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engines/teenagent/pack.h

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+/* ScummVM - Graphic Adventure Engine
+ *
+ * ScummVM is the legal property of its developers, whose names
+ * are too numerous to list here. Please refer to the COPYRIGHT
+ * file distributed with this source distribution.
+ *
+ * This program 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.
+ *
+ * This program 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 this program.  If not, see <http://www.gnu.org/licenses/>.
+ *
+ */
+
+
+#ifndef TEENAGENT_PACK_H
+#define TEENAGENT_PACK_H
+
+#include "common/file.h"
+#include "common/array.h"
+
+namespace TeenAgent {
+
+class Pack {
+protected:
+	uint32 _fileCount;
+public:
+	Pack(): _fileCount(0) {}
+	virtual ~Pack() {}
+	virtual bool open(const Common::Path &filename) = 0;
+	virtual void close() = 0;
+
+	virtual uint32 fileCount() const { return _fileCount; }
+	virtual uint32 getSize(uint32 id) const = 0;
+	virtual uint32 read(uint32 id, byte *dst, uint32 size) const = 0;
+	virtual Common::SeekableReadStream *getStream(uint32 id) const = 0;
+};
+
+///FilePack keeps opened file and returns substream for each request.
+class FilePack : public Pack {
+	mutable Common::File file;
+	uint32 *offsets;
+
+public:
+	FilePack();
+	~FilePack() override;
+
+	bool open(const Common::Path &filename) override;
+	void close() override;
+
+	uint32 getSize(uint32 id) const override;
+	uint32 read(uint32 id, byte *dst, uint32 size) const override;
+	Common::SeekableReadStream *getStream(uint32 id) const override;
+};
+
+/** Pack file which reopens file each request. Do not keep file descriptor open.
+ ** Useful for minimizing file descriptors opened at the same time. Critical for PSP backend.
+ **/
+class TransientFilePack : public Pack {
+	uint32 *offsets;
+	Common::Path _filename;
+
+public:
+	TransientFilePack();
+	~TransientFilePack() override;
+
+	bool open(const Common::Path &filename) override;
+	void close() override;
+
+	uint32 getSize(uint32 id) const override;
+	uint32 read(uint32 id, byte *dst, uint32 size) const override;
+	Common::SeekableReadStream *getStream(uint32 id) const override;
+};
+
+///MemoryPack loads whole pack in memory, currently unused.
+class MemoryPack : public Pack {
+	struct Chunk {
+		byte *data;
+		uint32 size;
+		inline Chunk(): data(0), size(0) {}
+		inline Chunk(const Chunk &c) : data(c.data), size(c.size) { c.reset(); }
+		inline Chunk &operator=(const Chunk &c) {
+			data = c.data;
+			size = c.size;
+			c.reset();
+			return *this;
+		}
+		inline ~Chunk() { delete[] data; }
+		inline void reset() const {
+			Chunk *c = const_cast<Chunk *>(this);
+			c->data = 0;
+			c->size = 0;
+		}
+	};
+	Common::Array<Chunk> chunks;
+
+public:
+	bool open(const Common::Path &filename) override;
+	void close() override;
+
+	uint32 getSize(uint32 id) const override;
+	uint32 read(uint32 id, byte *dst, uint32 size) const override;
+	Common::SeekableReadStream *getStream(uint32 id) const override;
+};
+
+} // End of namespace TeenAgent
+
+#endif