IDEA-134002 IDE very slow after file movements

platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VfsData.java

@@ -20,7 +20,6 @@ import com.intellij.openapi.application.ApplicationManager;
 import com.intellij.openapi.vfs.InvalidVirtualFileAccessException;
 import com.intellij.openapi.vfs.newvfs.persistent.FSRecords;
 import com.intellij.util.ArrayUtil;
-import com.intellij.util.SmartFMap;
 import com.intellij.util.concurrency.AtomicFieldUpdater;
 import com.intellij.util.containers.ConcurrentBitSet;
 import com.intellij.util.containers.ConcurrentIntObjectMap;
@@ -82,7 +81,7 @@ public class VfsData {
   private static final ConcurrentIntObjectMap<Segment> ourSegments = ContainerUtil.createConcurrentIntObjectMap();
   private static final ConcurrentBitSet ourInvalidatedIds = new ConcurrentBitSet();
   private static TIntHashSet ourDyingIds = new TIntHashSet();
-  private static volatile SmartFMap<VirtualFileSystemEntry, VirtualDirectoryImpl> ourChangedParents = SmartFMap.emptyMap();
+  private static final ConcurrentIntObjectMap<VirtualDirectoryImpl> ourChangedParents = ContainerUtil.createConcurrentIntObjectMap();
 
   static {
     ApplicationManager.getApplication().addApplicationListener(new ApplicationAdapter() {
@@ -102,7 +101,7 @@ public class VfsData {
       if (!ourDyingIds.isEmpty()) {
         for (int id : ourDyingIds.toArray()) {
           assertNotNull(getSegment(id, false)).myObjectArray.set(getOffset(id), ourDeadMarker);
-          ourChangedParents = ourChangedParents.minus(new VirtualFileImpl(id, null, null));
+          ourChangedParents.remove(id);
         }
         ourDyingIds = new TIntHashSet();
       }
@@ -165,15 +164,12 @@ public class VfsData {
   }
 
   @Nullable
-  static VirtualDirectoryImpl getChangedParent(VirtualFileSystemEntry child) {
-    SmartFMap<VirtualFileSystemEntry, VirtualDirectoryImpl> map = ourChangedParents;
-    return map == (SmartFMap)SmartFMap.emptyMap() ? null : map.get(child);
+  static VirtualDirectoryImpl getChangedParent(int id) {
+    return ourChangedParents.get(id);
   }
 
-  static void changeParent(VirtualFileSystemEntry child, VirtualDirectoryImpl parent) {
-    synchronized (ourDeadMarker) {
-      ourChangedParents = ourChangedParents.plus(child, parent);
-    }
+  static void changeParent(int id, VirtualDirectoryImpl parent) {
+    ourChangedParents.put(id, parent);
   }
 
   static void invalidateFile(int id) {

platform/platform-impl/src/com/intellij/openapi/vfs/newvfs/impl/VirtualFileSystemEntry.java

@@ -102,7 +102,7 @@ public abstract class VirtualFileSystemEntry extends NewVirtualFile {
 
   @Override
   public VirtualDirectoryImpl getParent() {
-    VirtualDirectoryImpl changedParent = VfsData.getChangedParent(this);
+    VirtualDirectoryImpl changedParent = VfsData.getChangedParent(myId);
     return changedParent != null ? changedParent : myParent;
   }
 
@@ -329,7 +329,7 @@ public abstract class VirtualFileSystemEntry extends NewVirtualFile {
     parent.removeChild(this);
 
     VirtualDirectoryImpl directory = (VirtualDirectoryImpl)newParent;
-    VfsData.changeParent(this, directory);
+    VfsData.changeParent(myId, directory);
     directory.addChild(this);
     updateLinkStatus();
   }

platform/platform-tests/testSrc/com/intellij/openapi/vfs/VfsUtilTest.java

@@ -417,6 +417,52 @@ public class VfsUtilTest extends PlatformLangTestCase {
 
   }
 
+  public void testGetParentPerformance() throws IOException {
+    File tempDir = createTempDirectory();
+    final VirtualFile vDir = refreshAndFindFile(tempDir);
+    assertNotNull(vDir);
+    assertTrue(vDir.isDirectory());
+    final int depth = 10;
+    new WriteCommandAction.Simple(getProject()) {
+      @Override
+      protected void run() throws Throwable {
+        VirtualFile dir = vDir;
+        for (int i=0; i<depth; i++) {
+          dir = dir.createChildDirectory(this, "foo");
+        }
+        final VirtualFile leafDir = dir;
+        ThrowableRunnable checkPerformance = new ThrowableRunnable() {
+          private VirtualFile findRoot(VirtualFile file) {
+            while (true) {
+              VirtualFile parent = file.getParent();
+              if (parent == null) {
+                return file;
+              }
+              file = parent;
+            }
+          }
+          @Override
+          public void run() throws Throwable {
+            for (int i = 0; i < 5000000; i++) {
+              checkRootsEqual();
+            }
+          }
+          private void checkRootsEqual() {
+            assertEquals(findRoot(vDir), findRoot(leafDir));
+          }
+        };
+        int time = 1200;
+        PlatformTestUtil.startPerformanceTest("getParent is slow before movement", time, checkPerformance).assertTiming();
+        VirtualFile dir1 = vDir.createChildDirectory(this, "dir1");
+        VirtualFile dir2 = vDir.createChildDirectory(this, "dir2");
+        for (int i = 0; i < 13; i++) {  /*13 is max length with THashMap capacity of 17, we get plenty collisions then*/
+          dir1.createChildData(this, "a" + i + ".txt").move(this, dir2);
+        }
+        PlatformTestUtil.startPerformanceTest("getParent is slow after movement", time, checkPerformance).assertTiming();
+      }
+    }.execute();
+  }
+
   public void testFindRootWithDenormalizedPath() throws IOException {
     File tempJar = IoTestUtil.createTestJar();
     VirtualFile jar = refreshAndFindFile(tempJar);