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/*
* Copyright © 2009,2021 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.
*
* Authors:
* Eric Anholt <eric@anholt.net>
*
*/
#ifndef IGT_MAP_H
#define IGT_MAP_H
#include <inttypes.h>
/**
* SECTION:igt_map
* @short_description: a linear-reprobing hashmap implementation
* @title: IGT Map
* @include: igt_map.h
*
* Implements an open-addressing, linear-reprobing hash table.
*
* For more information, see:
* http://cgit.freedesktop.org/~anholt/hash_table/tree/README
*
* Example usage:
*
*|[<!-- language="C" -->
* #define GOLDEN_RATIO_PRIME_32 0x9e370001UL
*
* static inline uint32_t hash_identifier(const void *val)
* {
* uint32_t hash = *(uint32_t *) val;
*
* hash = hash * GOLDEN_RATIO_PRIME_32;
* return hash;
* }
*
* static int equal_identifiers(const void *a, const void *b)
* {
* uint32_t *key1 = (uint32_t *) a, *key2 = (uint32_t *) b;
*
* return *key1 == *key2;
* }
*
* static void free_func(struct igt_map_entry *entry)
* {
* free(entry->data);
* }
*
* struct igt_map *map;
*
* struct record {
* int foo;
* uint32_t unique_identifier;
* };
*
* struct record *r1, r2, *record;
* struct igt_map_entry *entry;
*
* r1 = malloc(sizeof(struct record));
* map = igt_map_create(hash_identifier, equal_identifiers);
* igt_map_insert(map, &r1->unique_identifier, r1);
* igt_map_insert(map, &r2.unique_identifier, &r2);
*
* igt_map_foreach(map, entry) {
* record = entry->data;
* printf("key: %u, foo: %d\n", *(uint32_t *) entry->key, record->foo);
* }
*
* record = igt_map_search(map, &r1->unique_identifier);
* entry = igt_map_search_entry(map, &r2.unique_identifier);
*
* igt_map_remove(map, &r1->unique_identifier, free_func);
* igt_map_remove_entry(map, entry);
*
* igt_map_destroy(map, NULL);
* ]|
*/
struct igt_map_entry {
uint32_t hash;
const void *key;
void *data;
};
struct igt_map {
struct igt_map_entry *table;
uint32_t (*hash_function)(const void *key);
int (*key_equals_function)(const void *a, const void *b);
uint32_t size;
uint32_t rehash;
uint32_t max_entries;
uint32_t size_index;
uint32_t entries;
uint32_t deleted_entries;
};
struct igt_map *
igt_map_create(uint32_t (*hash_function)(const void *key),
int (*key_equals_function)(const void *a, const void *b));
void
igt_map_destroy(struct igt_map *map,
void (*delete_function)(struct igt_map_entry *entry));
struct igt_map_entry *
igt_map_insert(struct igt_map *map, const void *key, void *data);
void *
igt_map_search(struct igt_map *map, const void *key);
struct igt_map_entry *
igt_map_search_entry(struct igt_map *map, const void *key);
void
igt_map_remove(struct igt_map *map, const void *key,
void (*delete_function)(struct igt_map_entry *entry));
void
igt_map_remove_entry(struct igt_map *map, struct igt_map_entry *entry);
struct igt_map_entry *
igt_map_next_entry(struct igt_map *map, struct igt_map_entry *entry);
struct igt_map_entry *
igt_map_random_entry(struct igt_map *map,
int (*predicate)(struct igt_map_entry *entry));
/**
* igt_map_foreach
* @map: igt_map pointer
* @entry: igt_map_entry pointer
*
* Macro is a loop, which iterates through each map entry. Inside a
* loop block current element is accessible by the @entry pointer.
*
* This foreach function is safe against deletion (which just replaces
* an entry's data with the deleted marker), but not against insertion
* (which may rehash the table, making entry a dangling pointer).
*/
#define igt_map_foreach(map, entry) \
for (entry = igt_map_next_entry(map, NULL); \
entry != NULL; \
entry = igt_map_next_entry(map, entry))
/* Alternate interfaces to reduce repeated calls to hash function. */
struct igt_map_entry *
igt_map_search_pre_hashed(struct igt_map *map,
uint32_t hash,
const void *key);
struct igt_map_entry *
igt_map_insert_pre_hashed(struct igt_map *map,
uint32_t hash,
const void *key, void *data);
#endif
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