public DualBinaryStore(IStreamProvider provider, long start, long maxLength)
{
if (provider == null) throw new ArgumentNullException("provider");
if (start < 0) throw new ArgumentException("start parameter must have a value equal or greater than 0");
if (maxLength <= 0) throw new ArgumentException("maxLength parameter must have a value greater than 0");
_provider = provider;
_start = start;
_maxLength = maxLength;
_writeHeaderStream = provider.AcquireWriteStream();
_writeLeftStream = provider.AcquireWriteStream();
_writeRightStream = provider.AcquireWriteStream();
_writeHeaderStream.Seek(start, SeekOrigin.Begin);
if (_writeHeaderStream.Length > start)
{
using (var readStream = _provider.AcquireReadStream())
{
readStream.Seek(start, SeekOrigin.Begin);
var headerBuffer = new byte[16];
readStream.Read(headerBuffer, 0, headerBuffer.Length);
_leftOffset = BitConverter.ToInt64(headerBuffer, 0);
_rightOffset = BitConverter.ToInt64(headerBuffer, 8);
// If the buffer was not generated by the store
if (_leftOffset <= 0) _leftOffset = 16;
if (_rightOffset <= 0) _rightOffset = maxLength;
}
_writeLeftStream.Seek(start + _leftOffset, SeekOrigin.Begin);
_writeRightStream.Seek(start + _rightOffset, SeekOrigin.Begin);
}
else
{
_leftOffset = 16;
_rightOffset = maxLength;
var headerBuffer = BitConverter.GetBytes(_leftOffset);
_writeHeaderStream.Write(headerBuffer, 0, headerBuffer.Length);
headerBuffer = BitConverter.GetBytes(_rightOffset);
_writeHeaderStream.Write(headerBuffer, 0, headerBuffer.Length);
_writeHeaderStream.Seek(-16, SeekOrigin.Current);
_writeRightStream.Seek(start + _leftOffset, SeekOrigin.Begin);
var buffer = new byte[maxLength - _leftOffset];
_writeRightStream.Write(buffer, 0, buffer.Length);
_writeLeftStream.Seek(start + _leftOffset, SeekOrigin.Begin);
}
_lastFlushedLeftOffset = _leftOffset;
_lastFlushedRightOffset = _rightOffset;
_left = new LeftBinaryStoreSegment(this);
_right = new RightBinaryStoreSegment(this);
}
private BinaryStore(IStreamProvider provider, long start, long length, bool canGrow)
{
_writeStream = provider.AcquireWriteStream();
_provider = provider;
_start = start;
_length = length;
_canGrow = canGrow;
if (_writeStream.Length > start)
{
using (var readStream = _provider.AcquireReadStream())
{
readStream.Seek(start, SeekOrigin.Begin);
var offsetBuffer = new byte[8];
readStream.Read(offsetBuffer, 0, offsetBuffer.Length);
_currentOffset = BitConverter.ToInt64(offsetBuffer, 0);
}
}
else
{
_currentOffset = 8;
var offsetBuffer = BitConverter.GetBytes(_currentOffset);
_writeStream.Seek(start, SeekOrigin.Begin);
_writeStream.Write(offsetBuffer, 0, offsetBuffer.Length);
if (length > 0)
{
var requiredFileSize = _start + _length;
var buffer = new byte[requiredFileSize - _writeStream.Length - 8];
_writeStream.Write(buffer, 0, buffer.Length);
}
}
_lastFlushOffset = _currentOffset;
_writeStream.Seek(start + _currentOffset, SeekOrigin.Begin);
_offsetWriteStream = provider.AcquireWriteStream();
_offsetWriteStream.Seek(start, SeekOrigin.Begin);
}
private BinaryStore(IStreamProvider provider, long start, long maxLength)
{
_writeStream = provider.AcquireWriteStream();
_provider = provider;
_start = start;
_maxLength = maxLength;
if (_writeStream.Length > start)
{
using (var readStream = _provider.AcquireReadStream())
{
readStream.Seek(start, SeekOrigin.Begin);
var offsetBuffer = new byte[8];
readStream.Read(offsetBuffer, 0, offsetBuffer.Length);
_currentOffset = BitConverter.ToInt64(offsetBuffer, 0);
}
}
else
{
_currentOffset = 8;
var offsetBuffer = BitConverter.GetBytes(_currentOffset);
_writeStream.Seek(start, SeekOrigin.Begin);
_writeStream.Write(offsetBuffer, 0, offsetBuffer.Length);
if (maxLength > 0)
{
var requiredFileSize = _start + _maxLength;
var buffer = new byte[requiredFileSize - _writeStream.Length - 8];
_writeStream.Write(buffer, 0, buffer.Length);
}
}
_lastFlushOffset = _currentOffset;
_writeStream.Seek(start + _currentOffset, SeekOrigin.Begin);
_offsetWriteStream = provider.AcquireWriteStream();
_offsetWriteStream.Seek(start, SeekOrigin.Begin);
}
public void Write(long storeOffset, byte[] data)
{
using (_writeOffsetLock.Enter(storeOffset))
{
using (var offsetWriteStream = _provider.AcquireWriteStream())
{
offsetWriteStream.Seek(storeOffset, SeekOrigin.Begin);
offsetWriteStream.Write(data, 0, data.Length);
if (_lastFlushOffset > storeOffset)
{
_lastFlushOffset = storeOffset - 1;
}
}
}
}