Add netstandard2.0 to the targets

src/ZLogger/Formatters/PlainTextZLoggerFormatter.cs

@@ -98,17 +98,17 @@ static void Write(IBufferWriter<byte> writer, ReadOnlySpan<byte> message1, strin
         {
             var span = writer.GetSpan(message1.Length + Encoding.UTF8.GetMaxByteCount(message2.Length));
             message1.CopyTo(span);
-            var written2 = Encoding.UTF8.GetBytes(message2, span.Slice(message1.Length));
+            var written2 = Encoding.UTF8.GetBytes(message2.AsSpan(), span.Slice(message1.Length));
             writer.Advance(message1.Length + written2);
         }
 
         static void Write(IBufferWriter<byte> writer, string message1, string message2, string message3)
         {
             var span = writer.GetSpan(Encoding.UTF8.GetMaxByteCount(message1.Length + message2.Length + message3.Length));
 
-            var written1 = Encoding.UTF8.GetBytes(message1, span);
-            var written2 = Encoding.UTF8.GetBytes(message2, span.Slice(written1));
-            var written3 = Encoding.UTF8.GetBytes(message3, span.Slice(written1 + written2));
+            var written1 = Encoding.UTF8.GetBytes(message1.AsSpan(), span);
+            var written2 = Encoding.UTF8.GetBytes(message2.AsSpan(), span.Slice(written1));
+            var written3 = Encoding.UTF8.GetBytes(message3.AsSpan(), span.Slice(written1 + written2));
             writer.Advance(written1 + written2 + written3);
         }
     }

src/ZLogger/Formatters/SystemTextJsonZLoggerFormatter.cs

@@ -88,7 +88,7 @@ public void FormatLogEntry<TEntry>(IBufferWriter<byte> writer, TEntry entry) whe
                     // If `BeginScope(format, arg1, arg2)` style is used, the first argument `format` string is passed with this name
                     if (x.Key == "{OriginalFormat}") continue;
 
-                    WriteMutatedJsonKeyName(x.Key, jsonWriter, KeyNameMutator);
+                    WriteMutatedJsonKeyName(x.Key.AsSpan(), jsonWriter, KeyNameMutator);
 
                     if (x.Value is { } value)
                     {

src/ZLogger/Internal/EnumDictionary.cs

@@ -41,7 +41,14 @@ public static EnumDictionary Create<T>()
         {
             // dictionary key is enumValue, value is name.
             var unboxedEnumValue = (T)enumValue;
-            var key = MemoryMarshal.CreateReadOnlySpan(ref Unsafe.As<T, byte>(ref unboxedEnumValue), Unsafe.SizeOf<T>()).ToArray();
+
+            var keySpan =
+#if NETSTANDARD2_0                
+                Shims.CreateReadOnlySpan(ref Unsafe.As<T, byte>(ref unboxedEnumValue), Unsafe.SizeOf<T>());
+#else            
+                MemoryMarshal.CreateReadOnlySpan(ref Unsafe.As<T, byte>(ref unboxedEnumValue), Unsafe.SizeOf<T>());
+#endif            
+            var key = keySpan.ToArray();
 
             var value1 = Encoding.UTF8.GetBytes(name);
             var value2 = JsonEncodedText.Encode(value1);
@@ -154,20 +161,12 @@ static int GetBytesHashCode(ReadOnlySpan<byte> bytes)
         }
     }
 
-    readonly struct Entry
+    readonly struct Entry(byte[] key, string name, byte[] utf8Name, JsonEncodedText jsonEncoded)
     {
-        public readonly byte[] Key;
-        public readonly string Name;
-        public readonly byte[] Utf8Name;
-        public readonly JsonEncodedText JsonEncoded;
-
-        public Entry(byte[] key, string name, byte[] utf8Name, JsonEncodedText jsonEncoded)
-        {
-            Key = key;
-            Name = name;
-            Utf8Name = utf8Name;
-            JsonEncoded = jsonEncoded;
-        }
+        public readonly byte[] Key = key;
+        public readonly string Name = name;
+        public readonly byte[] Utf8Name = utf8Name;
+        public readonly JsonEncodedText JsonEncoded = jsonEncoded;
 
