zlog学习笔记（zc_hashtable）

zc_hashtable.h

/**
 * hashtable
 */

#ifndef __zc_hashtable_h
#define __zc_hashtable_h


typedef struct zc_hashtable_entry_s {
        unsigned int hash_key;
        void *key;
        void *value;
        struct zc_hashtable_entry_s *prev;
        struct zc_hashtable_entry_s *next;
} zc_hashtable_entry_t;

typedef struct zc_hashtable_s zc_hashtable_t;

typedef unsigned int (*zc_hashtable_hash_fn) (const void *key);
typedef int (*zc_hashtable_equal_fn) (const void *key1, const void *key2);
typedef void(*zc_hashtable_del_fn) (void *kv);

zc_hashtable_t *zc_hashtable_new(size_t a_size, 
                                zc_hashtable_hash_fn hash_fn,
                                zc_hashtable_equal_fn equal_fn,
                                zc_hashtable_del_fn key_del_fn,
                                zc_hashtable_del_fn value_del_fn);

void zc_hashtable_del(zc_hashtable_t *a_table);
void zc_hashtable_clean(zc_hashtable_t *a_table);
int zc_hashtable_put(zc_hashtable_t *a_table, void *a_key, void *a_value);

zc_hashtable_entry_t *zc_hashtable_get_entry(zc_hashtable_t *a_table, const void *a_key);

void *zc_hashtable_get(zc_hashtable_t *a_table, const void *a_key);
void zc_hashtable_remove(zc_hashtable_t *a_table, const void *a_key);

zc_hashtable_entry_t *zc_hashtable_begin(zc_hashtable_t *a_table);
zc_hashtable_entry_t *zc_hashtable_next(zc_hashtable_t *a_table, zc_hashtable_entry_t *a_entry);

struct zc_hashtable_s {
        //记录当前element的个数
        size_t nelem;

        zc_hashtable_entry_t **tab;
        size_t tab_size;

        zc_hashtable_hash_fn hash;
        zc_hashtable_equal_fn equal;
        zc_hashtable_del_fn key_del;
        zc_hashtable_del_fn value_del;
};

#define zc_hashtable_foreach(a_table, a_entry)\
for(a_entry = zc_hashtable_begin(a_table); a_entry; a_entry = zc_hashtable_next(a_table, a_entry))

unsigned int zc_hashtable_str_hash(const void *str);
int zc_hashtable_str_equal(const void *key1, const void *key2);

#endif

zc_hashtable.c

#include <stdlib.h>
#include <errno.h>
#include <pthread.h>

#include "zc_defs.h"
#include "zc_hashtable.h"

//struct zc_hashtable_s {
//      //记录当前element的个数
//      size_t nelem;
//
//      zc_hashtable_entry_t **tab;
//      size_t tab_size;
//
//      zc_hashtable_hash_fn hash;
//      zc_hashtable_equal_fn equal;
//      zc_hashtable_del_fn key_del;
//      zc_hashtable_del_fn value_del;
//};

zc_hashtable_t *zc_hashtable_new(size_t a_size,
                zc_hashtable_hash_fn hash,
                zc_hashtable_equal_fn equal,
                zc_hashtable_del_fn key_del,
                zc_hashtable_del_fn value_del){

        zc_hashtable_t *a_table;
        a_table = (zc_hashtable_t *)calloc(1, sizeof(zc_hashtable_t));
        if(!a_table){
                zc_error("calloc fail, errno[%d]", errno);
                return NULL;
        }

        a_table->tab = (zc_hashtable_entry_t **)calloc(a_size, sizeof(zc_hashtable_entry_t *));
        if(!a_table->tab){
                zc_error("calloc fail, errno[%d]", errno);
                free(a_table);
                return  NULL;
        }
        a_table->tab_size = a_size;

        a_table->nelem = 0;
        a_table->hash = hash;
        a_table->equal = equal;

