| /****************************************************************************** |
| * |
| * Copyright (C) 2014 Google, Inc. |
| * |
| * 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. |
| * |
| ******************************************************************************/ |
| |
| #pragma once |
| |
| #include <stdbool.h> |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| struct hash_map_t; |
| typedef struct hash_map_t hash_map_t; |
| |
| typedef struct hash_map_entry_t { |
| const void *key; |
| void *data; |
| const hash_map_t *hash_map; |
| } hash_map_entry_t; |
| |
| typedef size_t hash_index_t; |
| |
| // Takes a key structure and returns a hash value. |
| typedef hash_index_t (*hash_index_fn)(const void *key); |
| typedef bool (*hash_map_iter_cb)(hash_map_entry_t *hash_entry, void *context); |
| |
| typedef bool (*key_equality_fn)(const void *x, const void *y); |
| |
| typedef void (*key_free_fn)(void *key); |
| typedef void (*data_free_fn)(void *data); |
| |
| // Returns a new, empty hash_map. Returns NULL if not enough memory could be allocated |
| // for the hash_map structure. The returned hash_map must be freed with |hash_map_free|. |
| // The |num_bucket| specifies the number of hashable buckets for the map and must not |
| // be zero. The |hash_fn| specifies a hash function to be used and must not be NULL. |
| // The |key_fn| and |data_fn| are called whenever a hash_map element is removed from |
| // the hash_map. They can be used to release resources held by the hash_map element, |
| // e.g. memory or file descriptor. |key_fn| and |data_fn| may be NULL if no cleanup |
| // is necessary on element removal. |equality_fn| is used to check for key equality. |
| // If |equality_fn| is NULL, default pointer equality is used. |
| hash_map_t *hash_map_new( |
| size_t size, |
| hash_index_fn hash_fn, |
| key_free_fn key_fn, |
| data_free_fn data_fn, |
| key_equality_fn equality_fn); |
| |
| // Frees the hash_map. This function accepts NULL as an argument, in which case it |
| // behaves like a no-op. |
| void hash_map_free(hash_map_t *hash_map); |
| |
| // Returns true if the hash_map is empty (has no elements), false otherwise. |
| // Note that a NULL |hash_map| is not the same as an empty |hash_map|. This function |
| // does not accept a NULL |hash_map|. |
| bool hash_map_is_empty(const hash_map_t *hash_map); |
| |
| // Returns the number of elements in the hash map. This function does not accept a |
| // NULL |hash_map|. |
| size_t hash_map_size(const hash_map_t *hash_map); |
| |
| // Returns the number of buckets in the hash map. This function does not accept a |
| // NULL |hash_map|. |
| size_t hash_map_num_buckets(const hash_map_t *hash_map); |
| |
| // Returns true if the hash_map has a valid entry for the presented key. |
| // This function does not accept a NULL |hash_map|. |
| bool hash_map_has_key(const hash_map_t *hash_map, const void *key); |
| |
| // Returns the element indexed by |key| in the hash_map without removing it. |hash_map| |
| // may not be NULL. Returns NULL if no entry indexed by |key|. |
| void *hash_map_get(const hash_map_t *hash_map, const void *key); |
| |
| // Sets the value |data| indexed by |key| into the |hash_map|. Neither |data| nor |
| // |hash_map| may be NULL. This function does not make copies of |data| nor |key| |
| // so the pointers must remain valid at least until the element is removed from the |
| // hash_map or the hash_map is freed. Returns true if |data| could be set, false |
| // otherwise (e.g. out of memory). |
| bool hash_map_set(hash_map_t *hash_map, const void *key, void *data); |
| |
| // Removes data indexed by |key| from the hash_map. |hash_map| may not be NULL. |
| // If |key_fn| or |data_fn| functions were specified in |hash_map_new|, they |
| // will be called back with |key| or |data| respectively. This function returns true |
| // if |key| was found in the hash_map and removed, false otherwise. |
| bool hash_map_erase(hash_map_t *hash_map, const void *key); |
| |
| // Removes all elements in the hash_map. Calling this function will return the hash_map |
| // to the same state it was in after |hash_map_new|. |hash_map| may not be NULL. |
| void hash_map_clear(hash_map_t *hash_map); |
| |
| // Iterates through the entire |hash_map| and calls |callback| for each data |
| // element and passes through the |context| argument. If the hash_map is |
| // empty, |callback| will never be called. It is not safe to mutate the |
| // hash_map inside the callback. Neither |hash_map| nor |callback| may be NULL. |
| // If |callback| returns false, the iteration loop will immediately exit. |
| void hash_map_foreach(hash_map_t *hash_map, hash_map_iter_cb callback, void *context); |