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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

<?php function 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

<?php function 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; } $url_arr=array(   "taobao"=>"http://www.taobao.com",   "sohu"=>"http://www.sohu.com",   "sina"=>"http://www.sina.com.cn",   ); function microtime_float() {    list($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}"; ?>