PHP使用curl并发减少后端访问时间的方法

﹏ヽ暗。殇╰゛Y 2022-01-17 07:25 200阅读 0赞

**问题的引发**

在我们平时的程序中有时候会出现同时访问几个接口的情况，我们都是用curl进行访问，而这种访问一般都是单个、顺序访问的。那么问题来咯，假如有3个接口，每个接口耗时500毫秒，这样三个接口就要花费1500毫秒了，这个问题很严重，严重影响了页面访问速度。

**解决问题**

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

**看看单个，顺序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",
       "sina"=>"http://www.sina.com.cn",
    
       );
    
     $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}";
    
    ?>

以上代码运行结果如下：耗时:0.614秒  显然这是不可取的。来看看并发的效果

**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}";
    
    ?>

运行后的结果：耗时:0.316秒  很明显，时间减少了一半