Remove logging from the EMF Compare core

Most of these logs were only start/end information for comparison
phases. This depends on an external logger as the core is standalone.
Log4J 2 does not seem viable for eclipse as it requires an external
configuration file instead of being configurable through API, and we
can't have a global eclipse configuration just for compare. We wish to
remove the dependency towards Log4j 1.

Bug: 578953
Change-Id: Ib421d2f9487f84d8867f936faa0fc068e72e75d3

11 files changed, 1 insertions, 307 deletions

diff --git a/plugins/org.eclipse.emf.compare/META-INF/MANIFEST.MF b/plugins/org.eclipse.emf.compare/META-INF/MANIFEST.MF
index 54fe0226d..87150bc14 100644
--- a/plugins/org.eclipse.emf.compare/META-INF/MANIFEST.MF
+++ b/plugins/org.eclipse.emf.compare/META-INF/MANIFEST.MF
@@ -43,5 +43,4 @@ Bundle-ActivationPolicy: lazy
 Import-Package: com.google.common.base;version="[27.0.0,30.2.0)",
  com.google.common.cache;version="[27.0.0,30.2.0)",
  com.google.common.collect;version="[27.0.0,30.2.0)",
- com.google.common.eventbus;version="[27.0.0,30.2.0)",
- org.apache.log4j;version="[1.2.15,2.0.0)"
+ com.google.common.eventbus;version="[27.0.0,30.2.0)"
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/EMFCompare.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/EMFCompare.java
index d75ffc9f1..8512f6f44 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/EMFCompare.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/EMFCompare.java
@@ -16,14 +16,12 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import java.util.Iterator;
 import java.util.List;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.common.notify.Notifier;
 import org.eclipse.emf.common.util.BasicDiagnostic;
 import org.eclipse.emf.common.util.BasicMonitor;
 import org.eclipse.emf.common.util.Diagnostic;
 import org.eclipse.emf.common.util.DiagnosticChain;
-import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.conflict.IConflictDetector;
 import org.eclipse.emf.compare.conflict.MatchBasedConflictDetector;
@@ -70,15 +68,6 @@ public class EMFCompare {
 	 */
 	public static final String DIAGNOSTIC_SOURCE = "org.eclipse.emf.compare"; //$NON-NLS-1$
 
-	/** Constant for logging. */
-	private static final String START = " - START"; //$NON-NLS-1$
-
-	/** Constant for logging. */
-	private static final String FINISH = " - FINISH"; //$NON-NLS-1$
-
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(EMFCompare.class);
-
 	/** The registry we'll use to create a match engine for this comparison. */
 	private final IMatchEngine.Factory.Registry matchEngineFactoryRegistry;
 
@@ -204,19 +193,9 @@ public class EMFCompare {
 		checkNotNull(scope);
 		checkNotNull(monitor);
 
-		// Used to compute the time spent in the method
-		long startTime = System.currentTimeMillis();
-
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info("compare() - START"); //$NON-NLS-1$
-		}
-
 		Comparison comparison = null;
 		try {
 			Monitor subMonitor = new SafeSubMonitor(monitor);
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("compare() - starting step: MATCH"); //$NON-NLS-1$
-			}
 			comparison = matchEngineFactoryRegistry.getHighestRankingMatchEngineFactory(scope)
 					.getMatchEngine().match(scope, subMonitor);
 
@@ -226,62 +205,30 @@ public class EMFCompare {
 			List<IPostProcessor> postProcessors = postProcessorDescriptorRegistry.getPostProcessors(scope);
 
 			// CHECKSTYLE:OFF Yes, I want to have ifs here and no constant for "post-processor".
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("compare() - starting step: POST-MATCH with " + postProcessors.size() //$NON-NLS-1$
-						+ " post-processors"); //$NON-NLS-1$
-			}
 			postMatch(comparison, postProcessors, subMonitor);
 			monitor.worked(1);
 
