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// This file is part of par2cmdline (a PAR 2.0 compatible file verification and
// repair tool). See http://parchive.sourceforge.net for details of PAR 2.0.
//
// Copyright (c) 2003 Peter Brian Clements
//
// par2cmdline 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; either version 2 of the License, or
// (at your option) any later version.
//
// par2cmdline 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 for more details.
//
// You should have received a copy of the GNU General Public License
// along with this program; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA
#include "par2cmdline.h"
#ifdef _MSC_VER
#ifdef _DEBUG
#undef THIS_FILE
static char THIS_FILE[]=__FILE__;
#define new DEBUG_NEW
#endif
#endif
// Open the file associated with the data block if is not already open
bool DataBlock::Open(void)
{
if (diskfile == 0)
return false;
if (diskfile->IsOpen())
return true;
return diskfile->Open();
}
// Read some data at a specified position within a data block
// into a buffer in memory
bool DataBlock::ReadData(u64 position, // Position within the block
size_t size, // Size of the memory buffer
void *buffer) // Pointer to memory buffer
{
assert(diskfile != 0);
// Check to see if the position from which data is to be read
// is within the bounds of the data block
if (length > position)
{
// Compute the file offset and how much data to physically read from disk
u64 fileoffset = offset + position;
size_t want = (size_t)min((u64)size, length - position);
// Read the data from the file into the buffer
if (!diskfile->Read(fileoffset, buffer, want))
return false;
// If the read extends beyond the end of the data block,
// then the rest of the buffer is zeroed.
if (want < size)
{
memset(&((u8*)buffer)[want], 0, size-want);
}
}
else
{
// Zero the whole buffer
memset(buffer, 0, size);
}
return true;
}
// Write some data at a specified position within a datablock
// from memory to disk
bool DataBlock::WriteData(u64 position, // Position within the block
size_t size, // Size of the memory buffer
const void *buffer, // Pointer to memory buffer
size_t &wrote) // Amount actually written
{
assert(diskfile != 0);
wrote = 0;
// Check to see if the position from which data is to be written
// is within the bounds of the data block
if (length > position)
{
// Compute the file offset and how much data to physically write to disk
u64 fileoffset = offset + position;
size_t have = (size_t)min((u64)size, length - position);
// Write the data from the buffer to disk
if (!diskfile->Write(fileoffset, buffer, have))
return false;
wrote = have;
}
return true;
}
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