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/**************************************************************************

 *

 * Copyright 2008 Tungsten Graphics, Inc., Cedar Park, Texas.

 * 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 TUNGSTEN GRAPHICS 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.

 *

 **************************************************************************/

/**

 * Key lookup/associative container.

 *

 * Like Jose's util_hash_table, based on CSO cache code for now.

 *

 * Author: Brian Paul

 */

#include "pipe/p_compiler.h"

#include "util/u_debug.h"

#include "cso_cache/cso_hash.h"

#include "util/u_memory.h"

#include "util/u_keymap.h"

struct keymap

{

   struct cso_hash *cso;

   unsigned key_size;

   unsigned max_entries; /* XXX not obeyed net */

   unsigned num_entries;

   keymap_delete_func delete_func;

};

struct keymap_item

{

   void *key, *value;

};

/**

 * This the default key-delete function used when the client doesn't

 * provide one.

 */

static void

default_delete_func(const struct keymap *map,

                    const void *key, void *data, void *user)

{

   FREE((void*) data);

}

static INLINE struct keymap_item *

hash_table_item(struct cso_hash_iter iter)

{

   return (struct keymap_item *) cso_hash_iter_data(iter);

}

/**

 * Return 4-byte hash key for a block of bytes.

 */

static unsigned

hash(const void *key, unsigned keySize)

{

   unsigned i, hash;

   keySize /= 4; /* convert from bytes to uints */

   hash = 0;

   for (i = 0; i < keySize; i++) {

      hash ^= (i + 1) * ((const unsigned *) key)[i];

   }

   /*hash = hash ^ (hash >> 11) ^ (hash >> 22);*/

   return hash;

}

/**

 * Create a new map.

 * \param keySize  size of the keys in bytes

 * \param maxEntries  max number of entries to allow (~0 = infinity)

 * \param deleteFunc  optional callback to call when entries

 *                    are deleted/replaced

 */

struct keymap *

util_new_keymap(unsigned keySize, unsigned maxEntries,

                 keymap_delete_func deleteFunc)

{

   struct keymap *map = MALLOC_STRUCT(keymap);

   if (!map)

      return NULL;

   map->cso = cso_hash_create();

   if (!map->cso) {

      FREE(map);

      return NULL;

   }

   map->max_entries = maxEntries;

   map->num_entries = 0;

   map->key_size = keySize;

   map->delete_func = deleteFunc ? deleteFunc : default_delete_func;

   return map;

}

/**

 * Delete/free a keymap and all entries.  The deleteFunc that was given at

 * create time will be called for each entry.

 * \param user  user-provided pointer passed through to the delete callback

 */

void

util_delete_keymap(struct keymap *map, void *user)

{

   util_keymap_remove_all(map, user);

   cso_hash_delete(map->cso);

   FREE(map);

}

static INLINE struct cso_hash_iter

hash_table_find_iter(const struct keymap *map, const void *key,

                     unsigned key_hash)

{

   struct cso_hash_iter iter;

   struct keymap_item *item;

   iter = cso_hash_find(map->cso, key_hash);

   while (!cso_hash_iter_is_null(iter)) {

      item = (struct keymap_item *) cso_hash_iter_data(iter);

      if (!memcmp(item->key, key, map->key_size))

         break;

      iter = cso_hash_iter_next(iter);

   }

   return iter;

}

static INLINE struct keymap_item *

hash_table_find_item(const struct keymap *map, const void *key,

                     unsigned key_hash)

{

   struct cso_hash_iter iter = hash_table_find_iter(map, key, key_hash);

   if (cso_hash_iter_is_null(iter)) {

      return NULL;

   }

   else {

      return hash_table_item(iter);

   }

}

/**

 * Insert a new key + data pointer into the table.

 * Note: we create a copy of the key, but not the data!

 * If the key is already present in the table, replace the existing

 * entry (calling the delete callback on the previous entry).

 * If the maximum capacity of the map is reached an old entry

 * will be deleted (the delete callback will be called).

 */

boolean

util_keymap_insert(struct keymap *map, const void *key,

                   const void *data, void *user)

{

   unsigned key_hash;

   struct keymap_item *item;

   struct cso_hash_iter iter;

   assert(map);

   if (!map)

      return FALSE;

   key_hash = hash(key, map->key_size);

   item = hash_table_find_item(map, key, key_hash);

   if (item) {

      /* call delete callback for old entry/item */

      map->delete_func(map, item->key, item->value, user);

      item->value = (void *) data;

      return TRUE;

   }

   item = MALLOC_STRUCT(keymap_item);

   if (!item)

      return FALSE;

   item->key = mem_dup(key, map->key_size);

   item->value = (void *) data;

   iter = cso_hash_insert(map->cso, key_hash, item);

   if (cso_hash_iter_is_null(iter)) {

      FREE(item);

      return FALSE;

   }

   map->num_entries++;

   return TRUE;

}

/**

 * Look up a key in the map and return the associated data pointer.

 */

const void *

util_keymap_lookup(const struct keymap *map, const void *key)

{

   unsigned key_hash;

   struct keymap_item *item;

   assert(map);

   if (!map)

      return NULL;

   key_hash = hash(key, map->key_size);

   item = hash_table_find_item(map, key, key_hash);

   if (!item)

      return NULL;

   return item->value;

}

/**

 * Remove an entry from the map.

 * The delete callback will be called if the given key/entry is found.

 * \param user  passed to the delete callback as the last param.

 */

void

util_keymap_remove(struct keymap *map, const void *key, void *user)

{

   unsigned key_hash;

   struct cso_hash_iter iter;

   struct keymap_item *item;

   assert(map);

   if (!map)

      return;

   key_hash = hash(key, map->key_size);

   iter = hash_table_find_iter(map, key, key_hash);

   if (cso_hash_iter_is_null(iter))

      return;

   item = hash_table_item(iter);

   assert(item);

   if (!item)

      return;

   map->delete_func(map, item->key, item->value, user);

   FREE(item->key);

   FREE(item);

   map->num_entries--;

   cso_hash_erase(map->cso, iter);

}

/**

 * Remove all entries from the map, calling the delete callback for each.

 * \param user  passed to the delete callback as the last param.

 */

void

util_keymap_remove_all(struct keymap *map, void *user)

{

   struct cso_hash_iter iter;

   struct keymap_item *item;

   assert(map);

   if (!map)

      return;

   iter = cso_hash_first_node(map->cso);

   while (!cso_hash_iter_is_null(iter)) {

      item = (struct keymap_item *)

         cso_hash_take(map->cso, cso_hash_iter_key(iter));

      map->delete_func(map, item->key, item->value, user);

      FREE(item->key);

      FREE(item);

      iter = cso_hash_first_node(map->cso);

   }

}

extern void

util_keymap_info(const struct keymap *map)

{

   debug_printf("Keymap %p: %u of max %u entries\n",

                (void *) map, map->num_entries, map->max_entries);

}