Files
server/MareSynchronosServer/MareSynchronosStaticFilesServer/Utils/BlockFileDataStream.cs
2024-11-04 11:51:13 +01:00

109 lines
3.6 KiB
C#

namespace MareSynchronosStaticFilesServer.Utils;
public sealed class BlockFileDataStream : Stream
{
private readonly IEnumerable<BlockFileDataSubstream> _substreams;
private int _currentStreamIndex = 0;
public BlockFileDataStream(IEnumerable<BlockFileDataSubstream> substreams)
{
_substreams = substreams;
}
public override bool CanRead => true;
public override bool CanSeek => false;
public override bool CanWrite => false;
public override long Length => throw new NotSupportedException();
public override long Position { get => throw new NotSupportedException(); set => throw new NotSupportedException(); }
public override async Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
{
int totalRead = 0;
int currentOffset = 0;
int remainingCount = count;
while (totalRead < count && _currentStreamIndex < _substreams.Count())
{
var lastReadBytes = await _substreams.ElementAt(_currentStreamIndex).ReadAsync(buffer, currentOffset, remainingCount, cancellationToken).ConfigureAwait(false);
if (lastReadBytes < remainingCount)
{
_substreams.ElementAt(_currentStreamIndex).Dispose();
_currentStreamIndex++;
}
totalRead += lastReadBytes;
currentOffset += lastReadBytes;
remainingCount -= lastReadBytes;
}
return totalRead;
}
public override int Read(byte[] buffer, int offset, int count)
{
int totalRead = 0;
int currentOffset = 0;
int remainingCount = count;
while (totalRead < count && _currentStreamIndex < _substreams.Count())
{
var lastReadBytes = _substreams.ElementAt(_currentStreamIndex).Read(buffer, currentOffset, remainingCount);
if (lastReadBytes < remainingCount)
{
_substreams.ElementAt(_currentStreamIndex).Dispose();
_currentStreamIndex++;
}
totalRead += lastReadBytes;
currentOffset += lastReadBytes;
remainingCount -= lastReadBytes;
}
return totalRead;
}
public override async ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = default)
{
int totalRead = 0;
while (totalRead < buffer.Length && _currentStreamIndex < _substreams.Count())
{
var substream = _substreams.ElementAt(_currentStreamIndex);
int bytesRead = await substream.ReadAsync(buffer.Slice(totalRead), cancellationToken).ConfigureAwait(false);
if (bytesRead == 0)
{
substream.Dispose();
_currentStreamIndex++;
}
else
{
totalRead += bytesRead;
}
}
return totalRead;
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
foreach (var substream in _substreams)
{
// probably unnecessary but better safe than sorry
substream.Dispose();
}
}
base.Dispose(disposing);
}
public override void Flush() => throw new NotSupportedException();
public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
public override void SetLength(long value) => throw new NotSupportedException();
public override void Write(byte[] buffer, int offset, int count) => throw new NotSupportedException();
}