hashmap C语言实现
cheungmine
源代码(适合Linux和Windows)包括:
hashmap.c
hashmap.h
MSVC测试文件:
main.c
下面是源代码,最初来自github,我改写了几个地方,并重写了全部测试代码.没有内存泄露,请放心使用.
/**
* hashmap.h
*/
#ifndef _HASHMAP_H_INCLUDED
#define _HASHMAP_H_INCLUDED
#if defined(__cplusplus)
extern "C" {
#endif
#define HMAP_E_KEYUSED (-5) /* Key already existed */
#define HMAP_E_OUTMEM (-4) /* Out of Memory */
#define HMAP_E_NOTFOUND (-3) /* No such element */
#define HMAP_E_OVERFLOW (-2) /* Hashmap is full */
#define HMAP_E_FAIL (-1) /* Hashmap api fail */
#define HMAP_S_OK (0) /* Success */
/**
* void_ptr is a pointer. This allows you to put arbitrary structures in the hashmap.
*/
typedef void* void_ptr;
/**
* hmap_t is a pointer to an internally maintained data structure.
* Clients of this package do not need to know how hashmaps are
* represented. They see and manipulate only hmap_t's.
*/
typedef void_ptr hmap_t;
/**
* hmap_callback_func is a pointer to a function that can take two void_ptr arguments
* and return an integer. Returns status code..
*/
typedef int (*hmap_callback_func)(void_ptr, void_ptr);
/**
* prototype for map element type
*/
typedef struct _hmap_pair_t {
char *key;
void_ptr data;
} hmap_pair_t;
/**
* Return an empty hashmap. Returns NULL if empty.
*/
extern hmap_t hashmap_create();
/**
* Iteratively call fn with argument (value, arg) for each element data
* in the hashmap. The function returns anything other than HMAP_S_OK
* the traversal is terminated. fn must not modify any hashmap functions.
*/
extern int hashmap_iterate(hmap_t in, hmap_callback_func fnIterValue, void_ptr arg);
/**
* Add an element to the hashmap.
* Return HMAP_S_OK, HMAP_E_KEYUSED or HMAP_E_OUTMEM.
*/
extern int hashmap_put(hmap_t in, char* key, void_ptr elem);
/**
* Get an element from the hashmap. Return HMAP_S_OK or HMAP_E_NOTFOUND.
*/
extern int hashmap_get(hmap_t in, const char* key, void_ptr *elem);
/**
* Remove an element from the hashmap. Return HMAP_S_OK or HMAP_E_NOTFOUND.
*/
extern int hashmap_remove(hmap_t in, char* key, void_ptr *outValue);
/**
* Free the hashmap
*/
extern void hashmap_destroy(hmap_t in, hmap_callback_func fnFreeValue, void_ptr arg);
/**
* Get the current size of a hashmap
*/
extern int hashmap_size(hmap_t in);
#if defined(__cplusplus)
}
#endif
#endif /* _HASHMAP_H_INCLUDED */
/**
* hashmap.c
* Generic hash map implementation.
*/
#include "hashmap.h"
#include <stdlib.h>
#include <stdio.h>
#include <string.h>
#define HMAP_INITIAL_SIZE (256)
#define HMAP_CHAIN_LENGTH (8)
typedef enum _use_state {
unused_0 = 0,
used_1 = 1
} use_state;
/* A element to keep keys and values */
typedef struct _hashmap_elem_t{
char *key; /* pointer to actual key storage */
use_state used; /* unused_0, used_1 */
void_ptr data; /* pointer to value memory allocated by callee */
} hashmap_elem_t;
/* A hashmap has maximum size and current size, as well as the elems to hold */
typedef struct _hashmap_map_t{
int table_size;
int size;
hashmap_elem_t *elems;
} hashmap_map_t;
/**
* The implementation here was originally done by Gary S. Brown.
* I have borrowed the tables directly, and made some minor changes.
*
* COPYRIGHT (C) 1986 Gary S. Brown.
* You may use this program, or code or tables extracted from it,
* as desired without restriction.
