Revert "Refactorings to improve performance of MatchUtil"3.3.1RC3

This reverts commit c641126a25621add2fba4b603f189aa6cd2cc940.

Change-Id: I2589e1ca08e91ec53939037b31192e6a229db9fe

1 files changed, 49 insertions, 81 deletions

diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/MatchUtil.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/MatchUtil.java
index 4dc4dae4a..d8a526b16 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/MatchUtil.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/utils/MatchUtil.java
@@ -1,5 +1,5 @@
 /*******************************************************************************
- * Copyright (c) 2012, 2017 Obeo and others.
+ * Copyright (c) 2012, 2016 Obeo 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
@@ -8,7 +8,6 @@
  * Contributors:
  *     Obeo - initial API and implementation
  *     Michael Borkowski - bug 467576
- *     Philip Langer - performance improvements
  *******************************************************************************/
 package org.eclipse.emf.compare.utils;
 
@@ -21,11 +20,10 @@ import static org.eclipse.emf.compare.utils.EMFComparePredicates.CONTAINMENT_REF
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.ofKind;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.onFeature;
 import static org.eclipse.emf.compare.utils.EMFComparePredicates.valueIs;
-import static org.eclipse.emf.compare.utils.ReferenceUtil.safeEGet;
+import static org.eclipse.emf.compare.utils.ReferenceUtil.getAsList;
 
 import com.google.common.collect.Iterables;
 
-import java.util.Iterator;
 import java.util.List;
 
 import org.eclipse.emf.common.util.URI;
@@ -36,12 +34,11 @@ import org.eclipse.emf.compare.DifferenceKind;
 import org.eclipse.emf.compare.DifferenceSource;
 import org.eclipse.emf.compare.Match;
 import org.eclipse.emf.compare.ReferenceChange;
+import org.eclipse.emf.compare.util.CompareSwitch;
 import org.eclipse.emf.ecore.EObject;
 import org.eclipse.emf.ecore.EReference;
 import org.eclipse.emf.ecore.EStructuralFeature;
-import org.eclipse.emf.ecore.InternalEObject;
 import org.eclipse.emf.ecore.util.EcoreUtil;
-import org.eclipse.emf.ecore.util.InternalEList;
 
 /**
  * This utility class holds methods that will be used by the diff and merge processes.
@@ -289,18 +286,16 @@ public final class MatchUtil {
 					throw new IllegalArgumentException();
 				}
 				if (source == DifferenceSource.LEFT) {
-					final EObject left = match.getLeft();
-					if (featureContains(left, feature, value)) {
-						result = left;
+					if (featureContains(match.getLeft(), feature, value)) {
+						result = match.getLeft();
 					} else if (comparison.isThreeWay()) {
 						result = match.getOrigin();
 					} else {
 						result = match.getRight();
 					}
 				} else {
-					final EObject right = match.getRight();
-					if (featureContains(right, feature, value)) {
-						result = right;
+					if (featureContains(match.getRight(), feature, value)) {
+						result = match.getRight();
 					} else if (comparison.isThreeWay()) {
 						result = match.getOrigin();
 					} else {
@@ -331,50 +326,27 @@ public final class MatchUtil {
 	// public for testing
 	public static boolean featureContains(EObject eObject, EStructuralFeature feature, Object value) {
 		boolean contains = false;
-		
-		if (eObject != null && feature != null) {
-			final Object featureValue = safeEGet(eObject, feature);
-			if (feature.isMany()) {
-				// only compute the value's URI once, and only if needed
-				URI valueURI = null;
-				final Iterator<?> i;
-				if (featureValue instanceof InternalEList<?>) {
-					i = ((InternalEList<?>)featureValue).basicIterator();
-				} else {
-					i = ((List<?>)featureValue).iterator();
-				}
-				while (i.hasNext()) {
-					final Object element = i.next();
-					if (element == value) {
-						contains = true;
-						break;
-					}
-					if (element != null && element.equals(value)) {
-						contains = true;
-						break;
-					}
 
-					URI proxyURI = getProxyURI(element);
-					if (proxyURI != null) {
-						if (valueURI == null && value instanceof EObject) {
-							valueURI = EcoreUtil.getURI((EObject)value);
-						}
-						if (proxyURI.equals(valueURI)) {
-							contains = true;
-							break;
-						}
-					}
-				}
-			} else if (featureValue == value) {
+		// only compute the value's URI once, and only if needed
+		URI valueURI = null;
+
+		for (Object element : getAsList(eObject, feature)) {
+			if (element == value) {
 				contains = true;
-			} else if (featureValue != null && featureValue.equals(value)) {
+				break;
+			}
+			if (element != null && element.equals(value)) {
 				contains = true;
-			} else {
-				URI proxyURI = getProxyURI(featureValue);
-				if (proxyURI != null && value instanceof EObject) {
-					if (proxyURI.equals(EcoreUtil.getURI((EObject)value))) {
-						contains = true;
-					}
+				break;
+			}
+
+			if (element instanceof EObject && ((EObject)element).eIsProxy()) {
+				if (valueURI == null && value instanceof EObject) {
+					valueURI = EcoreUtil.getURI((EObject)value);
+				}
+				if (EcoreUtil.getURI((EObject)element).equals(valueURI)) {
+					contains = true;
+					break;
 				}
 			}
 		}
@@ -383,20 +355,6 @@ public final class MatchUtil {
 	}
 
 	/**
-	 * Returns the proxy URI of the object if it's an EObject.
-	 * 
-	 * @param object
-	 *            the object to test.
-	 * @return the proxy URI.
-	 */
-	private static URI getProxyURI(Object object) {
-		if (object instanceof InternalEObject) {
-			return ((InternalEObject)object).eProxyURI();
-		}
-		return null;
-	}
-
-	/**
 	 * Get the value of any difference.
 	 * 
 	 * @param input
@@ -404,14 +362,19 @@ public final class MatchUtil {
 	 * @return the value of the difference.
 	 */
 	public static Object getValue(Diff input) {
-		if (input instanceof AttributeChange) {
-			return ((AttributeChange)input).getValue();
-		}
-		if (input instanceof ReferenceChange) {
-			return ((ReferenceChange)input).getValue();
-		}
+		final CompareSwitch<Object> customSwitch = new CompareSwitch<Object>() {
+			@Override
+			public Object caseAttributeChange(AttributeChange object) {
+				return object.getValue();
+			}
 
-		return null;
+			@Override
+			public Object caseReferenceChange(ReferenceChange object) {
+				return object.getValue();
+			}
+
+		};
+		return customSwitch.doSwitch(input);
 	}
 
 	/**
@@ -422,14 +385,19 @@ public final class MatchUtil {
 	 * @return the structural feature.
 	 */
 	public static EStructuralFeature getStructuralFeature(Diff input) {
-		if (input instanceof AttributeChange) {
-			return ((AttributeChange)input).getAttribute();
-		}
-		if (input instanceof ReferenceChange) {
-			return ((ReferenceChange)input).getReference();
-		}
+		final CompareSwitch<EStructuralFeature> customSwitch = new CompareSwitch<EStructuralFeature>() {
+			@Override
+			public EStructuralFeature caseAttributeChange(AttributeChange object) {
+				return object.getAttribute();
+			}
 
-		return null;
+			@Override
+			public EStructuralFeature caseReferenceChange(ReferenceChange object) {
+				return object.getReference();
+			}
+
+		};
+		return customSwitch.doSwitch(input);
 	}
 
 	/**