function byteserve($filename, $mimeType = 'application/pdf')
{
/*
Byteserves the file $filename.
When there is a request for a single range, the content is transmitted
with a Content-Range header, and a Content-Length header showing the number
of bytes actually transferred.
When there is a request for multiple ranges, these are transmitted as a
multipart message. The multipart media type used for this purpose is
"multipart/byteranges".
*/
$filesize = filesize($filename);
$file = fopen($filename, "rb");
$ranges = NULL;
if ($_SERVER['REQUEST_METHOD'] == 'GET' && isset($_SERVER['HTTP_RANGE']) && ($range = stristr(trim($_SERVER['HTTP_RANGE']), 'bytes='))) {
$range = substr($range, 6);
$boundary = 'g45d64df96bmdf4sdgh45hf5';
//set a random boundary
$ranges = explode(',', $range);
}
if ($ranges && count($ranges)) {
header("HTTP/1.1 206 Partial content");
header("Accept-Ranges: bytes");
if (count($ranges) > 1) {
/*
More than one range is requested.
*/
//compute content length
$content_length = 0;
foreach ($ranges as $range) {
set_range($range, $filesize, $first, $last);
$content_length += strlen("\r\n--{$boundary}\r\n");
$content_length += strlen("Content-type: " . $mimeType . "\r\n");
$content_length += strlen("Content-range: bytes {$first}-{$last}/{$filesize}\r\n\r\n");
$content_length += $last - $first + 1;
}
$content_length += strlen("\r\n--{$boundary}--\r\n");
//output headers
header("Content-Length: {$content_length}");
//see http://httpd.apache.org/docs/misc/known_client_problems.html for an discussion of x-byteranges vs. byteranges
header("Content-Type: multipart/x-byteranges; boundary={$boundary}");
//output the content
foreach ($ranges as $range) {
set_range($range, $filesize, $first, $last);
echo "\r\n--{$boundary}\r\n";
echo "Content-type: " . $mimeType . "\r\n";
echo "Content-range: bytes {$first}-{$last}/{$filesize}\r\n\r\n";
fseek($file, $first);
buffered_read($file, $last - $first + 1);
}
echo "\r\n--{$boundary}--\r\n";
} else {
/*
A single range is requested.
*/
$range = $ranges[0];
set_range($range, $filesize, $first, $last);
header("Content-Length: " . ($last - $first + 1));
header("Content-Range: bytes {$first}-{$last}/{$filesize}");
header("Content-Type: " . $mimeType);
fseek($file, $first);
buffered_read($file, $last - $first + 1);
}
} else {
//no byteserving
while (ob_get_level()) {
ob_end_clean();
}
header("Accept-Ranges: bytes");
header("Content-Length: {$filesize}");
header("Content-Type: " . $mimeType);
ob_end_flush();
readfile($filename);
}
fclose($file);
}
function byteserve($filename)
{
/*
Byteserves the file $filename.
When there is a request for a single range, the content is transmitted
with a Content-Range header, and a Content-Length header showing the number
of bytes actually transferred.
When there is a request for multiple ranges, these are transmitted as a
multipart message. The multipart media type used for this purpose is
"multipart/byteranges".
*/
global $MAX_FILE_SIZE;
$filesize = filesize($filename);
$ranges = NULL;
if ($_SERVER['REQUEST_METHOD'] == 'GET' && isset($_SERVER['HTTP_RANGE']) && ($range = stristr(trim($_SERVER['HTTP_RANGE']), 'bytes='))) {
$range = substr($range, 6);
$ranges = explode(',', $range);
}
//If we don't find it in the header, check the query parameter
if ($range == NULL && $ranges == NULL) {
$strfirst = $_GET['start'];
$last = $_GET['end'];
$hasQueryStart = $strfirst != NULL;
if ($hasQueryStart) {
$first = (int) $strfirst;
$last = (int) $last;
}
}
if ($ranges && count($ranges) || $hasQueryStart) {
header("HTTP/1.1 206 Partial content", True, 206);
header("Accept-Ranges: bytes");
if (count($ranges) > 1) {
//unsatisfiable range
header("HTTP/1.1 501 Do not support multiple ranges", True, 501);
} else {
//A single range is requested.
$range = $ranges[0];
if ($hasQueryStart) {
//Nothing to do, $first and last already set
} else {
set_range($range, $filesize, $first, $last);
}
header("Content-Length: " . ($last - $first + 1));
$contRange = "Content-Range: bytes {$first}-{$last}/{$filesize}";
//log_message($contRange);
header($contRange);
$file = fopen($filename, "rb");
fseek($file, $first);
buffered_read($file, $last - $first + 1, 1024);
fclose($file);
}
} else {
$isHead = $_SERVER['REQUEST_METHOD'] == 'HEAD';
header("Accept-Ranges: bytes");
header("Content-Length: {$filesize}");
if (!$isHead) {
readfile($filename);
}
}
}
