Event擴(kuò)展

Event可以認(rèn)為是替代libevent最好的擴(kuò)展，因?yàn)閘ibevent已經(jīng)很久不更新了，而Event一直在更新，而且Event支持更多特性，使用起來(lái)也比libevent簡(jiǎn)單。

Event地址: http://pecl.php.net/package/event
Event文檔: http://docs.php.net/event

和libevent一樣，系統(tǒng)需要先安裝 Libevent 庫(kù)，因?yàn)槎际腔?Libevent 庫(kù)開(kāi)發(fā)的：

yum install libevent-dev

然后安裝PHP擴(kuò)展。

PHP7安裝：

pecl install event

Event擴(kuò)展不支持PHP5。

注：后面的代碼示例均使用的php7.1 + event環(huán)境。

基本使用

我們把libevent_tcp_server.php的例子改為Event實(shí)現(xiàn)的：

event_tcp_server.php

<?php /*** Created by PhpStorm.* User: 公眾號(hào): 飛鴻影的博客(fhyblog)* Date: 2018/6/23*/$receive = []; $master = []; $buffers = [];$socket = stream_socket_server ("tcp://0.0.0.0:9201", $errno, $errstr); if (false === $socket ) {echo "$errstr($errno)\n";exit(); } if (!$socket) die($errstr."--".$errno); //stream_set_blocking($socket,0); //可選 $id = (int)$socket; $master[$id] = $socket;echo "waiting client...\n";//accept事件回調(diào)函數(shù)，參數(shù)分別是$fd, $events, $arg function ev_accept($socket, $flag, $base){global $receive;global $master;global $buffers;$connection = stream_socket_accept($socket);stream_set_blocking($connection, 0);//必須$id = (int)$connection;echo "new Client $id\n";$event = new Event($base, $connection, Event::READ | Event::PERSIST, 'ev_read', $id); $event->add();$master[$id] = $connection; //根據(jù)業(yè)務(wù)可選$receive[$id] = ''; //根據(jù)業(yè)務(wù)可選$buffers[$id] = $event; //根據(jù)業(yè)務(wù)可選 }//read事件回調(diào)函數(shù) function ev_read($buffer, $flag, $id) {global $receive;global $master;global $buffers;//該方法里的$buffer和$master[$id]指向相同的內(nèi)容// var_dump(func_get_args(), $master[$id] );//循環(huán)讀取并解析客戶端消息while( 1 ) {$read = @fread($buffer, 1024);//客戶端異常斷開(kāi)if($read === '' || $read === false){break;}$pos = strpos($read, "\n");if($pos === false){$receive[$id] .= $read;// echo "received:".$read.";not all package,continue recdiveing\n";}else{$receive[$id] .= trim(substr ($read,0,$pos+1));$read = substr($read,$pos+1);switch ( $receive[$id] ){case "quit":echo "client close conn\n";//關(guān)閉客戶端連接unset($master[$id]);//斷開(kāi)客戶端連接unset($buffers[$id]);//刪除事件break;default:// echo "all package:\n";echo $receive[$id]."\n";break;}$receive[$id]='';}} }//創(chuàng)建全局event base $base = new EventBase(); //創(chuàng)建并設(shè)置 event：其中$events設(shè)置為READ | PERSIST ；回調(diào)事件為ev_accept，參數(shù) $base //PERSIST可以讓注冊(cè)的事件在執(zhí)行完后不被刪除,直到調(diào)用Event::del()刪除. $event = new Event($base, $socket, Event::READ | Event::PERSIST, 'ev_accept', $base); $event->add(); echo "start run...\n";//進(jìn)入事件循環(huán) $base->loop();//下面這句不會(huì)被執(zhí)行 echo "This code will not be executed.\n";

