/// <summary>
/// Removes a front portion of the memory stream.
/// </summary>
public static void TrimStart(this ChunkedMemoryStream stream, int length)
{
// TODO: change RecyclableMemoryStream to allow every block to have
// an offset, so we don't need to shift data
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
stream.Position = 0;
if (length == 0)
{
return;
}
var helper = stream.GetBlockOffset(length);
stream.RemoveBlockRange(0, helper.Block);
// Now we need to shift data in trailing blocks.
for (int i = 0; i < stream.BlockCount; i++)
{
var currentBlock = stream.GetBlock(i);
int previous = i - 1;
if (previous >= 0)
{
var previousBlock = stream.GetBlock(previous);
var bytesToMoveBack = currentBlock.Slice(0, helper.Offset);
var backDst = previousBlock[^ helper.Offset..];
/// <summary>
/// Removes a front portion of the memory stream.
/// </summary>
public static void TrimStart(this ChunkedMemoryStream stream, int length)
{
// TODO: change ChunkedMemoryStream to allow every block to have
// an offset, so we don't need to shift data at least as much?
if (stream == null)
{
throw new ArgumentNullException(nameof(stream));
}
stream.Position = 0;
if (length == 0)
{
return;
}
(int block, int offset) = stream.GetBlockOffset(length);
stream.RemoveBlockRange(0, block);
// Now we need to shift data in trailing blocks.
for (int i = 0; i < stream.BlockCount; i++)
{
Memory <byte> currentBlock = stream.GetBlock(i);
int previous = i - 1;
if (previous >= 0)
{
Memory <byte> bytesToMoveBack = currentBlock.Slice(0, offset);
Memory <byte> previousBlock = stream.GetBlock(previous);
Memory <byte> backDestination = previousBlock[^ offset..];
/// <summary>
/// Retrieve a new MemoryStream object with the given tag and with contents copied from the provided
/// buffer. The provided buffer is not wrapped or used after construction.
/// </summary>
/// <remarks>The new stream's position is set to the beginning of the stream when returned.</remarks>
/// <param name="id">A unique identifier which can be used to trace usages of the stream.</param>
/// <param name="tag">A tag which can be used to track the source of the stream.</param>
/// <param name="buffer">The byte buffer to copy data from.</param>
/// <param name="offset">The offset from the start of the buffer to copy from.</param>
/// <param name="count">The number of bytes to copy from the buffer.</param>
/// <returns>A MemoryStream.</returns>
public ChunkedMemoryStream GetStream(Guid id, string?tag, byte[] buffer, int offset, int count)
{
ChunkedMemoryStream?stream = null;
try
{
stream = new ChunkedMemoryStream(this, id, tag, count);
stream.Write(buffer, offset, count);
stream.Position = 0;
return(stream);
}
catch
{
stream?.Dispose();
throw;
}
}
