freelist: ");
|
|
|
|
/* Check all the tables.
|
|
*/
|
|
for (i = 0; (int)i < nRoot && sCheck.mxErr != 0; i++)
|
|
{
|
|
if (aRoot[i] == 0)
|
|
continue;
|
|
#if !SQLITE_OMIT_AUTOVACUUM
|
|
if (pBt.autoVacuum && aRoot[i] > 1)
|
|
{
|
|
checkPtrmap(sCheck, (u32)aRoot[i], PTRMAP_ROOTPAGE, 0, "");
|
|
}
|
|
#endif
|
|
checkTreePage(sCheck, aRoot[i], "List of tree roots: ", ref refNULL, ref refNULL, null, null);
|
|
}
|
|
|
|
/* Make sure every page in the file is referenced
|
|
*/
|
|
for (i = 1; i <= sCheck.nPage && sCheck.mxErr != 0; i++)
|
|
{
|
|
#if SQLITE_OMIT_AUTOVACUUM
|
|
if( sCheck.anRef[i]==null ){
|
|
checkAppendMsg(sCheck, 0, "Page %d is never used", i);
|
|
}
|
|
#else
|
|
/* If the database supports auto-vacuum, make sure no tables contain
|
|
** references to pointer-map pages.
|
|
*/
|
|
if (sCheck.anRef[i] == 0 &&
|
|
(PTRMAP_PAGENO(pBt, i) != i || !pBt.autoVacuum))
|
|
{
|
|
checkAppendMsg(sCheck, "", "Page %d is never used", i);
|
|
}
|
|
if (sCheck.anRef[i] != 0 &&
|
|
(PTRMAP_PAGENO(pBt, i) == i && pBt.autoVacuum))
|
|
{
|
|
checkAppendMsg(sCheck, "", "Pointer map page %d is referenced", i);
|
|
}
|
|
#endif
|
|
}
|
|
|
|
/* Make sure this analysis did not leave any unref() pages.
|
|
** This is an internal consistency check; an integrity check
|
|
** of the integrity check.
|
|
*/
|
|
if (NEVER(nRef != sqlite3PagerRefcount(pBt.pPager)))
|
|
{
|
|
checkAppendMsg(sCheck, "",
|
|
"Outstanding page count goes from %d to %d during this analysis",
|
|
nRef, sqlite3PagerRefcount(pBt.pPager)
|
|
);
|
|
}
|
|
|
|
/* Clean up and report errors.
|
|
*/
|
|
sqlite3BtreeLeave(p);
|
|
sCheck.anRef = null;// sqlite3_free( ref sCheck.anRef );
|
|
//if( sCheck.mallocFailed ){
|
|
// sqlite3StrAccumReset(sCheck.errMsg);
|
|
// pnErr = sCheck.nErr+1;
|
|
// return 0;
|
|
//}
|
|
pnErr = sCheck.nErr;
|
|
if (sCheck.nErr == 0)
|
|
sqlite3StrAccumReset(sCheck.errMsg);
|
|
return sqlite3StrAccumFinish(sCheck.errMsg);
|
|
}
|
|
|
|
#endif //* SQLITE_OMIT_INTEGRITY_CHECK */
|
|
|
|
/*
|
|
** Return the full pathname of the underlying database file.
|
|
**
|
|
** The pager filename is invariant as long as the pager is
|
|
** open so it is safe to access without the BtShared mutex.
|
|
*/
|
|
|
|
private static string sqlite3BtreeGetFilename(Btree p)
|
|
{
|
|
Debug.Assert(p.pBt.pPager != null);
|
|
return sqlite3PagerFilename(p.pBt.pPager);
|
|
}
|
|
|
|
/*
|
|
** Return the pathname of the journal file for this database. The return
|
|
** value of this routine is the same regardless of whether the journal file
|
|
** has been created or not.
|
|
**
|
|
** The pager journal filename is invariant as long as the pager is
|
|
** open so it is safe to access without the BtShared mutex.
|
|
*/
|
|
|
|
private static string sqlite3BtreeGetJournalname(Btree p)
|
|
{
|
|
Debug.Assert(p.pBt.pPager != null);
|
|
return sqlite3PagerJournalname(p.pBt.pPager);
|
|
}
|
|
|
|
/*
|
|
** Return non-zero if a transaction is active.
|
|
*/
|
|
|
|
private static bool sqlite3BtreeIsInTrans(Btree p)
|
|
{
|
|
Debug.Assert(p == null || sqlite3_mutex_held(p.db.mutex));
|
|
return (p != null && (p.inTrans == TRANS_WRITE));
