From e4c2ba61543bda2601347fbc1b90e7560f0c2d75 Mon Sep 17 00:00:00 2001
From: Anton Makeev <Anton.Makeev@jetbrains.com>
Date: Fri, 8 Oct 2010 18:14:09 +0400
Subject: [PATCH] correctly adding/removing listeners in documents

---
 .../openapi/editor/impl/DocumentImpl.java     | 45 +++++++++----------
 1 file changed, 20 insertions(+), 25 deletions(-)

diff --git a/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java b/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
index 5c5c5ffbbe09..b1e5f2cd43c9 100644
--- a/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
+++ b/platform/platform-impl/src/com/intellij/openapi/editor/impl/DocumentImpl.java
@@ -77,6 +77,7 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
   private final PropertyChangeSupport myPropertyChangeSupport = new PropertyChangeSupport(this);
 
   private volatile MarkupModelEx myMarkupModel;
+  private DocumentListener[] myCachedDocumentListeners;
   private final List<EditReadOnlyListener> myReadOnlyListeners = new ArrayList<EditReadOnlyListener>(1);
 
   private int myCheckGuardedBlocks = 0;
@@ -468,12 +469,11 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
       return null; // suppress events in shutdown hook
     }
     DocumentEvent event = new DocumentEventImpl(this, offset, oldString, newString, myModificationStamp, wholeTextReplaced);
-    //System.out.printf("%nbefore change: offset=%d, old text='%s', new text='%s', document modification stamp=%d%nDocument:'%s'%n",
-    //                  event.getOffset(), event.getOldFragment(), event.getNewFragment(), event.getDocument().getModificationStamp(),
-    //                  event.getDocument().getText());
-    for (int i = myDocumentListeners.size() - 1; i >= 0; i--) {
+
+    DocumentListener[] listeners = getCachedListeners();
+    for (int i = listeners.length - 1; i >= 0; i--) {
       try {
-        myDocumentListeners.get(i).beforeDocumentChange(event);
+        listeners[i].beforeDocumentChange(event);
       }
       catch (Throwable e) {
         LOG.error(e);
@@ -484,10 +484,7 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
     return event;
   }
 
-  @SuppressWarnings({"ForLoopReplaceableByForEach"})
   private void changedUpdate(DocumentEvent event, long newModificationStamp) {
-    //System.out.printf("after change: new modification stamp=%d%ndocument='%s'%n", event.getDocument().getModificationStamp(),
-    //                  event.getDocument().getText());
     if (ShutDownTracker.isShutdownHookRunning()) {
       return; // suppress events in shutdown hook
     }
@@ -497,10 +494,10 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
       myLineSet.changedUpdate(event);
       setModificationStamp(newModificationStamp);
 
-      // Don't use for-each in order to avoid unnecessary iterator construction during frequent document updates.
-      for (int i = 0; i < myDocumentListeners.size(); i++) {
+      DocumentListener[] listeners = getCachedListeners();
+      for (DocumentListener listener : listeners) {
         try {
-          myDocumentListeners.get(i).documentChanged(event);
+          listener.documentChanged(event);
         }
         catch (Throwable e) {
           LOG.error(e);
@@ -557,21 +554,9 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
 
 
   public void addDocumentListener(@NotNull DocumentListener listener) {
+    myCachedDocumentListeners = null;
     LOG.assertTrue(!myDocumentListeners.contains(listener), listener);
-    if (!(listener instanceof PrioritizedDocumentListener)) {
-      myDocumentListeners.add(listener);
-      return;
-    }
-    int i = Collections.binarySearch(myDocumentListeners, listener, PrioritizedDocumentListener.COMPARATOR);
-    if (i < 0) {
-      i = -i - 1;
-    }
-    if (i >= myDocumentListeners.size()) {
-      myDocumentListeners.add(listener);
-    }
-    else {
-      myDocumentListeners.add(i, listener);
-    }
+    myDocumentListeners.add(listener);
   }
 
   public void addDocumentListener(@NotNull final DocumentListener listener, @NotNull Disposable parentDisposable) {
@@ -584,6 +569,7 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
   }
 
   public void removeDocumentListener(@NotNull DocumentListener listener) {
+    myCachedDocumentListeners = null;
     boolean success = myDocumentListeners.remove(listener);
     LOG.assertTrue(success);
   }
@@ -631,6 +617,15 @@ public class DocumentImpl extends UserDataHolderBase implements DocumentEx {
     return lineCount;
   }
 
+  private DocumentListener[] getCachedListeners() {
+    if (myCachedDocumentListeners == null) {
+      Collections.sort(myDocumentListeners, PrioritizedDocumentListener.COMPARATOR);
+      myCachedDocumentListeners = myDocumentListeners.toArray(new DocumentListener[myDocumentListeners.size()]);
+    }
+
+    return myCachedDocumentListeners;
+  }
+
   public void fireReadOnlyModificationAttempt() {
     ApplicationManagerEx.getApplicationEx().assertReadAccessToDocumentsAllowed();
     EditReadOnlyListener[] listeners = myReadOnlyListeners.toArray(