        //these two could be NULL
        a_table->key_del = key_del;
        a_table->value_del = value_del;

        return a_table;
}

void zc_hashtable_del(zc_hashtable_t *a_table){
        size_t i;
        zc_hashtable_entry_t *p;
        zc_hashtable_entry_t *q;

        if(!a_table){
                zc_error("a_table[%p] is NULL, just do nothing", a_table);
                return ;
        }

        for(i = 0; i < a_table->tab_size; i++){
                //hash conflic
                for(p = (a_table->tab)[i]; p; p = q){
                        q = p->next;
                        if(a_table->key_del){
                                a_table->key_del(p->key);
                        }
                        if(a_table->value_del){
                                a_table->value_del(p->value);
                        }
                        free(p);
                }
        }
        if(a_table->tab){
                free(a_table->tab);
        }
        free(a_table);

        return;
}

void zc_hashtable_clean(zc_hashtable_t *a_table){
        size_t i;
        zc_hashtable_entry_t *p, *q;

        for(i = 0; i < a_table->tab_size; i++){
                for(p = (a_table->tab)[i]; p; p = q){
                        q = p->next;
                        if(a_table->key_del){
                                a_table->key_del(p->key);
                        }
                        if(a_table->value_del){
                                a_table->value_del(p->value);
                        }
                        free(p);
                }
                (a_table->tab)[i] = NULL;
        }
        a_table->nelem = 0;

        return;
}

static int zc_hashtable_rehash(zc_hashtable_t *a_table){
        size_t i, j, tab_size;
        zc_hashtable_entry_t **tab;
        zc_hashtable_entry_t *p;
        zc_hashtable_entry_t *q;

        tab_size = 2 * a_table->tab_size;
        tab = calloc(tab_size, sizeof(zc_hashtable_t *));
        if(!tab){
                zc_error("calloc fail, errno[%d]", errno);
                return -1;
        }

        for(i = 0; i < a_table->tab_size; i++){
                //优化
                for(p = a_table->tab[i]; p; p = q){
                        q = p->next;

                        p->prev = NULL;
                        p->next = NULL;
                        j = p->hash_key % tab_size;
                        if(tab[j]){
                                tab[j]->prev = p;
                                p->next = tab[j];
                        }
                        tab[j] = p;
                }
        }
        free(a_table->tab);
        a_table->tab = tab;
        a_table->tab_size = tab_size;

        return 0;
}

void *zc_hashtable_get(zc_hashtable_t *a_table, const void *a_key){
        size_t i;
        zc_hashtable_entry_t *p = NULL;

        i = a_table->hash(a_key) % a_table->tab_size;
        for(p = a_table->tab[i]; p; p = p->next){
                if(a_table->equal(a_key, p->key)){
                        return p->value;
                }
        }
        return NULL;
}

int zc_hashtable_put(zc_hashtable_t *a_table, void *a_key, void *a_value){
        int rc;
        size_t i;
        zc_hashtable_entry_t *p = NULL;

        i = a_table->hash(a_key) % a_table->tab_size;
        for(p = a_table->tab[i]; p; p = p->next){
                if(a_table->equal(a_key, p->key)){
                        break;
                }
        }

        //a_table->tab[i] have value
        if(p){
                if(a_table->key_del){
                        a_table->key_del(p->key);
                }
                if(a_table->value_del){
                        a_table->value_del(p->value);
                }
                p->key = a_key;
                p->value = a_value;
                return 0;
        }else{
                if(a_table->nelem > a_table->tab_size * 1.3){
                        rc = zc_hashtable_rehash(a_table);
                        if(rc){
                                zc_error("rehash fail");
                                return -1;
                        }
                }
                //如果sizeof(zc_hashtable_entry_t *) 会造成free失败
                p = calloc(1, sizeof(zc_hashtable_entry_t));
                if(!p){
                        zc_error("calloc fail, errno[%d]", errno);
                        return -1;
                }