|
|
}
|
|
|
|
#if !SQLITE_OMIT_WAL
|
|
/*
|
|
** Run a checkpoint on the Btree passed as the first argument.
|
|
**
|
|
** Return SQLITE_LOCKED if this or any other connection has an open
|
|
** transaction on the shared-cache the argument Btree is connected to.
|
|
**
|
|
** Parameter eMode is one of SQLITE_CHECKPOINT_PASSIVE, FULL or RESTART.
|
|
*/
|
|
static int sqlite3BtreeCheckpointBtree *p, int eMode, int *pnLog, int *pnCkpt){
|
|
int rc = SQLITE_OK;
|
|
if( p != null){
|
|
BtShared pBt = p.pBt;
|
|
sqlite3BtreeEnter(p);
|
|
if( pBt.inTransaction!=TRANS_NONE ){
|
|
rc = SQLITE_LOCKED;
|
|
}else{
|
|
rc = sqlite3PagerCheckpoint(pBt.pPager, eMode, pnLog, pnCkpt);
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
}
|
|
return rc;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
** Return non-zero if a read (or write) transaction is active.
|
|
*/
|
|
|
|
private static bool sqlite3BtreeIsInReadTrans(Btree p)
|
|
{
|
|
Debug.Assert(p != null);
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
return p.inTrans != TRANS_NONE;
|
|
}
|
|
|
|
private static bool sqlite3BtreeIsInBackup(Btree p)
|
|
{
|
|
Debug.Assert(p != null);
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
return p.nBackup != 0;
|
|
}
|
|
|
|
/*
|
|
** This function returns a pointer to a blob of memory associated with
|
|
** a single shared-btree. The memory is used by client code for its own
|
|
** purposes (for example, to store a high-level schema associated with
|
|
** the shared-btree). The btree layer manages reference counting issues.
|
|
**
|
|
** The first time this is called on a shared-btree, nBytes bytes of memory
|
|
** are allocated, zeroed, and returned to the caller. For each subsequent
|
|
** call the nBytes parameter is ignored and a pointer to the same blob
|
|
** of memory returned.
|
|
**
|
|
** If the nBytes parameter is 0 and the blob of memory has not yet been
|
|
** allocated, a null pointer is returned. If the blob has already been
|
|
** allocated, it is returned as normal.
|
|
**
|
|
** Just before the shared-btree is closed, the function passed as the
|
|
** xFree argument when the memory allocation was made is invoked on the
|
|
** blob of allocated memory. The xFree function should not call sqlite3_free()
|
|
** on the memory, the btree layer does that.
|
|
*/
|
|
|
|
private static Schema sqlite3BtreeSchema(Btree p, int nBytes, dxFreeSchema xFree)
|
|
{
|
|
BtShared pBt = p.pBt;
|
|
sqlite3BtreeEnter(p);
|
|
if (null == pBt.pSchema && nBytes != 0)
|
|
{
|
|
pBt.pSchema = new Schema();//sqlite3DbMallocZero(0, nBytes);
|
|
pBt.xFreeSchema = xFree;
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
return pBt.pSchema;
|
|
}
|
|
|
|
/*
|
|
** Return SQLITE_LOCKED_SHAREDCACHE if another user of the same shared
|
|
** btree as the argument handle holds an exclusive lock on the
|
|
** sqlite_master table. Otherwise SQLITE_OK.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSchemaLocked(Btree p)
|
|
{
|
|
int rc;
|
|
Debug.Assert(sqlite3_mutex_held(p.db.mutex));
|
|
sqlite3BtreeEnter(p);
|
|
rc = querySharedCacheTableLock(p, MASTER_ROOT, READ_LOCK);
|
|
Debug.Assert(rc == SQLITE_OK || rc == SQLITE_LOCKED_SHAREDCACHE);
|
|
sqlite3BtreeLeave(p);
|
|
return rc;
|
|
}
|
|
|
|
#if !SQLITE_OMIT_SHARED_CACHE
|
|
/*
|
|
** Obtain a lock on the table whose root page is iTab. The
|
|
** lock is a write lock if isWritelock is true or a read lock
|
|
** if it is false.
|
|
*/
|
|
int sqlite3BtreeLockTable(Btree p, int iTab, u8 isWriteLock){
|
|
int rc = SQLITE_OK;
|
|
Debug.Assert( p.inTrans!=TRANS_NONE );
|
|
if( p.sharable ){
|
|
u8 lockType = READ_LOCK + isWriteLock;
|
|
Debug.Assert( READ_LOCK+1==WRITE_LOCK );
|
|
Debug.Assert( isWriteLock==null || isWriteLock==1 );
|
|
|
|
sqlite3BtreeEnter(p);
|
|
rc = querySharedCacheTableLock(p, iTab, lockType);
|
|
if( rc==SQLITE_OK ){
|
|
rc = setSharedCacheTableLock(p, iTab, lockType);
|
|
}
|
|
sqlite3BtreeLeave(p);
|
|
}
|
|
return rc;
