mattercontrol/Community.CsharpSqlite/src/Hash_h.cs

using u32 = System.UInt32;

namespace Community.CsharpSqlite
{
	public partial class Sqlite3
	{
		/*
		** 2001 September 22
		**
		** The author disclaims copyright to this source code.  In place of
		** a legal notice, here is a blessing:
		**
		**    May you do good and not evil.
		**    May you find forgiveness for yourself and forgive others.
		**    May you share freely, never taking more than you give.
		**
		*************************************************************************
		** This is the header file for the generic hash-table implemenation
		** used in SQLite.
		*************************************************************************
		**  Included in SQLite3 port to C#-SQLite;  2008 Noah B Hart
		**  C#-SQLite is an independent reimplementation of the SQLite software library
		**
		**  SQLITE_SOURCE_ID: 2010-08-23 18:52:01 42537b60566f288167f1b5864a5435986838e3a3
		**
		*************************************************************************
		*/
		//#if !_SQLITE_HASH_H_
		//#define _SQLITE_HASH_H_

		/* Forward declarations of structures. */
		//typedef struct Hash Hash;
		//typedef struct HashElem HashElem;

		/* A complete hash table is an instance of the following structure.
		** The internals of this structure are intended to be opaque -- client
		** code should not attempt to access or modify the fields of this structure
		** directly.  Change this structure only by using the routines below.
		** However, some of the "procedures" and "functions" for modifying and
		** accessing this structure are really macros, so we can't really make
		** this structure opaque.
		**
		** All elements of the hash table are on a single doubly-linked list.
		** Hash.first points to the head of this list.
		**
		** There are Hash.htsize buckets.  Each bucket points to a spot in
		** the global doubly-linked list.  The contents of the bucket are the
		** element pointed to plus the next _ht.count-1 elements in the list.
		**
		** Hash.htsize and Hash.ht may be zero.  In that case lookup is done
		** by a linear search of the global list.  For small tables, the
		** Hash.ht table is never allocated because if there are few elements
		** in the table, it is faster to do a linear search than to manage
		** the hash table.
		*/

		public class _ht
		{            /* the hash table */
			public int count;               /* Number of entries with this hash */
			public HashElem chain;         /* Pointer to first entry with this hash */
		};

		public class Hash
		{
			public u32 htsize = 31;     /* Number of buckets in the hash table */
			public u32 count;           /* Number of entries in this table */
			public HashElem first;      /* The first element of the array */
			public _ht[] ht;

			public Hash Copy()
			{
				if (this == null)
					return null;
				else
				{
					Hash cp = (Hash)MemberwiseClone();
					return cp;
				}
			}
		};

		/* Each element in the hash table is an instance of the following
		** structure.  All elements are stored on a single doubly-linked list.
		**
		** Again, this structure is intended to be opaque, but it can't really
		** be opaque because it is used by macros.
		*/

		public class HashElem
		{
			public HashElem next;
			public HashElem prev;          /* Next and previous elements in the table */
			public object data;            /* Data associated with this element */
			public string pKey;
			public int nKey;               /* Key associated with this element */
		};

		/*
		** Access routines.  To delete, insert a NULL pointer.
		*/
		//void sqlite3HashInit(Hash);
		//void *sqlite3HashInsert(Hash*, string pKey, int nKey, object  *pData);
		//void *sqlite3HashFind(const Hash*, string pKey, int nKey);
		//void sqlite3HashClear(Hash);

		/*
		** Macros for looping over all elements of a hash table.  The idiom is
		** like this:
		**
		**   Hash h;
		**   HashElem p;
		**   ...
		**   for(p=sqliteHashFirst(&h); p; p=sqliteHashNext(p)){
		**     SomeStructure pData = sqliteHashData(p);
		**     // do something with pData
		**   }
		*/

		//#define sqliteHashFirst(H)  ((H).first)
		private static HashElem sqliteHashFirst(Hash H)
		{
			return H.first;
		}

		//#define sqliteHashNext(E)   ((E).next)
		private static HashElem sqliteHashNext(HashElem E)
		{
			return E.next;
		}

		//#define sqliteHashData(E)   ((E).data)
		private static object sqliteHashData(HashElem E)
		{
			return E.data;
		}

		/* #define sqliteHashKey(E)    ((E)->pKey) // NOT USED */
		/* #define sqliteHashKeysize(E) ((E)->nKey)  // NOT USED */

		/*
		** Number of entries in a hash table
		*/
		/* #define sqliteHashCount(H)  ((H)->count) // NOT USED */

		//#endif // * _SQLITE_HASH_H_ */
	}
}