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>
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>
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>
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>
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>
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>
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。
- 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
- 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
- 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
- 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。
성명
본 글의 내용은 네티즌들의 자발적인 기여로 작성되었으며, 저작권은 원저작자에게 있습니다. 본 사이트는 이에 상응하는 법적 책임을 지지 않습니다. 표절이나 침해가 의심되는 콘텐츠를 발견한 경우 admin@php.cn으로 문의하세요.
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