How to use phpcurl to implement multi-process download file classes-PHP Tutorial-php.cn

Batch download files generally use a loop method to download files one by one. However, if bandwidth and server performance permit, using multiple processes for downloading can greatly improve downloading efficiency. This article introduces PHP's multi-process request method using curl to achieve simultaneous downloading of files by multiple processes.

Principle:

Use curl's batch processing method to open multiple processes to download files in batches.

Main method:

curl_multi_init
Return a new cURL batch handle

curl_multi_add_handle
Add a separate curl handle to the curl batch session

curl_multi_exec
Run the current cURL handle Sub-connection

curl_multi_getcontent
If CURLOPT_RETURNTRANSFER is set, returns the text stream of the obtained output

curl_multi_remove_handle
Remove a handle resource in the curl batch handle resource

curl_multi_close
Close a group of cURL handles

The complete code is as follows:

BatchDownLoad.class.php

download_config = $download_config; $this->max_process_num = $max_process_num; $this->timeout = $timeout; // 日志文件 if($logfile){ $this->logfile = $logfile; }else{ $this->logfile = dirname(__FILE__).'/batch_download_'.date('Ymd').'.log'; } } /** * 执行下载 * @result Int */ public function download(){ // 已处理的数量 $handle_num = 0; // 未处理完成 while(count($this->download_config)>0){ // 需要处理的大于最大进程数 if(count($this->download_config)>$this->max_process_num){ $process_num = $this->max_process_num; // 需要处理的小于最大进程数 }else{ $process_num = count($this->download_config); } // 抽取指定数量进行下载 $tmp_download_config = array_splice($this->download_config, 0, $process_num); // 执行下载 $result = $this->process($tmp_download_config); // 写入日志 $this->to_log($tmp_download_config, $result); // 记录已处理的数量 $handle_num += count($result); } return $handle_num; } /** * 多进程下载文件 * @param Array $download_config 本次下载的设置 * @return Array */ public function process($download_config){ // 文件资源 $fp = array(); // curl会话 $ch = array(); // 执行结果 $result = array(); // 创建curl handle $mh = curl_multi_init(); // 循环设定数量 foreach($download_config as $k=>$config){ $ch[$k] = curl_init(); $fp[$k] = fopen($config[1], 'a'); curl_setopt($ch[$k], CURLOPT_URL, $config[0]); curl_setopt($ch[$k], CURLOPT_FILE, $fp[$k]); curl_setopt($ch[$k], CURLOPT_HEADER, 0); curl_setopt($ch[$k], CURLOPT_RETURNTRANSFER, true); curl_setopt($ch[$k], CURLOPT_USERAGENT, 'Mozilla/4.0 (compatible; MSIE 7.0; Windows NT 6.0)'); // 加入处理 curl_multi_add_handle($mh, $ch[$k]); } $active = null; do{ $mrc = curl_multi_exec($mh, $active); } while($active); // 获取数据 foreach($fp as $k=>$v){ fwrite($v, curl_multi_getcontent($ch[$k])); } // 关闭curl handle与文件资源 foreach($download_config as $k=>$config){ curl_multi_remove_handle($mh, $ch[$k]); fclose($fp[$k]); // 检查是否下载成功 if(file_exists($config[1])){ $result[$k] = true; }else{ $result[$k] = false; } } curl_multi_close($mh); return $result; } /** * 写入日志 * @param Array $data 下载文件数据 * @param Array $flag 下载文件状态数据 */ private function to_log($data, $flag){ // 临时日志数据 $tmp_log = ''; foreach($data as $k=>$v){ $tmp_log .= '['.date('Y-m-d H:i:s').'] url:'.$v[0].' file:'.$v[1].' status:'.$flag[$k].PHP_EOL; } // 创建日志目录 if(!is_dir(dirname($this->logfile))){ mkdir(dirname($this->logfile), 0777, true); } // 写入日志文件 file_put_contents($this->logfile, $tmp_log, FILE_APPEND); } }?>

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demo.php

download();echo 'download num:'.$handle_num.PHP_EOL;?>

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Log output after execution

[2017-07-16 18:04:21] url:http://www.example.com/p1.jpg file:/home/fdipzone/photo/p1.jpg status:1[2017-07-16 18:04:21] url:http://www.example.com/p2.jpg file:/home/fdipzone/photo/p2.jpg status:1[2017-07-16 18:04:21] url:http://www.example.com/p3.jpg file:/home/fdipzone/photo/p3.jpg status:1[2017-07-16 18:04:21] url:http://www.example.com/p4.jpg file:/home/fdipzone/photo/p4.jpg status:1[2017-07-16 18:04:21] url:http://www.example.com/p5.jpg file:/home/fdipzone/photo/p5.jpg status:1

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This article explains some ways to download files in batches. For more related content, please pay attention to php Chinese website .

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