Redis學習筆記--hiredis（C語言）

Redis學習中，C語言通過hiredis開源庫操作redis。

1 hiredis開源代碼的路徑。和說明文檔網址：
https://github.com/redis/hiredis

2 hiredis中部分API使用示例。

#include <stdio.h>
#include "hiredis.h"


const char* REDIS_IP = "127.0.0.1";
const int   REDIS_PORT = 6380;

//connect redis
redisContext* getRedisContext();
//free redis connect
void freeRedisContext(redisContext *rc);
//test redis key
int testRedisKey(redisContext *rc);
//string type 
void testRedisString(redisContext *rc);
//prase redisReplay
int praseRedisReply(redisReply*& redisCmdReply, const char*& redisCmd);

//main function
int main(int argc, char* argv[])
{
    //get redis connect
    redisContext* rc = getRedisContext();
    if(rc == NULL) return -1;
    int res = testRedisKey(rc);
    if(0 != res){
        return -1;
    }

    //free redis connect
    freeRedisContext(rc);
    return 0;
}
//get redis context
redisContext* getRedisContext()
{
    printf("Redis IP:%s Port:%d\n", REDIS_IP, REDIS_PORT);
    redisContext* rc = redisConnect(REDIS_IP, REDIS_PORT);
    if(NULL == rc || rc->err)
    {
        if(rc){
            printf("Connect Redis Error:%s\n", rc->errstr);
        }else{
            printf("Can't allocate redis context\n");
        }
        redisFree(rc);
        return NULL;
    }

    printf("Connect Redis OK\n");
    return rc;
}
//free redis context
void freeRedisContext(redisContext *c)
{
    printf("Free Redis Context.\n");
    redisFree(c);
    return ;
}

//redis key operate
int testRedisKey(redisContext *rc)
{
    printf("redis key operate\n");

    if(NULL == rc){
        printf("redisContext is NULL\n");
        return -1;
    }

    //KEYS * command
    const char* keysCommand = "KEYS *";
    redisReply* redisCmdReply = (redisReply*)redisCommand(rc, keysCommand);

    //parse redis reply
    int res = praseRedisReply(redisCmdReply, keysCommand);
    if(res != 0){
        freeReplyObject(redisCmdReply);
        freeRedisContext(rc);
        return -1;
    }

    //EXISTS command
    const char* existsCommand = "EXISTS bar";
    redisCmdReply = (redisReply*)redisCommand(rc, existsCommand);

    //parse redis reply
    res = praseRedisReply(redisCmdReply, existsCommand);
    if(res != 0){
        freeReplyObject(redisCmdReply);
        freeRedisContext(rc);
        return -1;
    }

    const char* existsHaoCommand = "EXISTS hao";
    redisCmdReply = (redisReply*)redisCommand(rc, existsHaoCommand);

    //parse redis reply
    res = praseRedisReply(redisCmdReply, existsHaoCommand);
    if(res != 0){
        freeReplyObject(redisCmdReply);
        freeRedisContext(rc);
        return -1;
    }

    //DELETE key command
    const char* delKeycomman = "DEL bar";
    redisCmdReply = (redisReply*)redisCommand(rc, delKeycomman);
    //parse redis reply
    res = praseRedisReply(redisCmdReply, delKeycomman);
    if(res != 0){
        freeReplyObject(redisCmdReply);
        freeRedisContext(rc);
        return -1;
    }

    redisCmdReply = (redisReply*)redisCommand(rc, keysCommand);
    //parse redis reply
    res = praseRedisReply(redisCmdReply, keysCommand);
    if(res != 0){
        freeReplyObject(redisCmdReply);
        freeRedisContext(rc);
        return -1;
    }

    //free redisReply
    freeReplyObject(redisCmdReply);

    return 0;
}

//string type 
void testRedisString(redisContext *rc)
{
    printf("Test Redius String Type.\n");
    return ;
}

//prase redis reply
int praseRedisReply(redisReply*& redisCmdReply, const char*& redisCmd)
{
    if(NULL == redisCmd){
        printf("Invalid Parameter: redisCmd is NULL\n");
        return -1;
    }
    if(NULL == redisCmdReply){
        printf("Execute Command [%s] Error: redisCmdReply is NULL.\n", redisCmd);
        return -1;
    }
    printf("redisReply Type:%d\n", redisCmdReply->type);

    int ret = 0;

    switch(redisCmdReply->type){
        case REDIS_REPLY_STRING:
            {
                printf("Execute Command [%s] return string[%s]", redisCmd, redisCmdReply->str);
                ret = 0;
                break;
            }
        case REDIS_REPLY_ARRAY:
            {   
                printf("Execute Command [%s] return context:\n", redisCmd);
                redisReply* temp =  NULL;
                for(int i=0; i<redisCmdReply->elements; i++){               
                    temp = redisCmdReply->element[i];
                    printf("(%d) %s\n", temp->type, temp->str);
                }
                ret = 0;
                break;
            }
        case REDIS_REPLY_INTEGER:
            {
                printf("Execute Command [%s] return intger[%lld].\n", redisCmd, redisCmdReply->integer);
                ret = 0;
                break;
            }
        case REDIS_REPLY_NIL:
            {
                printf("Execute Command [%s] return nil.\n", redisCmd);
                ret = -1;
                break;
            }
        case REDIS_REPLY_STATUS:
            {
                printf("Execute Command [%s] return status[%s].\n", redisCmd, redisCmdReply->str);
                ret = 0;
                break;
            }
        case REDIS_REPLY_ERROR:
            {
                printf("Execute Command [%s] return error[%s].\n", redisCmd, redisCmdReply->str);
                ret = -1;
                break;
            }
        default:
            {
                printf("Execute Command [%s] return unknown type\n", redisCmd);
                ret = -1;
                break;
            }
    }

    return ret;
}

3 編譯問題
使用hiredis的makefile文件編譯出hiredis的靜態庫（命令make static）。
文件目錄
hiredis Makefile testRedis.cpp
自己的makefile文件內容：

#g++
CXX = g++ -g -Wall

#REDIS DIR  
HREDIS_DIR = ./hiredis

#RELEASE DIR
RELEASE_DIR = ./release

#CFLAGS
CFLAGS = -I./ -I$(HREDIS_DIR)

#TERG
TARGETS = testRedis

#object
OBJS =  ./testRedis.o

all:$(TARGETS)

./testRedis.o: ./testRedis.cpp $(HREDIS_DIR)/hiredis.h
    $(CXX)  $(CFLAGS) -c ./testRedis.cpp -o $@

$(TARGETS):$(OBJS) $(HREDIS_DIR)/libhiredis.a
    test -d $(RELEASE_DIR) || mkdir -p $(RELEASE_DIR)
    $(CXX) -o $@ $^
    cp $@ $(RELEASE_DIR)

clean:
    rm -f $(TARGETS) $(RELEASE_DIR)/* ./*.o