Add poly fills for ReadOnlySpan<T> methods on Encoding/Stream

Author: Krusen

BencodeNET.Tests/Objects/BDictionaryTests.cs

@@ -17,7 +17,7 @@ public class BDictionaryTests
         public void Add_NullStringValue_ResultsInEmptyBString()
         {
             var dict = new BDictionary {{"key", (string) null}};
-            dict.Get<BString>("key").Value.Should().BeEmpty();
+            dict.Get<BString>("key").Value.ToArray().Should().BeEmpty();
         }
 
         [Fact]

BencodeNET.Tests/Objects/BStringTests.cs

@@ -14,14 +14,14 @@ public class BStringTests
         public void ConstructorEmpty_ResultsInEmptyValue()
         {
             var bstring = new BString();
-            bstring.Value.Should().BeEmpty();
+            bstring.Value.ToArray().Should().BeEmpty();
         }
 
         [Fact]
         public void ConstructorWithNullValue_ResultsInEmptyValue()
         {
             var bstring = new BString((string)null);
-            bstring.Value.Should().BeEmpty();
+            bstring.Value.ToArray().Should().BeEmpty();
         }
 
         #region Equals

BencodeNET/BencodeNET.csproj

@@ -1,8 +1,9 @@
-<Project Sdk="Microsoft.NET.Sdk">
+<Project Sdk="Microsoft.NET.Sdk">
 
   <PropertyGroup>
     <TargetFrameworks>netstandard2.0;netcoreapp2.1;netcoreapp3.0</TargetFrameworks>
     <LangVersion>7.3</LangVersion>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <GenerateDocumentationFile>True</GenerateDocumentationFile>
     <CodeAnalysisRuleSet>BencodeNET.ruleset</CodeAnalysisRuleSet>
   </PropertyGroup>

BencodeNET/Objects/BNumber.cs

@@ -64,12 +64,8 @@ protected override void EncodeObject(PipeWriter writer)
             buffer[0] = (byte) 'i';
             buffer = buffer.Slice(1);
 
-#if NETCOREAPP
             Encoding.ASCII.GetBytes(Value.ToString().AsSpan(), buffer);
-#else
-            var bytes = Encoding.ASCII.GetBytes(Value.ToString());
-            bytes.CopyTo(buffer);
-#endif
+
             buffer[buffer.Length - 1] = (byte) 'e';
 
             writer.Advance(size);
@@ -135,9 +131,7 @@ public static implicit operator bool(BNumber bint)
 
         public static bool operator ==(BNumber bnumber, BNumber other)
         {
-            if (ReferenceEquals(bnumber, null) && ReferenceEquals(other, null)) return true;
-            if (ReferenceEquals(bnumber, null) || ReferenceEquals(other, null)) return false;
-            return bnumber.Value == other.Value;
+            return bnumber?.Value == other?.Value;
         }
 
         public static bool operator !=(BNumber bnumber, BNumber other) => !(bnumber == other);

BencodeNET/Objects/BObjectExtensions.cs

@@ -1,11 +1,8 @@
-using System.Buffers;
+using System;
+using System.Buffers;
 using System.IO;
 using System.Text;
 
-#if NETCOREAPP
-using System;
-#endif
-
 namespace BencodeNET.Objects
 {
     /// <summary>
@@ -41,11 +38,7 @@ public static string EncodeAsString(this IBObject bobject, Encoding encoding)
                 using (var stream = new MemoryStream(buffer))
                 {
                     bobject.EncodeTo(stream);
-#if NETCOREAPP
                     return encoding.GetString(buffer.AsSpan().Slice(0, size));
-#else
-                    return encoding.GetString(buffer, 0, size);
-#endif
                 }
             }
             finally { ArrayPool<byte>.Shared.Return(buffer); }

BencodeNET/PolyFillExtensions.cs

@@ -0,0 +1,41 @@
+using System;
+using System.Buffers;
+using System.IO;
+using System.Runtime.InteropServices;
+using System.Text;
+
+namespace BencodeNET
+{
+#if !NETCOREAPP3_0
+    internal static class PolyFillExtensions
+    {
+        public static unsafe int GetBytes(this Encoding encoding, ReadOnlySpan<char> chars, Span<byte> bytes)
+        {
+            fixed (char* charsPtr = &MemoryMarshal.GetReference(chars))
+            fixed (byte* bytesPtr = &MemoryMarshal.GetReference(bytes))
+            {
+                return encoding.GetBytes(charsPtr, chars.Length, bytesPtr, bytes.Length);
+            }
+        }
+
+        public static unsafe string GetString(this Encoding encoding, ReadOnlySpan<byte> bytes)
+        {
+            fixed (byte* bytesPtr = &MemoryMarshal.GetReference(bytes))
+            {
+                return encoding.GetString(bytesPtr, bytes.Length);
+            }
+        }
+
+        public static void Write(this Stream stream, ReadOnlySpan<byte> buffer)
+        {
+            var array = ArrayPool<byte>.Shared.Rent(buffer.Length);
+            try
+            {
+                buffer.CopyTo(array);
+                stream.Write(array, 0, buffer.Length);
+            }
+            finally { ArrayPool<byte>.Shared.Return(array); }
+        }
+    }
+#endif
+}

BencodeNET/UtilityExtensions.cs

@@ -1,14 +1,10 @@
-using System;
+using System;
 using System.Collections.Generic;
 using System.IO;
 using System.IO.Pipelines;
 using System.Linq;
 using System.Text;
 
-#if !NETCOREAPP
-using System.Buffers;
-#endif
-
 namespace BencodeNET
 {
     internal static class UtilityExtensions
@@ -105,46 +101,23 @@ public static bool TrySetLength(this Stream stream, long length)
 
         public static void Write(this Stream stream, int number)
         {
-#if NETCOREAPP
             Span<byte> buffer = stackalloc byte[11];
             var bytesRead = Encoding.ASCII.GetBytes(number.ToString().AsSpan(), buffer);
             stream.Write(buffer.Slice(0, bytesRead));
-#else
-            var str = number.ToString();
-            var buffer = ArrayPool<byte>.Shared.Rent(str.Length);
-            var count = Encoding.ASCII.GetBytes(str, 0, str.Length, buffer, 0);
-            stream.Write(buffer, 0, count);
-            ArrayPool<byte>.Shared.Return(buffer);
-#endif
         }
 
         public static void Write(this Stream stream, long number)
         {
-#if NETCOREAPP
             Span<byte> buffer = stackalloc byte[20];
             var bytesRead = Encoding.ASCII.GetBytes(number.ToString().AsSpan(), buffer);
             stream.Write(buffer.Slice(0, bytesRead));
-#else
-            var str = number.ToString();
-            var buffer = ArrayPool<byte>.Shared.Rent(str.Length);
-            var count = Encoding.ASCII.GetBytes(str, 0, str.Length, buffer, 0);
-            stream.Write(buffer, 0, count);
-            ArrayPool<byte>.Shared.Return(buffer);
-#endif
         }
 
         public static void Write(this Stream stream, char c)
         {
             stream.WriteByte((byte) c);
         }
 
-#if !NETCOREAPP
-        public static void Write(this Stream stream, byte[] bytes)
-        {
-            stream.Write(bytes, 0, bytes.Length);
-        }
-#endif
-
         public static void WriteChar(this PipeWriter writer, char c)
         {
             writer.GetSpan(1)[0] = (byte) c;