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/*

 * Copyright © 2008 Intel Corporation

 *

 * 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, sublicense,

 * 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 NONINFRINGEMENT.  IN NO EVENT SHALL

 * THE AUTHORS OR COPYRIGHT HOLDERS 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 hash_table.c

 * \brief Implementation of a generic, opaque hash table data type.

 *

 * \author Ian Romanick 

 */

#include "main/imports.h"

#include "util/simple_list.h"

#include "hash_table.h"

struct node {

   struct node *next;

   struct node *prev;

};

struct hash_table {

    hash_func_t    hash;

    hash_compare_func_t  compare;

    unsigned num_buckets;

    struct node buckets[1];

};

struct hash_node {

    struct node link;

    const void *key;

    void *data;

};

struct hash_table *

hash_table_ctor(unsigned num_buckets, hash_func_t hash,

                hash_compare_func_t compare)

{

    struct hash_table *ht;

    unsigned i;

    if (num_buckets < 16) {

        num_buckets = 16;

    }

    ht = malloc(sizeof(*ht) + ((num_buckets - 1)

				     * sizeof(ht->buckets[0])));

    if (ht != NULL) {

        ht->hash = hash;

        ht->compare = compare;

        ht->num_buckets = num_buckets;

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

            make_empty_list(& ht->buckets[i]);

        }

    }

    return ht;

}

void

hash_table_dtor(struct hash_table *ht)

{

   hash_table_clear(ht);

   free(ht);

}

void

hash_table_clear(struct hash_table *ht)

{

   struct node *node;

   struct node *temp;

   unsigned i;

   for (i = 0; i < ht->num_buckets; i++) {

      foreach_s(node, temp, & ht->buckets[i]) {

	 remove_from_list(node);

	 free(node);

      }

      assert(is_empty_list(& ht->buckets[i]));

   }

}

static struct hash_node *

get_node(struct hash_table *ht, const void *key)

{

    const unsigned hash_value = (*ht->hash)(key);

    const unsigned bucket = hash_value % ht->num_buckets;

    struct node *node;

    foreach(node, & ht->buckets[bucket]) {

       struct hash_node *hn = (struct hash_node *) node;

       if ((*ht->compare)(hn->key, key) == 0) {

	  return hn;

       }

    }

    return NULL;

}

void *

hash_table_find(struct hash_table *ht, const void *key)

{

   struct hash_node *hn = get_node(ht, key);

   return (hn == NULL) ? NULL : hn->data;

}

void

hash_table_insert(struct hash_table *ht, void *data, const void *key)

{

    const unsigned hash_value = (*ht->hash)(key);

    const unsigned bucket = hash_value % ht->num_buckets;

    struct hash_node *node;

    node = calloc(1, sizeof(*node));

    if (node == NULL) {

       _mesa_error_no_memory(__func__);

       return;

    }

    node->data = data;

    node->key = key;

    insert_at_head(& ht->buckets[bucket], & node->link);

}

bool

hash_table_replace(struct hash_table *ht, void *data, const void *key)

{

    const unsigned hash_value = (*ht->hash)(key);

    const unsigned bucket = hash_value % ht->num_buckets;

    struct node *node;

    struct hash_node *hn;

    foreach(node, & ht->buckets[bucket]) {

       hn = (struct hash_node *) node;

       if ((*ht->compare)(hn->key, key) == 0) {

	  hn->data = data;

	  return true;

       }

    }

    hn = calloc(1, sizeof(*hn));

    if (hn == NULL) {

       _mesa_error_no_memory(__func__);

       return false;

    }

    hn->data = data;

    hn->key = key;

    insert_at_head(& ht->buckets[bucket], & hn->link);

    return false;

}

void

hash_table_remove(struct hash_table *ht, const void *key)

{

   struct node *node = (struct node *) get_node(ht, key);

   if (node != NULL) {

      remove_from_list(node);

      free(node);

      return;

   }

}

void

hash_table_call_foreach(struct hash_table *ht,

			void (*callback)(const void *key,

					 void *data,

					 void *closure),

			void *closure)

{

   unsigned bucket;

   for (bucket = 0; bucket < ht->num_buckets; bucket++) {

      struct node *node, *temp;

      foreach_s(node, temp, &ht->buckets[bucket]) {

	 struct hash_node *hn = (struct hash_node *) node;

	 callback(hn->key, hn->data, closure);

      }

   }

}

unsigned

hash_table_string_hash(const void *key)

{

    const char *str = (const char *) key;

    unsigned hash = 5381;

    while (*str != '\0') {

        hash = (hash * 33) + *str;

        str++;

    }

    return hash;

}

unsigned

hash_table_pointer_hash(const void *key)

{

   return (unsigned)((uintptr_t) key / sizeof(void *));

}

int

hash_table_pointer_compare(const void *key1, const void *key2)

{

   return key1 == key2 ? 0 : 1;

}