PHP使用range协议实现输出文件断点续传代码实例

时间:2021-11-05 11:30:47

range协议用途:一般是用在断点续传的时候,但是实际的用户很大,例如你的web server需要输出一个大文件,那么用range可以分段输出,缓解压力。同时在提供音乐视频等服务时可以缓冲下载,如果用户中途关闭,可以节约网络带宽。

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<?php
 
// 文件名
$filename = $_GET ['filename'];
 
// 文件路径
$location = 'media/' . $filename;
 
// 后缀
$extension = substr ( strrchr ( $filename, '.' ), 1 );
 
if ($extension == "mp3") {
    $mimeType = "audio/mpeg";
} else if ($extension == "ogg") {
    $mimeType = "audio/ogg";
}
 
if (! file_exists ( $location )) {
    header ( "HTTP/1.1 404 Not Found" );
    return;
}
 
$size = filesize ( $location );
$time = date ( 'r', filemtime ( $location ) );
 
$fm = @fopen ( $location, 'rb' );
if (! $fm) {
    header ( "HTTP/1.1 505 Internal server error" );
    return;
}
 
$begin = 0;
$end = $size - 1;
 
if (isset ( $_SERVER ['HTTP_RANGE'] )) {
    if (preg_match ( '/bytes=\h*(\d+)-(\d*)[\D.*]?/i', $_SERVER ['HTTP_RANGE'], $matches )) {
        // 读取文件,起始节点
        $begin = intval ( $matches [1] );
 
        // 读取文件,结束节点
        if (! empty ( $matches [2] )) {
            $end = intval ( $matches [2] );
        }
    }
}
 
if (isset ( $_SERVER ['HTTP_RANGE'] )) {
    header ( 'HTTP/1.1 206 Partial Content' );
} else {
    header ( 'HTTP/1.1 200 OK' );
}
 
header ( "Content-Type: $mimeType" );
header ( 'Cache-Control: public, must-revalidate, max-age=0' );
header ( 'Pragma: no-cache' );
header ( 'Accept-Ranges: bytes' );
header ( 'Content-Length:' . (($end - $begin) + 1) );
 
if (isset ( $_SERVER ['HTTP_RANGE'] )) {
    header ( "Content-Range: bytes $begin-$end/$size" );
}
 
header ( "Content-Disposition: inline; filename=$filename" );
header ( "Content-Transfer-Encoding: binary" );
header ( "Last-Modified: $time" );
 
$cur = $begin;
 
// 定位指针
fseek ( $fm, $begin, 0 );
 
while ( ! feof ( $fm ) && $cur <= $end && (connection_status () == 0) ) {
    print fread ( $fm, min ( 1024 * 16, ($end - $cur) + 1 ) );
    $cur += 1024 * 16;
}

range协议官方文档http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html