Home  >  Article  >  Backend Development  >  PHP supports breakpoint resumable downloads and chunked download classes. PHP supports breakpoint resumable downloads_PHP Tutorial

PHP supports breakpoint resumable downloads and chunked download classes. PHP supports breakpoint resumable downloads_PHP Tutorial

WBOY
WBOYOriginal
2016-07-12 08:53:04932browse

PHP supports breakpoint resumable downloads and chunked download classes. PHP supports breakpoint resumable downloads. Category, for your reference, the specific content is as follows

The above is the entire content of this article, I hope it will be helpful to everyone’s study.

<&#63;php
 
/**
 * User: djunny
 * Date: 2016-04-29
 * Time: 17:18
 * Mail: 199962760@qq.com
 * 支持断点下载的类
 */
class downloader {
 
  /**
   * download file to local path
   *
   * @param    $url
   * @param    $save_file
   * @param int  $speed
   * @param array $headers
   * @param int  $timeout
   * @return bool
   * @throws Exception
   */
  static function get($url, $save_file, $speed = 10240, $headers = array(), $timeout = 10) {
    $url_info = self::parse_url($url);
    if (!$url_info['host']) {
      throw new Exception('Url is Invalid');
    }
 
    // default header
    $def_headers = array(
      'Accept'     => '*/*',
      'User-Agent'   => 'Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 5.1; Trident/4.0)',
      'Accept-Encoding' => 'gzip, deflate',
      'Host'      => $url_info['host'],
      'Connection'   => 'Close',
      'Accept-Language' => 'zh-cn',
    );
 
    // merge heade
    $headers = array_merge($def_headers, $headers);
    // get content length
    $content_length = self::get_content_size($url_info['host'], $url_info['port'], $url_info['request'], $headers, $timeout);
 
    // content length not exist
    if (!$content_length) {
      throw new Exception('Content-Length is Not Exists');
    }
    // get exists length
    $exists_length = is_file($save_file) &#63; filesize($save_file) : 0;
    // get tmp data file
    $data_file = $save_file . '.data';
    // get tmp data
    $exists_data = is_file($data_file) &#63; json_decode(file_get_contents($data_file), 1) : array();
    // check file is valid
    if ($exists_length == $content_length) {
      $exists_data && @unlink($data_file);
      return true;
    }
    // check file is expire
    if ($exists_data['length'] != $content_length || $exists_length > $content_length) {
      $exists_data = array(
        'length' => $content_length,
      );
    }
    // write exists data
    file_put_contents($data_file, json_encode($exists_data));
 
    try {
      $download_status = self::download_content($url_info['host'], $url_info['port'], $url_info['request'], $save_file, $content_length, $exists_length, $speed, $headers, $timeout);
      if ($download_status) {
        @unlink($data_file);
      }
    } catch (Exception $e) {
      throw new Exception($e->getMessage());
    }
    return true;
  }
 
  /**
   * parse url
   *
   * @param $url
   * @return bool|mixed
   */
  static function parse_url($url) {
    $url_info = parse_url($url);
    if (!$url_info['host']) {
      return false;
    }
    $url_info['port']  = $url_info['port'] &#63; $url_info['host'] : 80;
    $url_info['request'] = $url_info['path'] . ($url_info['query'] &#63; '&#63;' . $url_info['query'] : '');
    return $url_info;
  }
 
