Refactor IO "read" core logic

Directory.Build.props

@@ -10,7 +10,7 @@
     <AllowUnsafeBlocks>true</AllowUnsafeBlocks>
     <CodeAnalysisRuleset>$(MSBuildThisFileDirectory)Shared.ruleset</CodeAnalysisRuleset>
     <MSBuildWarningsAsMessages>NETSDK1069</MSBuildWarningsAsMessages>
-    <NoWarn>$(NoWarn);NU5105;NU1507;SER001;SER002;SER003</NoWarn>
+    <NoWarn>$(NoWarn);NU5105;NU1507;SER001;SER002;SER003;SER004;SER005</NoWarn>
     <PackageReleaseNotes>https://stackexchange.github.io/StackExchange.Redis/ReleaseNotes</PackageReleaseNotes>
     <PackageProjectUrl>https://stackexchange.github.io/StackExchange.Redis/</PackageProjectUrl>
     <PackageLicenseExpression>MIT</PackageLicenseExpression>

Directory.Packages.props

@@ -10,6 +10,9 @@
     <PackageVersion Include="System.IO.Compression" Version="4.3.0" />
     <!-- note that this bumps System.Buffers, so is pinned in down-level in SE csproj --> 
     <PackageVersion Include="System.IO.Hashing" Version="10.0.2" />
+    <!-- for RESPite -->
+    <PackageVersion Include="System.Buffers" Version="4.6.1" />
+    <PackageVersion Include="System.Memory" Version="4.6.1" />
 
     <!-- For analyzers, tied to the consumer's build SDK; at the moment, that means "us" -->
     <PackageVersion Include="Microsoft.CodeAnalysis.CSharp" Version="4.12.0" />

StackExchange.Redis.sln

@@ -127,6 +127,10 @@ Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "eng", "eng", "{5FA0958E-6EB
 EndProject
 Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "StackExchange.Redis.Build", "eng\StackExchange.Redis.Build\StackExchange.Redis.Build.csproj", "{190742E1-FA50-4E36-A8C4-88AE87654340}"
 EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RESPite", "src\RESPite\RESPite.csproj", "{AEA77181-DDD2-4E43-828B-908C7460A12D}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "RESPite.Tests", "tests\RESPite.Tests\RESPite.Tests.csproj", "{1D324077-A15E-4EE2-9AD6-A9045636CEAC}"
+EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution
 		Debug|Any CPU = Debug|Any CPU
@@ -189,6 +193,14 @@ Global
 		{190742E1-FA50-4E36-A8C4-88AE87654340}.Debug|Any CPU.Build.0 = Debug|Any CPU
 		{190742E1-FA50-4E36-A8C4-88AE87654340}.Release|Any CPU.ActiveCfg = Release|Any CPU
 		{190742E1-FA50-4E36-A8C4-88AE87654340}.Release|Any CPU.Build.0 = Release|Any CPU
+		{AEA77181-DDD2-4E43-828B-908C7460A12D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{AEA77181-DDD2-4E43-828B-908C7460A12D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{AEA77181-DDD2-4E43-828B-908C7460A12D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{AEA77181-DDD2-4E43-828B-908C7460A12D}.Release|Any CPU.Build.0 = Release|Any CPU
+		{1D324077-A15E-4EE2-9AD6-A9045636CEAC}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{1D324077-A15E-4EE2-9AD6-A9045636CEAC}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{1D324077-A15E-4EE2-9AD6-A9045636CEAC}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{1D324077-A15E-4EE2-9AD6-A9045636CEAC}.Release|Any CPU.Build.0 = Release|Any CPU
 	EndGlobalSection
 	GlobalSection(SolutionProperties) = preSolution
 		HideSolutionNode = FALSE
@@ -212,6 +224,8 @@ Global
 		{69A0ACF2-DF1F-4F49-B554-F732DCA938A3} = {73A5C363-CA1F-44C4-9A9B-EF791A76BA6A}
 		{59889284-FFEE-82E7-94CB-3B43E87DA6CF} = {73A5C363-CA1F-44C4-9A9B-EF791A76BA6A}
 		{190742E1-FA50-4E36-A8C4-88AE87654340} = {5FA0958E-6EBD-45F4-808E-3447A293F96F}
+		{AEA77181-DDD2-4E43-828B-908C7460A12D} = {00CA0876-DA9F-44E8-B0DC-A88716BF347A}
+		{1D324077-A15E-4EE2-9AD6-A9045636CEAC} = {73A5C363-CA1F-44C4-9A9B-EF791A76BA6A}
 	EndGlobalSection
 	GlobalSection(ExtensibilityGlobals) = postSolution
 		SolutionGuid = {193AA352-6748-47C1-A5FC-C9AA6B5F000B}

