feat: DependsOnContext (#472)

CHANGELOG.md

@@ -8,6 +8,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ## [Unreleased]
 
 ### Added
+- [#472] Added the `DependsOnContext` attribute, for declaring dependencies between extension contexts.
 
 ### Fixed
 

Editor/API/Attributes/DependsOnContext.cs

@@ -0,0 +1,20 @@
+using System;
+
+namespace nadena.dev.ndmf
+{
+    /// <summary>
+    ///     This attribute declares a pass or an extension context to depend on another context.
+    ///     When an extension context depends on another, it will implicitly activate the other context whenever the
+    ///     depending context is activated.
+    /// </summary>
+    [AttributeUsage(AttributeTargets.Class, AllowMultiple = true)]
+    public sealed class DependsOnContext : Attribute
+    {
+        public Type ExtensionContext { get; }
+
+        public DependsOnContext(Type extensionContext)
+        {
+            ExtensionContext = extensionContext;
+        }
+    }
+}

Editor/API/IExtensionContext.cs

@@ -1,4 +1,7 @@
-namespace nadena.dev.ndmf
+using System;
+using System.Collections.Generic;
+
+namespace nadena.dev.ndmf
 {
     /// <summary>
     /// The IExtensionContext is declared by custom extension contexts.
@@ -17,4 +20,52 @@ public interface IExtensionContext
         /// <param name="context"></param>
         void OnDeactivate(BuildContext context);
     }
+
+    internal static class ExtensionContextUtil
+    {
+        public static IEnumerable<Type> ContextDependencies(this Type ty, bool recurse)
+        {
+            if (recurse)
+            {
+                return RecursiveContextDependencies(ty);
+            }
+
+            return ContextDependencies(ty);
+        }
+
+        public static IEnumerable<Type> ContextDependencies(this Type ty)
+        {
+            foreach (var attr in ty.GetCustomAttributes(typeof(DependsOnContext), true))
+            {
+                if (attr is DependsOnContext dependsOn && dependsOn.ExtensionContext != null)
+                {
+                    yield return dependsOn.ExtensionContext;
+                }
+            }
+        }
+
+        private static IEnumerable<Type> RecursiveContextDependencies(Type ty)
+        {
+            HashSet<Type> enqueued = new();
+            Queue<Type> queue = new();
+
+            queue.Enqueue(ty);
+            enqueued.Add(ty);
+
+            while (queue.Count > 0)
+            {
+                var current = queue.Dequeue();
+
+                yield return current;
+
+                foreach (var dep in ContextDependencies(current))
+                {
+                    if (enqueued.Add(dep))
+                    {
+                        queue.Enqueue(dep);
+                    }
+                }
+            }
+        }
+    }
 }

Editor/API/Model/SolverPass.cs

@@ -3,6 +3,7 @@
 using System;
 using System.Collections.Generic;
 using System.Collections.Immutable;
+using System.Linq;
 using nadena.dev.ndmf.preview;
 
 #endregion
@@ -26,9 +27,25 @@ internal class SolverPass
         internal IImmutableSet<string> CompatibleExtensions { get; set; }
         internal List<IRenderFilter> RenderFilters { get; } = new();
 
-        internal bool IsExtensionCompatible(Type ty)
+        internal bool IsExtensionCompatible(Type ty, ISet<Type> activeExtensions)
         {
-            return IsPhantom || RequiredExtensions.Contains(ty) || CompatibleExtensions.Contains(ty.FullName);
+            if (IsPhantom || RequiredExtensions.Contains(ty) || CompatibleExtensions.Contains(ty.FullName))
+            {
+                return true;
+            }
+
+            // See if any of the active extensions depends on the given type, and if so, if we are compatible with it.
+            foreach (var active in activeExtensions)
+            {
+                if (!CompatibleExtensions.Contains(active.FullName) && !RequiredExtensions.Contains(active))
+                {
+                    continue;
+                }
+
+                if (active.ContextDependencies(true).Contains(ty)) return true;
+            }
+
+            return false;
         }
 
         internal SolverPass(IPluginInternal plugin, IPass pass, BuildPhase phase, IImmutableSet<string> compatibleExtensions,
@@ -37,8 +54,8 @@ internal SolverPass(IPluginInternal plugin, IPass pass, BuildPhase phase, IImmut
             Plugin = plugin;
             Pass = pass;
             Phase = phase;
-            RequiredExtensions = requiredExtensions;
             CompatibleExtensions = compatibleExtensions;
+            RequiredExtensions = requiredExtensions.Union(pass.GetType().ContextDependencies());
         }
 
         public override string ToString()

