issue 96 (#98)

CHANGES.md

@@ -1,5 +1,8 @@
+## 1.3.8 (2023/03/17)
+* FIXED #96: fixed issue returning wrong compressed length when compressing into Span<byte> 
+
 ## 1.3.7-beta (2023/10/03)
-* ADDED #61: Partial decompression support (see #61, #90) (thanks: Sewer56)
+* ADDED #61: partial decompression support (see #61, #90) (thanks: Sewer56)
 * CHANGED: build process from FAKE (sorry!) to Nuke
 
 ## 1.3.6 (2023/08/15)

src/K4os.Compression.LZ4.Streams.Tests/Issue96.cs

@@ -0,0 +1,84 @@
+using System.Buffers;
+using TestHelpers;
+using Xunit;
+
+namespace K4os.Compression.LZ4.Streams.Tests;
+
+public class Issue96
+{
+	private static int EstimateLZ4FrameSize(byte[] source)
+	{
+		using var memory = new MemoryStream();
+		using (var target = LZ4Stream.Encode(memory, leaveOpen: true))
+			target.Write(source, 0, source.Length);
+		return (int)memory.Length;
+	}
+
+	public (byte[] Source, int Expected, int Maximum) PrepareTestCase(int length)
+	{
+		var source = Lorem.Create(length);
+		var expected = EstimateLZ4FrameSize(source);
+		var maximum = LZ4Codec.MaximumOutputSize(source.Length);
+		return (source, expected, maximum);
+	}
+
+	[Theory]
+	[InlineData(1337)]
+	[InlineData(0x10000)]
+	public void SequenceToBufferWriter(int length)
+	{
+		var testCase = PrepareTestCase(length);
+		var source = new ReadOnlySequence<byte>(testCase.Source);
+		var target = new BufferWriter();
+		var actual = LZ4Frame.Encode(source, target).WrittenMemory.Length;
+		Assert.Equal(testCase.Expected, actual);
+	}
+
+	[Theory]
+	[InlineData(1337)]
+	[InlineData(0x10000)]
+	public void SpanToBufferWriter(int length)
+	{
+		var testCase = PrepareTestCase(length);
+		var source = testCase.Source.AsSpan();
+		var target = new BufferWriter();
+		var actual = LZ4Frame.Encode(source, target).WrittenMemory.Length;
+		Assert.Equal(testCase.Expected, actual);
+	}
+
+	[Theory]
+	[InlineData(1337)]
+	[InlineData(0x10000)]
+	public void SequenceToSpan(int length)
+	{
+		var testCase = PrepareTestCase(length);
+		var source = new ReadOnlySequence<byte>(testCase.Source);
+		var target = new byte[testCase.Maximum].AsSpan();
+		var actual = LZ4Frame.Encode(source, target);
+		Assert.Equal(testCase.Expected, actual);
+	}
+
+	[Theory]
+	[InlineData(1337)]
+	[InlineData(0x10000)]
+	public void SpanToSpan(int length)
+	{
+		var testCase = PrepareTestCase(length);
+		var source = testCase.Source.AsSpan();
+		var target = new byte[testCase.Maximum].AsSpan();
+		var actual = LZ4Frame.Encode(source, target);
+		Assert.Equal(testCase.Expected, actual);
+	}
+
+	[Theory]
+	[InlineData(1337)]
+	[InlineData(0x10000)]
+	public void CallbackToSpan(int length)
+	{
+		var testCase = PrepareTestCase(length);
+		var source = testCase.Source;
+		var target = new byte[testCase.Maximum].AsSpan();
+		var actual = LZ4Frame.Encode(w => w.WriteManyBytes(source), target);
+		Assert.Equal(testCase.Expected, actual);
+	}
+}

src/K4os.Compression.LZ4.Streams/LZ4Frame.encode.cs

@@ -95,11 +95,11 @@ public static unsafe int Encode(
 		settings ??= LZ4EncoderSettings.Default;
 		fixed (byte* stream0 = target)
 		{
-			using var encoder = new ByteSpanLZ4FrameWriter(
+			var encoder = new ByteSpanLZ4FrameWriter(
 				UnsafeByteSpan.Create(stream0, target.Length),
 				i => i.CreateEncoder(settings.CompressionLevel, settings.ExtraMemory),
 				settings.CreateDescriptor());
-			encoder.CopyFrom(source);
+			using (encoder) encoder.CopyFrom(source);
 			return encoder.CompressedLength;
 		}
 	}
@@ -118,11 +118,11 @@ public static unsafe int Encode(
 		settings ??= LZ4EncoderSettings.Default;
 		fixed (byte* stream0 = target)
 		{
-			using var encoder = new ByteSpanLZ4FrameWriter(
+			var encoder = new ByteSpanLZ4FrameWriter(
 				UnsafeByteSpan.Create(stream0, target.Length),
 				i => i.CreateEncoder(settings.CompressionLevel, settings.ExtraMemory),
 				settings.CreateDescriptor());
-			encoder.WriteManyBytes(source);
+			using (encoder) encoder.WriteManyBytes(source);
 			return encoder.CompressedLength;
 		}
 	}
@@ -141,11 +141,11 @@ public static unsafe int Encode(
 		settings ??= LZ4EncoderSettings.Default;
 		fixed (byte* stream0 = target)
 		{
-			using var encoder = new ByteSpanLZ4FrameWriter(
+			var encoder = new ByteSpanLZ4FrameWriter(
 				UnsafeByteSpan.Create(stream0, target.Length),
 				i => i.CreateEncoder(settings.CompressionLevel, settings.ExtraMemory),
 				settings.CreateDescriptor());
-			source(encoder);
+			using (encoder) source(encoder);
 			return encoder.CompressedLength;
 		}
 	}

src/TestHelpers/Lorem.cs

@@ -17,6 +17,13 @@ public static class Lorem
 
 		public static readonly byte[] Bytes = Encoding.UTF8.GetBytes(Text);
 
+		public static byte[] Create(int length)
+		{
+			var result = new byte[length];
+			Fill(result, 0, length);
+			return result;
+		}
+
 		public static void Fill(byte[] output, int outputIndex, int outputLength)
 		{
 			while (outputLength > 0)