PHP supports breakpoint resumption and chunked download classes

This article is to share with you PHP classes that support breakpoint resuming and block downloading for your reference. The specific content is as follows

<&#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) ? filesize($save_file) : 0;
    // get tmp data file
    $data_file = $save_file . '.data';
    // get tmp data
    $exists_data = is_file($data_file) ? 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'] ? $url_info['host'] : 80;
    $url_info['request'] = $url_info['path'] . ($url_info['query'] ? '?' . $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';
}
*/
?>

The above is the entire content of this article. I hope it will be helpful to your study.

The above introduces the classes of PHP that support breakpoint resume downloading and chunked downloading, including the relevant content. I hope it will be helpful to friends who are interested in PHP tutorials.