- Fixed bug that overwrote nodes in hash buckets instead of adding them to

Sat Jan 23 22:45:59 1999  Jeff Garzik  <jgarzik@pobox.com>

        * ghash.c (g_hash_table_lookup_node, g_hash_table_lookup,
                   g_hash_table_insert, g_hash_table_remove,
                   g_hash_table_lookup_extended):
          - Fixed bug that overwrote nodes in hash buckets instead of
            adding them to the hash bucket node list.
            Hash tables now work as advertised.

        (g_hash_table_resize):
          - Use g_new0 instead of manual init.
          - Space out code a bit for readability.

        (g_hash_nodes_destroy):
          - Replaced "if (!hash_node) return;" with
            "if (hash_node) {do stuff}".
            Testing takes up less code space than explicit call to
            'return' before end of function.  (look at gcc -S)

        Updated module header copyright to 1999.
        New module macro G_HASH_BUCKET for (table,key)->bucket lookups.

        * tests/hash-test.c:
        - Add two new tests, one with strings as the keys and values, and
          one with ints as the keys and values.  Tests indirect (strings)
          and direct (ints) hashing.
        - Cleanup unused junk left over from testglib.c.
        - Converted a g_print call to g_assert_not_reached.
        - Updated copyright to 1999.

        * testglib.c, tests/string-test.c:
        - Init 'tmp_string' var to NULL, silencing uninit-var warning.

ghash.c

@@ -1,5 +1,6 @@
 /* GLIB - Library of useful routines for C programming
  * Copyright (C) 1995-1997  Peter Mattis, Spencer Kimball and Josh MacDonald
+ * Copyright (C) 1999 The Free Software Foundation
  *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Library General Public
@@ -49,13 +50,17 @@ struct _GHashTable
 
 
 static void		g_hash_table_resize	 (GHashTable	*hash_table);
-static GHashNode**	g_hash_table_lookup_node (GHashTable	*hash_table,
-						  gconstpointer	 key);
+static GHashNode*	g_hash_table_lookup_node (GHashTable    *hash_table,
+						  gconstpointer  key,
+						  GHashNode    **last_p,
+						  guint	        *bucket_p);
 static GHashNode*	g_hash_node_new		 (gpointer	 key,
 						  gpointer	 value);
 static void		g_hash_node_destroy	 (GHashNode	*hash_node);
 static void		g_hash_nodes_destroy	 (GHashNode	*hash_node);
 
+#define G_HASH_BUCKET(table,key) \
+    ((* (table)->hash_func) (key) % (table)->size)
 
 G_LOCK_DECLARE_STATIC (g_hash_global);
 
@@ -98,14 +103,17 @@ g_hash_table_destroy (GHashTable *hash_table)
   g_free (hash_table);
 }
 
-static inline GHashNode**
-g_hash_table_lookup_node (GHashTable	*hash_table,
-			  gconstpointer	 key)
+static inline GHashNode*
+g_hash_table_lookup_node (GHashTable	 *hash_table,
+			  gconstpointer	  key,
+			  GHashNode	**last_p,
+			  guint		*bucket_p)
 {
-  GHashNode **node;
+  GHashNode *node, *last = NULL;
+  guint bucket;
   
-  node = &hash_table->nodes
-    [(* hash_table->hash_func) (key) % hash_table->size];
+  bucket = G_HASH_BUCKET (hash_table, key);
+  node = hash_table->nodes [bucket];
   
   /* Hash table lookup needs to be fast.
    *  We therefore remove the extra conditional of testing
@@ -113,12 +121,23 @@ g_hash_table_lookup_node (GHashTable	*hash_table,
    *  the inner loop.
    */
   if (hash_table->key_compare_func)
-    while (*node && !(*hash_table->key_compare_func) ((*node)->key, key))
-      node = &(*node)->next;
+    while (node && !(*hash_table->key_compare_func) (node->key, key))
+      {
+	last = node;
+        node = node->next;
+      }
   else
-    while (*node && (*node)->key != key)
-      node = &(*node)->next;
+    while (node && node->key != key)
+      {
+	last = node;
+        node = node->next;
+      }
   
+  if (last_p)
+    *last_p = last;
+  if (bucket_p)
+    *bucket_p = bucket;
+
   return node;
 }
 
@@ -130,7 +149,7 @@ g_hash_table_lookup (GHashTable	  *hash_table,
   
   g_return_val_if_fail (hash_table != NULL, NULL);
   
