From 07a29bd9cbaeb48dd191cc3d7b94c7f9bdc30ff4 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Wed, 30 Oct 2013 09:07:05 +0100
Subject: [PATCH] RootIndex: less vfs lookups when searching for non-existing
 packages, don't cache empty results

---
 .../roots/impl/DirectoryIndexImpl.java        |  2 +-
 .../openapi/roots/impl/RootIndex.java         | 54 ++++++++-----------
 2 files changed, 22 insertions(+), 34 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java b/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java
index 0ce56f9172c0..dadbffc9f8f6 100644
--- a/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java
+++ b/platform/lang-impl/src/com/intellij/openapi/roots/impl/DirectoryIndexImpl.java
@@ -466,7 +466,7 @@ public class DirectoryIndexImpl extends DirectoryIndex {
     
     RootIndex rootIndex = getRootIndex();
     if (rootIndex != null) {
-      Collection<VirtualFile> riResult = rootIndex.getDirectoriesByPackageName(packageName, includeLibrarySources).findAll();
+      Collection<VirtualFile> riResult = rootIndex.getDirectoriesByPackageName(packageName, includeLibrarySources);
       Collection<VirtualFile> standard = standardResult.findAll();
       if (!new HashSet<VirtualFile>(riResult).equals(new HashSet<VirtualFile>(standard))) {
         for (VirtualFile file : standard) {
diff --git a/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootIndex.java b/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootIndex.java
index ceed40285cbe..4136f48ed03a 100644
--- a/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootIndex.java
+++ b/platform/lang-impl/src/com/intellij/openapi/roots/impl/RootIndex.java
@@ -29,8 +29,6 @@ import com.intellij.openapi.util.text.StringUtil;
 import com.intellij.openapi.vfs.VfsUtilCore;
 import com.intellij.openapi.vfs.VirtualFile;
 import com.intellij.openapi.vfs.newvfs.events.VFileEvent;
-import com.intellij.util.CollectionQuery;
-import com.intellij.util.Query;
 import com.intellij.util.containers.ContainerUtil;
 import com.intellij.util.containers.MultiMap;
 import gnu.trove.TObjectIntHashMap;
@@ -347,54 +345,44 @@ class RootIndex {
   }
 
   @NotNull
-  public Query<VirtualFile> getDirectoriesByPackageName(@NotNull final String packageName, final boolean includeLibrarySources) {
+  List<VirtualFile> getDirectoriesByPackageName(@NotNull final String packageName, final boolean includeLibrarySources) {
     Map<String, List<VirtualFile>> cacheMap = includeLibrarySources ? 
                                               myDirectoriesByPackageNameCacheWithLibSrc : 
                                               myDirectoriesByPackageNameCache;
     final List<VirtualFile> cachedResult = cacheMap.get(packageName);
     if (cachedResult != null) {
-      return new CollectionQuery<VirtualFile>(cachedResult);
+      return cachedResult;
     }
 
     final ArrayList<VirtualFile> result = ContainerUtil.newArrayList();
-    for (Map.Entry<String, HashSet<VirtualFile>> entry : myPackagePrefixRoots.entrySet()) {
-      if (!packageName.startsWith(entry.getKey())) {
-        continue;
-      }
-
-      if (packageName.equals(entry.getKey())) {
-        for (VirtualFile file : entry.getValue()) {
-          if (isValidPackageDirectory(includeLibrarySources, file)) {
-            result.add(file);
-          }
-        }
-        continue;
-      }
-
-      final String nestedPackageName = entry.getKey().isEmpty() ? packageName : packageName.substring( entry.getKey().length());
-      final List<String> nestedPackages = StringUtil.split(nestedPackageName, ".");
-
-      for (final VirtualFile root : entry.getValue()) {
-        VirtualFile file = root;
-        for (String name : nestedPackages) {
-          file = file.findChild(name);
-          if (file == null) {
-            break;
-          }
-        }
-
+    Set<VirtualFile> packagePrefixRoots = myPackagePrefixRoots.get(packageName);
+    if (packagePrefixRoots != null) {
+      for (VirtualFile file : packagePrefixRoots) {
         if (isValidPackageDirectory(includeLibrarySources, file)) {
           result.add(file);
         }
       }
     }
 
-    cacheMap.put(packageName, result);
-    return new CollectionQuery<VirtualFile>(result);
+    if (StringUtil.isNotEmpty(packageName)) {
+      String parentPackage = StringUtil.getPackageName(packageName);
+      String shortName = StringUtil.getShortName(packageName);
+      for (VirtualFile parentDir : getDirectoriesByPackageName(parentPackage, includeLibrarySources)) {
+        VirtualFile child = parentDir.findChild(shortName);
+        if (isValidPackageDirectory(includeLibrarySources, child)) {
+          result.add(child);
+        }
+      }
+    }
+
+    if (!result.isEmpty()) {
+      cacheMap.put(packageName, result);
+    }
+    return result;
   }
 
   private boolean isValidPackageDirectory(boolean includeLibrarySources, @Nullable VirtualFile file) {
-    if (file != null) {
+    if (file != null && file.isDirectory()) {
       DirectoryInfo info = getInfoForDirectory(file);
       if (info != null) {
         if (includeLibrarySources || !info.isInLibrarySource() || info.isInModuleSource() || info.hasLibraryClassRoot()) {