PHP使用range协议实现输出文件断点续传代码实例
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2022-07-20 23:21:34
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...
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。
<?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
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