g_hash_table_steal_extended()

[Ken Ishii <keni4i yahoo com>]

Hi,

When you want to steal a key/value pair from a GHashTable and at the same time
retrieve the pair's value, doing something like

value = g_hash_table_lookup (hash_table, key);
g_hash_table_steal (hash_table, key);

requires hashing the same key twice. So instead, something like

if (g_hash_table_steal_extended (hash_table, key, &value))
{
  /* pair stolen, value retrieved */
}

would be more efficient. The behavior of this new function is similar to that
of Java's Hashtable::remove(). The implementation is pasted below.

Just my two cents,
Ken

Index: glib/ghash.c
===================================================================
RCS file: /cvs/gnome/glib/glib/ghash.c,v
retrieving revision 1.47
diff -u -r1.47 ghash.c
--- glib/ghash.c        1 Jun 2006 14:16:39 -0000       1.47
+++ glib/ghash.c        18 Nov 2006 18:22:49 -0000
@@ -509,6 +509,35 @@
   return FALSE;
 }
 
+gboolean
+g_hash_table_steal_extended (GHashTable    *hash_table,
+                             gconstpointer  key,
+                             gpointer      *value)
+{
+  GHashNode **node, *dest;
+  
+  g_return_val_if_fail (hash_table != NULL, FALSE);
+  
+  node = g_hash_table_lookup_node (hash_table, key);
+  if (*node)
+    {
+      dest = *node;
+
+      if (value != NULL)
+        *value = dest->value;
+
+      (*node) = dest->next;
+      g_hash_node_destroy (dest, NULL, NULL);
+      hash_table->nnodes--;
+  
+      G_HASH_TABLE_RESIZE (hash_table);
+
+      return TRUE;
+    }
+
+  return FALSE;
+}
+
 /**
  * g_hash_table_steal_all:
  * @hash_table: a #GHashTable.




 
____________________________________________________________________________________
Sponsored Link

$420k for $1,399/mo. 
Think You Pay Too Much For Your Mortgage? 
Find Out! www.LowerMyBills.com/lre