Merge pull request #8607 from Game4all/rulesetstore-ruleset-dir

Load user rulesets from the game data directory

osu.Game/OsuGameBase.cs

@@ -168,7 +168,7 @@ private void load()
 
             var defaultBeatmap = new DummyWorkingBeatmap(Audio, Textures);
 
-            dependencies.Cache(RulesetStore = new RulesetStore(contextFactory));
+            dependencies.Cache(RulesetStore = new RulesetStore(contextFactory, Storage));
             dependencies.Cache(FileStore = new FileStore(contextFactory, Storage));
 
             // ordering is important here to ensure foreign keys rules are not broken in ModelStore.Cleanup()

osu.Game/Rulesets/RulesetStore.cs

@@ -7,6 +7,7 @@
 using System.Linq;
 using System.Reflection;
 using osu.Framework.Logging;
+using osu.Framework.Platform;
 using osu.Game.Database;
 
 namespace osu.Game.Rulesets
@@ -17,16 +18,24 @@ public class RulesetStore : DatabaseBackedStore, IDisposable
 
         private readonly Dictionary<Assembly, Type> loadedAssemblies = new Dictionary<Assembly, Type>();
 
-        public RulesetStore(IDatabaseContextFactory factory)
+        private readonly Storage rulesetStorage;
+
+        public RulesetStore(IDatabaseContextFactory factory, Storage storage = null)
             : base(factory)
         {
+            rulesetStorage = storage?.GetStorageForDirectory("rulesets");
+
             // On android in release configuration assemblies are loaded from the apk directly into memory.
             // We cannot read assemblies from cwd, so should check loaded assemblies instead.
             loadFromAppDomain();
             loadFromDisk();
-            addMissingRulesets();
 
-            AppDomain.CurrentDomain.AssemblyResolve += resolveRulesetAssembly;
+            // the event handler contains code for resolving dependency on the game assembly for rulesets located outside the base game directory.
+            // It needs to be attached to the assembly lookup event before the actual call to loadUserRulesets() else rulesets located out of the base game directory will fail
+            // to load as unable to locate the game core assembly.
+            AppDomain.CurrentDomain.AssemblyResolve += resolveRulesetDependencyAssembly;
+            loadUserRulesets();
+            addMissingRulesets();
         }
 
         /// <summary>
@@ -48,7 +57,21 @@ public RulesetStore(IDatabaseContextFactory factory)
         /// </summary>
         public IEnumerable<RulesetInfo> AvailableRulesets { get; private set; }
 
-        private Assembly resolveRulesetAssembly(object sender, ResolveEventArgs args) => loadedAssemblies.Keys.FirstOrDefault(a => a.FullName == args.Name);
+        private Assembly resolveRulesetDependencyAssembly(object sender, ResolveEventArgs args)
+        {
+            var asm = new AssemblyName(args.Name);
+
+            // the requesting assembly may be located out of the executable's base directory, thus requiring manual resolving of its dependencies.
+            // this attempts resolving the ruleset dependencies on game core and framework assemblies by returning assemblies with the same assembly name
+            // already loaded in the AppDomain.
+            foreach (var curAsm in AppDomain.CurrentDomain.GetAssemblies())
+            {
+                if (asm.Name.Equals(curAsm.GetName().Name, StringComparison.Ordinal))
+                    return curAsm;
+            }
+
+            return loadedAssemblies.Keys.FirstOrDefault(a => a.FullName == asm.FullName);
+        }
 
         private void addMissingRulesets()
         {
@@ -120,6 +143,16 @@ private void loadFromAppDomain()
             }
         }
 
+        private void loadUserRulesets()
+        {
+            if (rulesetStorage == null) return;
+
+            var rulesets = rulesetStorage.GetFiles(".", $"{ruleset_library_prefix}.*.dll");
+
+            foreach (var ruleset in rulesets.Where(f => !f.Contains("Tests")))
+                loadRulesetFromFile(rulesetStorage.GetFullPath(ruleset));
+        }
+
         private void loadFromDisk()
         {
             try
@@ -175,7 +208,7 @@ public void Dispose()
 
         protected virtual void Dispose(bool disposing)
         {
-            AppDomain.CurrentDomain.AssemblyResolve -= resolveRulesetAssembly;
+            AppDomain.CurrentDomain.AssemblyResolve -= resolveRulesetDependencyAssembly;
         }
     }
 }