Add IBM cost analysis

.build/Build.Tests.2.cs

@@ -49,6 +49,10 @@ partial class Build
         .Produces(TestResultDirectory / "*.trx")
         .Executes(() => RunTests(SourceDirectory / "HotChocolate" / "Core" / "HotChocolate.Core.sln"));
 
+    Target TestHotChocolateCostAnalysis => _ => _
+        .Produces(TestResultDirectory / "*.trx")
+        .Executes(() => RunTests(SourceDirectory / "HotChocolate" / "CostAnalysis" / "HotChocolate.CostAnalysis.sln"));
+
     Target TestHotChocolateData => _ => _
         .Produces(TestResultDirectory / "*.trx")
         .Executes(() => RunTests(SourceDirectory / "HotChocolate" / "Data" / "HotChocolate.Data.sln"));

.build/Helpers.cs

@@ -16,6 +16,7 @@ static class Helpers
         Path.Combine("HotChocolate", "AspNetCore"),
         Path.Combine("HotChocolate", "AzureFunctions"),
         Path.Combine("HotChocolate", "Core"),
+        Path.Combine("HotChocolate", "CostAnalysis"),
         Path.Combine("HotChocolate", "Caching"),
         Path.Combine("HotChocolate", "Diagnostics"),
         Path.Combine("HotChocolate", "Language"),

src/HotChocolate/Core/src/Execution/HotChocolate.Execution.csproj

@@ -14,6 +14,7 @@
   <ItemGroup>
     <InternalsVisibleTo Include="HotChocolate.Types.Mutations" />
     <InternalsVisibleTo Include="HotChocolate.AspNetCore.Tests" />
+    <InternalsVisibleTo Include="HotChocolate.CostAnalysis" />
     <InternalsVisibleTo Include="HotChocolate.Data" />
     <InternalsVisibleTo Include="HotChocolate.Data.Raven" />
     <InternalsVisibleTo Include="HotChocolate.Fusion" />

src/HotChocolate/Core/src/Types/HotChocolate.Types.csproj

@@ -16,6 +16,7 @@
   </ItemGroup>
 
   <ItemGroup>
+    <InternalsVisibleTo Include="HotChocolate.CostAnalysis" />
     <InternalsVisibleTo Include="HotChocolate.Execution" />
     <InternalsVisibleTo Include="HotChocolate.Execution.Tests" />
     <InternalsVisibleTo Include="HotChocolate.Types.Errors" />

src/HotChocolate/CostAnalysis/Directory.Build.props

@@ -0,0 +1,10 @@
+<Project>
+  <Import Project="$([MSBuild]::GetPathOfFileAbove('Directory.Build.props', '$(MSBuildThisFileDirectory)..\'))" />
+
+  <PropertyGroup>
+    <TargetFrameworks>$(Library3TargetFrameworks)</TargetFrameworks>
+    <Nullable>enable</Nullable>
+    <ImplicitUsings>enable</ImplicitUsings>
+  </PropertyGroup>
+
+</Project>

src/HotChocolate/CostAnalysis/HotChocolate.CostAnalysis.sln

@@ -0,0 +1,36 @@
+
+Microsoft Visual Studio Solution File, Format Version 12.00
+# Visual Studio Version 17
+VisualStudioVersion = 17.0.31903.59
+MinimumVisualStudioVersion = 10.0.40219.1
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "src", "src", "{3F8C3AE9-6085-43F1-A593-CC7C0B9A4989}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotChocolate.CostAnalysis", "src\CostAnalysis\HotChocolate.CostAnalysis.csproj", "{CBC13F2C-A2CC-43C7-A60B-DA83ADCD0314}"
+EndProject
+Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "test", "test", "{10D8894D-98C1-4F32-A6DE-8E2268E0D69B}"
+EndProject
+Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "HotChocolate.CostAnalysis.Tests", "test\CostAnalysis.Tests\HotChocolate.CostAnalysis.Tests.csproj", "{6F56773B-1192-4951-8F4A-6C2E5835410D}"
+EndProject
+Global
+	GlobalSection(SolutionConfigurationPlatforms) = preSolution
+		Debug|Any CPU = Debug|Any CPU
+		Release|Any CPU = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(SolutionProperties) = preSolution
+		HideSolutionNode = FALSE
+	EndGlobalSection
+	GlobalSection(ProjectConfigurationPlatforms) = postSolution
+		{CBC13F2C-A2CC-43C7-A60B-DA83ADCD0314}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{CBC13F2C-A2CC-43C7-A60B-DA83ADCD0314}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{CBC13F2C-A2CC-43C7-A60B-DA83ADCD0314}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{CBC13F2C-A2CC-43C7-A60B-DA83ADCD0314}.Release|Any CPU.Build.0 = Release|Any CPU
+		{6F56773B-1192-4951-8F4A-6C2E5835410D}.Debug|Any CPU.ActiveCfg = Debug|Any CPU
+		{6F56773B-1192-4951-8F4A-6C2E5835410D}.Debug|Any CPU.Build.0 = Debug|Any CPU
+		{6F56773B-1192-4951-8F4A-6C2E5835410D}.Release|Any CPU.ActiveCfg = Release|Any CPU
+		{6F56773B-1192-4951-8F4A-6C2E5835410D}.Release|Any CPU.Build.0 = Release|Any CPU
+	EndGlobalSection
+	GlobalSection(NestedProjects) = preSolution
+		{CBC13F2C-A2CC-43C7-A60B-DA83ADCD0314} = {3F8C3AE9-6085-43F1-A593-CC7C0B9A4989}
+		{6F56773B-1192-4951-8F4A-6C2E5835410D} = {10D8894D-98C1-4F32-A6DE-8E2268E0D69B}
+	EndGlobalSection
+EndGlobal