*/
static unsigned long crc32_tab[] = {
0x00000000L, 0x77073096L, 0xee0e612cL, 0x990951baL, 0x076dc419L,
0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0x0edb8832L, 0x79dcb8a4L,
0xe0d5e91eL, 0x97d2d988L, 0x09b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL,
0x1adad47dL, 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L,
0x646ba8c0L, 0xfd62f97aL, 0x8a65c9ecL, 0x14015c4fL, 0x63066cd9L,
0xfa0f3d63L, 0x8d080df5L, 0x3b6e20c8L, 0x4c69105eL, 0xd56041e4L,
0xa2677172L, 0x3c03e4d1L, 0x4b04d447L, 0xd20d85fdL, 0xa50ab56bL,
0x35b5a8faL, 0x42b2986cL, 0xdbbbc9d6L, 0xacbcf940L, 0x32d86ce3L,
0x45df5c75L, 0xdcd60dcfL, 0xabd13d59L, 0x26d930acL, 0x51de003aL,
0xc8d75180L, 0xbfd06116L, 0x21b4f4b5L, 0x56b3c423L, 0xcfba9599L,
0xb8bda50fL, 0x2802b89eL, 0x5f058808L, 0xc60cd9b2L, 0xb10be924L,
0x2f6f7c87L, 0x58684c11L, 0xc1611dabL, 0xb6662d3dL, 0x76dc4190L,
0x01db7106L, 0x98d220bcL, 0xefd5102aL, 0x71b18589L, 0x06b6b51fL,
0x9fbfe4a5L, 0xe8b8d433L, 0x7807c9a2L, 0x0f00f934L, 0x9609a88eL,
0xe10e9818L, 0x7f6a0dbbL, 0x086d3d2dL, 0x91646c97L, 0xe6635c01L,
0x6b6b51f4L, 0x1c6c6162L, 0x856530d8L, 0xf262004eL, 0x6c0695edL,
0x1b01a57bL, 0x8208f4c1L, 0xf50fc457L, 0x65b0d9c6L, 0x12b7e950L,
0x8bbeb8eaL, 0xfcb9887cL, 0x62dd1ddfL, 0x15da2d49L, 0x8cd37cf3L,
0xfbd44c65L, 0x4db26158L, 0x3ab551ceL, 0xa3bc0074L, 0xd4bb30e2L,
0x4adfa541L, 0x3dd895d7L, 0xa4d1c46dL, 0xd3d6f4fbL, 0x4369e96aL,
0x346ed9fcL, 0xad678846L, 0xda60b8d0L, 0x44042d73L, 0x33031de5L,
0xaa0a4c5fL, 0xdd0d7cc9L, 0x5005713cL, 0x270241aaL, 0xbe0b1010L,
0xc90c2086L, 0x5768b525L, 0x206f85b3L, 0xb966d409L, 0xce61e49fL,
0x5edef90eL, 0x29d9c998L, 0xb0d09822L, 0xc7d7a8b4L, 0x59b33d17L,
0x2eb40d81L, 0xb7bd5c3bL, 0xc0ba6cadL, 0xedb88320L, 0x9abfb3b6L,
0x03b6e20cL, 0x74b1d29aL, 0xead54739L, 0x9dd277afL, 0x04db2615L,
0x73dc1683L, 0xe3630b12L, 0x94643b84L, 0x0d6d6a3eL, 0x7a6a5aa8L,
0xe40ecf0bL, 0x9309ff9dL, 0x0a00ae27L, 0x7d079eb1L, 0xf00f9344L,
0x8708a3d2L, 0x1e01f268L, 0x6906c2feL, 0xf762575dL, 0x806567cbL,
0x196c3671L, 0x6e6b06e7L, 0xfed41b76L, 0x89d32be0L, 0x10da7a5aL,
0x67dd4accL, 0xf9b9df6fL, 0x8ebeeff9L, 0x17b7be43L, 0x60b08ed5L,
0xd6d6a3e8L, 0xa1d1937eL, 0x38d8c2c4L, 0x4fdff252L, 0xd1bb67f1L,
0xa6bc5767L, 0x3fb506ddL, 0x48b2364bL, 0xd80d2bdaL, 0xaf0a1b4cL,
0x36034af6L, 0x41047a60L, 0xdf60efc3L, 0xa867df55L, 0x316e8eefL,
0x4669be79L, 0xcb61b38cL, 0xbc66831aL, 0x256fd2a0L, 0x5268e236L,
0xcc0c7795L, 0xbb0b4703L, 0x220216b9L, 0x5505262fL, 0xc5ba3bbeL,
0xb2bd0b28L, 0x2bb45a92L, 0x5cb36a04L, 0xc2d7ffa7L, 0xb5d0cf31L,
0x2cd99e8bL, 0x5bdeae1dL, 0x9b64c2b0L, 0xec63f226L, 0x756aa39cL,
0x026d930aL, 0x9c0906a9L, 0xeb0e363fL, 0x72076785L, 0x05005713L,
0x95bf4a82L, 0xe2b87a14L, 0x7bb12baeL, 0x0cb61b38L, 0x92d28e9bL,
0xe5d5be0dL, 0x7cdcefb7L, 0x0bdbdf21L, 0x86d3d2d4L, 0xf1d4e242L,
0x68ddb3f8L, 0x1fda836eL, 0x81be16cdL, 0xf6b9265bL, 0x6fb077e1L,
0x18b74777L, 0x88085ae6L, 0xff0f6a70L, 0x66063bcaL, 0x11010b5cL,
0x8f659effL, 0xf862ae69L, 0x616bffd3L, 0x166ccf45L, 0xa00ae278L,
0xd70dd2eeL, 0x4e048354L, 0x3903b3c2L, 0xa7672661L, 0xd06016f7L,
