Community Learn Tools Library Leisure
search
English
Home > Database > Mysql Tutorial > 基于Hiredis异步API的聊天系统实现

基于Hiredis异步API的聊天系统实现

WBOY
Release： 2016-06-07 14:51:12
Original
1535 people have browsed it

基于Hiredis异步API的聊天系统实现 上一篇文章http://blog.csdn.net/qq_34788352/article/details/51313027使用Hiredis的同步API实现了发送消息的客户端，当我使用同步API实现订阅频道客户端时，一旦订阅频道，就会出现无法操作的情况，这是就是同步和异步的

基于Hiredis异步API的聊天系统实现

上一篇文章http://blog.csdn.net/qq_34788352/article/details/51313027使用Hiredis的同步API实现了发送消息的客户端，当我使用同步API实现订阅频道客户端时，一旦订阅频道，就会出现无法操作的情况，这是就是同步和异步的问题。使用同步API，订阅频道后，客户端会进入阻塞状态，等待订阅频道发布的消息，不能实现既订阅频道，又能发布消息的功能。为了实现一个客户端既能订阅频道，又能发布消息的功能，就需要使用Hiredis的异步API。

首先特别感谢黄天霸、tickTick、vah101，当我遇到各种各样奇怪问题的时候，你们的帖子给与了我解答，谢谢。

开始正题，hiredis异步的实现主要是依靠redis自带的ae事件库或者libev事件库或者libevent的事件库或者libuv事件库。网上一些人是通过libevent事件库来实现，本系统则使用Redis自带ae事件库来实现，Redis不用libevent事件库而选择重写一个ae事件库，必定有其道理。

首先介绍使用到的异步API，位于async.h中： 

<code class=" hljs perl">redisAsyncContext <span class="hljs-variable">*redisAsyncConnect</span>(const char <span class="hljs-variable">*ip</span>, <span class="hljs-keyword">int</span> port); <span class="hljs-regexp">//</span>用于建立异步连接

<span class="hljs-keyword">int</span> redisAsyncSetConnectCallback(redisAsyncContext <span class="hljs-variable">*ac</span>, redisConnectCallback <span class="hljs-variable">*fn</span>);  <span class="hljs-regexp">//</span>设置连接回调函数，回调函数形式：void callback(const redisAsyncContext <span class="hljs-variable">*c</span>, <span class="hljs-keyword">int</span> status);

<span class="hljs-keyword">int</span> redisAsyncSetDisconnectCallback(redisAsyncContext <span class="hljs-variable">*ac</span>, redisDisconnectCallback <span class="hljs-variable">*fn</span>);  <span class="hljs-regexp">//</span>设置断开连接回调函数,回调函数形式：void callback(const redisAsyncContext <span class="hljs-variable">*c</span>, <span class="hljs-keyword">int</span> status);

void redisAsyncDisconnect(redisAsyncContext <span class="hljs-variable">*ac</span>); <span class="hljs-regexp">//</span>断开异步连接

void redisAsyncFree(redisAsyncContext <span class="hljs-variable">*ac</span>); <span class="hljs-regexp">//</span>释放建立连接时，创建的redisAsyncContext结构

<span class="hljs-keyword">int</span> redisAsyncCommand(redisAsyncContext <span class="hljs-variable">*ac</span>, redisCallbackFn <span class="hljs-variable">*fn</span>, void <span class="hljs-variable">*privdata</span>, const char <span class="hljs-variable">*format</span>, ...); <span class="hljs-regexp">//</span>发送Redis命令，需要实现一个回调函数来出来命令的返回，fn是回调函数的地址,回调函数形式：void callback(redisAsyncContext <span class="hljs-variable">*c</span>, void <span class="hljs-variable">*reply</span>, void <span class="hljs-variable">*pridata</span>);
</code>
Copy after login

有了上面的异步API，就可以开始客户端的撰写。
首先封装订阅端

<code class=" hljs cpp"><span class="hljs-comment">//sub_client.h</span>

<span class="hljs-preprocessor">#ifndef REDIS_SUB_CLIENT_H  </span>
<span class="hljs-preprocessor">#define REDIS_SUB_CLIENT_H  </span>

