gallium: Simple and efficient cache.

Fixed size hash table. Collisions are handled by simply destroying the
previous entry.

It hasn't received much testing yet.

1 files changed, 87 insertions, 0 deletions

diff --git a/src/gallium/auxiliary/util/u_cache.h b/src/gallium/auxiliary/util/u_cache.h
new file mode 100644
index 00000000000..835e0837349
--- /dev/null
+++ b/src/gallium/auxiliary/util/u_cache.h
@@ -0,0 +1,87 @@
+/**************************************************************************
+ *
+ * Copyright 2008 VMware, Inc.
+ * All Rights Reserved.
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a
+ * copy of this software and associated documentation files (the
+ * "Software"), to deal in the Software without restriction, including
+ * without limitation the rights to use, copy, modify, merge, publish,
+ * distribute, sub license, and/or sell copies of the Software, and to
+ * permit persons to whom the Software is furnished to do so, subject to
+ * the following conditions:
+ *
+ * The above copyright notice and this permission notice (including the
+ * next paragraph) shall be included in all copies or substantial portions
+ * of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS
+ * OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
+ * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT.
+ * IN NO EVENT SHALL VMWARE AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,
+ * TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE
+ * SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
+ *
+ **************************************************************************/
+
+/**
+ * @file
+ * Simple cache.
+ *
+ * @author Jose Fonseca <[email protected]>
+ */
+
+#ifndef U_CACHE_H_
+#define U_CACHE_H_
+
+
+#include "pipe/p_compiler.h"
+
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+   
+/**
+ * Least Recently Used (LRU) cache.
+ */
+struct util_cache;
+
+
+/**
+ * Create a cache.
+ * 
+ * @param hash hash function
+ * @param compare should return 0 for two equal keys
+ * @param destroy destruction callback (optional)
+ * @param size maximum number of entries
+ */
+struct util_cache *
+util_cache_create(uint32_t (*hash)(void *key),
+                int (*compare)(void *key1, void *key2),
+                void (*destroy)(void *key, void *value),
+                uint32_t size);
+
+void
+util_cache_set(struct util_cache *cache,
+             void *key,
+             void *value);
+
+void *
+util_cache_get(struct util_cache *cache, 
+             void *key);
+
+void
+util_cache_clear(struct util_cache *cache);
+
+void
+util_cache_destroy(struct util_cache *cache);
+
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* U_CACHE_H_ */