0x4969474dL, 0x3e6e77dbL, 0xaed16a4aL, 0xd9d65adcL, 0x40df0b66L,
0x37d83bf0L, 0xa9bcae53L, 0xdebb9ec5L, 0x47b2cf7fL, 0x30b5ffe9L,
0xbdbdf21cL, 0xcabac28aL, 0x53b39330L, 0x24b4a3a6L, 0xbad03605L,
0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL, 0xc4614ab8L,
0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
0x2d02ef8dL
};
/**
* Return a 32-bit CRC of the contents of the buffer.
*/
static unsigned long crc32(const unsigned char *s, unsigned int len)
{
unsigned int i;
unsigned long crc32val = 0;
for (i = 0; i < len; i ++) {
crc32val = crc32_tab[(crc32val ^ s[i]) & 0xff] ^ (crc32val >> 8);
}
return crc32val;
}
/**
* Hashing function for a string
*/
static unsigned int _find_hash_index(hashmap_map_t * m, const char* keystring){
unsigned long key = crc32(keystring, strlen(keystring));
/* Robert Jenkins' 32 bit Mix Function */
key += (key << 12);
key ^= (key >> 22);
key += (key << 4);
key ^= (key >> 9);
key += (key << 10);
key ^= (key >> 2);
key += (key << 7);
key ^= (key >> 12);
/* Knuth's Multiplicative Method */
key = (key >> 3) * 0x9E3779B1;
return key % m->table_size;
}
/**
* Return the integer of the location in data to store the point to the item,
* or HMAP_E_OVERFLOW.
*/
static int _hashmap_hash(hmap_t in, char* key){
int curr;
int i;
hashmap_elem_t *elem;
hashmap_map_t *m = (hashmap_map_t *) in;
/* If full, return immediately */
if (m->size >= (m->table_size/2)) {
return HMAP_E_OVERFLOW;
}
/* Find the best index */
curr = _find_hash_index(m, key);
/* Linear probing */
for (i = 0; i< HMAP_CHAIN_LENGTH; i++) {
elem = m->elems + curr;
if(elem->used == unused_0) {
return curr;
}
if(elem->used == used_1 && (!strcmp(elem->key, key))) {
return curr;
}
curr = (curr + 1) % m->table_size;
}
return HMAP_E_OVERFLOW;
}
/**
* Doubles the size of the hashmap, and rehashes all the elements
*/
static int _hashmap_rehash(hmap_t in){
int i;
int old_size;
hashmap_elem_t *curr;
hashmap_elem_t *elem;
/* Setup the new elements */
hashmap_map_t *m = (hashmap_map_t *) in;
hashmap_elem_t *temp = (hashmap_elem_t *) calloc(2 * m->table_size, sizeof(hashmap_elem_t));
if (!temp) {
return HMAP_E_OUTMEM;
}
/* Update the array */
curr = m->elems;
m->elems = temp;
/* Update the size */
old_size = m->table_size;
m->table_size = 2 * m->table_size;
m->size = 0;
/* Rehash the elements */
for (i = 0; i < old_size; i++){
int status;
elem = curr + i;
if (elem->used == unused_0) {
continue;
}
status = hashmap_put(m, elem->key, elem->data);
if (status != HMAP_S_OK) {
return status;
}
}
free(curr);
return HMAP_S_OK;
}
/**
* Create an empty hashmap
*/
hmap_t hashmap_create() {
hashmap_map_t* m = (hashmap_map_t*) malloc(sizeof(hashmap_map_t));
if (!m) {
exit(HMAP_E_OUTMEM);
}
m->elems = (hashmap_elem_t*) calloc(HMAP_INITIAL_SIZE, sizeof(hashmap_elem_t));
if (!m->elems) {
free(m);
exit(HMAP_E_OUTMEM);
}
m->table_size = HMAP_INITIAL_SIZE;
m->size = 0;
return m;
}
/**
* Add a pair of key-value to the hashmap
*/
int hashmap_put(hmap_t in, char* key, void_ptr value){
int index;
hashmap_map_t *m;