StackExchange.Redis.sln.DotSettings

@@ -26,4 +26,5 @@
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=xreadgroup/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=xrevrange/@EntryIndexedValue">True</s:Boolean>
 	<s:Boolean x:Key="/Default/UserDictionary/Words/=zcard/@EntryIndexedValue">True</s:Boolean>
-	<s:Boolean x:Key="/Default/UserDictionary/Words/=zscan/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=zscan/@EntryIndexedValue">True</s:Boolean>
+	<s:Boolean x:Key="/Default/UserDictionary/Words/=zset/@EntryIndexedValue">True</s:Boolean></wpf:ResourceDictionary>

docs/exp/SER004.md

@@ -0,0 +1,15 @@
+# RESPite
+
+RESPite is an experimental library that provides high-performance low-level RESP (Redis, etc) parsing and serialization.
+It is used as the IO core for StackExchange.Redis v3+. You should not (yet) use it directly unless you have a very
+good reason to do so.
+
+```xml
+<NoWarn>$(NoWarn);SER004</NoWarn>
+```
+
+or more granularly / locally in C#:
+
+``` c#
+#pragma warning disable SER004
+```

docs/exp/SER005.md

@@ -0,0 +1,21 @@
+# Unit Testing
+
+Unit testing is great! Yay, do more of that!
+
+This type is provided for external unit testing, in particular by people using modules or server features
+not directly implemented by SE.Redis - for example to verify messsage parsing or formatting without
+talking to a RESP server.
+
+These types are considered slightly more... *mercurial*. We encourage you to use them, but *occasionally*
+(not just for fun) you might need to update your test code if we tweak something. This should not impact
+"real" library usage.
+
+```xml
+<NoWarn>$(NoWarn);SER005</NoWarn>
+```
+
+or more granularly / locally in C#:
+
+``` c#
+#pragma warning disable SER005
+```

eng/StackExchange.Redis.Build/FastHashGenerator.cs

@@ -5,6 +5,7 @@
 using Microsoft.CodeAnalysis;
 using Microsoft.CodeAnalysis.CSharp;
 using Microsoft.CodeAnalysis.CSharp.Syntax;
+using RESPite;
 
 namespace StackExchange.Redis.Build;
 
@@ -78,7 +79,15 @@ private static string GetName(INamedTypeSymbol type)
         string name = named.Name, value = "";
         foreach (var attrib in named.GetAttributes())
         {
-            if (attrib.AttributeClass?.Name == "FastHashAttribute")
+            if (attrib.AttributeClass is {
+                    Name: "FastHashAttribute",
+                    ContainingType: null,
+                    ContainingNamespace:
+                    {
+                        Name: "RESPite",
+                        ContainingNamespace.IsGlobalNamespace: true,
+                    }
+            })
             {
                 if (attrib.ConstructorArguments.Length == 1)
                 {
@@ -178,25 +187,28 @@ private void Generate(
                 // perform string escaping on the generated value (this includes the quotes, note)
                 var csValue = SyntaxFactory.LiteralExpression(SyntaxKind.StringLiteralExpression, SyntaxFactory.Literal(literal.Value)).ToFullString();
 
-                var hash = FastHash.Hash64(buffer.AsSpan(0, len));
+                var hashCS = FastHash.HashCS(buffer.AsSpan(0, len));
+                var hashCI = FastHash.HashCI(buffer.AsSpan(0, len));
                 NewLine().Append("static partial class ").Append(literal.Name);
                 NewLine().Append("{");
                 indent++;
                 NewLine().Append("public const int Length = ").Append(len).Append(';');
-                NewLine().Append("public const long Hash = ").Append(hash).Append(';');
+                NewLine().Append("public const long HashCS = ").Append(hashCS).Append(';');
+                NewLine().Append("public const long HashCI = ").Append(hashCI).Append(';');
                 NewLine().Append("public static ReadOnlySpan<byte> U8 => ").Append(csValue).Append("u8;");
                 NewLine().Append("public const string Text = ").Append(csValue).Append(';');
-                if (len <= 8)
+                if (len <= FastHash.MaxBytesHashIsEqualityCS)
                 {
-                    // the hash enforces all the values
-                    NewLine().Append("public static bool Is(long hash, in RawResult value) => hash == Hash && value.Payload.Length == Length;");
-                    NewLine().Append("public static bool Is(long hash, ReadOnlySpan<byte> value) => hash == Hash & value.Length == Length;");
+                    // the case-sensitive hash enforces all the values
+                    NewLine().Append("public static bool IsCS(long hash, ReadOnlySpan<byte> value) => hash == HashCS & value.Length == Length;");
+                    NewLine().Append("public static bool IsCI(long hash, ReadOnlySpan<byte> value) => (hash == HashCI & value.Length == Length) && (global::RESPite.FastHash.HashCS(value) == HashCS || global::RESPite.FastHash.EqualsCI(value, U8));");
                 }
                 else
                 {
-                    NewLine().Append("public static bool Is(long hash, in RawResult value) => hash == Hash && value.IsEqual(U8);");
-                    NewLine().Append("public static bool Is(long hash, ReadOnlySpan<byte> value) => hash == Hash && value.SequenceEqual(U8);");
+                    NewLine().Append("public static bool IsCS(long hash, ReadOnlySpan<byte> value) => hash == HashCS && value.SequenceEqual(U8);");
+                    NewLine().Append("public static bool IsCI(long hash, ReadOnlySpan<byte> value) => (hash == HashCI & value.Length == Length) && global::RESPite.FastHash.EqualsCI(value, U8);");
                 }
+
                 indent--;
                 NewLine().Append("}");
             }

eng/StackExchange.Redis.Build/StackExchange.Redis.Build.csproj

@@ -12,8 +12,11 @@
   </ItemGroup>
 
   <ItemGroup>
-    <Compile Include="..\..\src\StackExchange.Redis\FastHash.cs">
-      <Link>FastHash.cs</Link>
+    <Compile Include="..\..\src\RESPite\Shared\FastHash.cs">
+      <Link>Shared/FastHash.cs</Link>
+    </Compile>
+    <Compile Include="..\..\src\RESPite\Shared\Experiments.cs">
+      <Link>Shared/Experiments.cs</Link>
     </Compile>
   </ItemGroup>