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/*
* Copyright (C) 2007 The Android Open Source Project
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#ifndef __HASHMAP_H
#define __HASHMAP_H
#include <stdbool.h>
#include <stdint.h>
#include <stdlib.h>
#if defined(__amd64__) || defined(__aarch64__)
#define ARCH64
#else
#define ARCH32
#endif
#if defined(ARCH64)
typedef int64_t hash_t;
typedef uint64_t uhash_t;
#elif defined(ARCH32)
typedef int32_t hash_t;
typedef uint32_t uhash_t;
#endif
/** A hash map. */
typedef struct Hashmap Hashmap;
/**
* Creates a new hash map. Returns NULL if memory allocation fails.
*
* @param initialCapacity number of expected entries
* @param hash function which hashes keys
* @param equals function which compares keys for equality
*/
Hashmap *hashmap_create(size_t initialCapacity, hash_t (*hash)(void *key),
bool (*equals)(void *keyA, void *keyB));
/**
* Frees the hash map. Does not free the keys or values themselves.
*/
void hashmap_free(Hashmap *map);
/**
* Hashes the memory pointed to by key with the given size. Useful for
* implementing hash functions.
*/
hash_t hashmap_hash(void *key, size_t keySize);
/**
* Puts value for the given key in the map. Returns pre-existing value if
* any, otherwise it returns the given value.
*
* If memory allocation fails, this function returns NULL, the map's size
* does not increase, and errno is set to ENOMEM.
*/
void *hashmap_put(Hashmap *map, void *key, void *value);
/**
* Gets a value from the map. Returns NULL if no entry for the given key is
* found or if the value itself is NULL.
*/
void *hashmap_get(Hashmap *map, void *key);
/**
* Returns true if the map contains an entry for the given key.
*/
bool hashmap_contains_key(Hashmap *map, void *key);
/**
* Gets the value for a key. If a value is not found, this function gets a
* value and creates an entry using the given callback.
*
* If memory allocation fails, the callback is not called, this function
* returns NULL, and errno is set to ENOMEM.
*/
void *hashmap_memoize(Hashmap *map, void *key, void *(*initialValue)(void *key, void *context),
void *context);
/**
* Removes an entry from the map. Returns the removed value or NULL if no
* entry was present.
*/
void *hashmap_remove(Hashmap *map, void *key);
/**
* Gets the number of entries in this map.
*/
size_t hashmap_size(Hashmap *map);
/**
* Invokes the given callback on each entry in the map. Stops iterating if
* the callback returns false.
*/
void hashmap_for_each(Hashmap *map, bool (*callback)(void *key, void *value, void *context),
void *context);
/**
* Concurrency support.
*/
/**
* Locks the hash map so only the current thread can access it.
*/
void hashmap_lock(Hashmap *map);
/**
* Unlocks the hash map so other threads can access it.
*/
void hashmap_unlock(Hashmap *map);
/**
* Key utilities.
*/
hash_t hashmap_default_hash(void *key);
/**
* Compares two keys for equality.
*/
bool hashmap_default_equals(void *keyA, void *keyB);
/**
* Gets current capacity.
*/
size_t hashmap_current_capacity(Hashmap *map);
/**
* Counts the number of entry collisions.
*/
size_t hashmap_count_collisions(Hashmap *map);
/**
* Key utilities - use pointer as key.
*/
hash_t hashmap_ptr_hash(void *key);
/**
* Compares two pointers for equality.
*/
bool hashmap_ptr_equals(void *keyA, void *keyB);
#endif /* __HASHMAP_H */
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