public BlockStreamWriter(FragmentedFile file, long ordinal)
: this(file)
{
_current = _first = new FileBlock(file._blockSize, file._useAlignedIo);
_file.ReadBlock(ordinal, _current, file._blockSize, BlockFlags.ExternalBlock);
if ((_current.Flags & BlockFlags.ExternalBlock) != BlockFlags.ExternalBlock)
{
throw new InvalidOperationException();
}
if ((_current.Flags & BlockFlags.Temporary) == BlockFlags.Temporary)
{
_isNew = true;
_restore = null;
_current.Flags &= ~BlockFlags.Temporary;
}
else
{
_isNew = false;
_restore = _current.Clone();
_current.NextBlockId = 0;
}
_current.Length = 0;
}
public BlockStreamReader(FragmentedFile file, long ordinal, BlockFlags typeExpected, bool validated)
{
_file = file;
_blockPos = 0;
_validated = validated;
_block = new FileBlock(file._blockSize, file._useAlignedIo);
_file.ReadBlock(ordinal, _block, file._blockSize, typeExpected, _validated);
if (_validated)
{
_expectedSum = _block.CheckSum;
_checksum = new Crc32();
_checksum.Add(_block.BlockData, _block.DataOffset, _block.Length);
if (_block.NextBlockId == 0 && _checksum != _expectedSum)
{
throw new InvalidDataException();
}
}
}
private bool PrepareRead()
{
int remains = _block.Length - _blockPos;
if (remains <= 0 && _block.NextBlockId != 0)
{
_file.ReadBlock(_block.NextBlockId, _block, _file._blockSize, _validated ? BlockFlags.InternalBlock : 0, _validated);
remains = _block.Length;
_blockPos = 0;
if (_validated)
{
_checksum.Add(_block.BlockData, _block.DataOffset, _block.Length);
if (_block.NextBlockId == 0 && _checksum != _expectedSum)
{
throw new InvalidDataException();
}
}
}
return(remains > 0);
}
public BlockStreamReader(FragmentedFile file, long ordinal, BlockFlags typeExpected, bool validated)
{
_file = file;
_blockPos = 0;
_validated = validated;
_block = new FileBlock(file._blockSize, file._useAlignedIo);
_file.ReadBlock(ordinal, _block, file._blockSize, typeExpected, _validated);
if (_validated)
{
_expectedSum = _block.CheckSum;
_checksum = new Crc32();
_checksum.Add(_block.BlockData, _block.DataOffset, _block.Length);
if (_block.NextBlockId == 0 && _checksum != _expectedSum)
throw new InvalidDataException();
}
}
