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https://github.com/SabreTools/SabreTools.IO.git
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Add view stream type
This commit is contained in:
Matt Nadareski
378
SabreTools.IO.Test/Streams/ViewStreamTests.cs
Normal file
378
SabreTools.IO.Test/Streams/ViewStreamTests.cs
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@@ -0,0 +1,378 @@
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using System;
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using System.IO;
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using SabreTools.IO.Streams;
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using Xunit;
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namespace SabreTools.IO.Test.Streams
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{
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public class ViewStreamTests
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{
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#region Constructor
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[Theory]
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[InlineData(0, 0, 0, 0)]
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[InlineData(1024, 0, 1024, 1024)]
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[InlineData(1024, 256, 512, 512)]
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public void Constructor_Array(int size, long offset, long length, long expectedLength)
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{
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byte[] data = new byte[size];
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var stream = new ViewStream(data, offset, length);
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Assert.Equal(expectedLength, stream.Length);
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Assert.Equal(0, stream.Position);
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}
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[Theory]
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[InlineData(0, -1, 0)]
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[InlineData(0, 2048, 0)]
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[InlineData(1024, -1, 1024)]
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[InlineData(1024, 2048, 1024)]
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[InlineData(1024, -1, 512)]
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[InlineData(1024, 2048, 512)]
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public void Constructor_Array_InvalidOffset(int size, long offset, long length)
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{
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byte[] data = new byte[size];
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Assert.Throws<ArgumentOutOfRangeException>(() => _ = new ViewStream(data, offset, length));
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}
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[Theory]
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[InlineData(0, 0, -1)]
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[InlineData(0, 0, 2048)]
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[InlineData(1024, 0, -1)]
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[InlineData(1024, 0, 2048)]
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[InlineData(1024, 256, -1)]
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[InlineData(1024, 256, 2048)]
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public void Constructor_Array_InvalidLength(int size, long offset, long length)
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{
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byte[] data = new byte[size];
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Assert.Throws<ArgumentOutOfRangeException>(() => _ = new ViewStream(data, offset, length));
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}
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[Theory]
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[InlineData(0, 0, 0, 0)]
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[InlineData(1024, 0, 1024, 1024)]
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[InlineData(1024, 256, 512, 512)]
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public void Constructor_Stream(int size, long offset, long length, long expectedLength)
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{
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Stream data = new MemoryStream(new byte[size]);
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var stream = new ViewStream(data, offset, length);
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Assert.Equal(expectedLength, stream.Length);
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Assert.Equal(0, stream.Position);
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}
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[Theory]
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[InlineData(0, -1, 0)]
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[InlineData(0, 2048, 0)]
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[InlineData(1024, -1, 1024)]
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[InlineData(1024, 2048, 1024)]
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[InlineData(1024, -1, 512)]
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[InlineData(1024, 2048, 512)]
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public void Constructor_Stream_InvalidOffset(int size, long offset, long length)
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{
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Stream data = new MemoryStream(new byte[size]);
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Assert.Throws<ArgumentOutOfRangeException>(() => _ = new ViewStream(data, offset, length));
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}
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[Theory]
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[InlineData(0, 0, -1)]
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[InlineData(0, 0, 2048)]
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[InlineData(1024, 0, -1)]
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[InlineData(1024, 0, 2048)]
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[InlineData(1024, 256, -1)]
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[InlineData(1024, 256, 2048)]
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public void Constructor_Stream_InvalidLength(int size, long offset, long length)
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{
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Stream data = new MemoryStream(new byte[size]);
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Assert.Throws<ArgumentOutOfRangeException>(() => _ = new ViewStream(data, offset, length));
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}
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#endregion
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#region Position
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[Theory]
