Added Span support to Webencoders with direct encoding

Common.sln

@@ -71,6 +71,8 @@ Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Internal.AspNetCore.Analyze
 EndProject
 Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "Internal.AspNetCore.Analyzers.Tests", "test\Internal.AspNetCore.Analyzers.Tests\Internal.AspNetCore.Analyzers.Tests.csproj", "{1A579BD1-A4C4-4B1B-B092-D1670DF7F239}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "Microsoft.Extensions.Internal.Benchmarks", "benchmarks\Microsoft.Extensions.Internal.Benchmarks\Microsoft.Extensions.Internal.Benchmarks.csproj", "{7EAB9B74-5E5E-4D93-BA1E-865906C50676}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -137,6 +139,10 @@ Global
 		{1A579BD1-A4C4-4B1B-B092-D1670DF7F239}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{1A579BD1-A4C4-4B1B-B092-D1670DF7F239}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{1A579BD1-A4C4-4B1B-B092-D1670DF7F239}.Release|Any CPU.Build.0 = Release|Any CPU
+		{7EAB9B74-5E5E-4D93-BA1E-865906C50676}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{7EAB9B74-5E5E-4D93-BA1E-865906C50676}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{7EAB9B74-5E5E-4D93-BA1E-865906C50676}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{7EAB9B74-5E5E-4D93-BA1E-865906C50676}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -157,6 +163,7 @@ Global
 		{B439E0C8-F892-4AC5-BBF7-63BCDAACA7A9} = {6878D8F1-6DCE-4677-AA1A-4D14BA6D2D60}
 		{FACBCBCB-D043-4AE8-A22D-A683040999DD} = {FEAA3936-5906-4383-B750-F07FE1B156C5}
 		{1A579BD1-A4C4-4B1B-B092-D1670DF7F239} = {6878D8F1-6DCE-4677-AA1A-4D14BA6D2D60}
+		{7EAB9B74-5E5E-4D93-BA1E-865906C50676} = {A9A93AF9-2113-4321-AD20-51F60FF8B2BD}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {371030CF-B541-4BA9-9F54-3C7563415CF1}

benchmarks/Microsoft.Extensions.Internal.Benchmarks/Microsoft.Extensions.Internal.Benchmarks.csproj

@@ -0,0 +1,29 @@
+<Project Sdk="Microsoft.NET.Sdk">
+
+  <PropertyGroup>
+    <TargetFramework>netcoreapp2.1</TargetFramework>
+    <OutputType>Exe</OutputType>
+    <ServerGarbageCollection>true</ServerGarbageCollection>
+    <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
+    <IsPackable>false</IsPackable>
+    <LangVersion>latest</LangVersion>
+  </PropertyGroup>
+
+  <ItemGroup>
+    <Compile Include="..\..\shared\Microsoft.AspNetCore.BenchmarkRunner.Sources\**\*.cs">
+      <Link>Shared\%(FileName)%(Extension)</Link>
+    </Compile>
+  </ItemGroup>
+
+  <ItemGroup>
+    <PackageReference Include="BenchmarkDotNet" Version="$(BenchmarkDotNetPackageVersion)" />
+    <PackageReference Include="System.Runtime.CompilerServices.Unsafe" Version="$(SystemRuntimeCompilerServicesUnsafePackageVersion)" />
+    <PackageReference Include="Newtonsoft.Json" Version="$(NewtonsoftJsonPackageVersion)" />
+  </ItemGroup>
+
+  <ItemGroup>
+    <Compile Include="..\..\shared\Microsoft.Extensions.WebEncoders.Sources\**\*.cs" />
+    <EmbeddedResource Include="..\..\shared\*.Sources\**\*.resx" />
+  </ItemGroup>
+
+</Project>

