Introduce SubpackagesIndexService

In memory cache which provides faster response to getSubpackages() queries

core/descriptors/src/org/jetbrains/jet/lang/resolve/name/FqNamesUtil.kt

@@ -56,18 +56,6 @@ public fun FqName.tail(headFQN: FqName): FqName {
     }
 }
 
-/**
- * Add one segment of nesting to given qualified name according to the full qualified name.
- *
- * @param fullFQN
- * @return qualified name with one more segment or null if fqn is not head part of fullFQN or there's no additional segment.
- */
-public fun FqName.plusOneSegment(fullFQN: FqName): FqName? {
-    if (!isParent(fullFQN) || fullFQN == this) return null
-
-    return child(fullFQN.tail(this).pathSegments().first!!)
-}
-
 public fun FqName.isImported(importPath: ImportPath, skipAliasedImports: Boolean = true): Boolean {
     return when {
         skipAliasedImports && importPath.hasAlias() -> false

idea/idea-analysis/src/org/jetbrains/jet/plugin/stubindex/PackageIndexUtil.java

@@ -16,7 +16,6 @@
 
 package org.jetbrains.jet.plugin.stubindex;
 
-import com.google.common.collect.Sets;
 import com.intellij.openapi.project.Project;
 import com.intellij.openapi.util.Ref;
 import com.intellij.psi.search.GlobalSearchScope;
@@ -25,10 +24,8 @@ import com.intellij.util.Processor;
 import org.jetbrains.annotations.NotNull;
 import org.jetbrains.jet.lang.psi.JetFile;
 import org.jetbrains.jet.lang.resolve.name.FqName;
-import org.jetbrains.jet.lang.resolve.name.NamePackage;
 
 import java.util.Collection;
-import java.util.Set;
 
 public final class PackageIndexUtil {
     @NotNull
@@ -37,23 +34,7 @@ public final class PackageIndexUtil {
             @NotNull GlobalSearchScope scope,
             @NotNull Project project
     ) {
-        Collection<JetFile> files = JetAllPackagesIndex.getInstance().get(packageFqName.asString(), project, scope);
-
-        Set<FqName> result = Sets.newHashSet();
-        for (JetFile file : files) {
-            FqName fqName = file.getPackageFqName();
-
-            assert NamePackage.isSubpackageOf(fqName, packageFqName) :
-                    "Registered package is not a subpackage of actually declared package:\n" +
-                    "in index: " + packageFqName + "\n" +
-                    "declared: " + fqName;
-            FqName subpackage = NamePackage.plusOneSegment(packageFqName, fqName);
-            if (subpackage != null) {
-                result.add(subpackage);
-            }
-        }
-
-        return result;
+        return SubpackagesIndexService.OBJECT$.getInstance(project).getSubpackages(packageFqName, scope);
     }
 
     @NotNull

idea/idea-analysis/src/org/jetbrains/jet/plugin/stubindex/SubpackagesIndexService.kt

@@ -0,0 +1,81 @@
+/*
+ * Copyright 2010-2014 JetBrains s.r.o.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.jetbrains.jet.plugin.stubindex
+
+import com.intellij.openapi.project.Project
+import org.jetbrains.jet.lang.resolve.name.FqName
+import com.intellij.psi.search.GlobalSearchScope
+import java.util.HashSet
+import com.intellij.psi.util.CachedValuesManager
+import com.intellij.psi.util.CachedValueProvider
+import com.intellij.psi.util.PsiModificationTracker
+import com.intellij.util.containers.MultiMap
+import org.jetbrains.jet.lang.resolve.name.Name
+import com.intellij.openapi.components.ServiceManager
+
+public class SubpackagesIndexService(private val project: Project) {
+
+    private val cachedValue = CachedValuesManager.getManager(project).createCachedValue(
+            {
+                CachedValueProvider.Result(
+                        SubpackagesIndex(JetExactPackagesIndex.getInstance().getAllKeys(project)),
+                        PsiModificationTracker.OUT_OF_CODE_BLOCK_MODIFICATION_COUNT)
+            },
+            false
+    )
+
+    public inner class SubpackagesIndex(allPackageFqNames: Collection<String>) {
+        // a map from any existing package (in kotlin) to a set of subpackages (not necessarily direct) containing files
+        private val fqNameByPrefix = MultiMap.createSet<FqName, FqName>();
+
+        {
+            for (fqNameAsString in allPackageFqNames) {
+                val fqName = FqName(fqNameAsString)
+                var prefix = fqName
+                while (!prefix.isRoot()) {
+                    prefix = prefix.parent()
+                    fqNameByPrefix.putValue(prefix, fqName)
+                }
+            }
+        }
+
+        public fun getSubpackages(fqName: FqName, scope: GlobalSearchScope): Collection<FqName> {
+            val possibleFilesFqNames = fqNameByPrefix[fqName]
+            val existingSubPackagesShortNames = HashSet<Name>()
+            val len = fqName.pathSegments().size
+            for (filesFqName in possibleFilesFqNames) {
+                val candidateSubPackageShortName = filesFqName.pathSegments()[len]
+                if (candidateSubPackageShortName in existingSubPackagesShortNames) {
+                    continue
+                }
+                //TODO: better check
+                val existsInThisScope = !JetExactPackagesIndex.getInstance().get(filesFqName.asString(), project, scope).isEmpty()
+                if (existsInThisScope) {
+                    existingSubPackagesShortNames.add(candidateSubPackageShortName)
+                }
+            }
+
+            return existingSubPackagesShortNames.map { fqName.child(it) }
+        }
+    }
+
+    class object {
+        public fun getInstance(project: Project): SubpackagesIndex {
+            return ServiceManager.getService(project, javaClass<SubpackagesIndexService>())!!.cachedValue.getValue()!!
+        }
+    }
+}

idea/src/META-INF/plugin.xml

@@ -163,6 +163,9 @@
     <projectService serviceInterface="org.jetbrains.jet.lang.resolve.lazy.declarations.DeclarationProviderFactoryService"
                     serviceImplementation="org.jetbrains.jet.plugin.stubindex.resolve.PluginDeclarationProviderFactoryService"/>
 
+    <projectService serviceInterface="org.jetbrains.jet.plugin.stubindex.SubpackagesIndexService"
+                    serviceImplementation="org.jetbrains.jet.plugin.stubindex.SubpackagesIndexService"/>
+
     <errorHandler implementation="org.jetbrains.jet.plugin.reporter.KotlinReportSubmitter"/>
 
     <internalFileTemplate name="Kotlin File"/>