From 7c8937bd2dd9fa5037333ea05375df614e7db002 Mon Sep 17 00:00:00 2001
From: Stepan Koltsov <stepan.koltsov@jetbrains.com>
Date: Sat, 21 Apr 2012 18:03:53 +0400
Subject: [PATCH] JavaDescriptorResolver: negative package cache

Time spent in JavaDescriptorResolver.resolveNamespace reduced from 10% to 5%
in CompileCompilerDependenciesTest
---
 .../resolve/java/JavaDescriptorResolver.java  | 42 +++++++++++++++++--
 1 file changed, 39 insertions(+), 3 deletions(-)

diff --git a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
index 9f8015a8b06..248fca7c8a7 100644
--- a/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
+++ b/compiler/frontend.java/src/org/jetbrains/jet/lang/resolve/java/JavaDescriptorResolver.java
@@ -209,11 +209,9 @@ public class JavaDescriptorResolver {
         final PsiClass psiClass;
         @Nullable
         final PsiPackage psiPackage;
-        @NotNull
         final FqName fqName;
         final boolean staticMembers;
         final boolean kotlin;
-        @NotNull
         final ClassOrNamespaceDescriptor classOrNamespaceDescriptor;
 
         protected ResolverScopeData(@Nullable PsiClass psiClass, @Nullable PsiPackage psiPackage, @NotNull FqName fqName, boolean staticMembers, @NotNull ClassOrNamespaceDescriptor descriptor) {
@@ -237,6 +235,22 @@ public class JavaDescriptorResolver {
             classOrNamespaceDescriptor = descriptor;
         }
 
+        protected ResolverScopeData(boolean negative) {
+            if (!negative) {
+                throw new IllegalStateException();
+            }
+            this.psiClass = null;
+            this.psiPackage = null;
+            this.fqName = null;
+            this.staticMembers = false;
+            this.kotlin = false;
+            this.classOrNamespaceDescriptor = null;
+        }
+
+        public boolean isPositive() {
+            return this.classOrNamespaceDescriptor != null;
+        }
+
         @NotNull
         public PsiElement getPsiPackageOrPsiClass() {
             if (psiPackage != null) {
@@ -262,6 +276,13 @@ public class JavaDescriptorResolver {
             this.classDescriptor = classDescriptor;
         }
 
+        private ResolverBinaryClassData(boolean negative) {
+            super(negative);
+            this.classDescriptor = null;
+        }
+
+        static final ResolverBinaryClassData NEGATIVE = new ResolverBinaryClassData(true);
+
         List<TypeParameterDescriptorInitialization> typeParameters;
 
         @NotNull
@@ -286,6 +307,13 @@ public class JavaDescriptorResolver {
             this.namespaceDescriptor = namespaceDescriptor;
         }
 
+        private ResolverNamespaceData(boolean negative) {
+            super(negative);
+            this.namespaceDescriptor = null;
+        }
+
+        static final ResolverNamespaceData NEGATIVE = new ResolverNamespaceData(true);
+
         private JavaPackageScope memberScope;
 
         @NotNull
@@ -374,11 +402,15 @@ public class JavaDescriptorResolver {
         if (classData == null) {
             PsiClass psiClass = psiClassFinder.findPsiClass(qualifiedName, PsiClassFinder.RuntimeClassesHandleMode.THROW);
             if (psiClass == null) {
+                ResolverBinaryClassData oldValue = classDescriptorCache.put(qualifiedName, ResolverBinaryClassData.NEGATIVE);
+                if (oldValue != null) {
+                    throw new IllegalStateException("rewrite at " + qualifiedName);
+                }
                 return null;
             }
             classData = createJavaClassDescriptor(psiClass, tasks);
         }
-        return classData.getClassDescriptor();
+        return classData.classDescriptor;
     }
 
     private ResolverBinaryClassData createJavaClassDescriptor(@NotNull final PsiClass psiClass, List<Runnable> taskList) {
@@ -974,6 +1006,10 @@ public class JavaDescriptorResolver {
                 break lookingForPsi;
             }
 
+            ResolverNamespaceData oldValue = namespaceDescriptorCacheByFqn.put(fqName, ResolverNamespaceData.NEGATIVE);
+            if (oldValue != null) {
+                throw new IllegalStateException("rewrite at " + fqName);
+            }
             return null;
         }