mirror of
https://github.com/libretro/dolphin
synced 2024-11-09 06:53:01 -05:00
86 lines
2 KiB
C++
86 lines
2 KiB
C++
// Copyright 2010 Dolphin Emulator Project
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// Licensed under GPLv2+
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// Refer to the license.txt file included.
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#include <algorithm>
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#include <cstdio>
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#include <memory>
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#include <utility>
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#include "Common/CommonTypes.h"
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#include "Common/File.h"
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#include "DiscIO/CISOBlob.h"
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namespace DiscIO
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{
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CISOFileReader::CISOFileReader(File::IOFile file) : m_file(std::move(file))
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{
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m_size = m_file.GetSize();
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CISOHeader header;
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m_file.Seek(0, SEEK_SET);
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m_file.ReadArray(&header, 1);
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m_block_size = header.block_size;
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MapType count = 0;
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for (u32 idx = 0; idx < CISO_MAP_SIZE; ++idx)
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m_ciso_map[idx] = (1 == header.map[idx]) ? count++ : UNUSED_BLOCK_ID;
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}
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std::unique_ptr<CISOFileReader> CISOFileReader::Create(File::IOFile file)
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{
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CISOHeader header;
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if (file.Seek(0, SEEK_SET) && file.ReadArray(&header, 1) && header.magic == CISO_MAGIC)
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return std::unique_ptr<CISOFileReader>(new CISOFileReader(std::move(file)));
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return nullptr;
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}
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u64 CISOFileReader::GetDataSize() const
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{
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return static_cast<u64>(CISO_MAP_SIZE) * m_block_size;
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}
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u64 CISOFileReader::GetRawSize() const
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{
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return m_size;
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}
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bool CISOFileReader::Read(u64 offset, u64 nbytes, u8* out_ptr)
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{
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if (offset + nbytes > GetDataSize())
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return false;
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while (nbytes != 0)
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{
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u64 const block = offset / m_block_size;
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u64 const data_offset = offset % m_block_size;
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u64 const bytes_to_read = std::min(m_block_size - data_offset, nbytes);
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if (block < CISO_MAP_SIZE && UNUSED_BLOCK_ID != m_ciso_map[block])
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{
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// calculate the base address
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u64 const file_off = CISO_HEADER_SIZE + m_ciso_map[block] * (u64)m_block_size + data_offset;
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if (!(m_file.Seek(file_off, SEEK_SET) && m_file.ReadArray(out_ptr, bytes_to_read)))
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{
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m_file.Clear();
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return false;
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}
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}
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else
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{
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std::fill_n(out_ptr, bytes_to_read, 0);
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}
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out_ptr += bytes_to_read;
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offset += bytes_to_read;
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nbytes -= bytes_to_read;
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}
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return true;
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}
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} // namespace DiscIO
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