forked from mahalex/MatFileHandler
69 lines
2.0 KiB
C#
69 lines
2.0 KiB
C#
// Copyright 2017-2018 Alexander Luzgarev
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using System;
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using System.IO;
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namespace MatFileHandler
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{
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/// <summary>
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/// A stream which reads a finite section of another stream.
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/// </summary>
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internal sealed class Substream : Stream
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{
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private readonly Stream _baseStream;
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private long _bytesRead;
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/// <summary>
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/// Initializes a new instance of the <see cref="Substream"/> class.
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/// </summary>
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/// <param name="baseStream">The <see cref="Stream"/> to wrap.</param>
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/// <param name="length">The number of bytes readable from this <see cref="Substream"/>.</param>
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public Substream(Stream baseStream, long length)
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{
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_baseStream = baseStream;
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Length = length;
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}
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/// <inheritdoc/>
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public override bool CanRead => _baseStream.CanRead;
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/// <inheritdoc/>
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public override bool CanSeek => false;
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/// <inheritdoc/>
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public override bool CanWrite => false;
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/// <inheritdoc/>
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public override long Length { get; }
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/// <inheritdoc/>
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public override long Position
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{
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get => _bytesRead;
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set => throw new NotSupportedException();
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}
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/// <inheritdoc/>
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public override void Flush() => _baseStream.Flush();
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/// <inheritdoc/>
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public override int Read(byte[] buffer, int offset, int count)
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{
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int bytesRead = _baseStream.Read(buffer, offset, (int)Math.Min(count, Length - _bytesRead));
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_bytesRead += bytesRead;
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return bytesRead;
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}
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/// <inheritdoc/>
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public override long Seek(long offset, SeekOrigin origin) => throw new NotSupportedException();
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/// <inheritdoc/>
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public override void Write(byte[] buffer, int offset, int count) => throw new NotSupportedException();
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/// <inheritdoc/>
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public override void SetLength(long value) => throw new NotSupportedException();
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}
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}
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