[IO] Add StreamPeerGZIP for streaming compression/decompression.

Putting data results in writing the compressed/decompressed output into
a RingBuffer.
You can retrieve the content of the RingBuffer via get_data.

Support both gzip and deflate.

4 files changed, 329 insertions, 0 deletions

diff --git a/core/io/stream_peer_gzip.cpp b/core/io/stream_peer_gzip.cpp
new file mode 100644
index 0000000000..ca8be2d62e
--- /dev/null
+++ b/core/io/stream_peer_gzip.cpp
@@ -0,0 +1,209 @@
+/*************************************************************************/
+/*  stream_peer_gzip.cpp                                                 */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#include "core/io/stream_peer_gzip.h"
+
+#include "core/io/zip_io.h"
+#include <zlib.h>
+
+void StreamPeerGZIP::_bind_methods() {
+	ClassDB::bind_method(D_METHOD("start_compression", "use_deflate", "buffer_size"), &StreamPeerGZIP::start_compression, DEFVAL(false), DEFVAL(65535));
+	ClassDB::bind_method(D_METHOD("start_decompression", "use_deflate", "buffer_size"), &StreamPeerGZIP::start_decompression, DEFVAL(false), DEFVAL(65535));
+	ClassDB::bind_method(D_METHOD("finish"), &StreamPeerGZIP::finish);
+	ClassDB::bind_method(D_METHOD("clear"), &StreamPeerGZIP::clear);
+}
+
+StreamPeerGZIP::StreamPeerGZIP() {
+}
+
+StreamPeerGZIP::~StreamPeerGZIP() {
+	_close();
+}
+
+void StreamPeerGZIP::_close() {
+	if (ctx) {
+		z_stream *strm = (z_stream *)ctx;
+		if (compressing) {
+			deflateEnd(strm);
+		} else {
+			inflateEnd(strm);
+		}
+		memfree(strm);
+		ctx = nullptr;
+	}
+}
+
+void StreamPeerGZIP::clear() {
+	_close();
+	rb.clear();
+	buffer.clear();
+}
+
+Error StreamPeerGZIP::start_compression(bool p_is_deflate, int buffer_size) {
+	return _start(true, p_is_deflate, buffer_size);
+}
+
+Error StreamPeerGZIP::start_decompression(bool p_is_deflate, int buffer_size) {
+	return _start(false, p_is_deflate, buffer_size);
+}
+
+Error StreamPeerGZIP::_start(bool p_compress, bool p_is_deflate, int buffer_size) {
+	ERR_FAIL_COND_V(ctx != nullptr, ERR_ALREADY_IN_USE);
+	clear();
+	compressing = p_compress;
+	rb.resize(nearest_shift(buffer_size - 1));
+	buffer.resize(1024);
+
+	// Create ctx.
+	ctx = memalloc(sizeof(z_stream));
+	z_stream &strm = *(z_stream *)ctx;
+	strm.next_in = Z_NULL;
+	strm.avail_in = 0;
+	strm.zalloc = zipio_alloc;
+	strm.zfree = zipio_free;
+	strm.opaque = Z_NULL;
+	int window_bits = p_is_deflate ? 15 : (15 + 16);
+	int err = Z_OK;
+	int level = Z_DEFAULT_COMPRESSION;
+	if (compressing) {
+		err = deflateInit2(&strm, level, Z_DEFLATED, window_bits, 8, Z_DEFAULT_STRATEGY);
+	} else {
+		err = inflateInit2(&strm, window_bits);
+	}
+	ERR_FAIL_COND_V(err != Z_OK, FAILED);
+	return OK;
+}
+
+Error StreamPeerGZIP::_process(uint8_t *p_dst, int p_dst_size, const uint8_t *p_src, int p_src_size, int &r_consumed, int &r_out, bool p_close) {
+	ERR_FAIL_COND_V(!ctx, ERR_UNCONFIGURED);
+	z_stream &strm = *(z_stream *)ctx;
+	strm.avail_in = p_src_size;
+	strm.avail_out = p_dst_size;
+	strm.next_in = (Bytef *)p_src;
+	strm.next_out = (Bytef *)p_dst;
+	int flush = p_close ? Z_FINISH : Z_NO_FLUSH;
+	if (compressing) {
+		int err = deflate(&strm, flush);
+		ERR_FAIL_COND_V(err != (p_close ? Z_STREAM_END : Z_OK), FAILED);
+	} else {
+		int err = inflate(&strm, flush);
+		ERR_FAIL_COND_V(err != Z_OK && err != Z_STREAM_END, FAILED);
+	}
+	r_out = p_dst_size - strm.avail_out;
+	r_consumed = p_src_size - strm.avail_in;
+	return OK;
+}
+
+Error StreamPeerGZIP::put_data(const uint8_t *p_data, int p_bytes) {
+	int wrote = 0;
+	Error err = put_partial_data(p_data, p_bytes, wrote);
+	if (err != OK) {
+		return err;
+	}
+	ERR_FAIL_COND_V(p_bytes != wrote, ERR_OUT_OF_MEMORY);
+	return OK;
+}
+
+Error StreamPeerGZIP::put_partial_data(const uint8_t *p_data, int p_bytes, int &r_sent) {
+	ERR_FAIL_COND_V(!ctx, ERR_UNCONFIGURED);
+	ERR_FAIL_COND_V(p_bytes < 0, ERR_INVALID_PARAMETER);
+
+	// Ensure we have enough space in temporary buffer.
+	if (buffer.size() < p_bytes) {
+		buffer.resize(p_bytes);
+	}
+
+	r_sent = 0;
+	while (r_sent < p_bytes && rb.space_left() > 1024) { // Keep the ring buffer size meaningful.
+		int sent = 0;
+		int to_write = 0;
+		// Compress or decompress
+		Error err = _process(buffer.ptrw(), MIN(buffer.size(), rb.space_left()), p_data + r_sent, p_bytes - r_sent, sent, to_write);
+		if (err != OK) {
+			return err;
+		}
+		// When decompressing, we might need to do another round.
+		r_sent += sent;
+
+		// We can't write more than this buffer is full.
+		if (sent == 0 && to_write == 0) {
+			return OK;
+		}
+		if (to_write) {
+			// Copy to ring buffer.
+			int wrote = rb.write(buffer.ptr(), to_write);
+			ERR_FAIL_COND_V(wrote != to_write, ERR_BUG);
+		}
+	}
+	return OK;
+}
+
+Error StreamPeerGZIP::get_data(uint8_t *p_buffer, int p_bytes) {
+	int received = 0;
+	Error err = get_partial_data(p_buffer, p_bytes, received);
+	if (err != OK) {
+		return err;
+	}
+	ERR_FAIL_COND_V(p_bytes != received, ERR_UNAVAILABLE);
+	return OK;
+}
+
+Error StreamPeerGZIP::get_partial_data(uint8_t *p_buffer, int p_bytes, int &r_received) {
+	ERR_FAIL_COND_V(p_bytes < 0, ERR_INVALID_PARAMETER);
+
+	r_received = MIN(p_bytes, rb.data_left());
+	if (r_received == 0) {
