hashmap C語言實現

hashmap C語言實現cheungmine

原始碼(適合Linux和Windows)包括:

    hashmap.c

    hashmap.h

MSVC測試檔案:

    main.c

下面是原始碼,最初來自github,我改寫了幾個地方,並重寫了全部測試代碼.沒有記憶體泄露,請放心使用.

/** * 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;  /* 刪除整個子 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;  /* 建立 hashmap */  map = hashmap_create();  /* 插入 hashmap 元素 */  for (i=0; i<100; i++) {    dat = (userdata *)malloc(sizeof(userdata));    /* 建立子 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));  /* 刪除指定元素: 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);  /* 刪除指定元素: 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);  /* 查詢元素: 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);  /* 刪除整個 map */  hashmap_destroy(map, free_data, 0);  _CrtDumpMemoryLeaks();  return 0;}