         // for debugging
         public override string ToString()

src/ZLogger/Internal/MagicalBox.cs

@@ -1,4 +1,5 @@
-using System.Buffers;
+using System;
+using System.Buffers;
 using System.Collections.Concurrent;
 using System.Runtime.CompilerServices;
 using System.Runtime.InteropServices;
@@ -23,7 +24,7 @@ public MagicalBox(byte[] storage)
 
     public bool TryWrite<T>(T value, out int offset)
     {
-        if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+        if (!IsSupportedType<T>())
         {
             offset = 0;
             return false;
@@ -47,7 +48,7 @@ public bool TryWrite<T>(T value, out int offset)
 
     public bool TryRead<T>(int offset, out T value)
     {
-        if (RuntimeHelpers.IsReferenceOrContainsReferences<T>()
+        if (!IsSupportedType<T>()
             || offset < 0
             || (storage.Length < offset + Unsafe.SizeOf<T>()))
         {
@@ -77,7 +78,11 @@ public T Read<T>(int offset)
     public ReadOnlySpan<byte> ReadRawEnumValue(Type type, int offset)
     {
         var (_, size, _) = ReaderCache.GetEnumDictionaryAndValueSize(type);
+#if NETSTANDARD2_0        
+        return Shims.CreateReadOnlySpan(ref storage[offset], size);
+#else
         return MemoryMarshal.CreateReadOnlySpan(ref storage[offset], size);
+#endif
     }
 
     public bool TryReadTo(Type type, int offset, int alignment, string? format, ref Utf8StringWriter<IBufferWriter<byte>> handler)
@@ -136,7 +141,12 @@ public bool TryReadTo(Type type, int offset, int alignment, string? format, ref
         if (type.IsEnum)
         {
             var (dict, size, converter) = ReaderCache.GetEnumDictionaryAndValueSize(type);
-            var rawValue = MemoryMarshal.CreateReadOnlySpan(ref storage[offset], size);
+            var rawValue = 
+#if NETSTANDARD2_0
+                Shims.CreateReadOnlySpan(ref storage[offset], size);
+#else
+                MemoryMarshal.CreateReadOnlySpan(ref storage[offset], size);
+#endif            
             var name = dict.GetUtf8Name(rawValue);
             if (name == null)
             {
@@ -234,7 +244,11 @@ public bool TryReadTo(Type type, int offset, int alignment, string? format, ref
         if (type.IsEnum)
         {
             var (dict, size, converter) = ReaderCache.GetEnumDictionaryAndValueSize(type);
+#if NETSTANDARD2_0
+            var rawValue = Shims.CreateReadOnlySpan(ref storage[offset], size);
+#else            
             var rawValue = MemoryMarshal.CreateReadOnlySpan(ref storage[offset], size);
+#endif            
             var name = dict.GetStringName(rawValue);
             if (name == null)
             {
@@ -334,7 +348,12 @@ public bool TryReadTo(Type type, int offset, Utf8JsonWriter jsonWriter)
         if (type.IsEnum)
         {
             var (dict, size, converter) = ReaderCache.GetEnumDictionaryAndValueSize(type);
-            var rawValue = MemoryMarshal.CreateReadOnlySpan(ref storage[offset], size);
+            var rawValue =
+#if NETSTANDARD2_0                
+                 Shims.CreateReadOnlySpan(ref storage[offset], size);
+#else
+                MemoryMarshal.CreateReadOnlySpan(ref storage[offset], size);
+#endif
             var name = dict.GetJsonEncodedName(rawValue);
             if (name == null)
             {
@@ -362,6 +381,39 @@ public bool TryReadTo(Type type, int offset, Utf8JsonWriter jsonWriter)
         return true;
     }
 
