【数据库开发】C++测试redis中的publish/subscribe

运用

http://blog.csdn.net/xumaojun/article/details/51558237 中的redis_publisher.hredis_publisher.cpp
redis_subscriber.h redis_subscriber.cpp四个文件,做一个操作类进行测试.

头文件 Policy.h

#pragma once
#include "redis_publisher.h"
#include "redis_subscriber.h"
#include <iostream>  

using namespace std;  

class Policy
{
public:
    Policy();
    ~Policy();
    void publish();
    static void recieve_message(const char *channel_name,const char *message, int len);  

    CRedisPublisher publisher;
    CRedisSubscriber subscriber;
};  

代码文件 Policy.cpp

#include "Policy.h"  

Policy::Policy()
{
    bool ret = publisher.init();
    if (!ret) {
        printf("Init failed.\n");  

    }  

    ret = publisher.connect();
    if (!ret) {
        printf("connect failed.");  

    }  

    //***********************************
    CRedisSubscriber::NotifyMessageFn fn =
        bind(recieve_message, std::tr1::placeholders::_1,
             std::tr1::placeholders::_2, std::tr1::placeholders::_3);  

    bool ret1 = subscriber.init(fn);
    if (!ret1) {
        printf("Init failed.\n");
    }  

    ret1 = subscriber.connect();
    if (!ret1) {
        printf("Connect failed.\n");
    }
    subscriber.subscribe("test-channel");
}  

Policy::~Policy()
{
    publisher.disconnect();
    publisher.uninit();  

    subscriber.disconnect();
    subscriber.uninit();
}  

void Policy::publish()
{
    cout<<"Policy::publish()...\n"<<endl;
    publisher.publish("test-channel", "Test message");
}  

void Policy::recieve_message(const char *channel_name,
    const char *message, int len)
{
    printf("Recieve message:    channel name: %s    message: %s\n",
        channel_name, message);
}

测试文件 testPolicy.cpp

#include "Policy.h"
int main(int argc, char *argv[])
{
    Policy m_policy;
    int i=0;
    while(i<8){
        m_policy.publish();
        sleep(2);
        cout<<"main sleep...\n";
        i++;
    }
    return 0;
}  

Makefile

EXE=server_main client_main
CC=g++
FLAG=-lhiredis -levent -pthread
OBJ=redis_publisher.o redis_subscriber.o Policy.o testPolicy.o    

all:$(EXE)  

$(EXE):$(OBJ)
    $(CC) -o testPolicy  redis_publisher.o redis_subscriber.o Policy.o testPolicy.o  $(FLAG)  

redis_publisher.o:redis_publisher.h
redis_subscriber.o:redis_subscriber.h  

Policy.o:Policy.h  

这样编译之后,可以自发自收.

本例的用途在于可以简单地在项目中实现异构的数据收发.

附上原作代码:

redis_publisher.h

/*************************************************************************
    > File Name: redis_publisher.h
    > Author: chenzengba
    > Mail: chenzengba@gmail.com
    > Created Time: Sat 23 Apr 2016 10:15:09 PM CST
    > Description: 封装hiredis，实现消息发布给redis功能
 ************************************************************************/    

#ifndef REDIS_PUBLISHER_H
#define REDIS_PUBLISHER_H    

#include <stdlib.h>
#include <hiredis/async.h>
#include <hiredis/adapters/libevent.h>
#include <string>
#include <vector>
#include <unistd.h>
#include <pthread.h>
#include <semaphore.h>
#include <boost/tr1/functional.hpp>    

class CRedisPublisher
{
public:
    CRedisPublisher();
    ~CRedisPublisher();    

    bool init();
    bool uninit();
    bool connect();
    bool disconnect();    

    bool publish(const std::string &channel_name,
        const std::string &message);    

private:
     // 下面三个回调函数供redis服务调用
    // 连接回调
    static void connect_callback(const redisAsyncContext *redis_context,
        int status);    

    // 断开连接的回调
    static void disconnect_callback(const redisAsyncContext *redis_context,
        int status);    

    // 执行命令回调
    static void command_callback(redisAsyncContext *redis_context,
        void *reply, void *privdata);    

