Breaking change: Change extension method from Hash.AsSpanUnsafe to Ha…

…sh.AsSpan() and use UnscopeRef to protect usage

src/Blake3.Benchmarks/Blake3.Benchmarks.csproj

@@ -1,4 +1,4 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <OutputType>Exe</OutputType>
@@ -8,7 +8,7 @@
   </PropertyGroup>
 
   <ItemGroup>
-    <PackageReference Include="BenchmarkDotNet" Version="0.13.6" />
+    <PackageReference Include="BenchmarkDotNet" Version="0.13.9" />
     <PackageReference Include="SauceControl.Blake2Fast" Version="2.0.0" />
   </ItemGroup>
 

src/Blake3.Tests/Blake3.Tests.csproj

@@ -1,17 +1,16 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
-    <TargetFrameworks>net7.0;net48</TargetFrameworks>
+    <TargetFramework>net7.0</TargetFramework>
     <IsPackable>false</IsPackable>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
-    <LangVersion>9.0</LangVersion>
     <RuntimeIdentifier Condition="'$(RuntimeIdentifier)' == '' AND '$(PackAsTool)' != 'true'">$(NETCoreSdkRuntimeIdentifier)</RuntimeIdentifier>
   </PropertyGroup>
 
   <ItemGroup>
     <PackageReference Include="NUnit" Version="3.13.3" />
     <PackageReference Include="NUnit3TestAdapter" Version="4.5.0" />
-    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.6.3" />
+    <PackageReference Include="Microsoft.NET.Test.Sdk" Version="17.7.2" />
     <Content Include="..\Blake3\runtimes\$(RuntimeIdentifier)\native\*.*">
       <CopyToOutputDirectory>PreserveNewest</CopyToOutputDirectory>
     </Content>

src/Blake3.Tests/Blake3StreamTests.cs

@@ -13,11 +13,7 @@ public void TestHashRead()
         {
             var stream = new MemoryStream(HasherTests.BigData);
             using var blake3Stream = new Blake3Stream(stream);
-#if NET5_0
-            blake3Stream.Read(new byte[HasherTests.BigData.Length]);
-#else
-            blake3Stream.Read(new byte[HasherTests.BigData.Length], 0, HasherTests.BigData.Length);
-#endif
+            _ = blake3Stream.Read(new byte[HasherTests.BigData.Length]);
             AssertTextAreEqual(HasherTests.BigExpected, blake3Stream.ComputeHash().ToString());
         }
 
@@ -57,11 +53,7 @@ public void TestHashWrite()
         {
             var stream = new MemoryStream();
             using var blake3Stream = new Blake3Stream(stream);
-#if NET5_0
             blake3Stream.Write(HasherTests.BigData);
-#else
-            blake3Stream.Write(HasherTests.BigData, 0, HasherTests.BigData.Length);
-#endif
             AssertTextAreEqual(HasherTests.BigExpected, blake3Stream.ComputeHash().ToString());
         }
     }

src/Blake3.Tests/HashTests.cs

@@ -1,6 +1,4 @@
-using System;
 using System.Linq;
-using System.Text;
 using NUnit.Framework;
 
 namespace Blake3.Tests

src/Blake3/Blake3.csproj

@@ -3,15 +3,14 @@
   <Import Project="Blake3.props" />
 
   <PropertyGroup>
-    <TargetFrameworks>net6.0;netstandard2.0</TargetFrameworks>
+    <TargetFrameworks>net7.0</TargetFrameworks>
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <NoWarn>$(NoWarn);CS1591</NoWarn>
     <GenerateDocumentationFile>true</GenerateDocumentationFile>
     <!--Add support for sourcelink-->
     <PublishRepositoryUrl>true</PublishRepositoryUrl>
     <IncludeSymbols>true</IncludeSymbols>
     <SymbolPackageFormat>snupkg</SymbolPackageFormat>
-    <LangVersion>9.0</LangVersion>
   </PropertyGroup>
 
   <ItemGroup>
@@ -33,4 +32,23 @@
     <!--Add support for sourcelink-->
     <PackageReference Include="Microsoft.SourceLink.GitHub" Version="1.1.*" PrivateAssets="All" />
   </ItemGroup>
+
+  <ItemGroup>
+    <Service Include="{508349b6-6b84-4df5-91f0-309beebad82d}" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Update="Blake3Core.generated.cs">
+      <DesignTime>True</DesignTime>
+      <AutoGen>True</AutoGen>
+      <DependentUpon>Blake3Core.generated.tt</DependentUpon>
+    </Compile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <None Update="Blake3Core.generated.tt">
+      <Generator>TextTemplatingFileGenerator</Generator>
+      <LastGenOutput>Blake3Core.generated.cs</LastGenOutput>
+    </None>
+  </ItemGroup>
 </Project>

src/Blake3/Blake3Stream.cs

@@ -42,7 +42,6 @@ protected override void Dispose(bool disposing)
             }
         }
 
-#if NET5_0
         public override async ValueTask DisposeAsync()
         {
             _hasher.Dispose();
@@ -51,7 +50,6 @@ public override async ValueTask DisposeAsync()
                 await _stream.DisposeAsync();
             }
         }
-#endif
 
         public override void Flush()
         {
@@ -99,8 +97,6 @@ public override async Task<int> ReadAsync(byte[] buffer, int offset, int count,
             return length;
         }
 