+    static bool IsSupportedType<T>()
+    {
+#if NETSTANDARD2_0
+        var type = typeof(T);
+        var code = Type.GetTypeCode(type);
+        switch (code)
+        {
+            case TypeCode.Boolean:
+            case TypeCode.Byte:
+            case TypeCode.Char:
+            case TypeCode.DateTime:
+            case TypeCode.Decimal:
+            case TypeCode.Double:
+            case TypeCode.Int16:
+            case TypeCode.Int32:
+            case TypeCode.Int64:
+            case TypeCode.SByte:
+            case TypeCode.Single:
+            case TypeCode.UInt16:
+            case TypeCode.UInt32:
+            case TypeCode.UInt64:
+                return true;
+        }
+        if (type.IsEnum || type == typeof(Guid) || type == typeof(DateTimeOffset))
+        {
+            return true;
+        }
+        return false;
+#else
+        return !RuntimeHelpers.IsReferenceOrContainsReferences<T>();
+#endif
+    }
+
     static void ThrowArgumentOutOfRangeException()
     {
         throw new ArgumentOutOfRangeException();
@@ -391,7 +443,7 @@ static class ReaderCache<T>
     {
         static ReaderCache()
         {
-            if (RuntimeHelpers.IsReferenceOrContainsReferences<T>())
+            if (!IsSupportedType<T>())
             {
                 ReaderCache.readCache.TryAdd(typeof(T), null);
                 return;

src/ZLogger/Internal/Shims/DefaultInterpolatedStringHandler.cs

@@ -7,7 +7,7 @@ namespace System.Runtime.CompilerServices;
 
 /// <summary>Provides a handler used by the language compiler to process interpolated strings into <see cref="string"/> instances.</summary>
 [InterpolatedStringHandler]
-public ref struct DefaultInterpolatedStringHandler
+internal ref struct DefaultInterpolatedStringHandler
 {
     // Implementation note:
     // As this type lives in CompilerServices and is only intended to be targeted by the compiler,
@@ -94,7 +94,7 @@ internal static int GetDefaultLength(int literalLength, int formattedCount) =>
 
     /// <summary>Gets the built <see cref="string"/>.</summary>
     /// <returns>The built string.</returns>
-    public override string ToString() => new string(Text);
+    public override string ToString() => Text.ToString();
 
     /// <summary>Gets the built <see cref="string"/> and clears the handler.</summary>
     /// <returns>The built string.</returns>
@@ -106,7 +106,7 @@ internal static int GetDefaultLength(int literalLength, int formattedCount) =>
     /// </remarks>
     public string ToStringAndClear()
     {
-        string result = new string(Text);
+        string result = Text.ToString();
         Clear();
         return result;
     }
@@ -627,7 +627,7 @@ private void GrowCore(uint requiredMinCapacity)
 
         // uint newCapacity = Math.Max(requiredMinCapacity, Math.Min((uint)_chars.Length * 2, string.MaxLength));
         uint newCapacity = Math.Max(requiredMinCapacity, Math.Min((uint)_chars.Length * 2, 0x3FFFFFDF));
-        int arraySize = (int)Math.Clamp(newCapacity, MinimumArrayPoolLength, int.MaxValue);
+        var arraySize = (int)Math.Max(Math.Min(newCapacity, int.MaxValue), MinimumArrayPoolLength);
 
         char[] newArray = ArrayPool<char>.Shared.Rent(arraySize);
         _chars.Slice(0, _pos).CopyTo(newArray);

src/ZLogger/Internal/Shims/Shims.NetStandard2.cs

@@ -0,0 +1,36 @@
+#if NETSTANDARD2_0
+using System.Text;
+
+namespace ZLogger;
+
+internal static partial class Shims
+{
+    public static int GetBytes(this Encoding encoding, ReadOnlySpan<char> chars, ReadOnlySpan<byte> bytes)
+    {
+        unsafe 
+        {
+            fixed (char* charsPtr = &chars[0])
+            fixed (byte* bytesPtr = &bytes[0])
+            {
+                return encoding.GetBytes(charsPtr, chars.Length, bytesPtr, bytes.Length);
+            }
+        }
+    }
+
+     public static unsafe Span<T> CreateSpan<T>(ref T value, int length) where T : unmanaged
+     {
+         fixed(T* pointer = &value)
+         {
+             return new Span<T>(pointer, length);
+         }
+     }
+
+     public static unsafe ReadOnlySpan<T> CreateReadOnlySpan<T>(ref T value, int length) where T : unmanaged
+     {
+         fixed(T* pointer = &value)
+         {
+             return new ReadOnlySpan<T>(pointer, length);
+         }
+     }
+}
+#endif

