php支持断点续传、分块下载的类，php支持断点续传

php支持断点续传、分块下载的类，php支持断点续传

本文是为大家分享php支持断点续传、分块下载的类，供大家参考，具体内容如下

 '*/*',
      '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  $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';
}
*/
?>

以上就是本文的全部内容，希望对大家的学习有所帮助。