X-Git-Url: https://git.libre-soc.org/?a=blobdiff_plain;f=src%2Fgallium%2Fauxiliary%2Fcso_cache%2Fcso_hash.h;h=d6eeb04f1ac8e3e966b8cfa80c855ed4e5733043;hb=d8db5986cee83078e46895d695d698db87507019;hp=d5bca9d591114b658db514ff2418b6783e56e41f;hpb=7838aaffdb9d34427ebcb73aac585c85d9622018;p=mesa.git

diff --git a/src/gallium/auxiliary/cso_cache/cso_hash.h b/src/gallium/auxiliary/cso_cache/cso_hash.h
index d5bca9d5911..d6eeb04f1ac 100644
--- a/src/gallium/auxiliary/cso_cache/cso_hash.h
+++ b/src/gallium/auxiliary/cso_cache/cso_hash.h
@@ -1,6 +1,6 @@
 /**************************************************************************
  *
- * 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
@@ -18,62 +18,131 @@
  * 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
 
+#include "pipe/p_compiler.h"
 
 #ifdef	__cplusplus
 extern "C" {
 #endif
 
-struct cso_hash;
-struct cso_node;
+
+struct cso_node {
+   struct cso_node *next;
+   unsigned key;
+   void *value;
+};
+
+struct cso_hash {
+   union {
+      struct cso_hash_data *d;
+      struct cso_node      *e;
+   } data;
+};
 
 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);
 
+
 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);
+/**
+ * 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);
+
+/**
+ * Return an iterator pointing to the first entry in the collision list.
+ */
 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
+ */
+boolean   cso_hash_contains(struct cso_hash *hash, unsigned key);
+
 
-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);
 
 
-/* KW: a convenience routine: 
+/**
+ * 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, 
+				        unsigned hash_key,
 				        void *templ,
 				        int size );
 
+static inline int
+cso_hash_iter_is_null(struct cso_hash_iter iter)
+{
+   if (!iter.node || iter.node == iter.hash->data.e)
+      return 1;
+   return 0;
+}
+
+static inline void *
+cso_hash_iter_data(struct cso_hash_iter iter)
+{
+   if (!iter.node || iter.hash->data.e == iter.node)
+      return 0;
+   return iter.node->value;
+}
 
 #ifdef	__cplusplus
 }