    // 事件分发线程函数
    static void *event_thread(void *data);
    void *event_proc();    

private:
     // libevent事件对象
    event_base *_event_base;
    // 事件线程ID
    pthread_t _event_thread;
    // 事件线程的信号量
    sem_t _event_sem;
    // hiredis异步对象
    redisAsyncContext *_redis_context;
};    

redis_publisher.cpp

/*************************************************************************
    > File Name: redis_publisher.cpp
    > Author: chenzengba
    > Mail: chenzengba@gmail.com
    > Created Time: Sat 23 Apr 2016 10:15:09 PM CST
    > Description:
 ************************************************************************/    

#include <stddef.h>
#include <assert.h>
#include <string.h>
#include "redis_publisher.h"    

CRedisPublisher::CRedisPublisher():_event_base(0), _event_thread(0),
_redis_context(0)
{
}    

CRedisPublisher::~CRedisPublisher()
{
}    

bool CRedisPublisher::init()
{
    // initialize the event
    _event_base = event_base_new();    // 创建libevent对象
    if (NULL == _event_base)
    {
        printf(": Create redis event failed.\n");
        return false;
    }    

    memset(&_event_sem, 0, sizeof(_event_sem));
    int ret = sem_init(&_event_sem, 0, 0);
    if (ret != 0)
    {
        printf(": Init sem failed.\n");
        return false;
    }    

    return true;
}    

bool CRedisPublisher::uninit()
{
    _event_base = NULL;    

    sem_destroy(&_event_sem);
    return true;
}    

bool CRedisPublisher::connect()
{
    // connect redis
    _redis_context = redisAsyncConnect("127.0.0.1", 6379);    // 异步连接到redis服务器上，使用默认端口
    if (NULL == _redis_context)
    {
        printf(": Connect redis failed.\n");
        return false;
    }    

    if (_redis_context->err)
    {
        printf(": Connect redis error: %d, %s\n",
            _redis_context->err, _redis_context->errstr);    // 输出错误信息
        return false;
    }    

    // attach the event
    redisLibeventAttach(_redis_context, _event_base);    // 将事件绑定到redis context上，使设置给redis的回调跟事件关联    

    // 创建事件处理线程
    int ret = pthread_create(&_event_thread, 0, &CRedisPublisher::event_thread, this);
    if (ret != 0)
    {
        printf(": create event thread failed.\n");
        disconnect();
        return false;
    }    

    // 设置连接回调，当异步调用连接后，服务器处理连接请求结束后调用，通知调用者连接的状态
    redisAsyncSetConnectCallback(_redis_context,
        &CRedisPublisher::connect_callback);    

    // 设置断开连接回调，当服务器断开连接后，通知调用者连接断开，调用者可以利用这个函数实现重连
    redisAsyncSetDisconnectCallback(_redis_context,
        &CRedisPublisher::disconnect_callback);    

    // 启动事件线程
    sem_post(&_event_sem);
    return true;
}    

bool CRedisPublisher::disconnect()
{
    if (_redis_context)
    {
        redisAsyncDisconnect(_redis_context);
        redisAsyncFree(_redis_context);
        _redis_context = NULL;
    }    

    return true;
}    

bool CRedisPublisher::publish(const std::string &channel_name,
    const std::string &message)
{
    int ret = redisAsyncCommand(_redis_context,
        &CRedisPublisher::command_callback, this, "PUBLISH %s %s",
        channel_name.c_str(), message.c_str());
    if (REDIS_ERR == ret)
    {
        printf("Publish command failed: %d\n", ret);
        return false;
    }    

    return true;
}    

void CRedisPublisher::connect_callback(const redisAsyncContext *redis_context,
    int status)
{
    if (status != REDIS_OK)
    {
        printf(": Error: %s\n", redis_context->errstr);
    }
    else
    {
        printf(": Redis connected!\n");
    }
}    

void CRedisPublisher::disconnect_callback(
    const redisAsyncContext *redis_context, int status)
{
    if (status != REDIS_OK)
    {
        // 这里异常退出，可以尝试重连
        printf(": Error: %s\n", redis_context->errstr);
    }
}    

