bug 255678 - compare while mirroring

1 files changed, 52 insertions, 0 deletions

diff --git a/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/ArtifactComparatorFactory.java b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/ArtifactComparatorFactory.java
new file mode 100644
index 000000000..e65e32903
--- /dev/null
+++ b/bundles/org.eclipse.equinox.p2.artifact.repository/src/org/eclipse/equinox/internal/provisional/p2/artifact/repository/ArtifactComparatorFactory.java
@@ -0,0 +1,52 @@
+/*******************************************************************************
+ * Copyright (c) 2008 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
+ * http://www.eclipse.org/legal/epl-v10.html
+ *
+ * Contributors:
+ *     IBM Corporation - initial API and implementation
+ *		compeople AG (Stefan Liebig) - various ongoing maintenance
+ *******************************************************************************/
+package org.eclipse.equinox.internal.provisional.p2.artifact.repository;
+
+import org.eclipse.core.runtime.IConfigurationElement;
+import org.eclipse.core.runtime.Platform;
+import org.eclipse.equinox.internal.p2.artifact.repository.Messages;
+import org.eclipse.osgi.util.NLS;
+
+public class ArtifactComparatorFactory {
+	private static final String comparatorPoint = "org.eclipse.equinox.p2.artifact.repository.artifactComparators"; //$NON-NLS-1$
+	private static final String ATTR_ID = "id"; //$NON-NLS-1$
+	private static final String ATTR_CLASS = "class"; //$NON-NLS-1$
+
+	public static IArtifactComparator getArtifactComparator(String comparatorID) {
+		IConfigurationElement[] extensions = Platform.getExtensionRegistry().getConfigurationElementsFor(comparatorPoint);
+
+		IConfigurationElement element = null;
+		if (comparatorID == null && extensions.length > 0) {
+			element = extensions[0]; //just take the first one
+		} else {
+			for (int i = 0; i < extensions.length; i++) {
+				if (extensions[i].getAttribute(ATTR_ID).equals(comparatorID)) {
+					element = extensions[i];
+					break;
+				}
+			}
+		}
+		if (element != null) {
+			try {
+				Object execExt = element.createExecutableExtension(ATTR_CLASS);
+				if (execExt instanceof IArtifactComparator)
+					return (IArtifactComparator) execExt;
+			} catch (Exception e) {
+				//fall through
+			}
+		}
+
+		if (comparatorID != null)
+			throw new IllegalArgumentException(NLS.bind(Messages.exception_comparatorNotFound, comparatorID));
+		throw new IllegalArgumentException(Messages.exception_noComparators);
+	}
+}