src/HotChocolate/CostAnalysis/src/CostAnalysis/Attributes/CostAttribute.cs

@@ -0,0 +1,73 @@
+using System.Reflection;
+using HotChocolate.CostAnalysis.Directives;
+using HotChocolate.Types;
+using HotChocolate.Types.Descriptors;
+
+namespace HotChocolate.CostAnalysis.Attributes;
+
+/// <summary>
+/// Applies the <c>@cost</c> directive. The purpose of the <c>cost</c> directive is to define a
+/// <c>weight</c> for GraphQL types, fields, and arguments. Static analysis can use these weights
+/// when calculating the overall cost of a query or response.
+/// </summary>
+[AttributeUsage(
+    AttributeTargets.Class
+    | AttributeTargets.Enum
+    | AttributeTargets.Method
+    | AttributeTargets.Parameter
+    | AttributeTargets.Property
+    | AttributeTargets.Struct)]
+public sealed class CostAttribute : DescriptorAttribute
+{
+    private readonly string _weight;
+
+    /// <summary>
+    /// Initializes a new instance of <see cref="CostAttribute"/>.
+    /// </summary>
+    /// <param name="weight">
+    /// The <c>weight</c> argument defines what value to add to the overall cost for every
+    /// appearance, or possible appearance, of a type, field, argument, etc.
+    /// </param>
+    public CostAttribute(string weight)
+    {
+        if (weight is null)
+        {
+            throw new ArgumentNullException(nameof(weight));
+        }
+
+        _weight = weight;
+    }
+
+    protected internal override void TryConfigure(
+        IDescriptorContext context,
+        IDescriptor descriptor,
+        ICustomAttributeProvider element)
+    {
+        switch (descriptor)
+        {
+            case IArgumentDescriptor argumentDescriptor:
+                argumentDescriptor.Directive(new CostDirective(_weight));
+                break;
+
+            case IEnumTypeDescriptor enumTypeDescriptor:
+                enumTypeDescriptor.Directive(new CostDirective(_weight));
+                break;
+
+            case IInputFieldDescriptor inputFieldDescriptor:
+                inputFieldDescriptor.Directive(new CostDirective(_weight));
+                break;
+
+            case IObjectFieldDescriptor objectFieldDescriptor:
+                objectFieldDescriptor.Directive(new CostDirective(_weight));
+                break;
+
+            case IObjectTypeDescriptor objectTypeDescriptor:
+                objectTypeDescriptor.Directive(new CostDirective(_weight));
+                break;
+
+            case IScalarTypeDescriptor scalarTypeDescriptor:
+                scalarTypeDescriptor.Directive(new CostDirective(_weight));
+                break;
+        }
+    }
+}

