/**************************************************************************
*
- * Copyright 2007 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * Copyright 2007 VMware, Inc.
* All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a
* 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 TUNGSTEN GRAPHICS AND/OR ITS SUPPLIERS BE LIABLE FOR
+ * 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.
*
**************************************************************************/
- /*
- * Authors:
- * Zack Rusin <zack@tungstengraphics.com>
- */
+/**
+ * @file
+ * Hash table implementation.
+ *
+ * This file provides a hash implementation that is capable of dealing
+ * with collisions. It stores colliding entries in linked list. All
+ * functions operating on the hash return an iterator. The iterator
+ * itself points to the collision list. If there wasn't any collision
+ * the list will have just one entry, otherwise client code should
+ * iterate over the entries to find the exact entry among ones that
+ * had the same key (e.g. memcmp could be used on the data to check
+ * that)
+ *
+ * @author Zack Rusin <zackr@vmware.com>
+ */
#ifndef CSO_HASH_H
#define CSO_HASH_H
-struct cso_hash;
-struct cso_node;
+#include "pipe/p_compiler.h"
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+
+struct cso_node {
+ struct cso_node *next;
+ void *value;
+ unsigned key;
+};
struct cso_hash_iter {
struct cso_hash *hash;
struct cso_node *node;
};
-struct cso_hash *cso_hash_create(void);
-void cso_hash_delete(struct cso_hash *hash);
+struct cso_hash {
+ struct cso_node *fakeNext;
+ struct cso_node **buckets;
+ struct cso_node *end;
+ int size;
+ short userNumBits;
+ short numBits;
+ int numBuckets;
+};
+
+void cso_hash_init(struct cso_hash *hash);
+void cso_hash_deinit(struct cso_hash *hash);
+
+int cso_hash_size(struct cso_hash *hash);
+
+
+/**
+ * Adds a data with the given key to the hash. If entry with the given
+ * key is already in the hash, this current entry is instered before it
+ * in the collision list.
+ * Function returns iterator pointing to the inserted item in the hash.
+ */
struct cso_hash_iter cso_hash_insert(struct cso_hash *hash, unsigned key,
void *data);
-void *cso_hash_take(struct cso_hash *hash, unsigned key);
+/**
+ * Removes the item pointed to by the current iterator from the hash.
+ * Note that the data itself is not erased and if it was a malloc'ed pointer
+ * it will have to be freed after calling this function by the callee.
+ * Function returns iterator pointing to the item after the removed one in
+ * the hash.
+ */
+struct cso_hash_iter cso_hash_erase(struct cso_hash *hash, struct cso_hash_iter iter);
+
+void *cso_hash_take(struct cso_hash *hash, unsigned key);
+
+
struct cso_hash_iter cso_hash_first_node(struct cso_hash *hash);
-struct cso_hash_iter cso_hash_find(struct cso_hash *hash, unsigned key);
+/**
+ * Returns true if a value with the given key exists in the hash
+ */
+bool cso_hash_contains(struct cso_hash *hash, unsigned key);
+
+
+unsigned cso_hash_iter_key(struct cso_hash_iter iter);
-int cso_hash_iter_is_null(struct cso_hash_iter iter);
-unsigned cso_hash_iter_key(struct cso_hash_iter iter);
-void *cso_hash_iter_data(struct cso_hash_iter iter);
-struct cso_hash_iter cso_hash_iter_next(struct cso_hash_iter iter);
struct cso_hash_iter cso_hash_iter_prev(struct cso_hash_iter iter);
+
+/**
+ * Convenience routine to iterate over the collision list while doing a memory
+ * comparison to see which entry in the list is a direct copy of our template
+ * and returns that entry.
+ */
+void *cso_hash_find_data_from_template(struct cso_hash *hash,
+ unsigned hash_key,
+ void *templ,
+ int size);
+
+struct cso_node *cso_hash_data_next(struct cso_node *node);
+
+static inline bool
+cso_hash_iter_is_null(struct cso_hash_iter iter)
+{
+ return !iter.node || iter.node == iter.hash->end;
+}
+
+static inline void *
+cso_hash_iter_data(struct cso_hash_iter iter)
+{
+ if (!iter.node || iter.hash->end == iter.node)
+ return NULL;
+ return iter.node->value;
+}
+
+static inline struct cso_node **
+cso_hash_find_node(struct cso_hash *hash, unsigned akey)
+{
+ struct cso_node **node;
+
+ if (hash->numBuckets) {
+ node = &hash->buckets[akey % hash->numBuckets];
+ assert(*node == hash->end || (*node)->next);
+ while (*node != hash->end && (*node)->key != akey)
+ node = &(*node)->next;
+ } else {
+ node = &hash->end;
+ }
+ return node;
+}
+
+/**
+ * Return an iterator pointing to the first entry in the collision list.
+ */
+static inline struct cso_hash_iter
+cso_hash_find(struct cso_hash *hash, unsigned key)
+{
+ struct cso_node **nextNode = cso_hash_find_node(hash, key);
+ struct cso_hash_iter iter = {hash, *nextNode};
+ return iter;
+}
+
+static inline struct cso_hash_iter
+cso_hash_iter_next(struct cso_hash_iter iter)
+{
+ struct cso_hash_iter next = {iter.hash, cso_hash_data_next(iter.node)};
+ return next;
+}
+
+#ifdef __cplusplus
+}
+#endif
+
#endif
projects / mesa.git / blobdiff