use singleton instead of new

java/compiler/impl/src/com/intellij/compiler/impl/TranslatingCompilerFilesMonitor.java

@@ -584,7 +584,7 @@ public class TranslatingCompilerFilesMonitor implements ApplicationComponent {
   }
 
   private void initOutputRootsFile(File rootsFile) throws IOException {
-    myOutputRootsStorage = new PersistentHashMap<Integer, TIntObjectHashMap<Pair<Integer, Integer>>>(rootsFile, new EnumeratorIntegerDescriptor(), new DataExternalizer<TIntObjectHashMap<Pair<Integer, Integer>>>() {
+    myOutputRootsStorage = new PersistentHashMap<Integer, TIntObjectHashMap<Pair<Integer, Integer>>>(rootsFile, EnumeratorIntegerDescriptor.INSTANCE, new DataExternalizer<TIntObjectHashMap<Pair<Integer, Integer>>>() {
       public void save(DataOutput out, TIntObjectHashMap<Pair<Integer, Integer>> value) throws IOException {
         for (final TIntObjectIterator<Pair<Integer, Integer>> it = value.iterator(); it.hasNext();) {
           it.advance();

java/compiler/impl/src/com/intellij/compiler/make/BackwardDependenciesStorage.java

@@ -42,7 +42,7 @@ public class BackwardDependenciesStorage implements Flushable, Disposable {
   private static final int CLASS = 3;
 
   public BackwardDependenciesStorage(File file, final int cacheSize) throws IOException {
-    myMap = new PersistentHashMap<Integer, DependenciesSet>(file, new EnumeratorIntegerDescriptor(), new MyDataExternalizer());
+    myMap = new PersistentHashMap<Integer, DependenciesSet>(file, EnumeratorIntegerDescriptor.INSTANCE, new MyDataExternalizer());
 
     myCache = new SLRUCache<Integer, ReferencerSetHolder>(cacheSize * 2, cacheSize) {
       @NotNull

platform/lang-api/src/com/intellij/psi/stubs/IntStubIndexExtension.java

@@ -29,6 +29,6 @@ public abstract class IntStubIndexExtension<Psi extends PsiElement> extends Abst
   }
 
   public KeyDescriptor<Integer> getKeyDescriptor() {
-    return new EnumeratorIntegerDescriptor();
+    return EnumeratorIntegerDescriptor.INSTANCE;
   }
 }

platform/lang-impl/src/com/intellij/find/ngrams/TrigramIndex.java

@@ -76,7 +76,7 @@ public class TrigramIndex extends ScalarIndexExtension<Integer> {
 
   @Override
   public KeyDescriptor<Integer> getKeyDescriptor() {
-    return new EnumeratorIntegerDescriptor();
+    return EnumeratorIntegerDescriptor.INSTANCE;
   }
 
   @Override

platform/lang-impl/src/com/intellij/util/indexing/FileBasedIndex.java

@@ -532,7 +532,7 @@ public class FileBasedIndex implements ApplicationComponent {
     // cleared properly before updating (removed data will still be present on disk). See IDEA-52223 for illustration of possible effects.
 
     final PersistentHashMap<Integer, Collection<K>> map = new PersistentHashMap<Integer, Collection<K>>(
-      indexStorageFile, new EnumeratorIntegerDescriptor(), dataExternalizer
+      indexStorageFile, EnumeratorIntegerDescriptor.INSTANCE, dataExternalizer
     ) {
 
       @Override

plugins/ant/src/com/intellij/lang/ant/psi/impl/AntImportsIndex.java

@@ -96,7 +96,7 @@ public class AntImportsIndex extends ScalarIndexExtension<Integer>{
   }
 
   public KeyDescriptor<Integer> getKeyDescriptor() {
-    return new EnumeratorIntegerDescriptor();
+    return EnumeratorIntegerDescriptor.INSTANCE;
   }
 
   public FileBasedIndex.InputFilter getInputFilter() {