<span class="hljs-keyword">extern</span> <span class="hljs-string">"C"</span>
{  
<span class="hljs-preprocessor">#include <stdlib.h>  </span>
<span class="hljs-preprocessor">#include <async.h>  </span>
<span class="hljs-preprocessor">#include <adapters/ae.h> </span>
<span class="hljs-preprocessor">#include <unistd.h>  </span>
<span class="hljs-preprocessor">#include <pthread.h>  </span>
<span class="hljs-preprocessor">#include <semaphore.h> </span>
} 

<span class="hljs-preprocessor">#include <string>  </span>
<span class="hljs-preprocessor">#include <vector>  </span>

<span class="hljs-keyword">using</span> <span class="hljs-keyword">namespace</span> <span class="hljs-built_in">std</span>;

<span class="hljs-keyword">class</span> CRedisSubClient  
{  
<span class="hljs-keyword">public</span>:   

    CRedisSubClient();  
    ~CRedisSubClient();  

    <span class="hljs-keyword">bool</span> init();   <span class="hljs-comment">//初始化，事件对象，信号量  </span>
    <span class="hljs-keyword">bool</span> uninit();  <span class="hljs-comment">//释放对象</span>
    <span class="hljs-keyword">bool</span> connect();  <span class="hljs-comment">//连接服务器</span>
    <span class="hljs-keyword">bool</span> disconnect(); <span class="hljs-comment">//断开服务器</span>

    <span class="hljs-comment">//订阅频道 </span>
    <span class="hljs-keyword">bool</span> subscribe(<span class="hljs-keyword">const</span> <span class="hljs-built_in">string</span> &channel_name);  

<span class="hljs-keyword">private</span>:  
    <span class="hljs-comment">// 下面三个回调函数供redis服务调用  </span>
    <span class="hljs-comment">// 连接回调  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> connect_callback(<span class="hljs-keyword">const</span> redisAsyncContext *redis_context,  
        <span class="hljs-keyword">int</span> status);  

    <span class="hljs-comment">// 断开连接的回调  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> disconnect_callback(<span class="hljs-keyword">const</span> redisAsyncContext *redis_context,  
        <span class="hljs-keyword">int</span> status);  

    <span class="hljs-comment">// 执行命令回调  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> command_callback(redisAsyncContext *redis_context,  
        <span class="hljs-keyword">void</span> *reply, <span class="hljs-keyword">void</span> *privdata);  

    <span class="hljs-comment">// 事件分发线程函数  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> *event_thread(<span class="hljs-keyword">void</span> *data);  
    <span class="hljs-keyword">void</span> *event_proc();  

<span class="hljs-keyword">private</span>:  
    <span class="hljs-comment">// ae事件对象  </span>
    aeEventLoop *loop;  
    <span class="hljs-comment">// 事件线程ID  </span>
    pthread_t _event_thread;  
    <span class="hljs-comment">// 事件线程的信号量  </span>
    sem_t _event_sem;  
    <span class="hljs-comment">// hiredis异步对象  </span>
    redisAsyncContext *_redis_context;  

};  

<span class="hljs-preprocessor">#endif  </span>
</code>
Copy after login

使用extern “C”是因为redis和hiredis都是c写的，当使用c++链接c代码生成的库中的函数时，会出现undefined reference的问题。

订阅端的实现

<code class=" hljs cpp"><span class="hljs-comment">//sub_client.cpp</span>

<span class="hljs-preprocessor">#include <stddef.h>  </span>
<span class="hljs-preprocessor">#include <assert.h>  </span>
<span class="hljs-preprocessor">#include <string.h>  </span>
<span class="hljs-preprocessor">#include "sub_client.h" </span>

<span class="hljs-keyword">using</span> <span class="hljs-keyword">namespace</span> <span class="hljs-built_in">std</span>; 

CRedisSubClient::CRedisSubClient():loop(<span class="hljs-number">0</span>), _event_thread(<span class="hljs-number">0</span>),  
_redis_context(<span class="hljs-number">0</span>)  
{  
}  

