org.eclipse.virgo.ide.manifest.core/src/org/eclipse/virgo/ide/manifest/internal/core/BundleManifestDiffer.java

/*********************************************************************
 * Copyright (c) 2009, 2012 SpringSource, a division of VMware, Inc.
 *
 * This program and the accompanying materials are made
 * available under the terms of the Eclipse Public License 2.0
 * which is available at https://www.eclipse.org/legal/epl-2.0/
 *
 * SPDX-License-Identifier: EPL-2.0
**********************************************************************/

package org.eclipse.virgo.ide.manifest.internal.core;

import java.util.Collections;
import java.util.HashSet;
import java.util.Set;

import org.apache.commons.lang.ObjectUtils;
import org.eclipse.virgo.ide.manifest.core.IBundleManifestChangeListener;
import org.eclipse.virgo.ide.manifest.core.IBundleManifestChangeListener.Type;
import org.eclipse.virgo.util.osgi.manifest.BundleManifest;
import org.eclipse.virgo.util.osgi.manifest.ExportPackage;
import org.eclipse.virgo.util.osgi.manifest.ImportBundle;
import org.eclipse.virgo.util.osgi.manifest.ImportLibrary;
import org.eclipse.virgo.util.osgi.manifest.ImportPackage;
import org.eclipse.virgo.util.osgi.manifest.RequireBundle;
import org.osgi.framework.Constants;

/**
 * Utility that checks two {@link BundleManifest} instances for equality.
 *
 * @author Christian Dupuis
 * @since 1.0.1
 */
class BundleManifestDiffer {

    /**
     * Diffs the two given bundles and provides a set of changes.
     *
     * @param bundleManifest1 the first manifest to check
     * @param bundleManifest2 the second manifest to check
     * @return {@link Set} of {@link IBundleManifestChangeListener.Type} expressing the actual change.
     */
    static Set<Type> diff(BundleManifest bundleManifest1, BundleManifest bundleManifest2) {
        if (bundleManifest1 == null && bundleManifest2 == null) {
            return Collections.emptySet();
        } else if (bundleManifest1 == null && bundleManifest2 != null || bundleManifest1 != null && bundleManifest2 == null) {
            return BundleManifestManager.IMPORTS_CHANGED;
        }

        ImportPackage importPackageHeader1 = bundleManifest1.getImportPackage();
        ImportPackage importPackageHeader2 = bundleManifest2.getImportPackage();

        ExportPackage exportPackageHeader1 = bundleManifest1.getExportPackage();
        ExportPackage exportPackageHeader2 = bundleManifest2.getExportPackage();

        ImportLibrary importLibraryHeader1 = bundleManifest1.getImportLibrary();
        ImportLibrary importLibraryHeader2 = bundleManifest2.getImportLibrary();

        ImportBundle importBundleHeader1 = bundleManifest1.getImportBundle();
        ImportBundle importBundleHeader2 = bundleManifest2.getImportBundle();

        RequireBundle requireBundleHeader1 = bundleManifest1.getRequireBundle();
        RequireBundle requireBundleHeader2 = bundleManifest2.getRequireBundle();

        String execEnvironment1 = bundleManifest1.toDictionary().get(Constants.BUNDLE_REQUIREDEXECUTIONENVIRONMENT);
        String execEnvironment2 = bundleManifest2.toDictionary().get(Constants.BUNDLE_REQUIREDEXECUTIONENVIRONMENT);

        Set<Type> differences = new HashSet<Type>();

        if (!ObjectUtils.equals(importPackageHeader1.getImportedPackages(), importPackageHeader2.getImportedPackages())) {
            differences.add(Type.IMPORT_PACKAGE);
        }
        if (!ObjectUtils.equals(execEnvironment1, execEnvironment2)) {
            differences.add(Type.IMPORT_PACKAGE);
        }
        if (!ObjectUtils.equals(exportPackageHeader1.getExportedPackages(), exportPackageHeader2.getExportedPackages())) {
            differences.add(Type.EXPORT_PACKAGE);
        }
        if (!ObjectUtils.equals(importLibraryHeader1.getImportedLibraries(), importLibraryHeader2.getImportedLibraries())) {
            differences.add(Type.IMPORT_LIBRARY);
        }
        if (!ObjectUtils.equals(importBundleHeader1.getImportedBundles(), importBundleHeader2.getImportedBundles())) {
            differences.add(Type.IMPORT_BUNDLE);
        }
        if (!ObjectUtils.equals(requireBundleHeader1.getRequiredBundles(), requireBundleHeader2.getRequiredBundles())) {
            differences.add(Type.REQUIRE_BUNDLE);
        }

        return differences;
    }

}