本文实例讲述了php使用curl并发减少后端访问时间的方法。分享给大家供大家参考，具体如下：
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，
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", "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}";?> 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", "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}";?> 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
3、curl相关参数
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