  /**
   * download content by chunk
   *
   * @param $host
   * @param $port
   * @param $url_path
   * @param $headers
   * @param $timeout
   */
  static function download_content($host, $port, $url_path, $save_file, $content_length, $range_start, $speed, &$headers, $timeout) {
    $request = self::build_header('GET', $url_path, $headers, $range_start);
    $fsocket = @fsockopen($host, $port, $errno, $errstr, $timeout);
    stream_set_blocking($fsocket, TRUE);
    stream_set_timeout($fsocket, $timeout);
    fwrite($fsocket, $request);
    $status = stream_get_meta_data($fsocket);
    if ($status['timed_out']) {
      throw new Exception('Socket Connect Timeout');
    }
    $is_header_end = 0;
    $total_size  = $range_start;
    $file_fp    = fopen($save_file, 'a+');
    while (!feof($fsocket)) {
      if (!$is_header_end) {
        $line = @fgets($fsocket);
        if (in_array($line, array("\n", "\r\n"))) {
          $is_header_end = 1;
        }
        continue;
      }
      $resp    = fread($fsocket, $speed);
      $read_length = strlen($resp);
      if ($resp === false || $content_length < $total_size + $read_length) {
        fclose($fsocket);
        fclose($file_fp);
        throw new Exception('Socket I/O Error Or File Was Changed');
      }
      $total_size += $read_length;
      fputs($file_fp, $resp);
      // check file end
      if ($content_length == $total_size) {
        break;
      }
      sleep(1);
      // for test
      //break;
    }
    fclose($fsocket);
    fclose($file_fp);
    return true;
 
  }
 
  /**
   * get content length
   *
   * @param $host
   * @param $port
   * @param $url_path
   * @param $headers
   * @param $timeout
   * @return int
   */
  static function get_content_size($host, $port, $url_path, &$headers, $timeout) {
    $request = self::build_header('HEAD', $url_path, $headers);
    $fsocket = @fsockopen($host, $port, $errno, $errstr, $timeout);
    stream_set_blocking($fsocket, TRUE);
    stream_set_timeout($fsocket, $timeout);
    fwrite($fsocket, $request);
    $status = stream_get_meta_data($fsocket);
    $length = 0;
    if ($status['timed_out']) {
      return 0;
    }
    while (!feof($fsocket)) {
      $line = @fgets($fsocket);
      if (in_array($line, array("\n", "\r\n"))) {
        break;
      }
      $line = strtolower($line);
      // get location
      if (substr($line, 0, 9) == 'location:') {
        $location = trim(substr($line, 9));
        $url_info = self::parse_url($location);
        if (!$url_info['host']) {
          return 0;
        }
        fclose($fsocket);
        return self::get_content_size($url_info['host'], $url_info['port'], $url_info['request'], $headers, $timeout);
      }
      // get content length
      if (strpos($line, 'content-length:') !== false) {
        list(, $length) = explode('content-length:', $line);
        $length = (int)trim($length);
      }
    }
    fclose($fsocket);
    return $length;
 
  }
 
  /**
   * build header for socket
   *
   * @param   $action
   * @param   $url_path
   * @param   $headers
   * @param int $range_start
   * @return string
   */
  static function build_header($action, $url_path, &$headers, $range_start = -1) {
    $out = $action . " {$url_path} HTTP/1.0\r\n";
    foreach ($headers as $hkey => $hval) {
      $out .= $hkey . ': ' . $hval . "\r\n";
    }
    if ($range_start > -1) {
      $out .= "Accept-Ranges: bytes\r\n";
      $out .= "Range: bytes={$range_start}-\r\n";
    }
    $out .= "\r\n";
 
    return $out;
  }
}
 
 
#use age
/*
try {
  if (downloader::get('http://dzs.aqtxt.com/files/11/23636/201604230358308081.rar', 'test.rar')) {
    //todo
    echo 'Download Succ';
  }
} catch (Exception $e) {
  echo 'Download Failed';
}
*/
&#63;>

http://www.bkjia.com/PHPjc/1125251.html

www.bkjia.comtruehttp: //www.bkjia.com/PHPjc/1125251.htmlTechArticlephp supports breakpoint resumable downloads and chunked download classes. php supports breakpoint resumable downloads. This article is for everyone to share PHP supports breakpoint resumption and chunked download classes for your reference. The specific content is as follows php /**...
Statement:
The content of this article is voluntarily contributed by netizens, and the copyright belongs to the original author. This site does not assume corresponding legal responsibility. If you find any content suspected of plagiarism or infringement, please contact admin@php.cn