CRedisSubClient::~CRedisSubClient()  
{  
}  

<span class="hljs-keyword">bool</span> CRedisSubClient::init()  
{  

    loop = aeCreateEventLoop(<span class="hljs-number">64</span>);    <span class="hljs-comment">// 创建ae对象</span>

    <span class="hljs-keyword">if</span> (NULL == loop)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Create redis event failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-built_in">memset</span>(&_event_sem, <span class="hljs-number">0</span>, <span class="hljs-keyword">sizeof</span>(_event_sem)); 

    <span class="hljs-keyword">int</span> ret = sem_init(&_event_sem, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>);  <span class="hljs-comment">//初始化线程信号量</span>

    <span class="hljs-keyword">if</span> (ret != <span class="hljs-number">0</span>)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Init sem failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisSubClient::uninit()  
{  
    loop = NULL;  

    sem_destroy(&_event_sem);  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisSubClient::connect()  
{    
    _redis_context = redisAsyncConnect(<span class="hljs-string">"127.0.0.1"</span>, <span class="hljs-number">6379</span>);    <span class="hljs-comment">// 异步连接到redis服务器上，使用6380端口</span>

    <span class="hljs-keyword">if</span> (NULL == _redis_context)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">": Connect redis failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-keyword">if</span> (_redis_context->err)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Connect redis error: %d, %s\n"</span>,   
            _redis_context->err, _redis_context->errstr);    <span class="hljs-comment">// 输出错误信息  </span>
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    redisAeAttach(loop,_redis_context);   <span class="hljs-comment">// 将事件绑定到redis context上，使redis的回调跟事件关联  </span>

    <span class="hljs-comment">// 创建事件处理线程  </span>
    <span class="hljs-keyword">int</span> ret = pthread_create(&_event_thread, <span class="hljs-number">0</span>, &CRedisSubscriber::event_thread, <span class="hljs-keyword">this</span>);  

    <span class="hljs-keyword">if</span> (ret != <span class="hljs-number">0</span>)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Create event thread failed.\n"</span>);  
        disconnect();  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-comment">// 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  </span>
    redisAsyncSetConnectCallback(_redis_context,   
        &CRedisSubClient::connect_callback);  

    <span class="hljs-comment">// 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  </span>
    redisAsyncSetDisconnectCallback(_redis_context,  
        &CRedisSubClient::disconnect_callback);  

    <span class="hljs-comment">// 启动事件线程  </span>
    sem_post(&_event_sem);  
    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisSubClient::disconnect()  
{  
    <span class="hljs-keyword">if</span> (_redis_context)  
    {  
        redisAsyncDisconnect(_redis_context);  
        redisAsyncFree(_redis_context);  
        _redis_context = NULL;  
    }  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisSubClient::subscribe(<span class="hljs-keyword">const</span> <span class="hljs-built_in">string</span> &channel_name)  
{  
    <span class="hljs-keyword">int</span> ret = redisAsyncCommand(_redis_context,   
        &CRedisSubscriber::command_callback, <span class="hljs-keyword">this</span>, <span class="hljs-string">"SUBSCRIBE %s"</span>,   
        channel_name.c_str()); <span class="hljs-comment">//订阅一个频道</span>

    <span class="hljs-keyword">if</span> (REDIS_ERR == ret)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Subscribe command failed: %d\n"</span>, ret);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Subscribe success: %s\n"</span>, channel_name.c_str());  
    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">void</span> CRedisSubClient::connect_callback(<span class="hljs-keyword">const</span> redisAsyncContext *redis_context,  
    <span class="hljs-keyword">int</span> status)  
{  
    <span class="hljs-keyword">if</span> (status != REDIS_OK)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Error: %s\n"</span>, redis_context->errstr);  
    }  
    <span class="hljs-keyword">else</span>  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Redis connected!"</span>);  
    }  
}  

