1 files changed, 128 insertions, 0 deletions
diff --git a/util/cache.c b/util/cache.c
new file mode 100644
index 0000000..1fc8a8d
--- /dev/null
+++ b/util/cache.c
@@ -0,0 +1,128 @@
+/* -*- Mode: C; tab-width: 8; indent-tabs-mode: t; c-basic-offset: 8 -*- */
+/*  GMime
+ *  Copyright (C) 2000-2012 Jeffrey Stedfast
+ *
+ *  This library is free software; you can redistribute it and/or
+ *  modify it under the terms of the GNU Lesser General Public License
+ *  as published by the Free Software Foundation; either version 2.1
+ *  of the License, or (at your option) any later version.
+ *
+ *  This library is distributed in the hope that it will be useful,
+ *  but WITHOUT ANY WARRANTY; without even the implied warranty of
+ *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ *  Lesser General Public License for more details.
+ *
+ *  You should have received a copy of the GNU Lesser General Public
+ *  License along with this library; if not, write to the Free
+ *  Software Foundation, 51 Franklin Street, Fifth Floor, Boston, MA
+ *  02110-1301, USA.
+ */
+
+
+#ifdef HAVE_CONFIG_H
+#include <config.h>
+#endif
+
+#include "cache.h"
+
+
+static void
+cache_node_free (gpointer node_data)
+{
+	CacheNode *node = (CacheNode *) node_data;
+	Cache *cache = node->cache;
+	
+	cache->free_node (node);
+	g_free (node->key);
+	
+	g_slice_free1 (cache->node_size, node);
+}
+
+
+Cache *
+cache_new (CacheNodeExpireFunc expire, CacheNodeFreeFunc free_node, size_t node_size, size_t max_size)
+{
+	Cache *cache;
+	
+	cache = g_new (Cache, 1);
+	list_init (&cache->list);
+	cache->expire = expire;
+	cache->free_node = free_node;
+	cache->node_hash = g_hash_table_new_full (g_str_hash, g_str_equal, NULL, cache_node_free);
+	cache->node_size = node_size;
+	cache->max_size = max_size;
+	cache->size = 0;
+	
+	return cache;
+}
+
+
+void
+cache_free (Cache *cache)
+{
+	g_hash_table_destroy (cache->node_hash);
+	g_free (cache);
+}
+
+
+void
+cache_expire_unused (Cache *cache)
+{
+	ListNode *node, *prev;
+	
+	node = cache->list.tailpred;
+	while (node->prev && cache->size > cache->max_size) {
+		prev = node->prev;
+		if (cache->expire (cache, (CacheNode *) node)) {
+			list_unlink (node);
+			g_hash_table_remove (cache->node_hash, ((CacheNode *) node)->key);
+			cache->size--;
+		}
+		node = prev;
+	}
+}
+
+CacheNode *
+cache_node_insert (Cache *cache, const char *key)
+{
+	CacheNode *node;
+	
+	cache->size++;
+	
+	if (cache->size > cache->max_size)
+		cache_expire_unused (cache);
+	
+	node = g_slice_alloc (cache->node_size);
+	node->key = g_strdup (key);
+	node->cache = cache;
+	
+	g_hash_table_insert (cache->node_hash, node->key, node);
+	list_prepend (&cache->list, (ListNode *) node);
+	
+	return node;
+}
+
+CacheNode *
+cache_node_lookup (Cache *cache, const char *key, gboolean use)
+{
+	CacheNode *node;
+	
+	node = g_hash_table_lookup (cache->node_hash, key);
+	if (node && use) {
+		list_unlink ((ListNode *) node);
+		list_prepend (&cache->list, (ListNode *) node);
+	}
+	
+	return node;
+}
+
+void
+cache_node_expire (CacheNode *node)
+{
+	Cache *cache;
+	
+	cache = node->cache;
+	list_unlink ((ListNode *) node);
+	g_hash_table_remove (cache->node_hash, node->key);
+	cache->size--;
+}