 			if (!hasToStop(comparison, monitor)) {
-				if (LOGGER.isInfoEnabled()) {
-					LOGGER.info("compare() - starting step: DIFF"); //$NON-NLS-1$
-				}
 				diffEngine.diff(comparison, subMonitor);
 				monitor.worked(1);
-				if (LOGGER.isInfoEnabled()) {
-					LOGGER.info("compare() - starting step: POST-DIFF with " //$NON-NLS-1$
-							+ postProcessors.size() + " post-processors"); //$NON-NLS-1$
-				}
 				postDiff(comparison, postProcessors, subMonitor);
 				monitor.worked(1);
 
 				if (!hasToStop(comparison, monitor)) {
-					if (LOGGER.isInfoEnabled()) {
-						LOGGER.info("compare() - starting step: REQUIREMENTS"); //$NON-NLS-1$
-					}
 					reqEngine.computeRequirements(comparison, subMonitor);
 					monitor.worked(1);
-					if (LOGGER.isInfoEnabled()) {
-						LOGGER.info("compare() - starting step: POST-REQUIREMENTS with " //$NON-NLS-1$
-								+ postProcessors.size() + " post-processors"); //$NON-NLS-1$
-					}
 					postRequirements(comparison, postProcessors, subMonitor);
 					monitor.worked(1);
 
 					if (!hasToStop(comparison, monitor)) {
-						if (LOGGER.isInfoEnabled()) {
-							LOGGER.info("compare() - starting step: EQUIVALENCES"); //$NON-NLS-1$
-						}
 						equiEngine.computeEquivalences(comparison, subMonitor);
 						monitor.worked(1);
-						if (LOGGER.isInfoEnabled()) {
-							LOGGER.info("compare() - starting step: POST-EQUIVALENCES with " //$NON-NLS-1$
-									+ postProcessors.size() + " post-processors"); //$NON-NLS-1$
-						}
 						postEquivalences(comparison, postProcessors, subMonitor);
 						monitor.worked(1);
 
-						if (LOGGER.isInfoEnabled()) {
-							LOGGER.info("compare() - starting step: CONFLICT"); //$NON-NLS-1$
-						}
 						detectConflicts(comparison, postProcessors, subMonitor);
 						monitor.worked(1);
 
-						if (LOGGER.isInfoEnabled()) {
-							LOGGER.info("compare() - starting step: POST-COMPARISON with " //$NON-NLS-1$
-									+ postProcessors.size() + " post-processors"); //$NON-NLS-1$
-						}
 						// CHECKSTYLE:ON
 						postComparison(comparison, postProcessors, subMonitor);
 						monitor.worked(1);
@@ -289,9 +236,6 @@ public class EMFCompare {
 				}
 			}
 		} catch (ComparisonCanceledException e) {
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("compare() - Comparison has been canceled"); //$NON-NLS-1$
-			}
 			if (comparison == null) {
 				comparison = new ComparisonSpec();
 			}
@@ -307,10 +251,6 @@ public class EMFCompare {
 			monitor.done();
 		}
 
-		if (LOGGER.isInfoEnabled()) {
-			logEndOfComparison(comparison, startTime);
-		}
-
 		// Add scope to the comparison's adapters to make it available throughout the framework
 		if (scope instanceof Adapter) {
 			comparison.eAdapters().add((Adapter)scope);
@@ -353,32 +293,6 @@ public class EMFCompare {
 	}
 
 	/**
-	 * Log useful informations at the end of the comparison process.
-	 * 
-	 * @param comparison
-	 *            The comparison
-	 * @param start
-	 *            The time when the method start
-	 */
-	private void logEndOfComparison(Comparison comparison, long start) {
-		long duration = System.currentTimeMillis() - start;
-		int diffQuantity = comparison.getDifferences().size();
-		int conflictQuantity = comparison.getConflicts().size();
-		int matchQuantity = 0;
-		EList<Match> matches = comparison.getMatches();
-		for (Match match : matches) {
-			matchQuantity++;
-			Iterator<Match> subMatchIterator = match.getAllSubmatches().iterator();
-			while (subMatchIterator.hasNext()) {
-				matchQuantity++;
-				subMatchIterator.next();
-			}
-		}
-		LOGGER.info("compare() - FINISH - " + matchQuantity + " matches, " + diffQuantity + " diffs and " //$NON-NLS-1$ //$NON-NLS-2$ //$NON-NLS-3$
-				+ conflictQuantity + " conflicts found in " + duration + "ms"); //$NON-NLS-1$ //$NON-NLS-2$
-	}
-
-	/**
 	 * Launches the conflict detection engine, if any has been given and if the comparison is three way.
 	 * 
 	 * @param comparison
@@ -411,15 +325,7 @@ public class EMFCompare {
 		Iterator<IPostProcessor> processorsIterator = postProcessors.iterator();
 		while (!hasToStop(comparison, monitor) && processorsIterator.hasNext()) {
 			final IPostProcessor iPostProcessor = processorsIterator.next();
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postMatch with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + START);
-			}
 			iPostProcessor.postMatch(comparison, monitor);
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postMatch with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + FINISH);
-			}
 		}
 	}
 