src/HotChocolate/CostAnalysis/src/CostAnalysis/Attributes/ListSizeAttribute.cs

@@ -0,0 +1,55 @@
+using System.Reflection;
+using HotChocolate.CostAnalysis.Directives;
+using HotChocolate.Types;
+using HotChocolate.Types.Descriptors;
+
+namespace HotChocolate.CostAnalysis.Attributes;
+
+/// <summary>
+/// Applies the <c>@listSize</c> directive. The purpose of the <c>@listSize</c> directive is to
+/// either inform the static analysis about the size of returned lists (if that information is
+/// statically available), or to point the analysis to where to find that information.
+/// </summary>
+public sealed class ListSizeAttribute : ObjectFieldDescriptorAttribute
+{
+    private readonly int? _assumedSize;
+
+    /// <summary>
+    /// The maximum length of the list returned by this field.
+    /// </summary>
+    public int AssumedSize
+    {
+        get => _assumedSize ?? 0;
+        init => _assumedSize = value;
+    }
+
+    /// <summary>
+    /// The arguments of this field with numeric type that are slicing arguments. Their value
+    /// determines the size of the returned list.
+    /// </summary>
+    public string[]? SlicingArguments { get; init; }
+
+    /// <summary>
+    /// The subfield(s) that the list size applies to.
+    /// </summary>
+    public string[]? SizedFields { get; init; }
+
+    /// <summary>
+    /// Whether to require a single slicing argument in the query. If that is not the case (i.e., if
+    /// none or multiple slicing arguments are present), the static analysis will throw an error.
+    /// </summary>
+    public bool RequireOneSlicingArgument { get; init; } = true;
+
+    protected override void OnConfigure(
+        IDescriptorContext context,
+        IObjectFieldDescriptor descriptor,
+        MemberInfo member)
+    {
+        descriptor.Directive(
+            new ListSizeDirective(
+                _assumedSize,
+                SlicingArguments?.ToList(),
+                SizedFields?.ToList(),
+                RequireOneSlicingArgument));
+    }
+}

src/HotChocolate/CostAnalysis/src/CostAnalysis/Caching/DefaultCostMetricsCache.cs

@@ -0,0 +1,25 @@
+using System.Diagnostics.CodeAnalysis;
+using HotChocolate.Utilities;
+
+namespace HotChocolate.CostAnalysis.Caching;
+
+internal sealed class DefaultCostMetricsCache(int capacity = 100) : ICostMetricsCache
+{
+    private readonly Cache<CostMetrics> _cache = new(capacity);
+
+    public int Capacity => _cache.Capacity;
+
+    public int Count => _cache.Usage;
+
+    public bool TryGetCostMetrics(
+        string operationId,
+        [NotNullWhen(true)] out CostMetrics? costMetrics)
+        => _cache.TryGet(operationId, out costMetrics);
+
+    public void TryAddCostMetrics(
+        string operationId,
+        CostMetrics costMetrics)
+        => _cache.GetOrCreate(operationId, () => costMetrics);
+
+    public void Clear() => _cache.Clear();
+}

src/HotChocolate/CostAnalysis/src/CostAnalysis/Caching/ICostMetricsCache.cs

@@ -0,0 +1,53 @@
+using System.Diagnostics.CodeAnalysis;
+
+namespace HotChocolate.CostAnalysis.Caching;
+
+internal interface ICostMetricsCache
+{
+    /// <summary>
+    /// Gets the maximum number of <c>CostMetrics</c> instances that can be cached. The default
+    /// value is <c>100</c>. The minimum allowed value is <c>10</c>.
+    /// </summary>
+    int Capacity { get; }
+
+    /// <summary>
+    /// Gets the number of <c>CostMetrics</c> instances residing in the cache.
+    /// </summary>
+    int Count { get; }
+
+    /// <summary>
+    /// Tries to get a <c>CostMetrics</c> instance by <paramref name="operationId" />.
+    /// </summary>
+    /// <param name="operationId">
+    /// The internal operation ID.
+    /// </param>
+    /// <param name="costMetrics">
+    /// The <c>CostMetrics</c> instance that is associated with the ID or null
+    /// if no <c>CostMetrics</c> instance was found that matches the specified ID.
+    /// </param>
+    /// <returns>
+    /// <c>true</c> if a <c>CostMetrics</c> instance was found that matches the specified
+    /// <paramref name="operationId"/>, otherwise <c>false</c>.
+    /// </returns>
+    bool TryGetCostMetrics(
+        string operationId,
+        [NotNullWhen(true)] out CostMetrics? costMetrics);
+
+    /// <summary>
+    /// Tries to add a new <c>CostMetrics</c> instance to the cache.
+    /// </summary>
+    /// <param name="operationId">
+    /// The internal operation ID.
+    /// </param>
+    /// <param name="costMetrics">
+    /// The <c>CostMetrics</c> instance that shall be cached.
+    /// </param>
+    void TryAddCostMetrics(
+        string operationId,
+        CostMetrics costMetrics);
+
+    /// <summary>
+    /// Clears all items from the cache.
+    /// </summary>
+    void Clear();
+}

src/HotChocolate/CostAnalysis/src/CostAnalysis/Cost.cs

@@ -0,0 +1,7 @@
+namespace HotChocolate.CostAnalysis;
+
+/// <summary>https://ibm.github.io/graphql-specs/cost-spec.html#sec-__cost</summary>
+internal sealed class Cost(CostMetrics requestCosts)
+{
+    public CostMetrics RequestCosts { get; } = requestCosts;
+}