<span class="hljs-keyword">void</span> CRedisSubClient::disconnect_callback(  
    <span class="hljs-keyword">const</span> redisAsyncContext *redis_context, <span class="hljs-keyword">int</span> status)  
{  
    <span class="hljs-keyword">if</span> (status != REDIS_OK)  
    {    
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">": Error: %s\n"</span>, redis_context->errstr);  
    }  
}  

<span class="hljs-comment">// 消息接收回调函数  </span>
<span class="hljs-keyword">void</span> CRedisSubClient::command_callback(redisAsyncContext *redis_context,  
    <span class="hljs-keyword">void</span> *reply, <span class="hljs-keyword">void</span> *privdata)  
{  
    <span class="hljs-keyword">if</span> (NULL == reply || NULL == privdata) {  
        <span class="hljs-keyword">return</span> ;  
    }  

    redisReply *redis_reply = <span class="hljs-keyword">reinterpret_cast</span><redisReply *>(reply);  

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

<span class="hljs-keyword">void</span> *CRedisSubClient::event_thread(<span class="hljs-keyword">void</span> *data)  
{  
    <span class="hljs-keyword">if</span> (NULL == data)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">": Error!\n"</span>);  
        assert(<span class="hljs-keyword">false</span>);  
        <span class="hljs-keyword">return</span> NULL;  
    }  

    CRedisSubClient *self_this = <span class="hljs-keyword">reinterpret_cast</span><CRedisSubClient *>(data);  
    <span class="hljs-keyword">return</span> self_this->event_proc();  
}  

<span class="hljs-keyword">void</span> *CRedisSubClient::event_proc()  
{  
    sem_wait(&_event_sem);  

    <span class="hljs-comment">//进行事件处理循环  </span>
    aeMain(loop);  

    <span class="hljs-keyword">return</span> NULL;  
}  </code>
Copy after login

发布端的封装：

<code class=" hljs cpp"><span class="hljs-comment">//pub_client.h</span>

<span class="hljs-preprocessor">#ifndef REDIS_PUB_CLIENT_H  </span>
<span class="hljs-preprocessor">#define REDIS_PUB_CLIENT_H  </span>

<span class="hljs-keyword">extern</span> <span class="hljs-string">"C"</span>
{  
<span class="hljs-preprocessor">#include <stdlib.h>  </span>
<span class="hljs-preprocessor">#include <async.h>  </span>
<span class="hljs-preprocessor">#include <adapters/ae.h> </span>
<span class="hljs-preprocessor">#include <unistd.h>  </span>
<span class="hljs-preprocessor">#include <pthread.h>  </span>
<span class="hljs-preprocessor">#include <semaphore.h> </span>
} 

<span class="hljs-preprocessor">#include <string>  </span>
<span class="hljs-preprocessor">#include <vector>  </span>

<span class="hljs-keyword">using</span> <span class="hljs-keyword">namespace</span> <span class="hljs-built_in">std</span>;

<span class="hljs-keyword">class</span> CRedisPubClient  
{  
<span class="hljs-keyword">public</span>:   

    CRedisPubClient();  
    ~CRedisPubClient();  

    <span class="hljs-keyword">bool</span> init();   <span class="hljs-comment">//初始化，事件对象，信号量  </span>
    <span class="hljs-keyword">bool</span> uninit();  <span class="hljs-comment">//释放对象</span>
    <span class="hljs-keyword">bool</span> connect();  <span class="hljs-comment">//连接服务器</span>
    <span class="hljs-keyword">bool</span> disconnect();  <span class="hljs-comment">//断开服务器</span>

    <span class="hljs-comment">//订阅频道 </span>
    <span class="hljs-keyword">bool</span> publish(<span class="hljs-keyword">const</span> <span class="hljs-built_in">string</span> &channel_name, <span class="hljs-keyword">const</span> <span class="hljs-built_in">string</span> &message);  

<span class="hljs-keyword">private</span>:  
    <span class="hljs-comment">// 下面三个回调函数供redis服务调用  </span>
    <span class="hljs-comment">// 连接回调  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> connect_callback(<span class="hljs-keyword">const</span> redisAsyncContext *redis_context,  
        <span class="hljs-keyword">int</span> status);  