@@ -438,15 +344,7 @@ public class EMFCompare {
 		Iterator<IPostProcessor> processorsIterator = postProcessors.iterator();
 		while (!hasToStop(comparison, monitor) && processorsIterator.hasNext()) {
 			final IPostProcessor iPostProcessor = processorsIterator.next();
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postDiff with post-processor: " + iPostProcessor.getClass().getName() //$NON-NLS-1$
-						+ START);
-			}
 			iPostProcessor.postDiff(comparison, monitor);
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postDiff with post-processor: " + iPostProcessor.getClass().getName() //$NON-NLS-1$
-						+ FINISH);
-			}
 		}
 	}
 
@@ -465,15 +363,7 @@ public class EMFCompare {
 		Iterator<IPostProcessor> processorsIterator = postProcessors.iterator();
 		while (!hasToStop(comparison, monitor) && processorsIterator.hasNext()) {
 			final IPostProcessor iPostProcessor = processorsIterator.next();
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postRequirements with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + START);
-			}
 			iPostProcessor.postRequirements(comparison, monitor);
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postRequirements with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + FINISH);
-			}
 		}
 	}
 
@@ -492,15 +382,7 @@ public class EMFCompare {
 		Iterator<IPostProcessor> processorsIterator = postProcessors.iterator();
 		while (!hasToStop(comparison, monitor) && processorsIterator.hasNext()) {
 			final IPostProcessor iPostProcessor = processorsIterator.next();
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postEquivalences with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + START);
-			}
 			iPostProcessor.postEquivalences(comparison, monitor);
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postEquivalences with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + FINISH);
-			}
 		}
 	}
 
@@ -519,15 +401,7 @@ public class EMFCompare {
 		Iterator<IPostProcessor> processorsIterator = postProcessors.iterator();
 		while (!hasToStop(comparison, monitor) && processorsIterator.hasNext()) {
 			final IPostProcessor iPostProcessor = processorsIterator.next();
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postConflicts with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + START);
-			}
 			iPostProcessor.postConflicts(comparison, monitor);
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postConflicts with post-processor: " //$NON-NLS-1$
-						+ iPostProcessor.getClass().getName() + FINISH);
-			}
 		}
 	}
 
@@ -547,19 +421,11 @@ public class EMFCompare {
 		int postProcessorIndex = 1;
 		while (!hasToStop(comparison, monitor) && processorsIterator.hasNext()) {
 			final IPostProcessor postProcessor = processorsIterator.next();
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postComparison with post-processor: " //$NON-NLS-1$
-						+ postProcessor.getClass().getName() + START);
-			}
 			monitor.subTask(EMFCompareMessages.getString("PostComparison.monitor.postprocessor", //$NON-NLS-1$
 					postProcessor.getClass().getSimpleName(), String.valueOf(postProcessorIndex),
 					String.valueOf(postProcessors.size())));
 			postProcessor.postComparison(comparison, monitor);
 			postProcessorIndex++;
-			if (LOGGER.isInfoEnabled()) {
-				LOGGER.info("postComparison with post-processor: " //$NON-NLS-1$
-						+ postProcessor.getClass().getName() + FINISH);
-			}
 		}
 	}
 
