101 lines
2.7 KiB
C#
101 lines
2.7 KiB
C#
namespace MareSynchronos.Utils;
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// Limits the number of bytes read/written to an underlying stream
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public class LimitedStream : Stream
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{
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private readonly Stream _stream;
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public long _estimatedPosition = 0;
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public long MaxPosition { get; private init; }
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public bool DisposeUnderlying = true;
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public Stream UnderlyingStream { get => _stream; }
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public LimitedStream(Stream underlyingStream, long byteLimit)
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{
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_stream = underlyingStream;
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try
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{
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_estimatedPosition = Position;
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}
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catch { }
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MaxPosition = _estimatedPosition + byteLimit;
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}
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protected override void Dispose(bool disposing)
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{
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if (!DisposeUnderlying)
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return;
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_stream.Dispose();
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}
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public override bool CanRead => _stream.CanRead;
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public override bool CanSeek => _stream.CanSeek;
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public override bool CanWrite => _stream.CanWrite;
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public override long Length => _stream.Length;
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public override long Position { get => _stream.Position; set => _stream.Position = _estimatedPosition = value; }
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public override void Flush()
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{
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_stream.Flush();
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}
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public override int Read(byte[] buffer, int offset, int count)
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{
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int remainder = (int)long.Clamp(MaxPosition - _estimatedPosition, 0, int.MaxValue);
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if (count > remainder)
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count = remainder;
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int n = _stream.Read(buffer, offset, count);
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_estimatedPosition += n;
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return n;
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}
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public async override Task<int> ReadAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
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{
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int remainder = (int)long.Clamp(MaxPosition - _estimatedPosition, 0, int.MaxValue);
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if (count > remainder)
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count = remainder;
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int n = await _stream.ReadAsync(buffer, offset, count, cancellationToken);
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_estimatedPosition += n;
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return n;
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}
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public override long Seek(long offset, SeekOrigin origin)
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{
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long result = _stream.Seek(offset, origin);
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_estimatedPosition = result;
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return result;
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}
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public override void SetLength(long value)
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{
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_stream.SetLength(value);
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}
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public override void Write(byte[] buffer, int offset, int count)
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{
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int remainder = (int)long.Clamp(MaxPosition - _estimatedPosition, 0, int.MaxValue);
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if (count > remainder)
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count = remainder;
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_stream.Write(buffer, offset, count);
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_estimatedPosition += count;
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}
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public async override Task WriteAsync(byte[] buffer, int offset, int count, CancellationToken cancellationToken)
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{
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int remainder = (int)long.Clamp(MaxPosition - _estimatedPosition, 0, int.MaxValue);
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if (count > remainder)
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count = remainder;
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await _stream.WriteAsync(buffer, offset, count, cancellationToken);
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_estimatedPosition += count;
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}
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}
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