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
本文地址:https://www.stayed.cn/item/17657
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