src/ZLogger/LogStates/InterpolatedStringLogState.cs

@@ -93,7 +93,7 @@ public void WriteJsonParameterKeyValues(Utf8JsonWriter jsonWriter, JsonSerialize
             for (var i = 0; i < ParameterCount; i++)
             {
                 ref var p = ref parameters[i];
-                SystemTextJsonZLoggerFormatter.WriteMutatedJsonKeyName(p.Name, jsonWriter, keyNameMutator);
+                SystemTextJsonZLoggerFormatter.WriteMutatedJsonKeyName(p.Name.AsSpan(), jsonWriter, keyNameMutator);
 
                 if (magicalBox.TryReadTo(p.Type, p.BoxOffset, jsonWriter))
                 {
@@ -119,7 +119,7 @@ public ReadOnlySpan<byte> GetParameterKey(int index)
 
         public ReadOnlySpan<char> GetParameterKeyAsString(int index)
         {
-            return parameters[index].Name;
+            return parameters[index].Name.AsSpan();
         }
 
         public object? GetParameterValue(int index)

src/ZLogger/LogStates/StringFormatterLogState.cs

@@ -74,7 +74,7 @@ public ReadOnlySpan<char> GetParameterKeyAsString(int index)
         {
             if (originalStateParameters != null)
             {
-                return originalStateParameters[index].Key;
+                return originalStateParameters[index].Key.AsSpan();
             }
             throw new IndexOutOfRangeException(nameof(index));
         }

src/ZLogger/ZLogger.csproj

@@ -1,7 +1,7 @@
 <Project Sdk="Microsoft.NET.Sdk">
 
 	<PropertyGroup>
-		<TargetFrameworks>netstandard2.1;net6.0;net8.0</TargetFrameworks>
+		<TargetFrameworks>netstandard2.0;netstandard2.1;net6.0;net8.0</TargetFrameworks>
 		<Nullable>enable</Nullable>
 		<LangVersion>12.0</LangVersion>
 		<ImplicitUsings>enable</ImplicitUsings>
@@ -24,14 +24,14 @@
 		<PackageReference Include="Microsoft.Extensions.Logging.Configuration" Version="8.0.0" />
 		<PackageReference Include="System.Threading.Channels" Version="8.0.0" />
 		<PackageReference Include="System.IO.Hashing" Version="8.0.0" />
-		<PackageReference Include="Utf8StringInterpolation" Version="1.1.0" />
+		<PackageReference Include="Utf8StringInterpolation" Version="1.2.0" />
 	</ItemGroup>
 
 	<ItemGroup Condition="$(TargetFramework) == 'net6.0'">
 		<PackageReference Include="Microsoft.Bcl.TimeProvider" Version="8.0.0" />
 	</ItemGroup>
 
-	<ItemGroup Condition="$(TargetFramework) == 'netstandard2.1'">
+	<ItemGroup Condition="$(TargetFramework) == 'netstandard2.0' Or $(TargetFramework) == 'netstandard2.1'">
 		<PackageReference Include="System.Text.Json" Version="8.0.0" />
 		<PackageReference Include="Microsoft.Bcl.TimeProvider" Version="8.0.0" />
 		<PackageReference Include="Microsoft.Bcl.AsyncInterfaces" Version="8.0.0" />

src/ZLogger/ZLoggerInterpolatedStringHandler.cs

@@ -285,9 +285,18 @@ public bool Equals(LiteralList other)
             // convert const strings as address sequence
             static ReadOnlySpan<byte> AsBytes(ReadOnlySpan<string?> literals)
             {
+#if NETSTANDARD2_0
+                if (literals.IsEmpty)
+                    return default;
+
+                return Shims.CreateSpan(
+                    ref Unsafe.As<string?, byte>(ref Unsafe.AsRef(in literals[0])),
+                    literals.Length * Unsafe.SizeOf<string>());
+#else                
                 return MemoryMarshal.CreateSpan(
                     ref Unsafe.As<string?, byte>(ref MemoryMarshal.GetReference(literals)),
                     literals.Length * Unsafe.SizeOf<string>());
+#endif
             }
         }
     }