dolphin/Source/Core/DiscIO/Blob.cpp

130 lines
3.1 KiB
C++

// Copyright 2008 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <cstddef>
#include <cstring>
#include <limits>
#include <memory>
#include <string>
#include "Common/CDUtils.h"
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "DiscIO/Blob.h"
#include "DiscIO/CISOBlob.h"
#include "DiscIO/CompressedBlob.h"
#include "DiscIO/DriveBlob.h"
#include "DiscIO/FileBlob.h"
#include "DiscIO/WbfsBlob.h"
namespace DiscIO
{
// Provides caching and split-operation-to-block-operations facilities.
// Used for compressed blob reading and direct drive reading.
void SectorReader::SetSectorSize(int blocksize)
{
for (auto& cache_entry : m_cache)
cache_entry.resize(blocksize);
m_cache_tags.fill(std::numeric_limits<u64>::max());
m_blocksize = blocksize;
}
SectorReader::~SectorReader()
{
}
const std::vector<u8>& SectorReader::GetBlockData(u64 block_num)
{
// TODO : Expand usage of the cache to more than one block :P
if (m_cache_tags[0] == block_num)
return m_cache[0];
GetBlock(block_num, m_cache[0].data());
m_cache_tags[0] = block_num;
return m_cache[0];
}
bool SectorReader::Read(u64 offset, u64 size, u8* out_ptr)
{
u64 startingBlock = offset / m_blocksize;
u64 remain = size;
int positionInBlock = (int)(offset % m_blocksize);
u64 block = startingBlock;
while (remain > 0)
{
// Check if we are ready to do a large block read. > instead of >= so we don't bother if remain is only one block.
if (positionInBlock == 0 && remain > (u64)m_blocksize)
{
u64 num_blocks = remain / m_blocksize;
ReadMultipleAlignedBlocks(block, num_blocks, out_ptr);
block += num_blocks;
out_ptr += num_blocks * m_blocksize;
remain -= num_blocks * m_blocksize;
continue;
}
const std::vector<u8>& data = GetBlockData(block);
u32 to_copy = m_blocksize - positionInBlock;
if (to_copy >= remain)
{
// Yay, we are done!
std::copy(data.begin() + positionInBlock, data.begin() + positionInBlock + remain, out_ptr);
return true;
}
else
{
std::copy(data.begin() + positionInBlock, data.begin() + positionInBlock + to_copy, out_ptr);
out_ptr += to_copy;
remain -= to_copy;
positionInBlock = 0;
block++;
}
}
return true;
}
bool SectorReader::ReadMultipleAlignedBlocks(u64 block_num, u64 num_blocks, u8* out_ptr)
{
for (u64 i = 0; i < num_blocks; i++)
{
const std::vector<u8>& data = GetBlockData(block_num + i);
const u64 offset = i * m_blocksize;
std::copy(data.begin(), data.end(), out_ptr + offset);
}
return true;
}
std::unique_ptr<IBlobReader> CreateBlobReader(const std::string& filename)
{
if (cdio_is_cdrom(filename))
return DriveReader::Create(filename);
if (!File::Exists(filename))
return nullptr;
if (IsWbfsBlob(filename))
return WbfsFileReader::Create(filename);
if (IsGCZBlob(filename))
return CompressedBlobReader::Create(filename);
if (IsCISOBlob(filename))
return CISOFileReader::Create(filename);
// Still here? Assume plain file - since we know it exists due to the File::Exists check above.
return PlainFileReader::Create(filename);
}
} // namespace