1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
|
/*
* 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.
*/
/**
* Hash map.
*/
#ifndef __HASHMAP_H
#define __HASHMAP_H
#include <stdbool.h>
#include <stdlib.h>
#ifdef __cplusplus
extern "C" {
#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* hashmapCreate(size_t initialCapacity,
int (*hash)(void* key), bool (*equals)(void* keyA, void* keyB));
/**
* Frees the hash map. Does not free the keys or values themselves.
*/
void hashmapFree(Hashmap* map);
/**
* Hashes the memory pointed to by key with the given size. Useful for
* implementing hash functions.
*/
int hashmapHash(void* key, size_t keySize);
/**
* Puts value for the given key in the map. Returns pre-existing value if
* any.
*
* If memory allocation fails, this function returns NULL, the map's size
* does not increase, and errno is set to ENOMEM.
*/
void* hashmapPut(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* hashmapGet(Hashmap* map, void* key);
/**
* Returns true if the map contains an entry for the given key.
*/
bool hashmapContainsKey(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* hashmapMemoize(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* hashmapRemove(Hashmap* map, void* key);
/**
* Gets the number of entries in this map.
*/
size_t hashmapSize(Hashmap* map);
/**
* Invokes the given callback on each entry in the map. Stops iterating if
* the callback returns false.
*/
void hashmapForEach(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 hashmapLock(Hashmap* map);
/**
* Unlocks the hash map so other threads can access it.
*/
void hashmapUnlock(Hashmap* map);
/**
* Key utilities.
*/
/**
* Hashes int keys. 'key' is a pointer to int.
*/
int hashmapIntHash(void* key);
/**
* Compares two int keys for equality.
*/
bool hashmapIntEquals(void* keyA, void* keyB);
/**
* For debugging.
*/
/**
* Gets current capacity.
*/
size_t hashmapCurrentCapacity(Hashmap* map);
/**
* Counts the number of entry collisions.
*/
size_t hashmapCountCollisions(Hashmap* map);
#ifdef __cplusplus
}
#endif
#endif /* __HASHMAP_H */
|
