1<?php
2
3declare(strict_types=1);
4
5namespace GuzzleHttp\Psr7;
6
7use Psr\Http\Message\StreamInterface;
8
9/**
10 * Uses PHP's zlib.inflate filter to inflate zlib (HTTP deflate, RFC1950) or gzipped (RFC1952) content.
11 *
12 * This stream decorator converts the provided stream to a PHP stream resource,
13 * then appends the zlib.inflate filter. The stream is then converted back
14 * to a Guzzle stream resource to be used as a Guzzle stream.
15 *
16 * @see https://datatracker.ietf.org/doc/html/rfc1950
17 * @see https://datatracker.ietf.org/doc/html/rfc1952
18 * @see https://www.php.net/manual/en/filters.compression.php
19 */
20final class InflateStream implements StreamInterface
21{
22    use StreamDecoratorTrait;
23
24    /** @var StreamInterface */
25    private $stream;
26
27    public function __construct(StreamInterface $stream)
28    {
29        $resource = StreamWrapper::getResource($stream);
30        // Specify window=15+32, so zlib will use header detection to both gzip (with header) and zlib data
31        // See https://www.zlib.net/manual.html#Advanced definition of inflateInit2
32        // "Add 32 to windowBits to enable zlib and gzip decoding with automatic header detection"
33        // Default window size is 15.
34        stream_filter_append($resource, 'zlib.inflate', STREAM_FILTER_READ, ['window' => 15 + 32]);
35        $this->stream = $stream->isSeekable() ? new Stream($resource) : new NoSeekStream(new Stream($resource));
36    }
37}
38