hiredis中异步的实现小结

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <signal.h>

#include <hiredis.h>
#include <async.h>
#include <adapters/libevent.h>

//设置命令执行后的回调函数
void getCallback(redisAsyncContext *c, void *r, void *privdata) {
    redisReply *reply = r;
    if (reply == NULL) return;
    printf("argv[%s]: %s\n", (char*)privdata, reply->str);

    /* Disconnect after receiving the reply to GET */
    redisAsyncDisconnect(c);
}

//设置连接回调函数
void connectCallback(const redisAsyncContext *c, int status) {
    if (status != REDIS_OK) {
        printf("Error: %s\n", c->errstr);
        return;
    }
    printf("Connected...\n");
}

//设置断开连接回调函数
void disconnectCallback(const redisAsyncContext *c, int status) {
    if (status != REDIS_OK) {
        printf("Error: %s\n", c->errstr);
        return;
    }
    printf("Disconnected...\n");
}

int main (int argc, char **argv) {
    signal(SIGPIPE, SIG_IGN);//捕捉程序收到数据包时候的信号
    struct event_base *base = event_base_new();//新建一个libevent事件处理

    redisAsyncContext *c = redisAsyncConnect("127.0.0.1", 6379);//新建异步连接
    if (c->err) {
        /* Let *c leak for now... */
        printf("Error: %s\n", c->errstr);
        return 1;
    }

    redisLibeventAttach(c,base);//将连接添加到libevent事件处理
    redisAsyncSetConnectCallback(c,connectCallback);//设置连接回调
    redisAsyncSetDisconnectCallback(c,disconnectCallback);//设置断开连接回调
    redisAsyncCommand(c, NULL, NULL, "SET key %b", argv[argc-1], strlen(argv[argc-1]));//发送set命令
    redisAsyncCommand(c, getCallback, (char*)"end-1", "GET key");//发送get命令
    event_base_dispatch(base);//开始libevent循环。注意在这一步之前redis是不会进行连接的，前边调用的命令发送函数也没有真正发送命令
    return 0;
}