-#if NET5_0
-
         public override async ValueTask<int> ReadAsync(Memory<byte> buffer, CancellationToken cancellationToken = new CancellationToken())
         {
             var length = await _stream.ReadAsync(buffer, cancellationToken);
@@ -120,7 +116,6 @@ public override int Read(Span<byte> buffer)
             }
             return length;
         }
-#endif
 
         public override unsafe int ReadByte()
         {
@@ -151,13 +146,12 @@ public override async Task WriteAsync(byte[] buffer, int offset, int count, Canc
             }
         }
 
-#if NET5_0
         public override void Write(ReadOnlySpan<byte> buffer)
         {
             _stream.Write(buffer);
             _hasher.Update(buffer);
         }
-#endif
+
         public override unsafe void WriteByte(byte value)
         {
             _stream.WriteByte(value);

src/Blake3/Hash.cs

@@ -6,7 +6,6 @@
 using System.Diagnostics.CodeAnalysis;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
-using System.Text;
 
 namespace Blake3
 {
@@ -67,7 +66,7 @@ public struct Hash : IEquatable<Hash>
         public void CopyFromBytes(ReadOnlySpan<byte> data)
         {
             if (data.Length != 32) ThrowArgumentOutOfRange(data.Length);
-            data.CopyTo(this.AsSpanUnsafe());
+            data.CopyTo(this.AsSpan());
         }
 
         /// <summary>
@@ -86,7 +85,7 @@ public static Hash FromBytes(ReadOnlySpan<byte> data)
 
         public bool Equals(Hash other)
         {
-            return this.AsSpanUnsafe().SequenceCompareTo(other.AsSpanUnsafe()) == 0;
+            return this.AsSpan().SequenceCompareTo(other.AsSpan()) == 0;
         }
 
         public override bool Equals(object obj)
@@ -96,7 +95,7 @@ public override bool Equals(object obj)
 
         public override int GetHashCode()
         {
-            var values = MemoryMarshal.Cast<byte, int>(this.AsSpanUnsafe());
+            var values = MemoryMarshal.Cast<byte, int>(this.AsSpan());
             int hashcode = 0;
             for (int i = 0; i < values.Length; i++)
             {
@@ -107,33 +106,30 @@ public override int GetHashCode()
 
         public override string ToString()
         {
-#if NET5_0
             return string.Create(Size * 2, this, (span, hash) =>
             {
-                var data = MemoryMarshal.AsBytes(MemoryMarshal.CreateSpan(ref hash, 1));
-                for (int i = 0; i < Size; i++)
+                var data = hash.AsSpan();
+                for (int i = 0; i < data.Length; i++)
                 {
                     var b = data[i];
-                    span[i * 2] = Hex[(b >> 4) & 0xF];
-                    span[i * 2 + 1] = Hex[b & 0xF];
+                    span[i * 2] = (char)Hex[(b >> 4) & 0xF];
+                    span[i * 2 + 1] = (char)Hex[b & 0xF];
                 }
             });
-#else
-            unsafe
-            {
-                var builder = new StringBuilder(Size * 2);
-                fixed (byte* pBytes = &_byte1)
-                {
-                    for (int i = 0; i < Size; i++)
-                    {
-                        var b = pBytes[i];
-                        builder.Append(Hex[(b >> 4) & 0xF]);
-                        builder.Append(Hex[b & 0xF]);
-                    }
-                }
-                return builder.ToString();
-            }
-#endif
+        }
+
+        /// <summary>
+        /// Creates a span from a hash. The span returned has to follow the same lifetime than the hash referenced.
+        /// </summary>
+        /// <returns>The hash of the span</returns>
+        /// <remarks>This method is unsafe because you could return a Span from a local variable Hash that could be no longer valid on the stack.
+        /// Use this Span with the same variable scope of the original Hash.
+        /// It is safe to use this method if the referenced Hash is a field of a managed type.
+        /// </remarks>
+        [UnscopedRef]
+        public Span<byte> AsSpan()
+        {
+            return MemoryMarshal.AsBytes(MemoryMarshal.CreateSpan(ref this, 1));
         }
 
         public static bool operator ==(Hash left, Hash right)
@@ -153,24 +149,24 @@ private static void ThrowArgumentOutOfRange(int size)
             throw new ArgumentOutOfRangeException("data", $"Invalid size {size} of the data. Expecting 32");
         }
 
-        private static ReadOnlySpan<char> Hex => new ReadOnlySpan<char>(new char[]
+        private static ReadOnlySpan<byte> Hex => new ReadOnlySpan<byte>(new byte[]
         {
-            '0',
-            '1',
-            '2',
-            '3',
-            '4',
-            '5',
-            '6',
-            '7',
-            '8',
-            '9',
-            'a',
-            'b',
-            'c',
-            'd',
-            'e',
-            'f',
+            (byte)'0',
+            (byte)'1',
+            (byte)'2',
+            (byte)'3',
+            (byte)'4',
+            (byte)'5',
+            (byte)'6',
+            (byte)'7',
+            (byte)'8',
+            (byte)'9',
+            (byte)'a',
+            (byte)'b',
+            (byte)'c',
+            (byte)'d',
+            (byte)'e',
+            (byte)'f',
         });
     }
 }