Implementation code for PHP multi-threaded batch collection and downloading of images

Use curl's multi-threading. In addition, curl can set the request time. If you encounter a very slow URL resource, you can give up decisively, so there is no blocking. In addition, with multi-threaded requests, the efficiency should be relatively high.

/**
 * curl multi-threading
 * @param array $array parallel URL
 * @param int $timeout timeout time
 * @return mix
*/
 public function Curl_http($array,$timeout='15'){
 $res = array();

 $mh = curl_multi_init();//Create multiple curl handle

 foreach($array as $k=>$url){
 $conn[$k]=curl_init($url);//Initialization

 curl_setopt($conn[$k], CURLOPT_TIMEOUT, $timeout);//Set the timeout period
 curl_setopt($conn[$k], CURLOPT_USERAGENT, 'Mozilla/5.0 (compatible; MSIE 5.01; Windows NT 5.0)');
 curl_setopt($conn[$k], CURLOPT_MAXREDIRS, 7);//HTTp orientation level, 7 is the highest
 curl_setopt($conn[$k], CURLOPT_HEADER, false);//No header here, increase block efficiency
 curl_setopt($conn[$k], CURLOPT_FOLLOWLOCATION, 1); // 302 redirect
 curl_setopt($conn[$k], CURLOPT_RETURNTRANSFER,1); //Require the result to be a string and output it to the screen
 curl_setopt($conn[$k], CURLOPT_HTTPGET, true);

 curl_multi_add_handle ( $mh,$conn[$k]);
 }
 //Prevent the endless loop from consuming the CPU. This paragraph is based on the writing method on the Internet
 do {
 $mrc ​​= curl_multi_exec($mh,$active);//When there is no data , active=true
 } while ($mrc == CURLM_CALL_MULTI_PERFORM);//When data is being received
 while ($active and $mrc ​​== CURLM_OK) {//When there is no data or the request is suspended, active=true
 if (curl_multi_select($mh) != -1) {
 do {
 $mrc ​​= curl_multi_exec($mh, $active);
 } while ($mrc == CURLM_CALL_MULTI_PERFORM);
 }
 }

 foreach ($array as $k => $url) {
 if(!curl_errno($conn[$k])){
 $data[$k]=curl_multi_getcontent($conn[$k]);//Convert data to array
 $header[$k]=curl_getinfo($conn[$k]);//Return http header information
 curl_close($conn[$k]);//Close the handle
 curl_multi_remove_handle($mh, $conn[$k] ]); //Release resources
 }else{
 unset($k,$url);
 }
 }

 curl_multi_close($mh);

 return $data;

 }

//Parameter reception
$ callback = $_GET['callback'];
$hrefs = $_GET['hrefs'];
$urlarray = explode(',',trim($hrefs,','));
$date = date(' Ymd',time());
//Instantiation
$img = new HttpImg();
$stime = $img->getMicrotime();//Start time

$data = $img->Curl_http ($urlarray,'20');//List data
mkdir('./img/'.$date,0777);
foreach ((array)$data as $k=>$v){
 preg_match_all( "/(href|src)=(["|']?)([^ "'>]+.(jpg|png|PNG|JPG|gif))\2/i", $v, $matches[ $k]);

 if(count($matches[$k][3])>0){
 $dataimg = $img->Curl_http($matches[$k][3],'20' );//All image data binary
 $j = 0;
 foreach ((array)$dataimg as $kk=>$vv){
 if($vv !=''){
 $rand = rand(1000 ,9999);
 $basename = time()."_".$rand.".".jpg;//Save as a jpg format file
 $fname = './img/'.$date."/" ."$basename";
 file_put_contents($fname, $vv);
 $j++;
 echo "Create the ".$j."th picture"."$fname"."";
 }else{
 unset($kk,$vv);
 }
 }
 }else{
 unset($matches);
 }
}
$etime = $img->getMicrotime();//End time
 echo "Time".($etime-$stime)."Seconds";
exit;

Multi-threading, download pictures, PHP