// 消息接收回调函数
void CRedisPublisher::command_callback(redisAsyncContext *redis_context,
    void *reply, void *privdata)
{
    printf("command callback.\n");
    // 这里不执行任何操作
}    

void *CRedisPublisher::event_thread(void *data)
{
    if (NULL == data)
    {
        printf(": Error!\n");
        assert(false);
        return NULL;
    }    

    CRedisPublisher *self_this = reinterpret_cast<CRedisPublisher *>(data);
    return self_this->event_proc();
}    

void *CRedisPublisher::event_proc()
{
    sem_wait(&_event_sem);    

    // 开启事件分发，event_base_dispatch会阻塞
    event_base_dispatch(_event_base);    

    return NULL;
}

redis_subscriber.h

/*************************************************************************
    > File Name: redis_subscriber.h
    > Author: chenzengba
    > Mail: chenzengba@gmail.com
    > Created Time: Sat 23 Apr 2016 10:15:09 PM CST
    > Description: 封装hiredis，实现消息订阅redis功能
 ************************************************************************/    

#ifndef REDIS_SUBSCRIBER_H
#define REDIS_SUBSCRIBER_H    

#include <stdlib.h>
#include <hiredis/async.h>
#include <hiredis/adapters/libevent.h>
#include <string>
#include <vector>
#include <unistd.h>
#include <pthread.h>
#include <semaphore.h>
#include <boost/tr1/functional.hpp>    

class CRedisSubscriber
{
public:
    typedef std::tr1::function<void (const char *, const char *, int)>         NotifyMessageFn;   // 回调函数对象类型，当接收到消息后调用回调把消息发送出去    

    CRedisSubscriber();
    ~CRedisSubscriber();    

    bool init(const NotifyMessageFn &fn);   // 传入回调对象
    bool uninit();
    bool connect();
    bool disconnect();    

    // 可以多次调用，订阅多个频道
    bool subscribe(const std::string &channel_name);    

private:
    // 下面三个回调函数供redis服务调用
    // 连接回调
    static void connect_callback(const redisAsyncContext *redis_context,
        int status);    

    // 断开连接的回调
    static void disconnect_callback(const redisAsyncContext *redis_context,
        int status);    

    // 执行命令回调
    static void command_callback(redisAsyncContext *redis_context,
        void *reply, void *privdata);    

    // 事件分发线程函数
    static void *event_thread(void *data);
    void *event_proc();    

private:
    // libevent事件对象
    event_base *_event_base;
    // 事件线程ID
    pthread_t _event_thread;
    // 事件线程的信号量
    sem_t _event_sem;
    // hiredis异步对象
    redisAsyncContext *_redis_context;    

    // 通知外层的回调函数对象
    NotifyMessageFn _notify_message_fn;
};    

redis_subscriber.cpp

/*************************************************************************
    > File Name: redis_subscriber.cpp
    > Author: chenzengba
    > Mail: chenzengba@gmail.com
    > Created Time: Sat 23 Apr 2016 10:15:09 PM CST
    > Description:
 ************************************************************************/    

#include <stddef.h>
#include <assert.h>
#include <string.h>
#include "redis_subscriber.h"    

CRedisSubscriber::CRedisSubscriber():_event_base(0), _event_thread(0),
_redis_context(0)
{
}    

CRedisSubscriber::~CRedisSubscriber()
{
}    

bool CRedisSubscriber::init(const NotifyMessageFn &fn)
{
    // initialize the event
    _notify_message_fn = fn;
    _event_base = event_base_new();    // 创建libevent对象
    if (NULL == _event_base)
    {
        printf(": Create redis event failed.\n");
        return false;
    }    

    memset(&_event_sem, 0, sizeof(_event_sem));
    int ret = sem_init(&_event_sem, 0, 0);
    if (ret != 0)
    {
        printf(": Init sem failed.\n");
        return false;
    }    

    return true;
}    

bool CRedisSubscriber::uninit()
{
    _event_base = NULL;    

    sem_destroy(&_event_sem);
    return true;
}    

bool CRedisSubscriber::connect()
{
    // connect redis
    _redis_context = redisAsyncConnect("127.0.0.1", 6379);    // 异步连接到redis服务器上，使用默认端口
    if (NULL == _redis_context)
    {
        printf(": Connect redis failed.\n");
        return false;
    }    

    if (_redis_context->err)
    {
        printf(": Connect redis error: %d, %s\n",
            _redis_context->err, _redis_context->errstr);    // 输出错误信息
        return false;
    }    

