前端開發中的性能那點事（二）巧用curl 併發減小後端訪問時間

時間 2019-12-14

原文原文鏈接

前言：
在咱們平時的程序中不免出現同時訪問幾個接口的狀況，平時咱們用curl進行訪問的時候，通常都是單個、順序訪問，假若有3個接口，每一個接口耗時500毫秒那麼咱們三個接口就要花費1500毫秒了，這個問題太頭疼了嚴重影響了頁面訪問速度，有沒有可能併發訪問來提升速度呢？今天就簡單的說一下，利用curl併發來提升頁面訪問速度，
但願你們多指導。
一、老的curl訪問方式以及耗時統計 php

         <?php 
       
         functioncurl_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; 
       
         } 
       
         functionmicrotime_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($url_arras$key=>$val) 
       
          { 
       
              $data[$key]=curl_fetch($val); 
       
          } 
       
          $time_end= microtime_float(); 
       
          $time=$time_end-$time_start; 
       
          echo"耗時:{$time}"; 
       
         ?>

耗時:0.614秒
二、curl併發訪問方式以及耗時統計 node

         <?php 
       
         functioncurl_multi_fetch($urlarr=array()){ 
       
             $result=$res=$ch=array(); 
       
             $nch= 0; 
       
             $mh= curl_multi_init(); 
       
             foreach($urlarras$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($urlarras$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", 
       
              ); 
       
         functionmicrotime_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"耗時:{$time}"; 
       
         ?>

耗時:0.316秒
帥氣吧整個頁面訪問後端接口的時間節省了一半
三、curl相關參數
來自：http://cn2.php.net/manual/en/ref.curl.php
curl_close — Close a cURL session
curl_copy_handle — Copy a cURL handle along with all of its preferences
curl_errno — Return the last error number
curl_error — Return a string containing the last error for the current session
curl_exec — Perform a cURL session
curl_getinfo — Get information regarding a specific transfer
curl_init — Initialize a cURL session
curl_multi_add_handle — Add a normal cURL handle to a cURL multi handle
curl_multi_close — Close a set of cURL handles
curl_multi_exec — Run the sub-connections of the current cURL handle
curl_multi_getcontent — Return the content of a cURL handle if CURLOPT_RETURNTRANSFER is set
curl_multi_info_read — Get information about the current transfers
curl_multi_init — Returns a new cURL multi handle
curl_multi_remove_handle — Remove a multi handle from a set of cURL handles
curl_multi_select — Wait for activity on any curl_multi connection
curl_setopt_array — Set multiple options for a cURL transfer
curl_setopt — Set an option for a cURL transfer
curl_version — Gets cURL version information 後端