dolphin/Source/Core/DiscIO/Src/CISOBlob.cpp

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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 "Blob.h"
#include "CISOBlob.h"
namespace DiscIO
{
CISOFileReader::CISOFileReader(FILE* file__)
{
file_ = file__;
fseek(file_, 0, SEEK_END);
size = ftell(file_);
fseek(file_, 0, SEEK_SET);
memset(&header, 0, sizeof(header));
fread(&header, sizeof(header), 1, file_);
CISO_Map_t count = 0;
int idx;
for (idx = 0; idx < CISO_MAP_SIZE; idx++)
ciso_map[idx] = (header.map[idx] == 1) ? count++ : CISO_UNUSED_BLOCK;
}
CISOFileReader* CISOFileReader::Create(const char* filename)
{
if (IsCISOBlob(filename))
{
FILE* f = fopen(filename, "rb");
return new CISOFileReader(f);
}
else
return NULL;
}
CISOFileReader::~CISOFileReader()
{
fclose(file_);
}
bool CISOFileReader::Read(u64 offset, u64 nbytes, u8* out_ptr)
{
u64 bytesRead = 0;
while (bytesRead < nbytes)
{
u32 block = (u32)(offset / header.block_size);
u32 data_offset = offset % header.block_size;
u32 bytes_to_read = (u32)min((u64)(header.block_size - data_offset), nbytes);
if ((block >= CISO_MAP_SIZE) || (ciso_map[block] == CISO_UNUSED_BLOCK))
{
memset(out_ptr, 0, bytes_to_read);
out_ptr += bytes_to_read;
offset += bytes_to_read;
bytesRead += bytes_to_read;
}
else
{
// calcualte the base address
u64 file_off = CISO_HEAD_SIZE + ciso_map[block] * (u64)header.block_size + data_offset;
if (fseeko(file_, (long)file_off, SEEK_SET) != 0)
return false;
if (fread(out_ptr, 1, bytes_to_read, file_) != bytes_to_read)
return false;
out_ptr += bytes_to_read;
offset += bytes_to_read;
bytesRead += bytes_to_read;
}
}
return true;
}
bool IsCISOBlob(const char* filename)
{
FILE* f = fopen(filename, "rb");
if (!f)
return false;
CISO_Head_t header;
fread(&header, sizeof(header), 1, f);
fclose(f);
return (memcmp(header.magic, CISO_MAGIC, sizeof(header.magic)) == 0);
}
} // namespace