BookStack/app/Http/RangeSupportedStream.php
Dan Brown 91d8d6eaaa
Range requests: Added test cases to cover functionality
Fixed some found issues in the process.
2024-01-14 15:50:00 +00:00

135 lines
4.3 KiB
PHP

<?php
namespace BookStack\Http;
use BookStack\Util\WebSafeMimeSniffer;
use Illuminate\Http\Request;
/**
* Helper wrapper for range-based stream response handling.
* Much of this used symfony/http-foundation as a reference during build.
* URL: https://github.com/symfony/http-foundation/blob/v6.0.20/BinaryFileResponse.php
* License: MIT license, Copyright (c) Fabien Potencier.
*/
class RangeSupportedStream
{
protected string $sniffContent = '';
protected array $responseHeaders = [];
protected int $responseStatus = 200;
protected int $responseLength = 0;
protected int $responseOffset = 0;
public function __construct(
protected $stream,
protected int $fileSize,
Request $request,
) {
$this->responseLength = $this->fileSize;
$this->parseRequest($request);
}
/**
* Sniff a mime type from the stream.
*/
public function sniffMime(): string
{
$offset = min(2000, $this->fileSize);
$this->sniffContent = fread($this->stream, $offset);
return (new WebSafeMimeSniffer())->sniff($this->sniffContent);
}
/**
* Output the current stream to stdout before closing out the stream.
*/
public function outputAndClose(): void
{
// End & flush the output buffer, if we're in one, otherwise we still use memory.
// Output buffer may or may not exist depending on PHP `output_buffering` setting.
// Ignore in testing since output buffers are used to gather a response.
if (!empty(ob_get_status()) && !app()->runningUnitTests()) {
ob_end_clean();
}
$outStream = fopen('php://output', 'w');
$sniffLength = strlen($this->sniffContent);
$bytesToWrite = $this->responseLength;
if ($sniffLength > 0 && $this->responseOffset < $sniffLength) {
$sniffEnd = min($sniffLength, $bytesToWrite + $this->responseOffset);
$sniffOutLength = $sniffEnd - $this->responseOffset;
$sniffOutput = substr($this->sniffContent, $this->responseOffset, $sniffOutLength);
fwrite($outStream, $sniffOutput);
$bytesToWrite -= $sniffOutLength;
} else if ($this->responseOffset !== 0) {
fseek($this->stream, $this->responseOffset);
}
stream_copy_to_stream($this->stream, $outStream, $bytesToWrite);
fclose($this->stream);
fclose($outStream);
}
public function getResponseHeaders(): array
{
return $this->responseHeaders;
}
public function getResponseStatus(): int
{
return $this->responseStatus;
}
protected function parseRequest(Request $request): void
{
$this->responseHeaders['Accept-Ranges'] = $request->isMethodSafe() ? 'bytes' : 'none';
$range = $this->getRangeFromRequest($request);
if ($range) {
[$start, $end] = $range;
if ($start < 0 || $start > $end) {
$this->responseStatus = 416;
$this->responseHeaders['Content-Range'] = sprintf('bytes */%s', $this->fileSize);
} elseif ($end - $start < $this->fileSize - 1) {
$this->responseLength = $end < $this->fileSize ? $end - $start + 1 : -1;
$this->responseOffset = $start;
$this->responseStatus = 206;
$this->responseHeaders['Content-Range'] = sprintf('bytes %s-%s/%s', $start, $end, $this->fileSize);
$this->responseHeaders['Content-Length'] = $end - $start + 1;
}
}
if ($request->isMethod('HEAD')) {
$this->responseLength = 0;
}
}
protected function getRangeFromRequest(Request $request): ?array
{
$range = $request->headers->get('Range');
if (!$range || !$request->isMethod('GET') || !str_starts_with($range, 'bytes=')) {
return null;
}
if ($request->headers->has('If-Range')) {
return null;
}
[$start, $end] = explode('-', substr($range, 6), 2) + [0];
$end = ('' === $end) ? $this->fileSize - 1 : (int) $end;
if ('' === $start) {
$start = $this->fileSize - $end;
$end = $this->fileSize - 1;
} else {
$start = (int) $start;
}
$end = min($end, $this->fileSize - 1);
return [$start, $end];
}
}