-  node = *g_hash_table_lookup_node (hash_table, key);
+  node = g_hash_table_lookup_node (hash_table, key, NULL, NULL);
   
   return node ? node->value : NULL;
 }
@@ -140,13 +159,27 @@ g_hash_table_insert (GHashTable *hash_table,
 		     gpointer	 key,
 		     gpointer	 value)
 {
-  GHashNode **node;
+  GHashNode *node, *last;
+  guint bucket;
   
   g_return_if_fail (hash_table != NULL);
+
+  node = g_hash_table_lookup_node (hash_table, key, &last, &bucket);
   
-  node = g_hash_table_lookup_node (hash_table, key);
-  
-  if (*node)
+  if (node == NULL)
+    {
+      node = g_hash_node_new (key, value);
+
+      if (last == NULL)
+        hash_table->nodes [bucket] = node;
+      else
+        last->next = node;
+
+      hash_table->nnodes++;
+      if (!hash_table->frozen)
+        g_hash_table_resize (hash_table);
+    }
+  else
     {
       /* do not reset node->key in this place, keeping
        * the old key might be intended.
@@ -154,35 +187,36 @@ g_hash_table_insert (GHashTable *hash_table,
        * can be used otherwise.
        *
        * node->key = key; */
-      (*node)->value = value;
-    }
-  else
-    {
-      *node = g_hash_node_new (key, value);
-      hash_table->nnodes++;
-      if (!hash_table->frozen)
-	g_hash_table_resize (hash_table);
+      node->value = value;
     }
+      
 }
 
 void
 g_hash_table_remove (GHashTable	     *hash_table,
 		     gconstpointer    key)
 {
-  GHashNode **node, *dest;
+  GHashNode *node, *last;
+  guint bucket;
   
   g_return_if_fail (hash_table != NULL);
   
-  while (*(node = g_hash_table_lookup_node (hash_table, key)))
+  node = g_hash_table_lookup_node (hash_table, key, &last, &bucket);
+
+  if (node)
     {
-      dest = *node;
-      (*node) = dest->next;
-      g_hash_node_destroy (dest);
+      if (last == NULL)
+          hash_table->nodes [bucket] = node->next;
+      else
+	  last->next = node->next;
+
+      g_hash_node_destroy (node);
+
       hash_table->nnodes--;
-    }
   
-  if (!hash_table->frozen)
-    g_hash_table_resize (hash_table);
+      if (!hash_table->frozen)
+        g_hash_table_resize (hash_table);
+    }
 }
 
 gboolean
@@ -195,7 +229,7 @@ g_hash_table_lookup_extended (GHashTable	*hash_table,
   
   g_return_val_if_fail (hash_table != NULL, FALSE);
   
-  node = *g_hash_table_lookup_node (hash_table, lookup_key);
+  node = g_hash_table_lookup_node (hash_table, lookup_key, NULL, NULL);
   
   if (node)
     {
@@ -320,16 +354,15 @@ g_hash_table_resize (GHashTable *hash_table)
   new_size = CLAMP(g_spaced_primes_closest (hash_table->nnodes),
 		   HASH_TABLE_MIN_SIZE,
 		   HASH_TABLE_MAX_SIZE);
-  new_nodes = g_new (GHashNode*, new_size);
-  
-  for (i = 0; i < new_size; i++)
-    new_nodes[i] = NULL;
+  new_nodes = g_new0 (GHashNode*, new_size);
   
   for (i = 0; i < hash_table->size; i++)
     for (node = hash_table->nodes[i]; node; node = next)
       {
 	next = node->next;
+
 	hash_val = (* hash_table->hash_func) (node->key) % new_size;
+
 	node->next = new_nodes[hash_val];
 	new_nodes[hash_val] = node;
       }
@@ -381,18 +414,16 @@ g_hash_node_destroy (GHashNode *hash_node)
 static void
 g_hash_nodes_destroy (GHashNode *hash_node)
 {
-  GHashNode *node;
+  if (hash_node)
+    {
+      GHashNode *node = hash_node;
   
-  if (!hash_node)
-    return;
+      while (node->next)
+        node = node->next;
   
-  node = hash_node;
-  
-  while (node->next)
-    node = node->next;
-  
-  G_LOCK (g_hash_global);
-  node->next = node_free_list;
-  node_free_list = hash_node;
-  G_UNLOCK (g_hash_global);
+      G_LOCK (g_hash_global);
+      node->next = node_free_list;
+      node_free_list = hash_node;
+      G_UNLOCK (g_hash_global);
+    }
 }