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<?php
// Source: http://ibnuyahya.com/format-bytes-to-kb-mb-gb/
function format_bytes($size, $precision = 2){
$base = log($size) / log(1024);
$suffixes = array('B', 'KiB', 'MiB', 'GiB', 'TiB' , 'PiB' , 'EiB');
return round(pow(1024, $base - floor($base)), $precision) . $suffixes[floor($base)];
}
// Original source: http://www.phpfreaks.com/forums/index.php?topic=198274.msg895468#msg895468
function rangeDownload($file, $filename, $type)
{
$fp = @fopen($file, 'r');
$size = filesize($file); // File size
$length = $size; // Content length
$start = 0; // Start byte
$end = $size - 1; // End byte
// Now that we've gotten so far without errors we send the accept range header
/* At the moment we only support single ranges.
* Multiple ranges requires some more work to ensure it works correctly
* and comply with the spesifications: http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
*
* Multirange support annouces itself with:
* header('Accept-Ranges: bytes');
*
* Multirange content must be sent with multipart/byteranges mediatype,
* (mediatype = mimetype)
* as well as a boundry header to indicate the various chunks of data.
*/
header("Accept-Ranges: 0-$length");
// header('Accept-Ranges: bytes');
// multipart/byteranges
// http://www.w3.org/Protocols/rfc2616/rfc2616-sec19.html#sec19.2
if (isset($_SERVER['HTTP_RANGE']))
{
$c_start = $start;
$c_end = $end;
// Extract the range string
list(, $range) = explode('=', $_SERVER['HTTP_RANGE'], 2);
// Make sure the client hasn't sent us a multibyte range
if (strpos($range, ',') !== false)
{
// (?) Shoud this be issued here, or should the first
// range be used? Or should the header be ignored and
// we output the whole content?
header('HTTP/1.1 416 Requested Range Not Satisfiable');
header("Content-Range: bytes $start-$end/$size");
// (?) Echo some info to the client?
exit;
}
// If the range starts with an '-' we start from the beginning
// If not, we forward the file pointer
// And make sure to get the end byte if spesified
if ($range{0} == '-')
{
// The n-number of the last bytes is requested
$c_start = $size - substr($range, 1);
}
else
{
$range = explode('-', $range);
$c_start = $range[0];
$c_end = (isset($range[1]) && is_numeric($range[1])) ? $range[1] : $size;
}
/* Check the range and make sure it's treated according to the specs.
* http://www.w3.org/Protocols/rfc2616/rfc2616-sec14.html
*/
// End bytes can not be larger than $end.
$c_end = ($c_end > $end) ? $end : $c_end;
// Validate the requested range and return an error if it's not correct.
if ($c_start > $c_end || $c_start > $size - 1 || $c_end >= $size)
{
header('HTTP/1.1 416 Requested Range Not Satisfiable');
header("Content-Range: bytes $start-$end/$size");
// (?) Echo some info to the client?
exit;
}
$start = $c_start;
$end = $c_end;
$length = $end - $start + 1; // Calculate new content length
fseek($fp, $start);
header('HTTP/1.1 206 Partial Content');
}
// Notify the client the byte range we'll be outputting
header("Content-Range: bytes $start-$end/$size");
header("Content-Length: $length");
header("Content-disposition: inline; filename=\"".$filename."\"\n");
header("Content-Type: ".$type."\n");
// Start buffered download
$buffer = 1024 * 8;
while(!feof($fp) && ($p = ftell($fp)) <= $end)
{
if ($p + $buffer > $end)
{
// In case we're only outputtin a chunk, make sure we don't
// read past the length
$buffer = $end - $p + 1;
}
set_time_limit(0); // Reset time limit for big files
echo fread($fp, $buffer);
flush(); // Free up memory. Otherwise large files will trigger PHP's memory limit.
}
fclose($fp);
}
# vim: set noet:
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