hashmap_elem_t *elem;
m = (hashmap_map_t *) in;
/* Find a place to put our value */
index = _hashmap_hash(in, key);
while (index == HMAP_E_OVERFLOW) {
if (_hashmap_rehash(in) == HMAP_E_OUTMEM) {
return HMAP_E_OUTMEM;
}
index = _hashmap_hash(in, key);
}
/* Set the elems */
elem = m->elems + index;
if (elem->used == used_1) {
/* Find a repeated key */
return HMAP_E_KEYUSED;
}
elem->data = value;
elem->key = key; /* only set to a reference */
elem->used = used_1;
m->size++;
return HMAP_S_OK;
}
/**
* Get your pointer out of the hashmap with a key
*/
int hashmap_get(hmap_t in, const char* key, void_ptr *value){
int curr;
int i;
hashmap_map_t *m;
hashmap_elem_t *elem;
m = (hashmap_map_t *) in;
/* Find element location */
curr = _find_hash_index(m, key);
/* Linear probing, if necessary */
for (i = 0; i<HMAP_CHAIN_LENGTH; i++){
elem = m->elems + curr;
if (elem->used == used_1) {
if (!strcmp(elem->key, key)) {
*value = (elem->data);
return HMAP_S_OK;
}
}
curr = (curr + 1) % m->table_size;
}
*value = NULL;
return HMAP_E_NOTFOUND;
}
/**
* Iterate the function parameter over each element in the hashmap. The
* additional void_ptr argument is passed to the function as its first
* argument and the hashmap element is the second.
*/
int hashmap_iterate(hmap_t in, hmap_callback_func fnIterValue, void_ptr arg) {
int i;
hashmap_elem_t *elem;
hashmap_map_t *m = (hashmap_map_t*) in;
if (hashmap_size(m) <= 0) {
return HMAP_E_NOTFOUND;
}
for (i = 0; i< m->table_size; i++) {
elem = m->elems+i;
if(elem->used == used_1) {
int status = fnIterValue(elem->data, arg);
if (status != HMAP_S_OK) {
return status;
}
}
}
return HMAP_S_OK;
}
/**
* Remove an element with that key from the map
*/
int hashmap_remove(hmap_t in, char* key, void_ptr *outValue){
int i, curr;
hashmap_map_t* m;
hashmap_elem_t *elem;
/* Cast the hashmap */
m = (hashmap_map_t *) in;
if (outValue) {
*outValue = NULL;
}
/* Find key */
curr = _find_hash_index(m, key);
/* Linear probing, if necessary */
for (i = 0; i<HMAP_CHAIN_LENGTH; i++){
elem = m->elems + curr;
if (elem->used == used_1){
if (!strcmp(elem->key, key)){
/* Blank out the fields */
elem->used = unused_0;
elem->key = NULL;
if (outValue) {
*outValue = elem->data;
}
elem->data = NULL;
/* Reduce the size */
m->size--;
return HMAP_S_OK;
}
}
curr = (curr + 1) % m->table_size;
}
/* Data not found */
return HMAP_E_NOTFOUND;
}
/**
* Deallocate the hashmap
*/
void hashmap_destroy(hmap_t in, hmap_callback_func fnFreeValue, void_ptr arg){
hashmap_elem_t *elem;
void_ptr data;
hashmap_map_t* m = (hashmap_map_t*) in;
while (m->table_size-->0) {
elem = m->elems+(m->table_size);
if (elem->used == used_1) {
elem->used = unused_0;
elem->key = NULL;
data = elem->data;
elem->data = NULL;
if (fnFreeValue) {
fnFreeValue(data, arg);
}
}
}
free(m->elems);
free(m);
}
/**
* Return the length of the hashmap
*/
int hashmap_size(hmap_t in){
hashmap_map_t* m = (hashmap_map_t *) in;
if (m) {
return m->size;
}
else {
return 0;
}
}
/**
* main.c
*
* Detecting memory leaks only for windows .