    <span class="hljs-comment">// 断开连接的回调  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> disconnect_callback(<span class="hljs-keyword">const</span> redisAsyncContext *redis_context,  
        <span class="hljs-keyword">int</span> status);  

    <span class="hljs-comment">// 执行命令回调  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> command_callback(redisAsyncContext *redis_context,  
        <span class="hljs-keyword">void</span> *reply, <span class="hljs-keyword">void</span> *privdata);  

    <span class="hljs-comment">// 事件分发线程函数  </span>
    <span class="hljs-keyword">static</span> <span class="hljs-keyword">void</span> *event_thread(<span class="hljs-keyword">void</span> *data);  
    <span class="hljs-keyword">void</span> *event_proc();  

<span class="hljs-keyword">private</span>:  
    <span class="hljs-comment">// ae事件对象  </span>
    aeEventLoop *loop;  
    <span class="hljs-comment">// 事件线程ID  </span>
    pthread_t _event_thread;  
    <span class="hljs-comment">// 事件线程的信号量  </span>
    sem_t _event_sem;  
    <span class="hljs-comment">// hiredis异步对象  </span>
    redisAsyncContext *_redis_context;  

};  

<span class="hljs-preprocessor">#endif  </span></code>
Copy after login

发布端的实现：

<code class=" hljs cpp"><span class="hljs-comment">//pub_client.cpp</span>

<span class="hljs-preprocessor">#include <stddef.h>  </span>
<span class="hljs-preprocessor">#include <assert.h>  </span>
<span class="hljs-preprocessor">#include <string.h>  </span>
<span class="hljs-preprocessor">#include "pub_client.h" </span>

<span class="hljs-keyword">using</span> <span class="hljs-keyword">namespace</span> <span class="hljs-built_in">std</span>; 

CRedisPubClient::CRedisPubClient():loop(<span class="hljs-number">0</span>), _event_thread(<span class="hljs-number">0</span>),  
_redis_context(<span class="hljs-number">0</span>)  
{  
}  

CRedisPubClient::~CRedisPubClient()  
{  
}  

<span class="hljs-keyword">bool</span> CRedisPubClient::init()  
{  

    loop = aeCreateEventLoop(<span class="hljs-number">64</span>);    <span class="hljs-comment">// 创建ae对象</span>

    <span class="hljs-keyword">if</span> (NULL == loop)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Create redis event failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-built_in">memset</span>(&_event_sem, <span class="hljs-number">0</span>, <span class="hljs-keyword">sizeof</span>(_event_sem)); 

    <span class="hljs-keyword">int</span> ret = sem_init(&_event_sem, <span class="hljs-number">0</span>, <span class="hljs-number">0</span>);  <span class="hljs-comment">//初始化线程信号量</span>

    <span class="hljs-keyword">if</span> (ret != <span class="hljs-number">0</span>)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Init sem failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisPubClient::uninit()  
{  
    loop = NULL;  

    sem_destroy(&_event_sem);  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisPubClient::connect()  
{    
    _redis_context = redisAsyncConnect(<span class="hljs-string">"127.0.0.1"</span>, <span class="hljs-number">6379</span>);    <span class="hljs-comment">// 异步连接到redis服务器上，使用6380端口</span>

    <span class="hljs-keyword">if</span> (NULL == _redis_context)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">": Connect redis failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-keyword">if</span> (_redis_context->err)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Connect redis error: %d, %s\n"</span>,   
            _redis_context->err, _redis_context->errstr);    <span class="hljs-comment">// 输出错误信息  </span>
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    redisAeAttach(loop,_redis_context);   <span class="hljs-comment">// 将事件绑定到redis context上，使redis的回调跟事件关联  </span>

    <span class="hljs-comment">// 创建事件处理线程  </span>
    <span class="hljs-keyword">int</span> ret = pthread_create(&_event_thread, <span class="hljs-number">0</span>, &CRedisSubscriber::event_thread, <span class="hljs-keyword">this</span>);  

