Rumah > Artikel > pembangunan bahagian belakang > php长连接,奏是这么简单_PHP教程
说到长链接大家肯定不陌生,就是复用一个链接持续不断的进行数据交互,它不像那些一夜情似的服务,需要频繁的打开和关闭链接,效率低的同时还增加了业务的复杂度。在裆下很多互联网业务场景都需要长连接的支持,比如:游戏、聊天、信息推送等等等,今天我们就一步一步来揭秘php长连接的玩法。我相信任何一项技术的实施都是因为业务场景的需要,所以这次我们还拿聊天室说事儿。
0x00 初试牛刀
记得以前用php写聊天室还是用polling的方式,毫无疑问,一提到polling,肯定会有人说long polling,没错!long polling也很不错,但在nginx+fpm上面玩这个多少有些费劲,毕竟一个请求需要占一个php进程(就算是用apache+php_mod,也需要一个请求一个线程),所以要是几个人随便玩玩还行,一旦放到线上人多起来,这基本就废了。所以还是采用polling的方式,这样不会阻塞进程,并且一个请求能立即得到响应,但是带来的新问题是需要不停的向服务器发送请求,而且随着间隔的时间越大导致消息延迟就越大。
0x01 华丽变身
在经历了上面那种一秒一小卡,三秒一大卡的场面!再也看不下去了,于是决定变身为真正的男人,哦不对,应该是真正的长连接。去他妈的polling, 去他妈的long polling,去他妈的webserver,统统靠边站,让flash socket(或者说websocket)来统治这个世界!开始了真正意义上的长连接之旅。要玩长连接总是少不了跟socket打交道吧,作为世界上最好的语言(没有之一),socket的封装自然是少不了滴。抄起socket_***就开干,于是就有了下面这一托代码,长连接是吧?延迟是吧?socket是吧?汤药费是吧?so easy....
<ol class="dp-c"><li class="alt"><span><span class="vars">$sfd</span><span> = socket_create(AF_INET, SOCK_STREAM, 0); </span></span></li><li><span> </span></li><li class="alt"><span>socket_bind(<span class="vars">$sfd</span><span>, </span><span class="string">"0.0.0.0"</span><span>, 1234); </span></span></li><li><span> </span></li><li class="alt"><span>socket_listen(<span class="vars">$sfd</span><span>, 511); </span></span></li><li><span> </span></li><li class="alt"><span>socket_set_option(<span class="vars">$sfd</span><span>, SOL_SOCKET, SO_REUSEADDR, 1); </span></span></li><li><span> </span></li><li class="alt"><span>socket_set_nonblock(<span class="vars">$sfd</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$rfds</span><span> = </span><span class="keyword">array</span><span>(</span><span class="vars">$sfd</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$wfds</span><span> = </span><span class="keyword">array</span><span>(); </span></span></li><li><span> </span></li><li class="alt"><span><span class="keyword">do</span><span>{ </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$rs</span><span> = </span><span class="vars">$rfds</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$ws</span><span> = </span><span class="vars">$wfds</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$es</span><span> = </span><span class="keyword">array</span><span>(); </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$ret</span><span> = socket_select(</span><span class="vars">$rs</span><span>, </span><span class="vars">$ws</span><span>, </span><span class="vars">$es</span><span>, 3); </span></span></li><li><span> </span></li><li class="alt"><span> </span></li><li><span> </span></li><li class="alt"><span> <span class="comment">//read event</span><span> </span></span></li><li><span> </span></li><li class="alt"><span> <span class="keyword">foreach</span><span>(</span><span class="vars">$rs</span><span> </span><span class="keyword">as</span><span> </span><span class="vars">$fd</span><span>){ </span></span></li><li><span> </span></li><li class="alt"><span> <span class="keyword">if</span><span>(</span><span class="vars">$fd</span><span> == </span><span class="vars">$sfd</span><span>){ </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$cfd</span><span> = socket_accept(</span><span class="vars">$sfd</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span> socket_set_nonblock(<span class="vars">$cfd</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$rfds</span><span>[] = </span><span class="vars">$cfd</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span> <span class="func">echo</span><span> </span><span class="string">"new client coming, fd=$cfd\n"</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span> }<span class="keyword">else</span><span>{ </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$msg</span><span> = socket_read(</span><span class="vars">$fd</span><span>, 1024); </span></span></li><li><span> </span></li><li class="alt"><span> <span class="keyword">if</span><span>(</span><span class="vars">$msg</span><span> <= 0){ </span></span></li><li><span> </span></li><li class="alt"><span> <span class="comment">//close</span><span> </span></span></li><li><span> </span></li><li class="alt"><span> }<span class="keyword">else</span><span>{ </span></span></li><li><span> </span></li><li class="alt"><span> <span class="comment">//recv