/// <summary>
/// Sets a range of data to a specified position into the buffer.
/// </summary>
/// <param name="positionInBytes">Relative position in bytes from the beginning of the buffer to set the data to.</param>
/// <param name = "source">A pointer to the location to start copying from.</param>
/// <param name = "count">The number of bytes to copy from source to the current buffer.</param>
public void Set(int positionInBytes, IntPtr source, long count)
{
unsafe
{
SdxUtilities.CopyMemory((IntPtr)(_buffer + positionInBytes), source, (int)count);
}
}
/// <summary>
/// When overridden in a derived class, writes a sequence of bytes to the current stream and advances the current position within this stream by the number of bytes written.
/// </summary>
/// <param name="buffer">An array of bytes. This method copies <paramref name="count" /> bytes from <paramref name="buffer" /> to the current stream.</param>
/// <param name="offset">The zero-based byte offset in <paramref name="buffer" /> at which to begin copying bytes to the current stream.</param>
/// <param name="count">The number of bytes to be written to the current stream.</param>
public void Write(IntPtr buffer, int offset, int count)
{
unsafe
{
SdxUtilities.CopyMemory((IntPtr)(_buffer + _position), new IntPtr((byte *)buffer + offset), count);
_position += count;
}
}
internal unsafe DataBuffer(void *buffer, int sizeInBytes, bool makeCopy)
{
Debug.Assert(sizeInBytes > 0);
if (makeCopy)
{
_buffer = (sbyte *)SdxUtilities.AllocateMemory(sizeInBytes);
SdxUtilities.CopyMemory((IntPtr)_buffer, (IntPtr)buffer, sizeInBytes);
}
else
{
_buffer = (sbyte *)buffer;
}
_size = sizeInBytes;
_ownsBuffer = makeCopy;
}
internal unsafe DataStream(void *buffer, int sizeInBytes, bool canRead, bool canWrite, bool makeCopy)
{
Debug.Assert(sizeInBytes > 0);
if (makeCopy)
{
_buffer = (byte *)SdxUtilities.AllocateMemory(sizeInBytes);
SdxUtilities.CopyMemory((IntPtr)_buffer, (IntPtr)buffer, sizeInBytes);
}
else
{
_buffer = (byte *)buffer;
}
_size = sizeInBytes;
_canRead = canRead;
_canWrite = canWrite;
_ownsBuffer = makeCopy;
}
/// <summary>
/// Writes a range of bytes to the current stream, and advances the current position
/// within this stream by the number of bytes written.
/// </summary>
/// <remarks>
/// In order to provide faster read/write, this operation doesn't check stream bound.
/// A client must carefully not read/write above the size of this datastream.
/// </remarks>
/// <param name = "source">A pointer to the location to start copying from.</param>
/// <param name = "count">The number of bytes to copy from source to the current stream.</param>
/// <exception cref = "T:System.NotSupportedException">This stream does not support writing.</exception>
public void WriteRange(IntPtr source, long count)
{
unsafe
{
if (!_canWrite)
{
throw new NotSupportedException();
}
Debug.Assert(_canWrite);
Debug.Assert(source != IntPtr.Zero);
Debug.Assert(count > 0);
Debug.Assert((_position + count) <= _size);
// TODO: use Interop.memcpy
SdxUtilities.CopyMemory((IntPtr)(_buffer + _position), source, (int)count);
_position += count;
}
}
