From dba7e9a86aa4c75daebcb598fab5d18322968d66 Mon Sep 17 00:00:00 2001
From: peter <peter@jetbrains.com>
Date: Wed, 5 Feb 2014 13:52:55 +0100
Subject: [PATCH] lock-free FileBasedIndexImpl.myTransactionMap

---
 .../util/indexing/FileBasedIndexImpl.java     | 24 ++++++-------------
 .../util/src/com/intellij/util/SmartFMap.java |  6 +++++
 2 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java b/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java
index 466ce00f0a7c..290179f90bc7 100644
--- a/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java
+++ b/platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndexImpl.java
@@ -127,7 +127,7 @@ public class FileBasedIndexImpl extends FileBasedIndex {
   private final FileDocumentManager myFileDocumentManager;
   private final FileTypeManager myFileTypeManager;
   private final ConcurrentHashSet<ID<?, ?>> myUpToDateIndices = new ConcurrentHashSet<ID<?, ?>>();
-  private final Map<Document, PsiFile> myTransactionMap = new THashMap<Document, PsiFile>();
+  private volatile SmartFMap<Document, PsiFile> myTransactionMap = SmartFMap.emptyMap();
 
   @Nullable private final String myConfigPath;
   @Nullable private final String myLogPath;
@@ -157,18 +157,14 @@ public class FileBasedIndexImpl extends FileBasedIndex {
       @Override
       public void transactionStarted(final Document doc, final PsiFile file) {
         if (file != null) {
-          synchronized (myTransactionMap) {
-            myTransactionMap.put(doc, file);
-          }
+          myTransactionMap = myTransactionMap.plus(doc, file);
           myUpToDateIndices.clear();
         }
       }
 
       @Override
       public void transactionCompleted(final Document doc, final PsiFile file) {
-        synchronized (myTransactionMap) {
-          myTransactionMap.remove(doc);
-        }
+        myTransactionMap = myTransactionMap.minus(doc);
       }
     });
 
@@ -1403,9 +1399,7 @@ public class FileBasedIndexImpl extends FileBasedIndex {
 
   @NotNull
   private Set<Document> getTransactedDocuments() {
-    synchronized (myTransactionMap) {
-      return new THashSet<Document>(myTransactionMap.keySet());
-    }
+    return myTransactionMap.keySet();
   }
 
   private void indexUnsavedDocuments(@NotNull ID<?, ?> indexId,
@@ -1461,9 +1455,7 @@ public class FileBasedIndexImpl extends FileBasedIndex {
   }
 
   private boolean hasActiveTransactions() {
-    synchronized (myTransactionMap) {
-      return !myTransactionMap.isEmpty();
-    }
+    return !myTransactionMap.isEmpty();
   }
 
   private interface DocumentContent {
@@ -1588,10 +1580,8 @@ public class FileBasedIndexImpl extends FileBasedIndex {
 
   @Nullable
   private PsiFile findDominantPsiForDocument(@NotNull Document document, @Nullable Project project) {
-    synchronized (myTransactionMap) {
-      PsiFile psiFile = myTransactionMap.get(document);
-      if (psiFile != null) return psiFile;
-    }
+    PsiFile psiFile = myTransactionMap.get(document);
+    if (psiFile != null) return psiFile;
 
     return project == null ? null : findLatestKnownPsiForUncomittedDocument(document, project);
   }
diff --git a/platform/util/src/com/intellij/util/SmartFMap.java b/platform/util/src/com/intellij/util/SmartFMap.java
index f34144223541..a4b95a189bb5 100644
--- a/platform/util/src/com/intellij/util/SmartFMap.java
+++ b/platform/util/src/com/intellij/util/SmartFMap.java
@@ -203,6 +203,8 @@ public class SmartFMap<K,V> implements Map<K,V> {
   @NotNull
   @Override
   public Set<K> keySet() {
+    if (isEmpty()) return Collections.emptySet();
+    
     LinkedHashSet<K> result = new LinkedHashSet<K>();
     for (Entry<K, V> entry : entrySet()) {
       result.add(entry.getKey());
@@ -213,6 +215,8 @@ public class SmartFMap<K,V> implements Map<K,V> {
   @NotNull
   @Override
   public Collection<V> values() {
+    if (isEmpty()) return Collections.emptyList();
+    
     ArrayList<V> result = new ArrayList<V>();
     for (Entry<K, V> entry : entrySet()) {
       result.add(entry.getValue());
@@ -242,6 +246,8 @@ public class SmartFMap<K,V> implements Map<K,V> {
   @NotNull
   @Override
   public Set<Entry<K, V>> entrySet() {
+    if (isEmpty()) return Collections.emptySet();
+    
     LinkedHashSet<Entry<K, V>> set = new LinkedHashSet<Entry<K, V>>();
     if (myMap instanceof Map) {
       for (Entry<K, V> entry : ((Map<K, V>)myMap).entrySet()) {