可以發(fā)現(xiàn)做的改動(dòng)非常小，而且代碼更簡(jiǎn)潔了。運(yùn)行腳本后，我們使用telnet測(cè)試，效果一模一樣。

使用Buffer

直接看例子吧，還是基于上面的例子改的，注釋里寫得很清楚了：

event_buffer_tcp_server.php

<?php /*** Created by PhpStorm.* User: 公眾號(hào): 飛鴻影的博客(fhyblog)* Date: 2018/6/23*/$receive = []; $master = []; $buffers = [];$socket = stream_socket_server ("tcp://0.0.0.0:9201", $errno, $errstr); if (false === $socket ) {echo "$errstr($errno)\n";exit(); } if (!$socket) die($errstr."--".$errno); //stream_set_blocking($socket,0);//可選 $id = (int)$socket; $master[$id] = $socket;echo "waiting client...\n";//accept事件回調(diào)函數(shù)，參數(shù)分別是$fd, $events, $arg function ev_accept($socket, $flag, $base){global $receive;global $master;global $buffers;$connection = stream_socket_accept($socket);//stream_set_blocking($connection, 0);//可選$id = (int)$connection;echo "new Client $id\n";//新建EventBuffer 事件$event = new EventBufferEvent($base, $connection, 0, 'ev_read', 'ev_write', 'ev_status', $id); $event->setTimeouts(30, 30); //read and write timeout $event->setWatermark ( Event::READ, 0, 0xffffff ); //Adjusts read and/or write watermarks$event->setPriority(10);$event->enable(Event::READ | Event::PERSIST);$master[$id] = $connection; //如果去掉該行，客戶端直接被斷開(kāi)$receive[$id] = ''; //如果去掉該行，服務(wù)端無(wú)法正常收到消息$buffers[$id] = $event; //如果去掉該行，客戶端強(qiáng)制斷開(kāi)再連接，服務(wù)端無(wú)法正常收到消息 }//read事件回調(diào)函數(shù)，參數(shù)分別是EventBufferEvent，arg function ev_read($buffer, $id) {global $receive;global $master;global $buffers;//該方法里的$buffer和$buffers[$id]指向相同的內(nèi)容// var_dump(func_get_args(), $buffers[$id], $master[$id]);//循環(huán)讀取并解析客戶端消息while( 1 ) {$read = $buffer->read(65535);// var_dump($read);//客戶端異常斷開(kāi)；這里可能返回NULLif($read === '' || $read === false || $read === NULL){break;}$pos = strpos($read, "\n");if($pos === false){$receive[$id] .= $read;echo "received:".$read.";not all package,continue recdiveing\n";}else{$receive[$id] .= trim(substr ($read,0,$pos+1));$read = substr($read,$pos+1);switch ( $receive[$id] ){case "quit":echo "client close conn\n";//關(guān)閉客戶端連接unset($master[$id]);//斷開(kāi)客戶端連接unset($buffers[$id]);//刪除事件break;default:// echo "all package:\n";echo $receive[$id]."\n";break;}$receive[$id]='';}} }function ev_write($buffer, $id) {echo "$id -- " ."\n"; }function ev_status($buffer, $events, $id) {echo "ev_status - ".$events."\n"; }//創(chuàng)建全局event base $base = new EventBase(); //創(chuàng)建并設(shè)置 event：其中$events設(shè)置為READ | PERSIST ；回調(diào)事件為ev_accept，參數(shù) $base //PERSIST可以讓注冊(cè)的事件在執(zhí)行完后不被刪除,直到調(diào)用Event::del()刪除. $event = new Event($base, $socket, Event::READ | Event::PERSIST, 'ev_accept', $base); $event->add(); echo "start run...\n";//進(jìn)入事件循環(huán) $base->loop();//下面這句不會(huì)被執(zhí)行 echo "This code will not be executed.\n";

定時(shí)器(Timer)

直接看示例：
event_timer.php

<?php /*** Created by PhpStorm.* User: 公眾號(hào): 飛鴻影的博客(fhyblog)* Date: 2018/6/23*/$base = new EventBase (); $n = 2 ; //sec//初始化定時(shí)器 $e = Event :: timer ( $base , function( $arg ) use (& $e ) {echo " $arg seconds elapsed\n" ;$e -> delTimer (); }, $n );//添加定時(shí)器 $e -> addTimer ( $n ); //sec$base -> loop ();

運(yùn)行：

$ php event_timer.php 2 seconds elapsed

和libevent擴(kuò)展一樣，Event::timer也是對(duì)Event的封裝：

<?php /*** Created by PhpStorm.* User: 公眾號(hào): 飛鴻影的博客(fhyblog)* Date: 2018/6/23*/$base = new EventBase (); $n = 2 ; //sec//初始化定時(shí)器 $event = new Event($base, null, Event::TIMEOUT, 'ev_timer', $n ); $event->add($n);//secfunction ev_timer($fd, $what, $arg){echo " $arg seconds elapsed\n" ;global $event;$event->del(); }$base->loop();

Event提供的定時(shí)器精度是秒。

信號(hào)(Signal)

Event 擴(kuò)展提供了信號(hào)（Signal）操作的函數(shù)。

<?php /*** Created by PhpStorm.* User: 公眾號(hào): 飛鴻影的博客(fhyblog)* Date: 2018/6/23*/$base = new EventBase ();//初始化信號(hào)事件 $e = Event :: signal ( $base , SIGUSR1, function( $signum , $arg ) use (& $e ) {echo " Caught signal $signum\n" ;$e->delSignal(); //移除信號(hào) }, '');//安裝信號(hào) $e -> addSignal (); //sec//發(fā)送信號(hào) posix_kill(posix_getpid (), SIGUSR1);$base -> loop ();

相比pcntl_signal，Event :: signal 高效很多。

總結(jié)

Libevent 非常強(qiáng)大，Event實(shí)現(xiàn)了其很多的接口供PHP調(diào)用，我這里僅是使用了常用的幾個(gè)特性。由于Event能參考的資料實(shí)在是有限，這章寫起來(lái)也相對(duì)難一些，例子里還是留了一些待再次理解。

（未完待續(xù)）

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