<?php
namespace GuzzleHttp\Psr7;
use Psr\Http\Message\StreamInterface;
/**
* Uses PHP's zlib.inflate filter to inflate deflate or gzipped content.
*
* This stream decorator skips the first 10 bytes of the given stream to remove
* the gzip header, converts the provided stream to a PHP stream resource,
* then appends the zlib.inflate filter. The stream is then converted back
* to a Guzzle stream resource to be used as a Guzzle stream.
*
* @link http://tools.ietf.org/html/rfc1952
* @link http://php.net/manual/en/filters.compression.php
*/
class InflateStream implements StreamInterface
{
use StreamDecoratorTrait;
public function __construct(StreamInterface $stream)
{
// read the first 10 bytes, ie. gzip header
$header = $stream->read(10);
$filenameHeaderLength = $this->getLengthOfPossibleFilenameHeader($stream, $header);
// Skip the header, that is 10 + length of filename + 1 (nil) bytes
$stream = new LimitStream($stream, -1, 10 + $filenameHeaderLength);
$resource = StreamWrapper::getResource($stream);
stream_filter_append($resource, 'zlib.inflate', STREAM_FILTER_READ);
$this->stream = $stream->isSeekable() ? new Stream($resource) : new NoSeekStream(new Stream($resource));
}
/**
* @param StreamInterface $stream
* @param $header
* @return int
*/
private function getLengthOfPossibleFilenameHeader(StreamInterface $stream, $header)
{
$filename_header_length = 0;
if (substr(bin2hex($header), 6, 2) === '08') {
// we have a filename, read until nil
$filename_header_length = 1;
while ($stream->read(1) !== chr(0)) {
$filename_header_length++;
}
}
return $filename_header_length;
}
}