BlockDevices.h

// Copyright (c) 2012- PPSSPP Project.

// 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, version 2.0 or later versions.

// 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 2.0 for more details.

// A copy of the GPL 2.0 should have been included with the program.
// If not, see http://www.gnu.org/licenses/

// Official git repository and contact information can be found at
// https://github.com/hrydgard/ppsspp and http://www.ppsspp.org/.

#pragma once

// Abstractions around read-only blockdevices, such as PSP UMD discs.
// CISOFileBlockDevice implements compressed iso images, CISO format.
//
// The ISOFileSystemReader reads from a BlockDevice, so it automatically works
// with CISO images.

#include <mutex>

#include "Common/CommonTypes.h"
#include "Core/ELF/PBPReader.h"

class FileLoader;

class BlockDevice {
public:
	BlockDevice(FileLoader *fileLoader) : fileLoader_(fileLoader) {}
	virtual ~BlockDevice() {}
	virtual bool ReadBlock(int blockNumber, u8 *outPtr, bool uncached = false) = 0;
	virtual bool ReadBlocks(u32 minBlock, int count, u8 *outPtr) {
		for (int b = 0; b < count; ++b) {
			if (!ReadBlock(minBlock + b, outPtr)) {
				return false;
			}
			outPtr += GetBlockSize();
		}
		return true;
	}
	int GetBlockSize() const { return 2048;}  // forced, it cannot be changed by subclasses
	virtual u32 GetNumBlocks() = 0;
	virtual bool IsDisc() = 0;

	u32 CalculateCRC(volatile bool *cancel = nullptr);
	void NotifyReadError();

protected:
	FileLoader *fileLoader_;
	bool reportedError_ = false;
};

class CISOFileBlockDevice : public BlockDevice {
public:
	CISOFileBlockDevice(FileLoader *fileLoader);
	~CISOFileBlockDevice();
	bool ReadBlock(int blockNumber, u8 *outPtr, bool uncached = false) override;
	bool ReadBlocks(u32 minBlock, int count, u8 *outPtr) override;
	u32 GetNumBlocks() override { return numBlocks; }
	bool IsDisc() override { return true; }

private:
	u32 *index;
	u8 *readBuffer;
	u8 *zlibBuffer;
	u32 zlibBufferFrame;
	u8 indexShift;
	u8 blockShift;
	u32 frameSize;
	u32 numBlocks;
	u32 numFrames;
	int ver_;
};


class FileBlockDevice : public BlockDevice {
public:
	FileBlockDevice(FileLoader *fileLoader);
	~FileBlockDevice();
	bool ReadBlock(int blockNumber, u8 *outPtr, bool uncached = false) override;
	bool ReadBlocks(u32 minBlock, int count, u8 *outPtr) override;
	u32 GetNumBlocks() override {return (u32)(filesize_ / GetBlockSize());}
	bool IsDisc() override { return true; }

private:
	u64 filesize_;
};


// For encrypted ISOs in PBP files.

struct table_info {
	u8 mac[16];
	u32 offset;
	int size;
	int flag;
	int unk_1c;
};

class NPDRMDemoBlockDevice : public BlockDevice {
public:
	NPDRMDemoBlockDevice(FileLoader *fileLoader);
	~NPDRMDemoBlockDevice();

	bool ReadBlock(int blockNumber, u8 *outPtr, bool uncached = false) override;
	u32 GetNumBlocks() override {return (u32)lbaSize;}
	bool IsDisc() override { return false; }

private:
	static std::mutex mutex_;
	u32 lbaSize;

	u32 psarOffset;
	int blockSize;
	int blockLBAs;
	u32 numBlocks;

	u8 vkey[16];
	u8 hkey[16];
	struct table_info *table;

	int currentBlock;
	u8 *blockBuf;
	u8 *tempBuf;
};

struct CHDImpl;

class CHDFileBlockDevice : public BlockDevice {
public:
	CHDFileBlockDevice(FileLoader *fileLoader);
	~CHDFileBlockDevice();
	bool ReadBlock(int blockNumber, u8 *outPtr, bool uncached = false) override;
	bool ReadBlocks(u32 minBlock, int count, u8 *outPtr) override;
	u32 GetNumBlocks() override { return numBlocks; }
	bool IsDisc() override { return true; }

private:
	std::unique_ptr<CHDImpl> impl_;
	u8 *readBuffer;
	u32 currentHunk;
	u32 blocksPerHunk;
	u32 numBlocks;
};

BlockDevice *constructBlockDevice(FileLoader *fileLoader);