PHP 大文件下载,文件传输,支持断点续传。 2g以上超大文件也有效

<?php
/**
 * 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=28-175
380
         *  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 $e) {
            // null;
        }
    }
}
date_default_timezone_set("Asia/Shanghai");
error_reporting(E_STRICT);
function errorHandler($errno, $errstr, $errfile, $errline) {
    echo "<p>error:",$errstr,"</p>";
    exit();
}
set_error_handler("errorHandler");
define("IS_DEBUG",true);

//
//
$filePath = "/Movie/The.Hurt.Locker.2008.x264.AC3-WAF.mkv";
$mimeType = "audio/x-matroska";
$range = isset($_SERVER["HTTP_RANGE"])?$_SERVER["HTTP_RANGE"]:null;
if (IS_DEBUG) {
//    $range = "bytes=1000-1999
2000";
//    $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();
?>