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/DefaultConflictDetector.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/DefaultConflictDetector.java
index 6430febc7..2ed2a52f9 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/DefaultConflictDetector.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/DefaultConflictDetector.java
@@ -24,7 +24,6 @@ import java.util.function.Predicate;
 import java.util.stream.Stream;
 import java.util.stream.StreamSupport;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.AttributeChange;
 import org.eclipse.emf.compare.CompareFactory;
@@ -69,9 +68,6 @@ import org.eclipse.emf.ecore.util.FeatureMap;
  */
 public class DefaultConflictDetector implements IConflictDetector {
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(DefaultConflictDetector.class);
-
 	/**
 	 * {@inheritDoc}
 	 * 
@@ -79,10 +75,6 @@ public class DefaultConflictDetector implements IConflictDetector {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public void detect(Comparison comparison, Monitor monitor) {
-		long start = System.currentTimeMillis();
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("detect conflicts - START"); //$NON-NLS-1$
-		}
 		final List<Diff> differences = comparison.getDifferences();
 		final int diffCount = differences.size();
 
@@ -99,11 +91,6 @@ public class DefaultConflictDetector implements IConflictDetector {
 			Stream<Diff> conflictCandidates = differences.stream().filter(possiblyConflictingWith(diff));
 			checkConflict(comparison, diff, conflictCandidates::iterator);
 		}
-
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info(String.format("detect conflicts - END - Took %d ms", Long.valueOf(System //$NON-NLS-1$
-					.currentTimeMillis() - start)));
-		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/MatchBasedConflictDetector.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/MatchBasedConflictDetector.java
index 2a03ffae9..f31e26f25 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/MatchBasedConflictDetector.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/conflict/MatchBasedConflictDetector.java
@@ -12,7 +12,6 @@ package org.eclipse.emf.compare.conflict;
 
 import java.util.List;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.Comparison;
 import org.eclipse.emf.compare.ComparisonCanceledException;
@@ -38,9 +37,6 @@ import org.eclipse.emf.ecore.EObject;
  */
 public class MatchBasedConflictDetector implements IConflictDetector {
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(MatchBasedConflictDetector.class);
-
 	/**
 	 * {@inheritDoc}
 	 * 
@@ -48,10 +44,6 @@ public class MatchBasedConflictDetector implements IConflictDetector {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public void detect(Comparison comparison, Monitor monitor) {
-		long start = System.currentTimeMillis();
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug("detect conflicts - START"); //$NON-NLS-1$
-		}
 		final List<Diff> differences = comparison.getDifferences();
 		final int diffCount = differences.size();
 
