*/ private readonly LocalCache $contentTypeCache; /** * @param positive-int $minimumLength Minimum body length before body is compressed. * @param non-empty-string $contentRegex Content-Type regex. */ public function __construct( private readonly int $minimumLength = self::DEFAULT_MINIMUM_LENGTH, private readonly string $contentRegex = self::DEFAULT_CONTENT_TYPE_REGEX, private readonly float $bufferTimeout = self::DEFAULT_BUFFER_TIMEOUT, ) { if (!\extension_loaded('zlib')) { throw new \Error(__CLASS__ . ' requires ext-zlib'); } /** @psalm-suppress DocblockTypeContradiction */ if ($minimumLength < 1) { throw new \Error("The minimum length must be positive"); } if ($bufferTimeout <= 0) { throw new \Error("The buffer timeout must be positive"); } $this->contentTypeCache = new LocalCache(self::MAX_CACHE_SIZE); } public function handleRequest(Request $request, RequestHandler $requestHandler): Response { $response = $requestHandler->handleRequest($request); $headers = $response->getHeaders(); if (isset($headers["content-encoding"])) { return $response; // Another request handler or middleware has already encoded the response. } $contentLength = $headers["content-length"][0] ?? null; if ($contentLength !== null) { if ($contentLength < $this->minimumLength) { return $response; // Content-Length too small, no need to compress. } } // We can't deflate if we don't know the content-type if (empty($headers["content-type"])) { return $response; } $contentType = $headers["content-type"][0]; $weight = 0; foreach ($request->getHeaderArray("accept-encoding") as $values) { foreach (\array_map("trim", \explode(",", $values)) as $value) { if (\preg_match('/^(gzip|deflate)(?:;q=(1(?:\.0{1,3})?|0(?:\.\d{1,3})?))?$/i', $value, $matches)) { $qValue = (float) ($matches[2] ?? 1); if ($qValue <= $weight) { continue; } $weight = $qValue; $encoding = \strtolower($matches[1]); } } } if (!isset($encoding)) { return $response; } $doDeflate = $this->contentTypeCache->get($contentType); if ($doDeflate === null) { $doDeflate = \preg_match($this->contentRegex, \trim(\strstr($contentType, ";", true) ?: $contentType)); $this->contentTypeCache->set($contentType, (bool) $doDeflate); } if (!$doDeflate) { return $response; } $body = $response->getBody(); $bodyBuffer = ''; if ($contentLength === null && !$this->shouldCompress($body, $bodyBuffer)) { $response->setBody($bodyBuffer); return $response; } $mode = match ($encoding) { "deflate" => \ZLIB_ENCODING_RAW, "gzip" => \ZLIB_ENCODING_GZIP, default => throw new \RuntimeException("Invalid encoding type"), }; if (($context = \deflate_init($mode)) === false) { throw new \RuntimeException( "Failed initializing deflate context" ); } // Once we decide to compress output we no longer know what the // final Content-Length will be. We need to update our headers // according to the HTTP protocol in use to reflect this. $response->removeHeader("content-length"); if ($request->getProtocolVersion() === "1.0") { // Cannot chunk 1.0 responses. $response->setHeader("connection", "close"); } $response->setHeader("content-encoding", $encoding); $response->addHeader("vary", "accept-encoding"); /** @psalm-suppress InvalidArgument Psalm stubs are out of date, deflate_init returns a \DeflateContext */ $response->setBody( new ReadableIterableStream(self::readBody($context, $body, $bodyBuffer)) ); return $response; } private function shouldCompress(ReadableStream $body, string &$bodyBuffer): bool { try { $cancellation = new TimeoutCancellation($this->bufferTimeout); do { $bodyBuffer .= $chunk = $body->read($cancellation); if (isset($bodyBuffer[$this->minimumLength])) { return true; } if ($chunk === null) { return false; } } while (true); } catch (CancelledException) { // Not enough bytes buffered within timeout to determine body size, so use compression by default. } return true; } /** * @psalm-suppress InvalidArgument */ private static function readBody( \DeflateContext $context, ReadableStream $body, string $chunk, ): \Generator { self::$errorHandler ??= static function (int $code, string $message): never { throw new \RuntimeException('Compression error: ' . $message, $code); }; do { if ($chunk !== '') { \set_error_handler(self::$errorHandler); try { $chunk = \deflate_add($context, $chunk, \ZLIB_SYNC_FLUSH); } finally { \restore_error_handler(); } yield $chunk; } $chunk = $body->read(); } while ($chunk !== null); \set_error_handler(self::$errorHandler); try { $chunk = \deflate_add($context, '', \ZLIB_FINISH); } finally { \restore_error_handler(); } yield $chunk; } }