openspades/Sources/Core/DeflateStream.h

/*
 Copyright (c) 2013 yvt

 This file is part of OpenSpades.

 OpenSpades is free software: you can redistribute it and/or modify
 it under the terms of the GNU General Public License as published by
 the Free Software Foundation, either version 3 of the License, or
 (at your option) any later version.

 OpenSpades is distributed in the hope that it will be useful,
 but WITHOUT ANY WARRANTY; without even the implied warranty of
 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 GNU General Public License for more details.

 You should have received a copy of the GNU General Public License
 along with OpenSpades.  If not, see <http://www.gnu.org/licenses/>.

 */

#pragma once

#include <vector>

#include <zlib.h>

#include "IStream.h"

namespace spades {
	class DeflateStream : public IStream {
		IStream *baseStream;
		CompressMode mode;
		z_stream zstream;
		bool autoClose;
		bool valid;
		uint64_t position;

		// when compressing:
		//  input buffer
		// when decompressing:
		//  output buffer
		std::vector<char> buffer;

		// input buffer that wasn't used in FillBuffer
		// is stored here
		std::vector<char> nextbuffer;

		// decompression only
		bool reachedEOF;
		size_t bufferPos;

		void CompressBuffer();
		void FillBuffer();

	public:
		DeflateStream(IStream *stream, CompressMode mode, bool autoClose = false);
		~DeflateStream();

		int ReadByte() override;
		size_t Read(void *, size_t bytes) override;

		void WriteByte(int) override;
		void Write(const void *, size_t bytes) override;

		uint64_t GetPosition() override;
		void SetPosition(uint64_t) override;

		uint64_t GetLength() override;
		void SetLength(uint64_t) override;

		/** Must be called when all data was written, in case of compressing, or output will be
		 * corrupted */
		void DeflateEnd();
	};
}