From ecd6fe37015c39b8b0f2293984fb67d49e482a97 Mon Sep 17 00:00:00 2001
From: Jim Nelson <jim@yorba.org>
Date: Tue, 3 Sep 2013 14:53:32 -0700
Subject: [PATCH] Small fixes discovered while working on #7426

MessageIntData doesn't need to be so sophisticated about calculating
a hash; slight optimization to the hash_memory() function.
---
 src/engine/common/common-message-data.vala |  7 +-----
 src/engine/util/util-collection.vala       | 28 +++++++---------------
 2 files changed, 10 insertions(+), 25 deletions(-)

diff --git a/src/engine/common/common-message-data.vala b/src/engine/common/common-message-data.vala
index ea79fb4e..d716e2f7 100644
--- a/src/engine/common/common-message-data.vala
+++ b/src/engine/common/common-message-data.vala
@@ -66,21 +66,16 @@ public abstract class Geary.MessageData.IntMessageData : AbstractMessageData,
     Gee.Hashable<IntMessageData> {
     public int value { get; private set; }
     
-    private uint stored_hash = uint.MAX;
-    
     public IntMessageData(int value) {
         this.value = value;
     }
     
     public virtual bool equal_to(IntMessageData other) {
-        if (this == other)
-            return true;
-        
         return (value == other.value);
     }
     
     public virtual uint hash() {
-        return (stored_hash != uint.MAX) ? stored_hash : (stored_hash = int_hash(value));
+        return value;
     }
     
     public override string to_string() {
diff --git a/src/engine/util/util-collection.vala b/src/engine/util/util-collection.vala
index 64e09580..042526f5 100644
--- a/src/engine/util/util-collection.vala
+++ b/src/engine/util/util-collection.vala
@@ -106,32 +106,22 @@ public Gee.MultiMap<V, K> reverse_multi_map<K, V>(Gee.MultiMap<K, V> map) {
 /**
  * To be used by a Hashable's to_hash() method.
  */
-public static uint int64_hash(int64 value) {
+public inline static uint int64_hash(int64 value) {
     return hash_memory(&value, sizeof(int64));
 }
 
 /**
- * To be used as a raw HashFunc where an int64 is being stored directly.
- */
-public static uint bare_int64_hash(void *ptr) {
-    return hash_memory(ptr, sizeof(int64));
-}
-
-/**
- * A HashFunc for DateTime.
- */
-public static uint date_time_hash(void *a) {
-    return ((DateTime) a).hash();
-}
-
-/**
- * A rotating-XOR hash that can be used to hash memory buffers of any size.  Use only if
- * equality is determined by memory contents.
+ * A rotating-XOR hash that can be used to hash memory buffers of any size.
  */
 public static uint hash_memory(void *ptr, size_t bytes) {
+    if (bytes == 0)
+        return 0;
+    
     uint8 *u8 = (uint8 *) ptr;
-    uint hash = 0;
-    for (int ctr = 0; ctr < bytes; ctr++)
+    
+    // initialize hash to first byte value and then rotate-XOR from there
+    uint hash = *u8;
+    for (int ctr = 1; ctr < bytes; ctr++)
         hash = (hash << 4) ^ (hash >> 28) ^ (*u8++);
     
     return hash;