    <span class="hljs-keyword">if</span> (ret != <span class="hljs-number">0</span>)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Create event thread failed.\n"</span>);  
        disconnect();  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-comment">// 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  </span>
    redisAsyncSetConnectCallback(_redis_context,   
        &CRedisSubClient::connect_callback);  

    <span class="hljs-comment">// 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  </span>
    redisAsyncSetDisconnectCallback(_redis_context,  
        &CRedisSubClient::disconnect_callback);  

    <span class="hljs-comment">// 启动事件线程  </span>
    sem_post(&_event_sem);  
    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisPubClient::disconnect()  
{  
    <span class="hljs-keyword">if</span> (_redis_context)  
    {  
        redisAsyncDisconnect(_redis_context);  
        redisAsyncFree(_redis_context);  
        _redis_context = NULL;  
    }  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;  
}  

<span class="hljs-keyword">bool</span> CRedisPubClient::publish(<span class="hljs-keyword">const</span> <span class="hljs-built_in">string</span> &channel_name, <span class="hljs-keyword">const</span> <span class="hljs-built_in">string</span> &message)  
{  
    <span class="hljs-keyword">int</span> ret = redisAsyncCommand(_redis_context,   
        &CRedisPublisher::command_callback, <span class="hljs-keyword">this</span>, <span class="hljs-string">"PUBLISH %s %s"</span>,   
        channel_name.c_str(), message.c_str());  <span class="hljs-comment">//发布消息  </span>

    <span class="hljs-keyword">if</span> (REDIS_ERR == ret)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Publish command failed: %d\n"</span>, ret);  
        <span class="hljs-keyword">return</span> <span class="hljs-keyword">false</span>;  
    }  

    <span class="hljs-keyword">return</span> <span class="hljs-keyword">true</span>;    
}  

<span class="hljs-keyword">void</span> CRedisPubClient::connect_callback(<span class="hljs-keyword">const</span> redisAsyncContext *redis_context,  
    <span class="hljs-keyword">int</span> status)  
{  
    <span class="hljs-keyword">if</span> (status != REDIS_OK)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Error: %s\n"</span>, redis_context->errstr);  
    }  
    <span class="hljs-keyword">else</span>  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Redis connected!"</span>);  
    }  
}  

<span class="hljs-keyword">void</span> CRedisPubClient::disconnect_callback(  
    <span class="hljs-keyword">const</span> redisAsyncContext *redis_context, <span class="hljs-keyword">int</span> status)  
{  
    <span class="hljs-keyword">if</span> (status != REDIS_OK)  
    {    
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">": Error: %s\n"</span>, redis_context->errstr);  
    }  
}  

<span class="hljs-comment">// 消息接收回调函数  </span>
<span class="hljs-keyword">void</span> CRedisPubClient::command_callback(redisAsyncContext *redis_context,  
    <span class="hljs-keyword">void</span> *reply, <span class="hljs-keyword">void</span> *privdata)  
{  
    <span class="hljs-keyword">if</span> (NULL == reply || NULL == privdata) 
    {  
        <span class="hljs-keyword">return</span> ;  
    }  

    redisReply *redis_reply = <span class="hljs-keyword">reinterpret_cast</span><redisReply *>(reply); 

    <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Publish: %s"</span>,redis_reply.str);
}  

<span class="hljs-keyword">void</span> *CRedisPubClient::event_thread(<span class="hljs-keyword">void</span> *data)  
{  
    <span class="hljs-keyword">if</span> (NULL == data)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">": Error!\n"</span>);  
        assert(<span class="hljs-keyword">false</span>);  
        <span class="hljs-keyword">return</span> NULL;  
    }  

    CRedisPubClient *self_this = <span class="hljs-keyword">reinterpret_cast</span><CRedisPubClient *>(data);  
    <span class="hljs-keyword">return</span> self_this->event_proc();  
}  

<span class="hljs-keyword">void</span> *CRedisPubClient::event_proc()  
{  
    sem_wait(&_event_sem);  

    <span class="hljs-comment">//进行事件处理循环  </span>
    aeMain(loop);  