* Place the following snippet where leak to be tested:
* #if defined(_CRTDBG_MAP_ALLOC)
* _CrtDumpMemoryLeaks();
* #endif
*/
#if defined(WIN32) && defined(_DEBUG)
#ifndef _CRTDBG_MAP_ALLOC
#pragma message( __FILE__": _CRTDBG_MAP_ALLOC defined only for DEBUG on Win32." )
#define _CRTDBG_MAP_ALLOC
#include<stdlib.h>
#include<crtdbg.h>
#endif
#endif
#include <assert.h>
#include <stdio.h>
#include <string.h>
#include "hashmap.h"
typedef struct userelem_t {
char key[20];
char *value;
} userelem;
typedef struct userdata_t {
char name[20];
hmap_t map; /* userelem map */
} userdata;
static int iter_elem(void* elem, void *arg) {
userelem *el = (userelem *) elem;
printf("key=%s; value=%s\n", el->key, el->value);
return 0;
}
static int free_elem(void* elem, void *arg) {
userelem *el = (userelem *) elem;
free(el->value);
free(el);
return 0;
}
static int free_data(void* data, void *arg) {
userdata *dat = (userdata *) data;
/* 删除整个子 map */
hashmap_destroy(dat->map, free_elem, 0);
free(dat);
return 0;
}
int main(int argc, char* argv[])
{
hmap_t map;
userdata *dat;
userelem *el;
int ret, i, j;
/* 创建 hashmap */
map = hashmap_create();
/* 插入 hashmap 元素 */
for (i=0; i<100; i++) {
dat = (userdata *)malloc(sizeof(userdata));
/* 创建子 hashmap */
dat->map = hashmap_create();
/* 插入子 hashmap 元素 */
for (j=0; j<10; j++) {
el = (userelem *)malloc(sizeof(userelem));
sprintf(el->key, "%d", j);
el->value = (char*) malloc(30);
sprintf(el->value, "%d", j+1000);
ret = hashmap_put(dat->map, el->key, el);
assert(ret==HMAP_S_OK);
}
sprintf(dat->name, "%d", i);
ret = hashmap_put(map, dat->name, dat);
assert(ret==HMAP_S_OK);
}
printf("hashmap_size: %d\n", hashmap_size(map));
/* 删除指定元素: key="10" */
ret = hashmap_remove(map, "10", &dat);
assert(ret==HMAP_S_OK);
printf("hashmap_remove: name=%s. size=%d\n", dat->name, hashmap_size(map));
hashmap_iterate(dat->map, iter_elem, 0);
free_data(dat, 0);
/* 删除指定元素: key="11" */
ret = hashmap_remove(map, "11", &dat);
assert(ret==HMAP_S_OK);
printf("hashmap_remove: name=%s. size=%d\n", dat->name, hashmap_size(map));
hashmap_iterate(dat->map, iter_elem, 0);
free_data(dat, 0);
/* 查询元素: key="99" */
ret = hashmap_get(map, "99", &dat);
assert(ret==HMAP_S_OK);
printf("hashmap_get: name=%s. size=%d\n", dat->name, hashmap_size(map));
hashmap_iterate(dat->map, iter_elem, 0);
/* 删除整个 map */
hashmap_destroy(map, free_data, 0);
_CrtDumpMemoryLeaks();
return 0;
}
