### Eclipse Workspace Patch 1.0
#P org.eclipse.compare
Index: compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java,v
retrieving revision 1.7
diff -u -r1.7 CompareContentViewerSwitchingPane.java
--- compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java	22 Mar 2010 13:13:07 -0000	1.7
+++ compare/org/eclipse/compare/internal/CompareContentViewerSwitchingPane.java	27 Mar 2010 09:48:23 -0000
@@ -23,6 +23,8 @@
 import org.eclipse.osgi.util.NLS;
 import org.eclipse.swt.SWT;
 import org.eclipse.swt.custom.CLabel;
+import org.eclipse.swt.events.DisposeEvent;
+import org.eclipse.swt.events.DisposeListener;
 import org.eclipse.swt.events.MenuAdapter;
 import org.eclipse.swt.events.MenuEvent;
 import org.eclipse.swt.events.MouseAdapter;
@@ -46,12 +48,16 @@
 public class CompareContentViewerSwitchingPane extends
 		CompareViewerSwitchingPane {
 
+	private static final String OPTIMIZED_WARNING_IMAGE_NAME = "obj16/warning_st_obj.gif"; //$NON-NLS-1$
+	public static final String OPTIMIZED_ALGORITHM_USED = "OPTIMIZED_ALGORITHM_USED"; //$NON-NLS-1$
+
 	private CompareEditorInput fCompareEditorInput;
 
 	private ViewerDescriptor fSelectedViewerDescriptor;
 
 	private ToolBar toolBar;
-	
+	private CLabel clOptimized;
+
 	private boolean menuShowing;
 
 	public CompareContentViewerSwitchingPane(Splitter parent, int style,
@@ -122,6 +128,23 @@
 				showMenu();
 			}
 		});
+
+		clOptimized = new CLabel(composite, SWT.NONE);
+		clOptimized
+				.setText(CompareMessages.CompareContentViewerSwitchingPane_optimized);
+		clOptimized
+				.setToolTipText(CompareMessages.CompareContentViewerSwitchingPane_optimizedTooltip);
+		clOptimized.setImage(CompareUIPlugin.getImageDescriptor(
+				OPTIMIZED_WARNING_IMAGE_NAME).createImage());
+		clOptimized.addDisposeListener(new DisposeListener() {
+			public void widgetDisposed(DisposeEvent e) {
+				Image img = clOptimized.getImage();
+				if ((img != null) && (!img.isDisposed())) {
+					img.dispose();
+				}
+			}
+		});
+
 		return composite;
 	}
 	
@@ -138,6 +161,9 @@
 				.findContentViewerDescriptor(getViewer(), getInput(),
 						getCompareConfiguration());
 		toolBar.setVisible(vd != null && vd.length > 1);
+		CompareConfiguration cc = getCompareConfiguration();
+		Boolean isOptimized = (Boolean) cc.getProperty(OPTIMIZED_ALGORITHM_USED);
+		clOptimized.setVisible(isOptimized != null && isOptimized.booleanValue());
 	}
 
