php实现大文件断点续传下载实例代码

require_once('download.class.php'); 
date_default_timezone_set('Asia/Shanghai'); 
error_reporting(E_STRICT); 
function errorHandler($errno, $errstr, $errfile, $errline) { 
 echo '<p error:', $errstr, '</p '; 
 exit(); 
} 
set_error_handler('errorHandler'); 
define('IS_DEBUG', true); 
$filePath = 'test.zip'; 
$mimeType = 'audio/x-matroska'; 
$range = isset($_SERVER['HTTP_RANGE']) ? $_SERVER['HTTP_RANGE'] : null; 
if (IS_DEBUG) { 
// $range = "bytes=1000-1999n2000"; 
// $range = "bytes=1000-1999,2000"; 
// $range = "bytes=1000-1999,-2000"; 
// $range = "bytes=1000-1999,2000-2999"; 
} 
set_time_limit(0); 
$transfer = new Transfer($filePath, $mimeType, $range); 
if (IS_DEBUG) { 
 $transfer- setIsLog(true); 
} 
$transfer- send();

/** 
* 文件传输，支持断点续传。 
* 2g以上超大文件也有效 
* @author MoXie 
*/ 
class Transfer { 
/** 
* 缓冲单元 
*/ 
const BUFF_SIZE = 5120; // 1024 * 5 
/** 
* 文件地址 
* @var <String  
*/ 
private $filePath; 
/** 
* 文件大小 
* @var <String  Php超大数字 字符串形式描述 
*/ 
private $fileSize; 
/** 
* 文件类型 
* @var <String  
*/ 
private $mimeType; 
/** 
* 请求区域（范围） 
* @var <String  
*/ 
private $range; 
/** 
* 是否写入日志 
* @var <Boolean  
*/ 
private $isLog = false; 
/** 
* 
* @param <String  $filePath 文件路径 
* @param <String  $mimeType 文件类型 
* @param <String  $range 请求区域（范围） 
*/ 
function __construct($filePath, $mimeType = null, $range = null) { 
$this- filePath = $filePath; 
$this- fileSize = sprintf('%u', filesize($filePath)); 
$this- mimeType = ($mimeType != null) ? $mimeType : "application/octet-stream"; // bin 
$this- range = trim($range); 
} 
/** 
* 获取文件区域 
* @return <Map  {'start':long,'end':long} or null 
*/ 
private function getRange() { 
/** 
* Range: bytes=-128 
* Range: bytes=-128 
* Range: bytes=28-175,382-399,510-541,644-744,977-980 
* Range: bytes=28-175n380 
* type 1 
* RANGE: bytes=1000-9999 
* RANGE: bytes=2000-9999 
* type 2 
* RANGE: bytes=1000-1999 
* RANGE: bytes=2000-2999 
* RANGE: bytes=3000-3999 
*/ 
if (!empty($this- range)) { 
$range = preg_replace('/[s|,].*/', '', $this- range); 
$range = explode('-', substr($range, 6)); 
if (count($range) < 2) { 
$range[1] = $this- fileSize; // Range: bytes=-100 
} 
$range = array_combine(array('start', 'end'), $range); 
if (empty($range['start'])) { 
$range['start'] = 0; 
} 
if (!isset($range['end']) || empty($range['end'])) { 
$range['end'] = $this- fileSize; 
} 
return $range; 
} 
return null; 
} 
/** 
* 向客户端发送文件 
*/ 
public function send() { 
$fileHande = fopen($this- filePath, 'rb'); 
if ($fileHande) { 
// setting 
ob_end_clean(); // clean cache 
ob_start(); 
ini_set('output_buffering', 'Off'); 
ini_set('zlib.output_compression', 'Off'); 
$magicQuotes = get_magic_quotes_gpc(); 
//   set_magic_quotes_runtime(0); 
// init 
$lastModified = gmdate('D, d M Y H:i:s', filemtime($this- filePath)) . ' GMT'; 
$etag = sprintf('w/"%s:%s"', md5($lastModified), $this- fileSize); 
$ranges = $this- getRange(); 
// headers 
header(sprintf('Last-Modified: %s', $lastModified)); 
header(sprintf('ETag: %s', $etag)); 
header(sprintf('Content-Type: %s', $this- mimeType)); 
$disposition = 'attachment'; 
if (strpos($this- mimeType, 'image/') !== FALSE) { 
$disposition = 'inline'; 
} 
header(sprintf('Content-Disposition: %s; filename="%s"', $disposition, basename($this- filePath))); 
if ($ranges != null) { 
if ($this- isLog) { 
$this- log(json_encode($ranges) . ' ' . $_SERVER['HTTP_RANGE']); 
} 
header('HTTP/1.1 206 Partial Content'); 
header('Accept-Ranges: bytes'); 
header(sprintf('Content-Length: %u', $ranges['end'] - $ranges['start'])); 
header(sprintf('Content-Range: bytes %s-%s/%s', $ranges['start'], $ranges['end'], $this- fileSize)); 
// 
fseek($fileHande, sprintf('%u', $ranges['start'])); 
} else { 
header("HTTP/1.1 200 OK"); 
header(sprintf('Content-Length: %s', $this- fileSize)); 
} 
// read file 
$lastSize = 0; 
while (!feof($fileHande) && !connection_aborted()) { 
$lastSize = sprintf("%u", bcsub($this- fileSize, sprintf("%u", ftell($fileHande)))); 
if (bccomp($lastSize, self::BUFF_SIZE)   0) { 
$lastSize = self::BUFF_SIZE; 
} 
echo fread($fileHande, $lastSize); 
ob_flush(); 
flush(); 
} 
set_magic_quotes_runtime($magicQuotes); 
ob_end_flush(); 
} 
if ($fileHande != null) { 
fclose($fileHande); 
} 
} 
/** 
* 设置记录 
* @param <Boolean  $isLog 是否记录 
*/ 
public function setIsLog($isLog = true) { 
$this- isLog = $isLog; 
} 
/** 
* 记录 
* @param <String  $msg 记录信息 
*/ 
private function log($msg) { 
try { 
$handle = fopen('transfer_log.txt', 'a'); 
fwrite($handle, sprintf('%s : %s' . PHP_EOL, date('Y-m-d H:i:s'), $msg)); 
fclose($handle); 
} catch (Exception $e) { 
// null; 
} 
} 
}