PHP中巧用curl 并发减小获取第三方网页内容时间

PHP中巧用curl 并发减少获取第三方网页内容时间
前言：


在我们平时的程序中难免出现同时访问几个接口的情况，平时我们用curl进行访问的时候，一般都是单个、顺序访问，假如有3个接口，每个接口耗时500毫秒那么我们三个接口就要花费1500毫秒了，这个问题太头疼了严重影响了页面访问速度，有没有可能并发访问来提高速度呢？今天就简单的说一下，利用curl并发来提高页面访问速度， 希望大家多指导。

1、老的curl访问方式以及耗时统计

<?phpfunction curl_fetch($url, $timeout=3){    $ch = curl_init();    curl_setopt($ch, CURLOPT_URL, $url);    curl_setopt($ch, CURLOPT_TIMEOUT, $timeout);    curl_setopt($ch, CURLOPT_RETURNTRANSFER, 1);    $data = curl_exec($ch);    $errno = curl_errno($ch);    if ($errno>0) {        $data = false;    }    curl_close($ch);    return $data;}function microtime_float(){   list($usec, $sec) = explode(" ", microtime());   return ((float)$usec + (float)$sec);}$url_arr=array(     "taobao"=>"http://www.taobao.com",     "sohu"=>"http://www.sohu.com",     "lai18"=>"http://www.lai18.com",);$time_start = microtime_float();$data=array();foreach ($url_arr as $key=>$val){     $data[$key]=curl_fetch($val);}$time_end = microtime_float();$time = $time_end - $time_start;echo "耗时:{$time}";?>

耗时:0.614秒


2、curl并发访问方式以及耗时统计

<?phpfunction curl_multi_fetch($urlarr=array()){    $result=$res=$ch=array();    $nch = 0;    $mh = curl_multi_init();    foreach ($urlarr as $nk => $url) {        $timeout=2;        $ch[$nch] = curl_init();        curl_setopt_array($ch[$nch], array(            CURLOPT_URL => $url,            CURLOPT_HEADER => false,            CURLOPT_RETURNTRANSFER => true,            CURLOPT_TIMEOUT => $timeout,        ));        curl_multi_add_handle($mh, $ch[$nch]);        ++$nch;    }    /* wait for performing request */    do {        $mrc = curl_multi_exec($mh, $running);    } while (CURLM_CALL_MULTI_PERFORM == $mrc);     while ($running && $mrc == CURLM_OK) {        // wait for network        if (curl_multi_select($mh, 0.5) > -1) {            // pull in new data;            do {                $mrc = curl_multi_exec($mh, $running);            } while (CURLM_CALL_MULTI_PERFORM == $mrc);        }    }     if ($mrc != CURLM_OK) {        error_log("CURL Data Error");    }     /* get data */    $nch = 0;    foreach ($urlarr as $moudle=>$node) {        if (($err = curl_error($ch[$nch])) == '') {            $res[$nch]=curl_multi_getcontent($ch[$nch]);            $result[$moudle]=$res[$nch];        }        else        {            error_log("curl error");        }        curl_multi_remove_handle($mh,$ch[$nch]);        curl_close($ch[$nch]);        ++$nch;    }    curl_multi_close($mh);    return  $result;}$url_arr=array(     "taobao"=>"http://www.taobao.com",     "sohu"=>"http://www.sohu.com",     "lai18"=>"http://www.lai18.com",     );function microtime_float(){   list($usec, $sec) = explode(" ", microtime());   return ((float)$usec + (float)$sec);}$time_start = microtime_float();$data=curl_multi_fetch($url_arr);$time_end = microtime_float();$time = $time_end - $time_start; echo "耗时:{$time}";?>

耗时:0.316秒 帅气吧整个页面访问后端接口的时间节省了一半

《CURL技术知识教程》系列技术文章整理收藏

http://blog.csdn.net/hello_katty/article/details/45557423