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[InlineData(0, 0, 0, -1, 0)]
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[InlineData(0, 0, 0, 0, 0)]
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[InlineData(0, 0, 0, 256, 0)]
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[InlineData(0, 0, 0, 2048, 0)]
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[InlineData(1024, 0, 1024, -1, 0)]
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[InlineData(1024, 0, 1024, 0, 0)]
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[InlineData(1024, 0, 1024, 256, 256)]
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[InlineData(1024, 0, 1024, 2048, 1023)]
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[InlineData(1024, 256, 512, -1, 0)]
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[InlineData(1024, 256, 512, 0, 0)]
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[InlineData(1024, 256, 512, 256, 256)]
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[InlineData(1024, 256, 512, 2048, 511)]
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public void Position_Array(int size, long offset, long length, long position, long expectedPosition)
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{
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byte[] data = new byte[size];
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var stream = new ViewStream(data, offset, length);
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stream.Position = position;
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Assert.Equal(expectedPosition, stream.Position);
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}
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[Theory]
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[InlineData(0, 0, 0, -1, 0)]
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[InlineData(0, 0, 0, 0, 0)]
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[InlineData(0, 0, 0, 256, 0)]
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[InlineData(0, 0, 0, 2048, 0)]
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[InlineData(1024, 0, 1024, -1, 0)]
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[InlineData(1024, 0, 1024, 0, 0)]
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[InlineData(1024, 0, 1024, 256, 256)]
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[InlineData(1024, 0, 1024, 2048, 1023)]
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[InlineData(1024, 256, 512, -1, 0)]
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[InlineData(1024, 256, 512, 0, 0)]
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[InlineData(1024, 256, 512, 256, 256)]
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[InlineData(1024, 256, 512, 2048, 511)]
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public void Position_Stream(int size, long offset, long length, long position, long expectedPosition)
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{
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Stream data = new MemoryStream(new byte[size]);
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var stream = new ViewStream(data, offset, length);
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stream.Position = position;
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Assert.Equal(expectedPosition, stream.Position);
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}
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#endregion
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#region SegmentValid
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[Theory]
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[InlineData(0, 0, 0, -1, 0, false)]
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[InlineData(0, 0, 0, 2048, 0, false)]
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[InlineData(0, 0, 0, 0, 0, true)]
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[InlineData(0, 0, 0, 0, -1, false)]
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[InlineData(0, 0, 0, 0, 2048, false)]
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[InlineData(1024, 0, 1024, -1, 0, false)]
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[InlineData(1024, 0, 1024, 2048, 0, false)]
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[InlineData(1024, 0, 1024, 0, 0, true)]
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[InlineData(1024, 0, 1024, 256, 0, true)]
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[InlineData(1024, 0, 1024, 256, 256, true)]
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[InlineData(1024, 0, 1024, 0, -1, false)]
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[InlineData(1024, 0, 1024, 0, 2048, false)]
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[InlineData(1024, 256, 512, -1, 0, false)]
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[InlineData(1024, 256, 512, 2048, 0, false)]
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[InlineData(1024, 256, 512, 0, 0, true)]
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[InlineData(1024, 256, 512, 256, 0, true)]
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[InlineData(1024, 256, 512, 256, 256, true)]
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[InlineData(1024, 256, 512, 0, -1, false)]
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[InlineData(1024, 256, 512, 0, 2048, false)]
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public void SegmentValid_Array(int size, long offset, long length, int segmentStart, int segmentLength, bool expected)
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{
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byte[] data = new byte[size];
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var stream = new ViewStream(data, offset, length);
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bool actual = stream.SegmentValid(segmentStart, segmentLength);
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Assert.Equal(expected, actual);
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}
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[Theory]
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[InlineData(0, 0, 0, -1, 0, false)]
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[InlineData(0, 0, 0, 2048, 0, false)]
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[InlineData(0, 0, 0, 0, 0, true)]
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[InlineData(0, 0, 0, 0, -1, false)]
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[InlineData(0, 0, 0, 0, 2048, false)]
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[InlineData(1024, 0, 1024, -1, 0, false)]
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[InlineData(1024, 0, 1024, 2048, 0, false)]
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[InlineData(1024, 0, 1024, 0, 0, true)]
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[InlineData(1024, 0, 1024, 256, 0, true)]
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[InlineData(1024, 0, 1024, 256, 256, true)]
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[InlineData(1024, 0, 1024, 0, -1, false)]
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[InlineData(1024, 0, 1024, 0, 2048, false)]