@@ -68,10 +60,5 @@ public class MatchBasedConflictDetector implements IConflictDetector {
 			AbstractConflictSearch<? extends Diff> search = conflictSearchFactory.doSwitch(diff);
 			search.detectConflicts();
 		}
-
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info(String.format("detect conflicts - END - Took %d ms", Long.valueOf(System //$NON-NLS-1$
-					.currentTimeMillis() - start)));
-		}
 	}
 }
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/diff/DefaultDiffEngine.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/diff/DefaultDiffEngine.java
index 9b95b5193..a4b73aae8 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/diff/DefaultDiffEngine.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/diff/DefaultDiffEngine.java
@@ -20,7 +20,6 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.Comparison;
 import org.eclipse.emf.compare.ComparisonCanceledException;
@@ -61,9 +60,6 @@ public class DefaultDiffEngine implements IDiffEngine {
 	 */
 	protected static final Object UNMATCHED_VALUE = new Object();
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(DefaultDiffEngine.class);
-
 	/**
 	 * The diff processor that will be used by this engine. Should be passed by the constructor and accessed
 	 * by {@link #getDiffProcessor()}.
@@ -120,18 +116,10 @@ public class DefaultDiffEngine implements IDiffEngine {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public void diff(Comparison comparison, Monitor monitor) {
-		long start = System.currentTimeMillis();
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug(String.format("detect differences - START")); //$NON-NLS-1$
-		}
 		monitor.subTask(EMFCompareMessages.getString("DefaultDiffEngine.monitor.diff")); //$NON-NLS-1$
 		for (Match rootMatch : comparison.getMatches()) {
 			checkForDifferences(rootMatch, monitor);
 		}
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info(String.format("detect differences - END - Took %d ms", Long.valueOf(System //$NON-NLS-1$
-					.currentTimeMillis() - start)));
-		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/equi/DefaultEquiEngine.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/equi/DefaultEquiEngine.java
index 87ac0b681..d880940e8 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/equi/DefaultEquiEngine.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/equi/DefaultEquiEngine.java
@@ -15,7 +15,6 @@ import java.util.LinkedHashSet;
 import java.util.Set;
 import java.util.function.Predicate;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.CompareFactory;
 import org.eclipse.emf.compare.Comparison;
@@ -46,9 +45,6 @@ import org.eclipse.emf.ecore.util.FeatureMap;
  */
 public class DefaultEquiEngine implements IEquiEngine {
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(DefaultEquiEngine.class);
-
 	/**
 	 * {@inheritDoc}
 	 * 
@@ -56,10 +52,6 @@ public class DefaultEquiEngine implements IEquiEngine {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public void computeEquivalences(Comparison comparison, Monitor monitor) {
-		long start = System.currentTimeMillis();
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug(String.format("detect equivalences - START")); //$NON-NLS-1$
-		}
 		monitor.subTask(EMFCompareMessages.getString("DefaultEquiEngine.monitor.eq")); //$NON-NLS-1$
 		for (Diff difference : comparison.getDifferences()) {
 			if (monitor.isCanceled()) {
@@ -67,10 +59,6 @@ public class DefaultEquiEngine implements IEquiEngine {
 			}
 			checkForEquivalences(comparison, difference);
 		}
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info(String.format("detect equivalences - END - Took %d ms", Long.valueOf(System //$NON-NLS-1$
-					.currentTimeMillis() - start)));
-		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/match/DefaultMatchEngine.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/match/DefaultMatchEngine.java
index 65f660d78..29c78dd5d 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/match/DefaultMatchEngine.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/match/DefaultMatchEngine.java
@@ -21,7 +21,6 @@ import java.util.Collection;
 import java.util.Iterator;
 import java.util.List;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.notify.Notifier;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.common.util.URI;
@@ -63,9 +62,6 @@ public class DefaultMatchEngine implements IMatchEngine {
 	 */
 	public static final int DEFAULT_EOBJECT_URI_CACHE_MAX_SIZE = 1024;
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(DefaultMatchEngine.class);
-
 	/** The delegate {@link IEObjectMatcher matcher} that will actually pair EObjects together. */
 	private final IEObjectMatcher eObjectMatcher;
 
@@ -113,10 +109,6 @@ public class DefaultMatchEngine implements IMatchEngine {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public Comparison match(IComparisonScope scope, Monitor monitor) {
-		long start = System.currentTimeMillis();
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug(String.format("detect matches - START")); //$NON-NLS-1$
-		}
 		Comparison comparison = comparisonFactory.createComparison();
 
 		final Notifier left = scope.getLeft();
@@ -127,10 +119,6 @@ public class DefaultMatchEngine implements IMatchEngine {
 
 		match(comparison, scope, left, right, origin, monitor);
 
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info(String.format("detect matches - END - Took %d ms", Long.valueOf(System //$NON-NLS-1$
-					.currentTimeMillis() - start)));
-		}
 		return comparison;
 	}
 
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/AbstractMerger.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/AbstractMerger.java
index 42914a8f4..9f7ffc37c 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/AbstractMerger.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/AbstractMerger.java
@@ -45,7 +45,6 @@ import java.util.List;
 import java.util.Map;
 import java.util.Set;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.Comparison;
@@ -80,9 +79,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 	/** The key of the merge option that allows to the mergers to consider sub-diffs of a diff as a whole. */
 	public static final String SUB_DIFF_AWARE_OPTION = "subDiffAwareOption"; //$NON-NLS-1$
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(AbstractMerger.class);
-
 	/** A predicate for diffs with an unresolved state. */
 	private static final Predicate<? super Diff> HAS_UNRESOLVED_STATE = EMFComparePredicates
 			.hasState(UNRESOLVED);
@@ -206,8 +202,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 	 * @since 3.2
 	 */
 	public Set<Diff> getDirectMergeDependencies(Diff diff, boolean mergeRightToLeft) {
-		long start = System.currentTimeMillis();
-
 		final Set<Diff> dependencies = new LazyLinkedHashSet<Diff>();
 		if (isAccepting(diff, mergeRightToLeft)) {
 			dependencies.addAll(diff.getRequires());
@@ -224,14 +218,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 			}
 		}
 