msg</span><span> </span></span></li><li><span> </span></li><li class="alt"><span> <span class="func">echo</span><span> </span><span class="string">"on message, fd=$fd data=$msg\n"</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span> } </span></li><li><span> </span></li><li class="alt"><span> } </span></li><li><span> </span></li><li class="alt"><span> } </span></li><li><span> </span></li><li class="alt"><span> </span></li><li><span> </span></li><li class="alt"><span> <span class="comment">//write event</span><span> </span></span></li><li><span> </span></li><li class="alt"><span> <span class="keyword">foreach</span><span>(</span><span class="vars">$ws</span><span> </span><span class="keyword">as</span><span> </span><span class="vars">$fd</span><span>){ </span></span></li><li><span> </span></li><li class="alt"><span> socket_write(<span class="vars">$fd</span><span>, ........); </span></span></li><li><span> </span></li><li class="alt"><span> } </span></li><li><span> </span></li><li class="alt"><span> </span></li><li><span> </span></li><li class="alt"><span>}<span class="keyword">while</span><span>(true); </span></span></li></ol>
0x02 登峰造极
从玩socket的那天起,google就轻言细语的跟我说,高并发下的select不要用啊,效率底啊,win要用iocp啊, linux要用epoll啊,blablablabla...哦!好吧,既然google都这么说了,我也不能跟他老人家较真不是,又一次决定(为什么要说又呢?)要听google话,把epoll搞起来,可总不能自己写啊?像我这么懒的人还是整个扩展好了,libevent走你!经过疯狂的编(co)码(py),神作终于出山,具体能有多高效,能撑多少并发,不造,反正没用select了,我奏是屌!
<ol class="dp-c"><li class="alt"><span><span class="vars">$sfd</span><span> = stream_socket_server (</span><span class="string">'tcp://0.0.0.0:1234'</span><span>, </span><span class="vars">$errno</span><span>, </span><span class="vars">$errstr</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span>stream_set_blocking(<span class="vars">$sfd</span><span>, 0); </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$base</span><span> = event_base_new(); </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$event</span><span> = event_new(); </span></span></li><li><span> </span></li><li class="alt"><span>event_set(<span class="vars">$event</span><span>, </span><span class="vars">$sfd</span><span>, EV_READ | EV_PERSIST, </span><span class="string">'ev_accept'</span><span>, </span><span class="vars">$base</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span>event_base_set(<span class="vars">$event</span><span>, </span><span class="vars">$base</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span>event_add(<span class="vars">$event</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span>event_base_loop(<span class="vars">$base</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="keyword">function</span><span> ev_accept(</span><span class="vars">$socket</span><span>, </span><span class="vars">$flag</span><span>, </span><span class="vars">$base</span><span>) </span></span></li><li><span> </span></li><li class="alt"><span>{ </span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$connection</span><span> = stream_socket_accept(</span><span class="vars">$socket</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span> stream_set_blocking(<span class="vars">$connection</span><span>, 0); </span></span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$buffer</span><span> = event_buffer_new(</span><span class="vars">$connection</span><span>, </span><span class="string">'ev_read'</span><span>, NULL, </span><span class="string">'ev_error'</span><span>, </span><span class="vars">$connection</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span> event_buffer_base_set(<span class="vars">$buffer</span><span>, </span><span class="vars">$base</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span> event_buffer_timeout_set(<span class="vars">$buffer</span><span>, 30, 30); </span></span></li><li><span> </span></li><li class="alt"><span> event_buffer_watermark_set(<span class="vars">$buffer</span><span>, EV_READ, 0, 0xffffff); </span></span></li><li><span> </span></li><li class="alt"><span> event_buffer_priority_set(<span class="vars">$buffer</span><span>, 10); </span></span></li><li><span> </span></li><li class="alt"><span> event_buffer_enable(<span class="vars">$buffer</span><span>, EV_READ | EV_PERSIST); </span></span></li><li><span> </span></li><li