libretro-dolphin/Source/Core/DiscIO/CompressedBlob.h
2020-06-21 20:47:23 +02:00

80 lines
2.1 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
// WARNING Code not big-endian safe.
// To create new compressed BLOBs, use CompressFileToBlob.
// File format
// * Header
// * [Block Pointers interleaved with block hashes (hash of decompressed data)]
// * [Data]
#pragma once
#include <memory>
#include <string>
#include <vector>
#include "Common/CommonTypes.h"
#include "Common/File.h"
#include "DiscIO/Blob.h"
namespace DiscIO
{
static constexpr u32 GCZ_MAGIC = 0xB10BC001;
// GCZ file structure:
// BlobHeader
// u64 offsetsToBlocks[n], top bit specifies whether the block is compressed, or not.
// compressed data
// Blocks that won't compress to less than 97% of the original size are stored as-is.
struct CompressedBlobHeader // 32 bytes
{
u32 magic_cookie; // 0xB10BB10B
u32 sub_type; // GC image, whatever
u64 compressed_data_size;
u64 data_size;
u32 block_size;
u32 num_blocks;
};
class CompressedBlobReader : public SectorReader
{
public:
static std::unique_ptr<CompressedBlobReader> Create(File::IOFile file,
const std::string& filename);
~CompressedBlobReader();
const CompressedBlobHeader& GetHeader() const { return m_header; }
BlobType GetBlobType() const override { return BlobType::GCZ; }
u64 GetRawSize() const override { return m_file_size; }
u64 GetDataSize() const override { return m_header.data_size; }
bool IsDataSizeAccurate() const override { return true; }
u64 GetBlockSize() const override { return m_header.block_size; }
bool HasFastRandomAccessInBlock() const override { return false; }
std::string GetCompressionMethod() const override { return "Deflate"; }
u64 GetBlockCompressedSize(u64 block_num) const;
bool GetBlock(u64 block_num, u8* out_ptr) override;
private:
CompressedBlobReader(File::IOFile file, const std::string& filename);
CompressedBlobHeader m_header;
std::vector<u64> m_block_pointers;
std::vector<u32> m_hashes;
int m_data_offset;
File::IOFile m_file;
u64 m_file_size;
std::vector<u8> m_zlib_buffer;
std::string m_file_name;
};
} // namespace DiscIO