-		if (LOGGER.isDebugEnabled()) {
-			Long duration = new Long(System.currentTimeMillis() - start);
-			String log = String.format(
-					"getDirectMergeDependencies(Diff, boolean) - %d dependencies found in %d ms for diff %d", //$NON-NLS-1$
-					new Integer(dependencies.size()), duration, new Integer(diff.hashCode()));
-			LOGGER.debug(log);
-		}
-
 		return dependencies;
 	}
 
@@ -241,20 +227,10 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 	 * @since 3.2
 	 */
 	public Set<Diff> getDirectResultingMerges(Diff target, boolean mergeRightToLeft) {
-		long start = System.currentTimeMillis();
-
 		final Set<Diff> resulting = new LazyLinkedHashSet<Diff>();
 		resulting.addAll(getImpliedMerges(target, mergeRightToLeft));
 		resulting.addAll(getLogicallyResultingMerges(target, mergeRightToLeft));
 
-		if (LOGGER.isDebugEnabled()) {
-			Long duration = new Long(System.currentTimeMillis() - start);
-			String log = String.format(
-					"getDirectResultingMerges(Diff, boolean) - %d resulting merges found in %d ms for diff %d", //$NON-NLS-1$
-					new Integer(resulting.size()), duration, new Integer(target.hashCode()));
-			LOGGER.debug(log);
-		}
-
 		return resulting;
 	}
 
@@ -358,8 +334,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 	 * @since 3.2
 	 */
 	public Set<Diff> getDirectResultingRejections(Diff target, boolean rightToLeft) {
-		long start = System.currentTimeMillis();
-
 		final Set<Diff> directlyImpliedRejections = new LazyLinkedHashSet<Diff>();
 		final Conflict conflict = target.getConflict();
 		if (conflict != null && conflict.getKind() == ConflictKind.REAL) {
@@ -369,14 +343,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 			}
 		}
 
-		if (LOGGER.isDebugEnabled()) {
-			Long duration = new Long(System.currentTimeMillis() - start);
-			String log = String.format(
-					"getDirectResultingMerges(Diff, boolean) - %d implied rejections found in %d ms for diff %d", //$NON-NLS-1$
-					new Integer(directlyImpliedRejections.size()), duration, new Integer(target.hashCode()));
-			LOGGER.debug(log);
-		}
-
 		return directlyImpliedRejections;
 	}
 
@@ -649,8 +615,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 	 * @since 3.5
 	 */
 	protected Set<Diff> getLogicallyResultingMerges(Diff diff, boolean mergeRightToLeft) {
-		long start = System.currentTimeMillis();
-
 		final Set<Diff> resulting = new LazyLinkedHashSet<Diff>();
 
 		// we need to add the implication side that actually needs merging
@@ -670,14 +634,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 			Iterables.addAll(resulting, directSubDiffs);
 		}
 
-		if (LOGGER.isDebugEnabled()) {
-			Long duration = new Long(System.currentTimeMillis() - start);
-			String log = String.format(
-					"getLogicallyResultingMerges(Diff, boolean) - %d merges found in %d ms for diff %d", //$NON-NLS-1$
-					new Integer(resulting.size()), duration, new Integer(diff.hashCode()));
-			LOGGER.debug(log);
-		}
-
 		return resulting;
 	}
 
@@ -695,7 +651,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 	 * @since 3.5
 	 */
 	protected Set<Diff> getImpliedMerges(Diff target, boolean mergeRightToLeft) {
-		long start = System.currentTimeMillis();
 		final Set<Diff> impliedMerges = new LazyLinkedHashSet<Diff>();
 
 		if (isAccepting(target, mergeRightToLeft)) {
@@ -744,13 +699,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 			}
 		}
 