benchmarks/Microsoft.Extensions.Internal.Benchmarks/Properties/AssemblyInfo.cs

@@ -0,0 +1,4 @@
+// Copyright (c) .NET Foundation. All rights reserved.
+// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.
+
+[assembly: BenchmarkDotNet.Attributes.AspNetCoreBenchmark]

benchmarks/Microsoft.Extensions.Internal.Benchmarks/WebEncodersBenchmarks.cs

@@ -0,0 +1,80 @@
+using System;
+using System.Linq;
+using BenchmarkDotNet.Attributes;
+using BenchmarkDotNet.Running;
+
+namespace Microsoft.Extensions.Internal.Benchmarks
+{
+    public class WebEncodersBenchmarks
+    {
+        private const int ByteArraySize = 500;
+        private readonly byte[] _data;
+        private readonly string _dataEncoded;
+        private readonly byte[] _dataWithOffset;
+        private readonly string _dataWithOffsetEncoded;
+        private readonly byte[] _guid;
+        private readonly string _guidEncoded;
+
+        public WebEncodersBenchmarks()
+        {
+            var random = new Random();
+            _data = new byte[ByteArraySize];
+            random.NextBytes(_data);
+            _dataEncoded = WebEncoders.Base64UrlEncode(_data);
+
+            _dataWithOffset = new byte[3].Concat(_data).Concat(new byte[2]).ToArray();
+            _dataWithOffsetEncoded = "xx" + _dataEncoded + "yyy";
+
+            _guid = Guid.NewGuid().ToByteArray();
+            _guidEncoded = WebEncoders.Base64UrlEncode(_guid);
+        }
+
+        [Benchmark]
+        public byte[] Base64UrlDecode_Data()
+        {
+            return WebEncoders.Base64UrlDecode(_dataEncoded);
+        }
+
+        [Benchmark]
+        public byte[] Base64UrlDecode_DataWithOffset()
+        {
+            return WebEncoders.Base64UrlDecode(_dataWithOffsetEncoded, 2, _dataEncoded.Length);
+        }
+
+        [Benchmark]
+        public byte[] Base64UrlDecode_Guid()
+        {
+            return WebEncoders.Base64UrlDecode(_guidEncoded);
+        }
+
+        [Benchmark]
+        public string Base64UrlEncode_Data()
+        {
+            return WebEncoders.Base64UrlEncode(_data);
+        }
+
+        [Benchmark]
+        public string Base64UrlEncode_DataWithOffset()
+        {
+            return WebEncoders.Base64UrlEncode(_dataWithOffset, 3, _data.Length);
+        }
+
+        [Benchmark]
+        public string Base64UrlEncode_Guid()
+        {
+            return WebEncoders.Base64UrlEncode(_guid);
+        }
+
+        [Benchmark]
+        public int GetArraySizeRequiredToDecode()
+        {
+            return WebEncoders.GetArraySizeRequiredToDecode(ByteArraySize);
+        }
+
+        [Benchmark]
+        public int GetArraySizeRequiredToEncode()
+        {
+            return WebEncoders.GetArraySizeRequiredToEncode(ByteArraySize);
+        }
+    }
+}

shared/Microsoft.Extensions.WebEncoders.Sources/Properties/EncoderResources.cs

@@ -19,6 +19,16 @@ internal static class EncoderResources
         /// </summary>
         internal static readonly string WebEncoders_MalformedInput = "Malformed input: {0} is an invalid input length.";
 
+        /// <summary>
+        /// Invalid input, that doesn't conform a base64 string.
+        /// </summary>
+        internal static readonly string WebEncoders_InvalidInput = "The input is not a valid Base-64 string as it contains a non-base 64 character, more than two padding characters, or an illegal character among the padding characters.";
+
+        /// <summary>
+        /// Destination buffer is too small.
+        /// </summary>
+        internal static readonly string WebEncoders_DestinationTooSmall = "The destination buffer is too small.";
+
         /// <summary>
         /// Invalid {0}, {1} or {2} length.
         /// </summary>