    <span class="hljs-keyword">return</span> NULL;  
}  </code>
Copy after login

测试封装的sub_client和pub_client类:

<code class=" hljs cpp"><span class="hljs-comment">//test_subpub.cpp</span>

<span class="hljs-preprocessor">#include "pub_client.h"</span>
<span class="hljs-preprocessor">#include "sub_client.h"  </span>

<span class="hljs-keyword">int</span> main(<span class="hljs-keyword">int</span> argc, <span class="hljs-keyword">char</span> *argv[])  
{  
    CRedisPubClient publisher;  
    CRedisSubClient subcriber;

    <span class="hljs-keyword">bool</span> ret_pub = publisher.init();  
    <span class="hljs-keyword">bool</span> ret_sub = subcriber.init();

    <span class="hljs-keyword">if</span> (!ret_sub&&!ret_pub)   
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"Init failed.\n"</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;  
    }  

    ret_pub = publisher.connect(); 
    ret_sub = subcriber.connect(); 

    <span class="hljs-keyword">if</span> (!ret_sub&&!ret_pub)  
    {  
        <span class="hljs-built_in">printf</span>(<span class="hljs-string">"connect failed."</span>);  
        <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;  
    }  

    subscriber.subcribe(<span class="hljs-string">"sports"</span>);

    <span class="hljs-keyword">while</span> (<span class="hljs-keyword">true</span>)  
    {  
        publisher.publish(<span class="hljs-string">"sports"</span>, <span class="hljs-string">"ball"</span>);  
        sleep(<span class="hljs-number">1</span>);  
    }  

    publisher.disconnect();  
    publisher.uninit();  
    subscriber.disconnect();
    subscriber.disconnect();
    <span class="hljs-keyword">return</span> <span class="hljs-number">0</span>;  

} </code>
Copy after login

终于到了编译链接运行的阶段，我在这个地方卡了快一天，期间各种编译、链接的错误。直接编译链接会出现找到不aeCreateFileEvent，aeDeleteFileEvent，aeMain等等错误。

  1. 先将redis/src文件夹中的ae.c，ae.h，ae_epoll.c，config.h，zmalloc.c，zmalloc.h拷贝至hiredis目录下
  2. 用gcc -c ae.c gcc -c zmalloc.c生成ae.o和zmalloc.o，利用这两个文件生成静态库 ar -r libar.a ae.o zmalloc.o
  3. 然后编译g++ -o test_subpub test_subpub.cpp pub_client.cpp sub_client.cpp -pthread -I ../ -I./ -I ../adapters ../libhiredis.a ../libae.a
  4. 运行./test_subpub

可以看到，客户端中消息在不断地滚动，即同时实现了订阅频道和发送消息的功能。

Related labels：
api based on accomplish asynchronous system chat
source：php.cn
Previous article：[置顶] Mongodb的主从模式搭建实例 Next article：MySQL常见问题和应用技巧
Statement of this Website
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn
Latest Articles by Author
Latest Issues
Where is the courseware about CSS mind mapping? Courseware
From 2024-04-16 10:10:18
0
0
1335
Move the content to the left by adding the Width property I have provided margins to the body. main {left margin: 200px; right margin: 200px; text a...
From 2024-04-06 22:01:35
0
3
816
Where should I place CustomLog directive in apache I'm using php:7.2-apachedocker. I need to disable health check url login access log. Based...
From 2024-04-06 22:03:59
0
1
990
The query and formula form the entire table, with new columns, where the new columns are formulas involving other conditional column values EDIT: The formula should be the "value" column - the "value" column wi...
From 2024-04-06 21:23:40
0
2
530
Creating this specific design using a grid: a step-by-step guide I'm trying to create a layout similar to this image, I've tried using this grid but can't ...
From 2024-04-06 20:29:08
0
2
492
Related Topics
More>
Popular Recommendations
Popular Tutorials
More>
Related Tutorials
Popular Recommendations
Latest courses
Latest Downloads
More>
Web Effects
Website Source Code
Website Materials
Front End Template