-		if (LOGGER.isDebugEnabled()) {
-			Long duration = new Long(System.currentTimeMillis() - start);
-			String log = String.format(
-					"getImpliedMerges(Diff, boolean) - %d implied merges found in %d ms for diff %d", //$NON-NLS-1$
-					new Integer(impliedMerges.size()), duration, new Integer(target.hashCode()));
-			LOGGER.debug(log);
-		}
 		return impliedMerges;
 	}
 
@@ -771,8 +719,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 			return;
 		}
 
-		long start = System.currentTimeMillis();
-
 		// Change the diff's state before we actually merge it : this allows us to avoid requirement cycles.
 		target.setState(MERGING);
 
@@ -799,13 +745,6 @@ public abstract class AbstractMerger implements IMerger2, IMergeOptionAware, IMe
 			reject(target, rightToLeft);
 			target.setState(DISCARDED);
 		}
-
-		if (LOGGER.isDebugEnabled()) {
-			long duration = System.currentTimeMillis() - start;
-			LOGGER.debug("copyDiff(Diff, Monitor, Boolean) - diff " + target.hashCode() //$NON-NLS-1$
-					+ " merged (rightToLeft: " + rightToLeft + ") in " //$NON-NLS-1$ //$NON-NLS-2$
-					+ duration + "ms"); //$NON-NLS-1$
-		}
 	}
 
 	/**
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/BatchMerger.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/BatchMerger.java
index cde9540b5..81fd3bf5e 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/BatchMerger.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/BatchMerger.java
@@ -16,7 +16,6 @@ import static com.google.common.base.Predicates.alwaysTrue;
 import com.google.common.base.Predicate;
 import com.google.common.collect.Iterables;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.util.Monitor;
 import org.eclipse.emf.compare.Diff;
 
@@ -29,9 +28,6 @@ import org.eclipse.emf.compare.Diff;
  */
 public class BatchMerger implements IBatchMerger {
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(BatchMerger.class);
-
 	/** The registry from which we'll retrieve our mergers. */
 	private final IMerger.Registry2 registry;
 
@@ -134,26 +130,13 @@ public class BatchMerger implements IBatchMerger {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public void copyAllLeftToRight(Iterable<? extends Diff> differences, Monitor monitor) {
-		long start = 0;
-		if (LOGGER.isDebugEnabled()) {
-			start = System.currentTimeMillis();
-			LOGGER.debug("copyAllLeftToRight(differences, monitor) - Start"); //$NON-NLS-1$
-		}
 		ComputeDiffsToMerge computer = new ComputeDiffsToMerge(false, relationshipComputer);
 		for (Diff toMerge : computer.getAllDiffsToMerge(Iterables.filter(differences, filter))) {
 			if (!AbstractMerger.isInTerminalState(toMerge)) {
 				final IMerger merger = registry.getHighestRankingMerger(toMerge);
-				if (LOGGER.isDebugEnabled()) {
-					LOGGER.debug("copyAllLeftToRight - Selected merger: " //$NON-NLS-1$
-							+ merger.getClass().getSimpleName());
-				}
 				merger.copyLeftToRight(toMerge, monitor);
 			}
 		}
-		if (LOGGER.isDebugEnabled()) {
-			long duration = System.currentTimeMillis() - start;
-			LOGGER.debug("copyAllLeftToRight(differences, monitor) - Stop - Time spent: " + duration + "ms"); //$NON-NLS-1$ //$NON-NLS-2$
-		}
 	}
 