Editor/API/Solver/PluginResolver.cs

@@ -182,7 +182,7 @@ ImmutableList<ConcretePass> ToConcretePasses(BuildPhase phase, IEnumerable<Solve
                 var toActivate = new List<Type>();
                 activeExtensions.RemoveWhere(t =>
                 {
-                    if (!pass.IsExtensionCompatible(t))
+                    if (!pass.IsExtensionCompatible(t, activeExtensions))
                     {
                         toDeactivate.Add(t);
                         return true;
@@ -191,7 +191,7 @@ ImmutableList<ConcretePass> ToConcretePasses(BuildPhase phase, IEnumerable<Solve
                     return false;
                 });
 
-                foreach (var t in pass.RequiredExtensions.ToImmutableSortedSet(new TypeComparer()))
+                foreach (var t in ResolveExtensionDependencies(pass.RequiredExtensions))
                 {
                     if (!activeExtensions.Contains(t))
                     {
@@ -222,6 +222,42 @@ ImmutableList<ConcretePass> ToConcretePasses(BuildPhase phase, IEnumerable<Solve
             return concrete.ToImmutableList();
         }
 
+        private IEnumerable<Type> ResolveExtensionDependencies(IImmutableSet<Type> passRequiredExtensions)
+        {
+            var resultSet = new HashSet<Type>();
+            var results = new List<Type>();
+            var stack = new Stack<Type>();
+
+            foreach (var type in new SortedSet<Type>(passRequiredExtensions, new TypeComparer()))
+            {
+                VisitType(type);
+            }
+
+            return results;
+
+            void VisitType(Type ty)
+            {
+                if (stack.Contains(ty))
+                {
+                    throw new Exception("Circular dependency detected: " + string.Join(" -> ", stack));
+                }
+
+                if (resultSet.Contains(ty)) return;
+
+                stack.Push(ty);
+
+                foreach (var dep in new SortedSet<Type>(ty.ContextDependencies(), new TypeComparer()))
+                {
+                    VisitType(dep);
+                }
+
+                stack.Pop();
+
+                resultSet.Add(ty);
+                results.Add(ty);
+            }
+        }
+
         internal PreviewSession PreviewSession
         {
             get

UnitTests~/PluginResolverTests/ExtensionDependenciesTest.cs

@@ -0,0 +1,88 @@
+using System.Linq;
+using nadena.dev.ndmf;
+using NUnit.Framework;
+
+namespace UnitTests.PluginResolverTests
+{
+    [DependsOnContext(typeof(Ctx3))]
+    [DependsOnContext(typeof(Ctx2))]
+    public class Ctx1 : IExtensionContext
+    {
+        public void OnActivate(BuildContext context)
+        {
+
+        }
+
+        public void OnDeactivate(BuildContext context)
+        {
+
+        }
+    }
+
+    public class Ctx2 : IExtensionContext
+    {
+        public void OnActivate(BuildContext context)
+        {
+
+        }
+
+        public void OnDeactivate(BuildContext context)
+        {
+
+        }
+    }
+
+    public class Ctx3 : IExtensionContext
+    {
+        public void OnActivate(BuildContext context)
+        {
+
+        }
+
+        public void OnDeactivate(BuildContext context)
+        {
+
+        }
+    }
+
+    [DependsOnContext(typeof(Ctx1))]
+    public class Pass1 : Pass<Pass1>
+    {
+        protected override void Execute(BuildContext context)
+        {
+
+        }
+    }
+
+    public class Plugin1 : Plugin<Plugin1>
+    {
+        protected override void Configure()
+        {
+            InPhase(BuildPhase.Generating)
+                .Run(Pass1.Instance)
+                .Then.WithCompatibleExtension(typeof(Ctx1), seq =>
+                {
+                    seq.Run("test test", _ => { });
+                });
+        }
+    }
+
+    public class ExtensionDependenciesTest
+    {
+        [Test]
+        public void AssertCorrectPassDependencies()
+        {
+            var resolver = new PluginResolver(new[] { typeof(Plugin1) });
+
+            var phase = resolver.Passes.First(p => p.Item1 == BuildPhase.Generating).Item2;
+            var pass1 = phase.First(pass => pass.InstantiatedPass is Pass1);
+
+            Assert.That(pass1.ActivatePlugins, Is.EquivalentTo(new[] { typeof(Ctx2), typeof(Ctx3), typeof(Ctx1) }));
+            Assert.That(pass1.DeactivatePlugins, Is.Empty);
+
+            var pass2 = phase.First(pass => pass.InstantiatedPass.DisplayName == "test test");
+            Assert.That(pass2.ActivatePlugins.IsEmpty);
+            Assert.That(pass2.DeactivatePlugins.IsEmpty);
+        }
+    }
+}