Cache null package results in findPackages

Fixed #KT-33394

compiler/frontend.java/src/org/jetbrains/kotlin/resolve/jvm/KotlinJavaPsiFacade.java

@@ -59,6 +59,21 @@ import java.util.concurrent.ConcurrentMap;
 public class KotlinJavaPsiFacade {
     private volatile KotlinPsiElementFinderWrapper[] elementFinders;
 
+    private static final PsiPackage NULL_PSI_PACKAGE = new PsiPackageImpl(null, null) {
+        @Override
+        public String toString() {
+            return "NULL_PSI_PACKAGE";
+        }
+    };
+
+    private static PsiPackage wrap(PsiPackage aPackage) {
+        return aPackage == null ? NULL_PSI_PACKAGE : aPackage;
+    }
+
+    private static PsiPackage unwrap(PsiPackage aPackage) {
+        return aPackage == null || aPackage == NULL_PSI_PACKAGE ? null : aPackage;
+    }
+
     private static class PackageCache {
         final ConcurrentMap<Pair<String, GlobalSearchScope>, PsiPackage> packageInScopeCache = ContainerUtil.newConcurrentMap();
         final ConcurrentMap<String, Boolean> hasPackageInAllScopeCache = ContainerUtil.newConcurrentMap();
@@ -90,7 +105,7 @@ public class KotlinJavaPsiFacade {
                 if (lastTimeSeen != now) {
                     lastTimeSeen = now;
 
-                    packageCache = null;
+                    //packageCache = null;
                 }
             }
         });
@@ -105,7 +120,7 @@ public class KotlinJavaPsiFacade {
     }
 
     public JavaClass findClass(@NotNull JavaClassFinder.Request request, @NotNull GlobalSearchScope scope) {
-        ProgressIndicatorAndCompilationCanceledStatus.checkCanceled(); // We hope this method is being called often enough to cancel daemon processes smoothly
+        ProgressIndicatorAndCompilationCanceledStatus.checkCanceled();
 
         ClassId classId = request.getClassId();
         String qualifiedName = classId.asSingleFqName().asString();
@@ -215,7 +230,7 @@ public class KotlinJavaPsiFacade {
 
         elementFinders.addAll(CollectionsKt.map(nonKotlinFinders, KotlinJavaPsiFacade::wrap));
 
-        return elementFinders.toArray(new KotlinPsiElementFinderWrapper[elementFinders.size()]);
+        return elementFinders.toArray(new KotlinPsiElementFinderWrapper[0]);
     }
 
     @NotNull
@@ -238,7 +253,7 @@ public class KotlinJavaPsiFacade {
         Pair<String, GlobalSearchScope> key = new Pair<>(qualifiedName, searchScope);
         PsiPackage aPackage = cache.packageInScopeCache.get(key);
         if (aPackage != null) {
-            return aPackage;
+            return unwrap(aPackage);
         }
 
         KotlinPsiElementFinderWrapper[] finders = filteredFinders();
@@ -250,20 +265,25 @@ public class KotlinJavaPsiFacade {
             // Package was found in AllScope with some of finders but is absent in packageCache for current scope.
             // We check only finders that depend on scope.
             for (KotlinPsiElementFinderWrapper finder : finders) {
+                //ProgressIndicatorAndCompilationCanceledStatus.checkCanceled();
                 if (!finder.isSameResultForAnyScope()) {
                     aPackage = finder.findPackage(qualifiedName, searchScope);
+                    PsiPackage wrapper = ConcurrencyUtil.cacheOrGet(cache.packageInScopeCache, key, wrap(aPackage));
                     if (aPackage != null) {
-                        return ConcurrencyUtil.cacheOrGet(cache.packageInScopeCache, key, aPackage);
+                        return unwrap(wrapper);
                     }
+                } else {
+                    cache.packageInScopeCache.putIfAbsent(key, NULL_PSI_PACKAGE);
                 }
             }
         }
         else {
             for (KotlinPsiElementFinderWrapper finder : finders) {
+                //ProgressIndicatorAndCompilationCanceledStatus.checkCanceled();
                 aPackage = finder.findPackage(qualifiedName, searchScope);
-
+                PsiPackage wrapper = ConcurrencyUtil.cacheOrGet(cache.packageInScopeCache, key, wrap(aPackage));
                 if (aPackage != null) {
-                    return ConcurrencyUtil.cacheOrGet(cache.packageInScopeCache, key, aPackage);
+                    return unwrap(wrapper);
                 }
             }
 
@@ -290,7 +310,7 @@ public class KotlinJavaPsiFacade {
         KotlinPsiElementFinderWrapper[] finders = finders();
         if (dumbService.isDumb()) {
             List<KotlinPsiElementFinderWrapper> list = dumbService.filterByDumbAwareness(Arrays.asList(finders));
-            finders = list.toArray(new KotlinPsiElementFinderWrapper[list.size()]);
+            finders = list.toArray(new KotlinPsiElementFinderWrapper[0]);
         }
         return finders;
     }

idea/idea-analysis/src/org/jetbrains/kotlin/idea/caches/project/IdeaModuleInfos.kt

@@ -261,6 +261,8 @@ private class ModuleProductionSourceScope(module: Module) : ModuleSourceScope(mo
     // KT-6206
     override fun hashCode(): Int = 31 * module.hashCode()
 
+    override fun calcHashCode(): Int = 31 * module.hashCode()
+
     override fun contains(file: VirtualFile) =
         moduleFileIndex.isInSourceContentWithoutInjected(file) && !moduleFileIndex.isInTestSourceContentKotlinAware(file)