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[InlineData(1024, 256, 512, -1, 0, false)]
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[InlineData(1024, 256, 512, 2048, 0, false)]
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[InlineData(1024, 256, 512, 0, 0, true)]
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[InlineData(1024, 256, 512, 256, 0, true)]
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[InlineData(1024, 256, 512, 256, 256, true)]
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[InlineData(1024, 256, 512, 0, -1, false)]
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[InlineData(1024, 256, 512, 0, 2048, false)]
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public void SegmentValid_Stream(int size, long offset, long length, int segmentStart, int segmentLength, bool expected)
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{
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Stream data = new MemoryStream(new byte[size]);
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var stream = new ViewStream(data, offset, length);
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bool actual = stream.SegmentValid(segmentStart, segmentLength);
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Assert.Equal(expected, actual);
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}
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#endregion
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#region Read
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[Theory]
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[InlineData(0, 0, 0, -1, 0)]
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[InlineData(0, 0, 0, 0, 0)]
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[InlineData(0, 0, 0, 2048, 0)]
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[InlineData(1024, 0, 1024, -1, 0)]
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[InlineData(1024, 0, 1024, 0, 0)]
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[InlineData(1024, 0, 1024, 256, 256)]
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[InlineData(1024, 0, 1024, 1024, 1024)]
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[InlineData(1024, 0, 1024, 2048, 0)]
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[InlineData(1024, 256, 512, -1, 0)]
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[InlineData(1024, 256, 512, 0, 0)]
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[InlineData(1024, 256, 512, 256, 256)]
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[InlineData(1024, 256, 512, 512, 512)]
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[InlineData(1024, 256, 512, 2048, 0)]
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public void Read_Array(int size, long offset, long length, int count, int expectedRead)
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{
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byte[] data = new byte[size];
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var stream = new ViewStream(data, offset, length);
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byte[] buffer = new byte[1024];
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int actual = stream.Read(buffer, 0, count);
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Assert.Equal(expectedRead, actual);
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}
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[Theory]
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[InlineData(0, 0, 0, -1, 0)]
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[InlineData(0, 0, 0, 0, 0)]
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[InlineData(0, 0, 0, 2048, 0)]
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[InlineData(1024, 0, 1024, -1, 0)]
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[InlineData(1024, 0, 1024, 0, 0)]
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[InlineData(1024, 0, 1024, 256, 256)]
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[InlineData(1024, 0, 1024, 1024, 1024)]
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[InlineData(1024, 0, 1024, 2048, 0)]
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[InlineData(1024, 256, 512, -1, 0)]
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[InlineData(1024, 256, 512, 0, 0)]
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[InlineData(1024, 256, 512, 256, 256)]
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[InlineData(1024, 256, 512, 512, 512)]
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[InlineData(1024, 256, 512, 2048, 0)]
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public void Read_Stream(int size, long offset, long length, int count, int expectedRead)
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{
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Stream data = new MemoryStream(new byte[size]);
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var stream = new ViewStream(data, offset, length);
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byte[] buffer = new byte[1024];
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int actual = stream.Read(buffer, 0, count);
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Assert.Equal(expectedRead, actual);
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}
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#endregion
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#region Seek
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[Theory]
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[InlineData(0, 0, 0, -1, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, -1, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, -1, SeekOrigin.Current, 0)]
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[InlineData(0, 0, 0, 0, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, 0, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, 0, SeekOrigin.Current, 0)]
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[InlineData(0, 0, 0, 256, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, 256, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, 256, SeekOrigin.Current, 0)]
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[InlineData(0, 0, 0, 2048, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, 2048, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, 2048, SeekOrigin.Current, 0)]
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[InlineData(1024, 0, 1024, -1, SeekOrigin.Begin, 0)]
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[InlineData(1024, 0, 1024, -1, SeekOrigin.End, 1022)]
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[InlineData(1024, 0, 1024, -1, SeekOrigin.Current, 0)]
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[InlineData(1024, 0, 1024, 0, SeekOrigin.Begin, 0)]
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[InlineData(1024, 0, 1024, 0, SeekOrigin.End, 1023)]
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[InlineData(1024, 0, 1024, 0, SeekOrigin.Current, 0)]
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[InlineData(1024, 0, 1024, 256, SeekOrigin.Begin, 256)]
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[InlineData(1024, 0, 1024, 256, SeekOrigin.End, 1023)]