 	private void showMenu() {
@@ -254,4 +280,9 @@
 			}
 		}
 	}
+
+	public void dispose () {
+		
+	}
+
 }
Index: compare/org/eclipse/compare/internal/CompareMessages.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/CompareMessages.java,v
retrieving revision 1.28
diff -u -r1.28 CompareMessages.java
--- compare/org/eclipse/compare/internal/CompareMessages.java	22 Jun 2009 10:07:23 -0000	1.28
+++ compare/org/eclipse/compare/internal/CompareMessages.java	27 Mar 2010 09:48:23 -0000
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2000, 2009 IBM Corporation and others.
+ * Copyright (c) 2000, 2010 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -121,6 +121,8 @@
 	public static String CompareContentViewerSwitchingPane_defaultViewer;
 	public static String CompareContentViewerSwitchingPane_switchButtonTooltip;
 	public static String CompareContentViewerSwitchingPane_discoveredLabel;
+	public static String CompareContentViewerSwitchingPane_optimized;
+	public static String CompareContentViewerSwitchingPane_optimizedTooltip;
 	public static String CompareStructureViewerSwitchingPane_defaultViewer;
 	public static String CompareStructureViewerSwitchingPane_switchButtonTooltip;
 	public static String CompareStructureViewerSwitchingPane_discoveredLabel;
Index: compare/org/eclipse/compare/internal/CompareMessages.properties
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/CompareMessages.properties,v
retrieving revision 1.39
diff -u -r1.39 CompareMessages.properties
--- compare/org/eclipse/compare/internal/CompareMessages.properties	22 Jun 2009 10:07:23 -0000	1.39
+++ compare/org/eclipse/compare/internal/CompareMessages.properties	27 Mar 2010 09:48:23 -0000
@@ -1,5 +1,5 @@
 ###############################################################################
-# Copyright (c) 2000, 2009 IBM Corporation and others.
+# Copyright (c) 2000, 2010 IBM Corporation and others.
 # All rights reserved. This program and the accompanying materials
 # are made available under the terms of the Eclipse Public License v1.0
 # which accompanies this distribution, and is available at
@@ -134,6 +134,8 @@
 CompareContentViewerSwitchingPane_defaultViewer=Default Compare
 CompareContentViewerSwitchingPane_switchButtonTooltip=Switch Compare Viewer
 CompareContentViewerSwitchingPane_discoveredLabel={0} Compare
+CompareContentViewerSwitchingPane_optimized=Optimized algorithm used
+CompareContentViewerSwitchingPane_optimizedTooltip=To avoid long computation time an optimized comparison algorithm has been used. As a result a non-optimal matching could be found.
 CompareStructureViewerSwitchingPane_defaultViewer=Default Structure Compare
 CompareStructureViewerSwitchingPane_switchButtonTooltip=Switch Structure Compare Viewer
 CompareStructureViewerSwitchingPane_discoveredLabel={0} Structure Compare
Index: compare/org/eclipse/compare/internal/merge/DocumentMerger.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare/compare/org/eclipse/compare/internal/merge/DocumentMerger.java,v
retrieving revision 1.8
diff -u -r1.8 DocumentMerger.java
--- compare/org/eclipse/compare/internal/merge/DocumentMerger.java	20 Jan 2009 10:33:16 -0000	1.8
+++ compare/org/eclipse/compare/internal/merge/DocumentMerger.java	27 Mar 2010 09:48:24 -0000
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2007, 2009 IBM Corporation and others.
+ * Copyright (c) 2007, 2010 IBM Corporation and others.
  * All rights reserved. This program and the accompanying materials
  * are made available under the terms of the Eclipse Public License v1.0
  * which accompanies this distribution, and is available at
@@ -16,6 +16,7 @@
 import org.eclipse.compare.CompareConfiguration;
 import org.eclipse.compare.contentmergeviewer.ITokenComparator;
 import org.eclipse.compare.internal.*;
+import org.eclipse.compare.internal.core.LCS;
 import org.eclipse.compare.rangedifferencer.*;
 import org.eclipse.compare.structuremergeviewer.Differencer;
 import org.eclipse.core.runtime.*;
@@ -447,7 +448,12 @@
 		} catch (InterruptedException ex) {
 			// 
 		}
-		
+
+		if (isCapped(sa, sl, sr))
+			fInput.getCompareConfiguration().setProperty(
+					CompareContentViewerSwitchingPane.OPTIMIZED_ALGORITHM_USED,
+					new Boolean(true));
+
 		ArrayList newAllDiffs = new ArrayList();
 		for (int i= 0; i < e.length; i++) {
 			RangeDifference es= e[i];
@@ -520,6 +526,18 @@
 		fAllDiffs = newAllDiffs;
 	}
 
+	private boolean isCapped(DocLineComparator ancestor,
+			DocLineComparator left, DocLineComparator right) {
+		int aLength = ancestor == null? 0 : ancestor.getRangeCount();
+		int lLength = left.getRangeCount();
+		int rLength = right.getRangeCount();
+		if (aLength * lLength > LCS.TOO_LONG
+				|| aLength * rLength > LCS.TOO_LONG
+				|| lLength * lLength > LCS.TOO_LONG)
+			return true;
+		return false;
+	}
+
 	public Diff findDiff(char type, int pos) throws CoreException {
 		
 		IDocument aDoc= null;
#P org.eclipse.compare.core
Index: src/org/eclipse/compare/internal/core/LCS.java
===================================================================
RCS file: /cvsroot/eclipse/org.eclipse.compare/plugins/org.eclipse.compare.core/src/org/eclipse/compare/internal/core/LCS.java,v
retrieving revision 1.2
diff -u -r1.2 LCS.java
--- src/org/eclipse/compare/internal/core/LCS.java	9 Feb 2010 12:10:44 -0000	1.2
+++ src/org/eclipse/compare/internal/core/LCS.java	27 Mar 2010 09:48:26 -0000
@@ -16,7 +16,7 @@
 
 /* Used to determine the change set responsible for each line */
 public abstract class LCS {
-	private static final double TOO_LONG = 10000000.0; // the value of N*M when
+	public static final double TOO_LONG = 10000000.0; // the value of N*M when
 														// to start binding the
 														// run time