dolphin/Source/Core/DiscIO/CISOBlob.cpp

97 lines
1.9 KiB
C++

// Copyright 2010 Dolphin Emulator Project
// Licensed under GPLv2+
// Refer to the license.txt file included.
#include <algorithm>
#include <cstdio>
#include "Common/CommonTypes.h"
#include "Common/FileUtil.h"
#include "DiscIO/CISOBlob.h"
namespace DiscIO
{
static const char CISO_MAGIC[] = "CISO";
CISOFileReader::CISOFileReader(std::FILE* file)
: m_file(file)
{
m_size = m_file.GetSize();
CISOHeader header;
m_file.ReadArray(&header, 1);
m_block_size = header.block_size;
MapType count = 0;
for (u32 idx = 0; idx < CISO_MAP_SIZE; ++idx)
m_ciso_map[idx] = (1 == header.map[idx]) ? count++ : UNUSED_BLOCK_ID;
}
CISOFileReader* CISOFileReader::Create(const std::string& filename)
{
if (IsCISOBlob(filename))
{
File::IOFile f(filename, "rb");
return new CISOFileReader(f.ReleaseHandle());
}
else
{
return nullptr;
}
}
u64 CISOFileReader::GetDataSize() const
{
return CISO_MAP_SIZE * m_block_size;
}
u64 CISOFileReader::GetRawSize() const
{
return m_size;
}
bool CISOFileReader::Read(u64 offset, u64 nbytes, u8* out_ptr)
{
while (nbytes != 0)
{
u64 const block = offset / m_block_size;
u64 const data_offset = offset % m_block_size;
u64 const bytes_to_read = std::min(m_block_size - data_offset, nbytes);
if (block < CISO_MAP_SIZE && UNUSED_BLOCK_ID != m_ciso_map[block])
{
// calculate the base address
u64 const file_off = CISO_HEADER_SIZE + m_ciso_map[block] * (u64)m_block_size + data_offset;
if (!(m_file.Seek(file_off, SEEK_SET) && m_file.ReadArray(out_ptr, bytes_to_read)))
{
m_file.Clear();
return false;
}
}
else
{
std::fill_n(out_ptr, bytes_to_read, 0);
}
out_ptr += bytes_to_read;
offset += bytes_to_read;
nbytes -= bytes_to_read;
}
return true;
}
bool IsCISOBlob(const std::string& filename)
{
File::IOFile f(filename, "rb");
CISOHeader header;
return (f.ReadArray(&header, 1) &&
std::equal(header.magic, header.magic + sizeof(header.magic), CISO_MAGIC));
}
} // namespace