class="alt"><span>} </span></li><li><span> </span></li><li class="alt"><span><span class="keyword">function</span><span> ev_error(</span><span class="vars">$buffer</span><span>, </span><span class="vars">$error</span><span>, </span><span class="vars">$connection</span><span>) </span></span></li><li><span> </span></li><li class="alt"><span>{ </span></li><li><span> </span></li><li class="alt"><span> event_buffer_disable(<span class="vars">$buffer</span><span>, EV_READ | EV_WRITE); </span></span></li><li><span> </span></li><li class="alt"><span> event_buffer_free(<span class="vars">$buffer</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span> fclose(<span class="vars">$connection</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span>} </span></li><li><span> </span></li><li class="alt"><span><span class="keyword">function</span><span> ev_read(</span><span class="vars">$buffer</span><span>, </span><span class="vars">$connection</span><span>) </span></span></li><li><span> </span></li><li class="alt"><span>{ </span></li><li><span> </span></li><li class="alt"><span> <span class="vars">$read</span><span> = event_buffer_read(</span><span class="vars">$buffer</span><span>, 256); </span></span></li><li><span> </span></li><li class="alt"><span> <span class="comment">//do something....</span><span> </span></span></li><li><span> </span></li><li class="alt"><span>} </span></li></ol>
0x03 绝处逢生
随着人数的增长,并发的提升,单个进程已经满足不了需求了,田伯光的故事告诉我们,单挑是斗不过群P的,咋整?俗话说,大事化小,小事化,停!!别化了,再化就没了。拆吧,把单进程拆成多进程,可是拆完之后又面临新的问题,进程间通信、负载均衡、session唯一等。既然已经提出这样的问题,肯定是有解决方案,现成的就有扩展和库来解决这个事,比如:swoole,workerman等?相比之下swoole更屌一些,性、功能,呃!好像这样简写不太雅观,好吧,性能和功能更屌一些(桶哥,请原谅我的无聊~)。。。。等一下!!!但是,我们在使用php来开发web的时候,也没有使用webserver相关的库来做开发对不对?咱只是简单的echo而已。这些繁杂的事都交给了nginx或者是apache,是他们义无反顾的顶在前面,让我们可以专心写逻辑。写web我们只需要简单的配置nginx和fpm就好了,那写socket服务呢?我们为什么不能像nginx+fpm一样简单配置就好了呢??当然能,必须能。。。。。看这个剧情怕是广告要来了。。。
0x04 出其不意
写socket服务不比写web高级,都是打码,都是完成需求,通信那层都是固定的,只不过一个由nginx完成,另一个由自己完成。。可是现在不需要自己完成了,类似nginx+fpm的方案,fooking+fpm=php长连接,gateway用于承载连接,router用于转发消息,进程间通信?负载均衡?session唯一?so easy..
<ol class="dp-c"><li class="alt"><span><span class="vars">$sid</span><span> = </span><span class="vars">$_SERVER</span><span>[</span><span class="string">'SESSIONID'</span><span>];</span><span class="comment">//这是sessionid</span><span> </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$data</span><span> = </span><span class="func">file_get_contents</span><span>(</span><span class="string">"php://input"</span><span>);//这样就能拿到请求内容了 </span></span></li><li><span> </span></li><li class="alt"><span><span class="comment">//想要返回消息只需要两步</span><span> </span></span></li><li><span> </span></li><li class="alt"><span>header(<span class="string">'Content-Length: 11'</span><span>);</span><span class="comment">//返回给客户端字节数</span><span> </span></span></li><li><span> </span></li><li class="alt"><span><span class="func">echo</span><span> </span><span class="string">"hello world"</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span><span class="comment">//想要给别的用户发消息</span><span> </span></span></li><li><span> </span></li><li class="alt"><span><span class="keyword">include</span><span> </span><span class="string">'api.php'</span><span>; </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$router</span><span> = </span><span class="keyword">new</span><span> RouterClient(</span><span class="string">'router host'</span><span>, </span><span class="string">'router port'</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$router</span><span>->sendMsg(用户sessionid, </span><span class="string">"fuck you"</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="comment">//想要给所有人要消息</span><span> </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$router</span><span>->sendAllMsg(</span><span class="string">"fuck all"</span><span>); </span></span></li><li><span> </span></li><li class="alt"><span><span class="comment">//想给指定组发消息(类似redis的pub/sub)</span><span> </span></span></li><li><span> </span></li><li class="alt"><span><span class="vars">$router</span><span>->publish(</span><span class="string">"channel name"</span><span>, </span><span class="string">"fuck all"</span><span>); </span></span></li></ol>
项目地址: http://git.oschina.net/scgywx/fooking
文档地址(不定期更新):http://my.oschina.net/scgywx/blog/465186