+		return OK;
+	}
+	int received = rb.read(p_buffer, r_received);
+	ERR_FAIL_COND_V(received != r_received, ERR_BUG);
+	return OK;
+}
+
+int StreamPeerGZIP::get_available_bytes() const {
+	return rb.data_left();
+}
+
+Error StreamPeerGZIP::finish() {
+	ERR_FAIL_COND_V(!ctx || !compressing, ERR_UNAVAILABLE);
+	// Ensure we have enough space in temporary buffer.
+	if (buffer.size() < 1024) {
+		buffer.resize(1024); // 1024 should be more than enough.
+	}
+	int consumed = 0;
+	int to_write = 0;
+	Error err = _process(buffer.ptrw(), 1024, nullptr, 0, consumed, to_write, true); // compress
+	if (err != OK) {
+		return err;
+	}
+	int wrote = rb.write(buffer.ptr(), to_write);
+	ERR_FAIL_COND_V(wrote != to_write, ERR_OUT_OF_MEMORY);
+	return OK;
+}
diff --git a/core/io/stream_peer_gzip.h b/core/io/stream_peer_gzip.h
new file mode 100644
index 0000000000..5bafdbca9b
--- /dev/null
+++ b/core/io/stream_peer_gzip.h
@@ -0,0 +1,76 @@
+/*************************************************************************/
+/*  stream_peer_gzip.h                                                   */
+/*************************************************************************/
+/*                       This file is part of:                           */
+/*                           GODOT ENGINE                                */
+/*                      https://godotengine.org                          */
+/*************************************************************************/
+/* Copyright (c) 2007-2022 Juan Linietsky, Ariel Manzur.                 */
+/* Copyright (c) 2014-2022 Godot Engine contributors (cf. AUTHORS.md).   */
+/*                                                                       */
+/* Permission is hereby granted, free of charge, to any person obtaining */
+/* a copy of this software and associated documentation files (the       */
+/* "Software"), to deal in the Software without restriction, including   */
+/* without limitation the rights to use, copy, modify, merge, publish,   */
+/* distribute, sublicense, and/or sell copies of the Software, and to    */
+/* permit persons to whom the Software is furnished to do so, subject to */
+/* the following conditions:                                             */
+/*                                                                       */
+/* The above copyright notice and this permission notice shall be        */
+/* included in all copies or substantial portions of the Software.       */
+/*                                                                       */
+/* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,       */
+/* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF    */
+/* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.*/
+/* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY  */
+/* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT,  */
+/* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE     */
+/* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.                */
+/*************************************************************************/
+
+#ifndef STREAM_PEER_GZIP_H
+#define STREAM_PEER_GZIP_H
+
+#include "core/io/stream_peer.h"
+
+#include "core/core_bind.h"
+#include "core/io/compression.h"
+#include "core/templates/ring_buffer.h"
+
+class StreamPeerGZIP : public StreamPeer {
+	GDCLASS(StreamPeerGZIP, StreamPeer);
+
+private:
+	void *ctx = nullptr; // Will hold our z_stream instance.
+	bool compressing = true;
+
+	RingBuffer<uint8_t> rb;
+	Vector<uint8_t> buffer;
+
+	Error _process(uint8_t *p_dst, int p_dst_size, const uint8_t *p_src, int p_src_size, int &r_consumed, int &r_out, bool p_close = false);
+	void _close();
+	Error _start(bool p_compress, bool p_is_deflate, int buffer_size = 65535);
+
+protected:
+	static void _bind_methods();
+
+public:
+	Error start_compression(bool p_is_deflate, int buffer_size = 65535);
+	Error start_decompression(bool p_is_deflate, int buffer_size = 65535);
+
+	Error finish();
+	void clear();
+
+	virtual Error put_data(const uint8_t *p_data, int p_bytes) override;
+	virtual Error put_partial_data(const uint8_t *p_data, int p_bytes, int &r_sent) override;
+
+	virtual Error get_data(uint8_t *p_buffer, int p_bytes) override;
+	virtual Error get_partial_data(uint8_t *p_buffer, int p_bytes, int &r_received) override;
+
+	virtual int get_available_bytes() const override;
+
+	StreamPeerGZIP();
+	~StreamPeerGZIP();
+};
+
+#endif // STREAM_PEER_GZIP_H
diff --git a/core/register_core_types.cpp b/core/register_core_types.cpp
index 0233afe199..64cc6f2aab 100644
--- a/core/register_core_types.cpp
+++ b/core/register_core_types.cpp
@@ -58,6 +58,7 @@
 #include "core/io/resource_format_binary.h"
 #include "core/io/resource_importer.h"
 #include "core/io/resource_uid.h"
+#include "core/io/stream_peer_gzip.h"
 #include "core/io/stream_peer_tls.h"
 #include "core/io/tcp_server.h"
 #include "core/io/translation_loader_po.h"
@@ -184,6 +185,7 @@ void register_core_types() {
 	GDREGISTER_ABSTRACT_CLASS(StreamPeer);
 	GDREGISTER_CLASS(StreamPeerExtension);
 	GDREGISTER_CLASS(StreamPeerBuffer);
+	GDREGISTER_CLASS(StreamPeerGZIP);
 	GDREGISTER_CLASS(StreamPeerTCP);
 	GDREGISTER_CLASS(TCPServer);
 