 	/**
@@ -163,25 +146,12 @@ public class BatchMerger implements IBatchMerger {
 	 *      org.eclipse.emf.common.util.Monitor)
 	 */
 	public void copyAllRightToLeft(Iterable<? extends Diff> differences, Monitor monitor) {
-		long start = 0;
-		if (LOGGER.isDebugEnabled()) {
-			start = System.currentTimeMillis();
-			LOGGER.debug("copyAllRightToLeft(differences, monitor) - Start"); //$NON-NLS-1$
-		}
 		ComputeDiffsToMerge computer = new ComputeDiffsToMerge(true, relationshipComputer);
 		for (Diff toMerge : computer.getAllDiffsToMerge(Iterables.filter(differences, filter))) {
 			if (!AbstractMerger.isInTerminalState(toMerge)) {
 				final IMerger merger = registry.getHighestRankingMerger(toMerge);
-				if (LOGGER.isDebugEnabled()) {
-					LOGGER.debug("copyAllLeftToRight - Selected merger: " //$NON-NLS-1$
-							+ merger.getClass().getSimpleName());
-				}
 				merger.copyRightToLeft(toMerge, monitor);
 			}
 		}
-		if (LOGGER.isDebugEnabled()) {
-			long duration = System.currentTimeMillis() - start;
-			LOGGER.debug("copyAllRightToLeft(differences, monitor) - Stop - Time spent: " + duration + "ms"); //$NON-NLS-1$ //$NON-NLS-2$
-		}
 	}
 }
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/ResourceAttachmentChangeMerger.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/ResourceAttachmentChangeMerger.java
index 5066828b5..ba7a925fd 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/ResourceAttachmentChangeMerger.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/merge/ResourceAttachmentChangeMerger.java
@@ -17,7 +17,6 @@ import static org.eclipse.emf.compare.merge.IMergeCriterion.NONE;
 import java.util.Collections;
 import java.util.List;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.notify.Notifier;
 import org.eclipse.emf.common.util.URI;
 import org.eclipse.emf.compare.Comparison;
@@ -42,8 +41,6 @@ import org.eclipse.emf.ecore.xmi.XMIResource;
  * @author <a href="mailto:laurent.goubet@obeo.fr">Laurent Goubet</a>
  */
 public class ResourceAttachmentChangeMerger extends AbstractMerger {
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(ResourceAttachmentChangeMerger.class);
 
 	/**
 	 * {@inheritDoc}
@@ -406,9 +403,6 @@ public class ResourceAttachmentChangeMerger extends AbstractMerger {
 				} else {
 					target = existing;
 				}
-				if (LOGGER.isInfoEnabled()) {
-					LOGGER.info("Created resource " + targetURI); //$NON-NLS-1$
-				}
 
 				if (rightToLeft) {
 					soughtMatch.setLeft(target);
diff --git a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java
index 236a5b712..ca25e5339 100644
--- a/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java
+++ b/plugins/org.eclipse.emf.compare/src/org/eclipse/emf/compare/req/DefaultReqEngine.java
@@ -35,7 +35,6 @@ import java.util.concurrent.TimeUnit;
 import java.util.function.Predicate;
 import java.util.stream.Stream;
 
-import org.apache.log4j.Logger;
 import org.eclipse.emf.common.notify.Adapter;
 import org.eclipse.emf.common.util.EList;
 import org.eclipse.emf.common.util.Monitor;
@@ -69,9 +68,6 @@ import org.eclipse.emf.ecore.util.FeatureMap;
  */
 public class DefaultReqEngine implements IReqEngine {
 
-	/** The logger. */
-	private static final Logger LOGGER = Logger.getLogger(DefaultReqEngine.class);
-
 	/** The time before we expire the values in {@link #cachedDifferences} after access, in seconds. */
 	private static final long CACHE_EXPIRATION_TIME = 30L;
 
@@ -94,10 +90,6 @@ public class DefaultReqEngine implements IReqEngine {
 	 * @see org.eclipse.emf.compare.req.IReqEngine#computeRequirements(Comparison, Monitor)
 	 */
 	public void computeRequirements(Comparison comparison, Monitor monitor) {
-		long start = System.currentTimeMillis();
-		if (LOGGER.isDebugEnabled()) {
-			LOGGER.debug(String.format("detect requirements - START")); //$NON-NLS-1$
-		}
 		monitor.subTask(EMFCompareMessages.getString("DefaultReqEngine.monitor.req")); //$NON-NLS-1$
 		for (Diff difference : comparison.getDifferences()) {
 			if (monitor.isCanceled()) {
@@ -105,10 +97,6 @@ public class DefaultReqEngine implements IReqEngine {
 			}
 			checkForRequiredDifferences(comparison, difference);
 		}
-		if (LOGGER.isInfoEnabled()) {
-			LOGGER.info(String.format("detect requirement - END - Took %d ms", Long.valueOf(System //$NON-NLS-1$
-					.currentTimeMillis() - start)));
-		}
 	}
 
 	/**