                p->hash_key = a_table->hash(a_key);
                p->key = a_key;
                p->value = a_value;
                p->next = NULL;
                p->prev = NULL;

                i = p->hash_key % a_table->tab_size;
                //has value
                if(a_table->tab[i]){
                        a_table->tab[i]->prev = p;
                        p->next = a_table->tab[i];
                }
                a_table->tab[i] = p;
                a_table->nelem++;
        }

        return 0;
}

void zc_hashtable_remove(zc_hashtable_t *a_table, const void *a_key){
        size_t i;
        zc_hashtable_entry_t *p;

        if(!a_table || !a_key){
                zc_error("a_table[%p] or a_key[%p] is NULL, just do nothing", a_table, a_key);
                return ;
        }
        i = a_table->hash(a_key) % a_table->tab_size;
        for(p = a_table->tab[i]; p; p = p->next){
                if(a_table->equal(a_key, p->key)){
                        break;
                }
        }

        if(!p){
                zc_error("p[%p] is not found in hashtable", p);
                return;
        }

        if(a_table->key_del){
                a_table->key_del(p->key);
        }
        if(a_table->value_del){
                a_table->value_del(p->value);
        }

        if(p->next){
                p->next->prev = p->prev;
        }
        if(p->prev){
                p->prev->next = p->next;
        }else{
                //notice
                a_table->tab[i] = p->next;
        }

        free(p);
        a_table->nelem--;

        return;
}

zc_hashtable_entry_t *zc_hashtable_begin(zc_hashtable_t *a_table){
        size_t i;
        zc_hashtable_entry_t *p;
        for(i= 0; i < a_table->tab_size; i++){
                for(p = a_table->tab[i]; p; p->next){
                        if(p){
                                return p;
                        }
                }
        }
        printf("%d\n", i);
        return NULL;
}

zc_hashtable_entry_t *zc_hashtable_next(zc_hashtable_t *a_table, zc_hashtable_entry_t *a_entry){
        size_t i, j;

        if(a_entry->next){
                return a_entry->next;
        }

        i = a_entry->hash_key % a_table->tab_size;

        for(j = i + 1; j < a_table->tab_size; j++){
                if(a_table->tab[j]){
                        return a_table->tab[j];
                }
        }

        return NULL;
}

/**************************************************hash、equal**********************************************/

int zc_hashtable_str_equal(const void *key1, const void *key2){
        return (STRCMP((const char *)key1, ==, (const char *)key2));
}

unsigned int zc_hashtable_str_hash(const void *str){
        size_t h = 5381;
        const char *p = (const char *)str;

        while(*p != '\0'){
                h = ((h << 5) + h) + (*p++);    /* hash * 33 + c*/
        }

        return h;
}

 

测试

#include <stdio.h>

#include "zc_defs.h"
#include "zc_hashtable.c"
#include "zc_profile.c"

void myfree(void *kv){

}

int main(){
        zc_hashtable_t *a_table;
        zc_hashtable_entry_t *a_entry;

        a_table = zc_hashtable_new(20,
                zc_hashtable_str_hash,
                zc_hashtable_str_equal,
                myfree,myfree
        );

        zc_hashtable_put(a_table, "aaa", "123");
        zc_hashtable_put(a_table, "bbb", "123456");
        zc_hashtable_put(a_table, "ccc", "123456789");

        zc_hashtable_foreach(a_table, a_entry){
                printf("k[%s], v[%s]\n", a_entry->key, a_entry->value);
        }

        printf("getv[%s]\n", (char *)zc_hashtable_get(a_table, "ccc"));

        zc_hashtable_remove(a_table, "ccc");

        zc_hashtable_foreach(a_table, a_entry){
                printf("k[%s], v[%s]\n", a_entry->key, a_entry->value);
        }

        zc_hashtable_remove(a_table, NULL);
        zc_hashtable_del(NULL);

        zc_hashtable_del(a_table);

        return 0;
}