    // attach the event
    redisLibeventAttach(_redis_context, _event_base);    // 将事件绑定到redis context上，使设置给redis的回调跟事件关联    

    // 创建事件处理线程
    int ret = pthread_create(&_event_thread, 0, &CRedisSubscriber::event_thread, this);
    if (ret != 0)
    {
        printf(": create event thread failed.\n");
        disconnect();
        return false;
    }    

    // 设置连接回调，当异步调用连接后，服务器处理连接请求结束后调用，通知调用者连接的状态
    redisAsyncSetConnectCallback(_redis_context,
        &CRedisSubscriber::connect_callback);    

    // 设置断开连接回调，当服务器断开连接后，通知调用者连接断开，调用者可以利用这个函数实现重连
    redisAsyncSetDisconnectCallback(_redis_context,
        &CRedisSubscriber::disconnect_callback);    

    // 启动事件线程
    sem_post(&_event_sem);
    return true;
}    

bool CRedisSubscriber::disconnect()
{
    if (_redis_context)
    {
        redisAsyncDisconnect(_redis_context);
        redisAsyncFree(_redis_context);
        _redis_context = NULL;
    }    

    return true;
}    

bool CRedisSubscriber::subscribe(const std::string &channel_name)
{
    int ret = redisAsyncCommand(_redis_context,
        &CRedisSubscriber::command_callback, this, "SUBSCRIBE %s",
        channel_name.c_str());
    if (REDIS_ERR == ret)
    {
        printf("Subscribe command failed: %d\n", ret);
        return false;
    }    

    printf(": Subscribe success: %s\n", channel_name.c_str());
    return true;
}    

void CRedisSubscriber::connect_callback(const redisAsyncContext *redis_context,
    int status)
{
    if (status != REDIS_OK)
    {
        printf(": Error: %s\n", redis_context->errstr);
    }
    else
    {
        printf(": Redis connected!");
    }
}    

void CRedisSubscriber::disconnect_callback(
    const redisAsyncContext *redis_context, int status)
{
    if (status != REDIS_OK)
    {
        // 这里异常退出，可以尝试重连
        printf(": Error: %s\n", redis_context->errstr);
    }
}    

// 消息接收回调函数
void CRedisSubscriber::command_callback(redisAsyncContext *redis_context,
    void *reply, void *privdata)
{
    if (NULL == reply || NULL == privdata) {
        return ;
    }    

    // 静态函数中，要使用类的成员变量，把当前的this指针传进来，用this指针间接访问
    CRedisSubscriber *self_this = reinterpret_cast<CRedisSubscriber *>(privdata);
    redisReply *redis_reply = reinterpret_cast<redisReply *>(reply);    

    // 订阅接收到的消息是一个带三元素的数组
    if (redis_reply->type == REDIS_REPLY_ARRAY &&
    redis_reply->elements == 3)
    {
        printf(": Recieve message:%s:%d:%s:%d:%s:%d\n",
        redis_reply->element[0]->str, redis_reply->element[0]->len,
        redis_reply->element[1]->str, redis_reply->element[1]->len,
        redis_reply->element[2]->str, redis_reply->element[2]->len);    

        // 调用函数对象把消息通知给外层
        self_this->_notify_message_fn(redis_reply->element[1]->str,
            redis_reply->element[2]->str, redis_reply->element[2]->len);
    }
}    

void *CRedisSubscriber::event_thread(void *data)
{
    if (NULL == data)
    {
        printf(": Error!\n");
        assert(false);
        return NULL;
    }    

    CRedisSubscriber *self_this = reinterpret_cast<CRedisSubscriber *>(data);
    return self_this->event_proc();
}    

void *CRedisSubscriber::event_proc()
{
    sem_wait(&_event_sem);    

    // 开启事件分发，event_base_dispatch会阻塞
    event_base_dispatch(_event_base);    

    return NULL;
}