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[InlineData(1024, 0, 1024, 256, SeekOrigin.Current, 256)]
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[InlineData(1024, 0, 1024, 2048, SeekOrigin.Begin, 1023)]
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[InlineData(1024, 0, 1024, 2048, SeekOrigin.End, 1023)]
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[InlineData(1024, 0, 1024, 2048, SeekOrigin.Current, 1023)]
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[InlineData(1024, 256, 512, -1, SeekOrigin.Begin, 0)]
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[InlineData(1024, 256, 512, -1, SeekOrigin.End, 510)]
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[InlineData(1024, 256, 512, -1, SeekOrigin.Current, 0)]
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[InlineData(1024, 256, 512, 0, SeekOrigin.Begin, 0)]
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[InlineData(1024, 256, 512, 0, SeekOrigin.End, 511)]
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[InlineData(1024, 256, 512, 0, SeekOrigin.Current, 0)]
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[InlineData(1024, 256, 512, 256, SeekOrigin.Begin, 256)]
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[InlineData(1024, 256, 512, 256, SeekOrigin.End, 511)]
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[InlineData(1024, 256, 512, 256, SeekOrigin.Current, 256)]
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[InlineData(1024, 256, 512, 2048, SeekOrigin.Begin, 511)]
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[InlineData(1024, 256, 512, 2048, SeekOrigin.End, 511)]
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[InlineData(1024, 256, 512, 2048, SeekOrigin.Current, 511)]
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public void Seek_Array(int size, long offset, long length, long position, SeekOrigin seekOrigin, long expectedPosition)
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{
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byte[] data = new byte[size];
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var stream = new ViewStream(data, offset, length);
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stream.Seek(position, seekOrigin);
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Assert.Equal(expectedPosition, stream.Position);
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}
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[Theory]
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[InlineData(0, 0, 0, -1, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, -1, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, -1, SeekOrigin.Current, 0)]
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[InlineData(0, 0, 0, 0, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, 0, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, 0, SeekOrigin.Current, 0)]
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[InlineData(0, 0, 0, 256, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, 256, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, 256, SeekOrigin.Current, 0)]
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[InlineData(0, 0, 0, 2048, SeekOrigin.Begin, 0)]
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[InlineData(0, 0, 0, 2048, SeekOrigin.End, 0)]
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[InlineData(0, 0, 0, 2048, SeekOrigin.Current, 0)]
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[InlineData(1024, 0, 1024, -1, SeekOrigin.Begin, 0)]
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[InlineData(1024, 0, 1024, -1, SeekOrigin.End, 1022)]
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[InlineData(1024, 0, 1024, -1, SeekOrigin.Current, 0)]
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[InlineData(1024, 0, 1024, 0, SeekOrigin.Begin, 0)]
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[InlineData(1024, 0, 1024, 0, SeekOrigin.End, 1023)]
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[InlineData(1024, 0, 1024, 0, SeekOrigin.Current, 0)]
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[InlineData(1024, 0, 1024, 256, SeekOrigin.Begin, 256)]
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[InlineData(1024, 0, 1024, 256, SeekOrigin.End, 1023)]
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[InlineData(1024, 0, 1024, 256, SeekOrigin.Current, 256)]
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[InlineData(1024, 0, 1024, 2048, SeekOrigin.Begin, 1023)]
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[InlineData(1024, 0, 1024, 2048, SeekOrigin.End, 1023)]
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[InlineData(1024, 0, 1024, 2048, SeekOrigin.Current, 1023)]
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[InlineData(1024, 256, 512, -1, SeekOrigin.Begin, 0)]
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[InlineData(1024, 256, 512, -1, SeekOrigin.End, 510)]
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[InlineData(1024, 256, 512, -1, SeekOrigin.Current, 0)]
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[InlineData(1024, 256, 512, 0, SeekOrigin.Begin, 0)]
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[InlineData(1024, 256, 512, 0, SeekOrigin.End, 511)]
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[InlineData(1024, 256, 512, 0, SeekOrigin.Current, 0)]
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[InlineData(1024, 256, 512, 256, SeekOrigin.Begin, 256)]
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[InlineData(1024, 256, 512, 256, SeekOrigin.End, 511)]
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[InlineData(1024, 256, 512, 256, SeekOrigin.Current, 256)]
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[InlineData(1024, 256, 512, 2048, SeekOrigin.Begin, 511)]
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[InlineData(1024, 256, 512, 2048, SeekOrigin.End, 511)]
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[InlineData(1024, 256, 512, 2048, SeekOrigin.Current, 511)]
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public void Seek_Stream(int size, long offset, long length, long position, SeekOrigin seekOrigin, long expectedPosition)
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{
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Stream data = new MemoryStream(new byte[size]);
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var stream = new ViewStream(data, offset, length);
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stream.Seek(position, seekOrigin);
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Assert.Equal(expectedPosition, stream.Position);
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}
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#endregion
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#region Unimplemented
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[Fact]
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public void SetLength_Array_Throws()
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{
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byte[] data = new byte[1024];
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var stream = new ViewStream(data, 0, 1024);
