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

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}";

?>

耗时:0.614秒

2、curl并发访问方式以及耗时统计

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}";

?>

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

希望本文所述对大家PHP程序设计有所帮助。