← All changes | vendor/wp-php-toolkit/reprint-server/src/class-gzip-output-stream.php +116 -0 16.2-beta → 16.3-beta View file →

		@@ -1,0 +1,116 @@
	1	+<?php
	2	+
	3	+// Declared here rather than in export.php so it can live in this package's
	4	+// namespace. export.php is a global-namespace file of endpoint functions that
	5	+// callers reach by unqualified name.
	6	+
	7	+namespace WordPress\Reprint\Server;
	8	+
	9	+/**
	10	+ * Incremental response writer.
	11	+ *
	12	+ * PHP 7.0 and newer can gzip each bounded write without buffering the whole
	13	+ * response. PHP 5.6 lacks the incremental zlib API, so it sends the same
	14	+ * multipart stream without a Content-Encoding header.
	15	+ *
	16	+ * PHP-side gzip also gives outbound WAF rules that do not decode
	17	+ * Content-Encoding the encoded byte stream; server-level compression can run
	18	+ * after those rules inspect the body.
	19	+ */
	20	+class GzipOutputStream
	21	+{
	22	+ private $deflate_ctx;
	23	+ /** @var bool */
	24	+ private $enabled = true;
	25	+
	26	+ public function __construct(bool $enabled = true)
	27	+ {
	28	+ $this->enabled = $enabled
	29	+ && function_exists('deflate_init')
	30	+ && function_exists('deflate_add');
	31	+ if ($this->enabled) {
	32	+ $this->deflate_ctx = deflate_init(ZLIB_ENCODING_GZIP, ["level" => 6]);
	33	+ if ($this->deflate_ctx === false) {
	34	+ throw new \RuntimeException(
	35	+ "deflate_init() failed — zlib may be misconfigured"
	36	+ );
	37	+ }
	38	+ if (!headers_sent()) {
	39	+ @header("Content-Encoding: gzip");
	40	+ }
	41	+ }
	42	+ }
	43	+
	44	+ /**
	45	+ * Writes data without forcing a sync point.
	46	+ *
	47	+ * Uses ZLIB_NO_FLUSH so the compressor can build back-references across
	48	+ * multiple write() calls, producing significantly better compression
	49	+ * ratios than ZLIB_SYNC_FLUSH on every call. Data still flows out
	50	+ * whenever zlib's internal buffer fills — the decompressor on the other
	51	+ * end will decompress incrementally.
	52	+ *
	53	+ * Call sync() after each complete multipart part to guarantee the client
	54	+ * can decompress everything emitted so far.
	55	+ */
	56	+ public function write(string $data): void
	57	+ {
	58	+ if (!$this->enabled) {
	59	+ echo $data;
	60	+ return;
	61	+ }
	62	+ $compressed = deflate_add(
	63	+ $this->deflate_ctx,
	64	+ $data,
	65	+ ZLIB_NO_FLUSH
	66	+ );
	67	+ if ($compressed === false) {
	68	+ throw new \RuntimeException("deflate_add() failed during gzip write");
	69	+ }
	70	+ if ($compressed !== "") {
	71	+ echo $compressed;
	72	+ }
	73	+ }
	74	+
	75	+ /**
	76	+ * Forces a sync flush so the client can decompress all data written so far.
	77	+ */
	78	+ public function sync(): void
	79	+ {
	80	+ if (!$this->enabled) {
	81	+ flush();
	82	+ return;
	83	+ }
	84	+ $compressed = deflate_add(
	85	+ $this->deflate_ctx,
	86	+ "",
	87	+ ZLIB_SYNC_FLUSH
	88	+ );
	89	+ if ($compressed === false) {
	90	+ throw new \RuntimeException("deflate_add() failed during gzip sync");
	91	+ }
	92	+ if ($compressed !== "") {
	93	+ echo $compressed;
	94	+ }
	95	+ flush();
	96	+ }
	97	+
	98	+ /**
	99	+ * Finalizes the gzip stream with ZLIB_FINISH.
	100	+ */
	101	+ public function finish(): void
	102	+ {
	103	+ if (!$this->enabled) {
	104	+ flush();
	105	+ return;
	106	+ }
	107	+ $final = deflate_add($this->deflate_ctx, "", ZLIB_FINISH);
	108	+ if ($final === false) {
	109	+ throw new \RuntimeException("deflate_add() failed during gzip finish");
	110	+ }
	111	+ if ($final !== "") {
	112	+ echo $final;
	113	+ }
	114	+ flush();
	115	+ }
	116	+}