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Assert.Throws<NotImplementedException>(() => stream.SetLength(0));
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}
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[Fact]
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public void SetLength_Stream_Throws()
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{
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Stream data = new MemoryStream(new byte[1024]);
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var stream = new ViewStream(data, 0, 1024);
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Assert.Throws<NotImplementedException>(() => stream.SetLength(0));
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}
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[Fact]
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public void Write_Array_Throws()
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{
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byte[] data = new byte[1024];
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var stream = new ViewStream(data, 0, 1024);
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Assert.Throws<NotImplementedException>(() => stream.Write([], 0, 0));
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}
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[Fact]
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public void Write_Stream_Throws()
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{
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Stream data = new MemoryStream(new byte[1024]);
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var stream = new ViewStream(data, 0, 1024);
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Assert.Throws<NotImplementedException>(() => stream.Write([], 0, 0));
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}
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#endregion
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}
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||||
}
|
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221
SabreTools.IO/Streams/ViewStream.cs
Normal file
221
SabreTools.IO/Streams/ViewStream.cs
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using System;
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using System.IO;
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namespace SabreTools.IO.Streams
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{
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/// <summary>
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/// Stream representing a view into a source
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/// </summary>
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public class ViewStream : Stream
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{
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#region Properties
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/// <summary>
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/// Filename from the source, if possible
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/// </summary>
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public string? Filename
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{
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get
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{
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// Only file streams can have a filename
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if (_source is not FileStream fs)
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return null;
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// Return the name
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return fs.Name;
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}
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}
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/// <inheritdoc/>
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public override long Length => _length;
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/// <inheritdoc/>
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public override long Position
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{
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get
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{
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// Handle 0-length sources
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if (_length <= 0)
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return 0;
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return _source.Position - _initialPosition;
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}
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set
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{
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// Handle 0-length sources
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if (_length <= 0)
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{
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_source.Position = 0;
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return;
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}
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long position = value;
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// Handle out-of-bounds seeks
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if (position < 0)
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position = 0;
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else if (position >= _length)
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position = _length - 1;
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_source.Position = _initialPosition + position;
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}
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}
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#endregion
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#region Instance Variables
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/// <summary>
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/// Initial position within the underlying data
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/// </summary>
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protected long _initialPosition;
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/// <summary>
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/// Usable length in the underlying data
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/// </summary>
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protected long _length;
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/// <summary>
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/// Source data
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/// </summary>
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protected Stream _source;
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/// <summary>
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/// Lock object for reading from the source
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/// </summary>
