在php程序中难免出现同时访问几个接口的情况，平时用curl进行访问时，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，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？
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
复制代码 代码示例:
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
复制代码 代码示例:
<?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}";
?>
输出结果array('taobao'=>result,'sina'=>result,'baidu'=>result) ;
耗时:0.316秒
整个页面访问后端接口的时间节省了一半
3、curl相关参数
来自：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