diff --git a/doc/classes/StreamPeerGZIP.xml b/doc/classes/StreamPeerGZIP.xml
new file mode 100644
index 0000000000..71dd36160d
--- /dev/null
+++ b/doc/classes/StreamPeerGZIP.xml
@@ -0,0 +1,42 @@
+<?xml version="1.0" encoding="UTF-8" ?>
+<class name="StreamPeerGZIP" inherits="StreamPeer" is_experimental="true" version="4.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:noNamespaceSchemaLocation="../class.xsd">
+	<brief_description>
+		Stream peer handling GZIP and deflate compression/decompresison.
+	</brief_description>
+	<description>
+		This class allows to compress or decompress data using GZIP/deflate in a streaming fashion. This is particularly useful when compressing or decompressing files that has to be sent through the network without having to allocate them all in memory.
+		After starting the stream via [method start_compression] (or [method start_decompression]), calling [method StreamPeer.put_partial_data] on this stream will compress (or decompress) the data, writing it to the internal buffer. Calling [method StreamPeer.get_available_bytes] will return the pending bytes in the internal buffer, and [method StreamPeer.get_partial_data] will retrieve the compressed (or decompressed) bytes from it. When the stream is over, you must call [method finish] to ensure the internal buffer is properly flushed (make sure to call [method StreamPeer.get_available_bytes] on last time to check if more data needs to be read after that).
+	</description>
+	<tutorials>
+	</tutorials>
+	<methods>
+		<method name="clear">
+			<return type="void" />
+			<description>
+				Clears this stream, resetting the internal state.
+			</description>
+		</method>
+		<method name="finish">
+			<return type="int" enum="Error" />
+			<description>
+				Finalizes the stream, compressing or decompressing any buffered chunk left.
+			</description>
+		</method>
+		<method name="start_compression">
+			<return type="int" enum="Error" />
+			<param index="0" name="use_deflate" type="bool" default="false" />
+			<param index="1" name="buffer_size" type="int" default="65535" />
+			<description>
+				Start the stream in compression mode with the given [param buffer_size], if [param use_deflate] is [code]true[/code] uses deflate instead of GZIP.
+			</description>
+		</method>
+		<method name="start_decompression">
+			<return type="int" enum="Error" />
+			<param index="0" name="use_deflate" type="bool" default="false" />
+			<param index="1" name="buffer_size" type="int" default="65535" />
+			<description>
+				Start the stream in decompression mode with the given [param buffer_size], if [param use_deflate] is [code]true[/code] uses deflate instead of GZIP.
+			</description>
+		</method>
+	</methods>
+</class>