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private readonly object _sourceLock = new();
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#endregion
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#region Constructors
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/// <summary>
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/// Construct a new ViewStream from a Stream
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/// </summary>
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public ViewStream(Stream data, long offset, long length)
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{
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if (!data.CanRead)
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throw new ArgumentException(nameof(data));
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if (offset < 0 || offset > data.Length)
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throw new ArgumentOutOfRangeException(nameof(offset));
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if (length < 0 || offset + length > data.Length)
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throw new ArgumentOutOfRangeException(nameof(length));
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_source = data;
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_initialPosition = offset;
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_length = length;
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_source.Seek(_initialPosition, SeekOrigin.Begin);
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}
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/// <summary>
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/// Construct a new ViewStream from a byte array
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/// </summary>
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public ViewStream(byte[] data, long offset, long length)
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{
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if (offset < 0 || offset > data.Length)
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throw new ArgumentOutOfRangeException(nameof(offset));
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if (length < 0 || offset + length > data.Length)
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throw new ArgumentOutOfRangeException(nameof(length));
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_source = new MemoryStream(data, (int)offset, (int)length);
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_initialPosition = 0;
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_length = length;
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_source.Seek(_initialPosition, SeekOrigin.Begin);
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}
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#endregion
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#region Data
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/// <summary>
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/// Check if a data segment is valid in the data source
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/// </summary>
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/// <param name="offset">Position in the source</param>
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/// <param name="count">Length of the data to check</param>
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/// <returns>True if the positional data is valid, false otherwise</returns>
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public bool SegmentValid(long offset, long count)
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{
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if (offset < 0 || offset > Length)
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return false;
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if (count < 0 || offset + count > Length)
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return false;
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return true;
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}
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#endregion
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#region Stream Implementations
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/// <inheritdoc/>
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public override bool CanRead => true;
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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 bool CanSeek => _source.CanSeek;
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/// <inheritdoc/>
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public override void Flush() => _source.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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// Invalid cases always return 0
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||||
if (buffer.Length == 0)
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return 0;
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if (offset < 0 || offset > buffer.Length)
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return 0;
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if (count < 0 || offset + count > buffer.Length)
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return 0;
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if (!SegmentValid(Position, count))
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return 0;
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||||
// Short-circuit 0-byte reads
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||||
if (count == 0)
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||||
return 0;
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||||
|
||||
try
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||||
{
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||||
lock (_sourceLock)
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||||
{
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||||
return _source.Read(buffer, offset, count);
|
||||
}
|
||||
|
||||
}
|
||||
catch
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||||
{
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||||
// Absorb the error
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||||
return 0;
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||||
}
|
||||
}
|
||||
|
||||
/// <inheritdoc/>
|
||||
public override long Seek(long offset, SeekOrigin origin)
|
||||
{
|
||||
// Handle the "seek"
|
||||
switch (origin)
|
||||
{
|
||||
case SeekOrigin.Begin: Position = offset; break;
|
||||
case SeekOrigin.Current: Position += offset; break;
|
||||
case SeekOrigin.End: Position = _length + offset - 1; break;
|
||||
default: throw new ArgumentException($"Invalid value for {nameof(origin)}");
|
||||
}
|
||||
|
||||
return Position;
|
||||
}
|
||||
|
||||
/// <inheritdoc/>
|
||||
public override void SetLength(long value)
|
||||
=> throw new NotImplementedException();
|
||||
|
||||
/// <inheritdoc/>
|
||||
public override void Write(byte[] buffer, int offset, int count)
|
||||
=> throw new NotImplementedException();
|
||||
|
||||
#endregion
|
||||
}
|
||||
}
|
||||
Reference in New Issue
Block a user