|
|
}
|
|
#endif
|
|
|
|
#if !SQLITE_OMIT_INCRBLOB
|
|
/*
|
|
** Argument pCsr must be a cursor opened for writing on an
|
|
** INTKEY table currently pointing at a valid table entry.
|
|
** This function modifies the data stored as part of that entry.
|
|
**
|
|
** Only the data content may only be modified, it is not possible to
|
|
** change the length of the data stored. If this function is called with
|
|
** parameters that attempt to write past the end of the existing data,
|
|
** no modifications are made and SQLITE_CORRUPT is returned.
|
|
*/
|
|
int sqlite3BtreePutData(BtCursor pCsr, u32 offset, u32 amt, void *z){
|
|
int rc;
|
|
Debug.Assert( cursorHoldsMutex(pCsr) );
|
|
Debug.Assert( sqlite3_mutex_held(pCsr.pBtree.db.mutex) );
|
|
Debug.Assert( pCsr.isIncrblobHandle );
|
|
|
|
rc = restoreCursorPosition(pCsr);
|
|
if( rc!=SQLITE_OK ){
|
|
return rc;
|
|
}
|
|
Debug.Assert( pCsr.eState!=CURSOR_REQUIRESEEK );
|
|
if( pCsr.eState!=CURSOR_VALID ){
|
|
return SQLITE_ABORT;
|
|
}
|
|
|
|
/* Check some assumptions:
|
|
** (a) the cursor is open for writing,
|
|
** (b) there is a read/write transaction open,
|
|
** (c) the connection holds a write-lock on the table (if required),
|
|
** (d) there are no conflicting read-locks, and
|
|
** (e) the cursor points at a valid row of an intKey table.
|
|
*/
|
|
if( !pCsr.wrFlag ){
|
|
return SQLITE_READONLY;
|
|
}
|
|
Debug.Assert( !pCsr.pBt.readOnly && pCsr.pBt.inTransaction==TRANS_WRITE );
|
|
Debug.Assert( hasSharedCacheTableLock(pCsr.pBtree, pCsr.pgnoRoot, 0, 2) );
|
|
Debug.Assert( !hasReadConflicts(pCsr.pBtree, pCsr.pgnoRoot) );
|
|
Debug.Assert( pCsr.apPage[pCsr.iPage].intKey );
|
|
|
|
return accessPayload(pCsr, offset, amt, (byte[] *)z, 1);
|
|
}
|
|
|
|
/*
|
|
** Set a flag on this cursor to cache the locations of pages from the
|
|
** overflow list for the current row. This is used by cursors opened
|
|
** for incremental blob IO only.
|
|
**
|
|
** This function sets a flag only. The actual page location cache
|
|
** (stored in BtCursor.aOverflow[]) is allocated and used by function
|
|
** accessPayload() (the worker function for sqlite3BtreeData() and
|
|
** sqlite3BtreePutData()).
|
|
*/
|
|
static void sqlite3BtreeCacheOverflow(BtCursor pCur){
|
|
Debug.Assert( cursorHoldsMutex(pCur) );
|
|
Debug.Assert( sqlite3_mutex_held(pCur.pBtree.db.mutex) );
|
|
invalidateOverflowCache(pCur)
|
|
pCur.isIncrblobHandle = 1;
|
|
}
|
|
#endif
|
|
|
|
/*
|
|
** Set both the "read version" (single byte at byte offset 18) and
|
|
** "write version" (single byte at byte offset 19) fields in the database
|
|
** header to iVersion.
|
|
*/
|
|
|
|
private static int sqlite3BtreeSetVersion(Btree pBtree, int iVersion)
|
|
{
|
|
BtShared pBt = pBtree.pBt;
|
|
int rc; /* Return code */
|
|
|
|
Debug.Assert(pBtree.inTrans == TRANS_NONE);
|
|
Debug.Assert(iVersion == 1 || iVersion == 2);
|
|
|
|
/* If setting the version fields to 1, do not automatically open the
|
|
** WAL connection, even if the version fields are currently set to 2.
|
|
*/
|
|
pBt.doNotUseWAL = iVersion == 1;
|
|
|
|
rc = sqlite3BtreeBeginTrans(pBtree, 0);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
u8[] aData = pBt.pPage1.aData;
|
|
if (aData[18] != (u8)iVersion || aData[19] != (u8)iVersion)
|
|
{
|
|
rc = sqlite3BtreeBeginTrans(pBtree, 2);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
rc = sqlite3PagerWrite(pBt.pPage1.pDbPage);
|
|
if (rc == SQLITE_OK)
|
|
{
|
|
aData[18] = (u8)iVersion;
|
|
aData[19] = (u8)iVersion;
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
pBt.doNotUseWAL = false;
|
|
return rc;
|
|
}
|
|
}
|
|
} |