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// Copyright (C) 2003 Dolphin 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.
// 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 SVN repository and contact information can be found at
// http://code.google.com/p/dolphin-emu/
#include "Common.h"
#include "FileUtil.h"
#include "CDUtils.h"
#include "Blob.h"
#include "CompressedBlob.h"
#include "FileBlob.h"
#include "DriveBlob.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 (int i = 0; i < CACHE_SIZE; i++)
{
cache[i] = new u8[blocksize];
cache_tags[i] = (u64)(s64) - 1;
}
m_blocksize = blocksize;
}
SectorReader::~SectorReader() {
for (int i = 0; i < CACHE_SIZE; i++)
delete [] cache[i];
}
const u8 *SectorReader::GetBlockData(u64 block_num)
{
// TODO : Expand usage of the cache to more than one block :P
if (cache_tags[0] == block_num)
{
return cache[0];
}
else
{
GetBlock(block_num, cache[0]);
cache_tags[0] = block_num;
return 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;
}
u32 toCopy = m_blocksize - positionInBlock;
if (toCopy >= remain)
{
const u8* data = GetBlockData(block);
if (!data)
return false;
// Yay, we are done!
memcpy(out_ptr, data + positionInBlock, (size_t)remain);
return true;
}
else
{
const u8* data = GetBlockData(block);
if (!data)
return false;
memcpy(out_ptr, data + positionInBlock, toCopy);
out_ptr += toCopy;
remain -= toCopy;
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 u8 *data = GetBlockData(block_num + i);
if (!data)
return false;
memcpy(out_ptr + i * m_blocksize, data, m_blocksize);
}
return true;
}
IBlobReader* CreateBlobReader(const char* filename)
{
if (cdio_is_cdrom(std::string(filename)))
return DriveReader::Create(filename);
if (!File::Exists(filename))
return 0;
if (IsCompressedBlob(filename))
return CompressedBlobReader::Create(filename);
// Still here? Assume plain file - since we know it exists due to the File::Exists check above.
return PlainFileReader::Create(filename);
}
} // namespace
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