/*
* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS HEADER.
*
* Copyright (c) 1997-2012 Oracle and/or its affiliates. All rights reserved.
*
* The contents of this file are subject to the terms of either the GNU
* General Public License Version 2 only ("GPL") or the Common Development
* and Distribution License("CDDL") (collectively, the "License"). You
* may not use this file except in compliance with the License. You can
* obtain a copy of the License at
* http://glassfish.java.net/public/CDDL+GPL_1_1.html
* or packager/legal/LICENSE.txt. See the License for the specific
* language governing permissions and limitations under the License.
*
* When distributing the software, include this License Header Notice in each
* file and include the License file at packager/legal/LICENSE.txt.
*
* GPL Classpath Exception:
* Oracle designates this particular file as subject to the "Classpath"
* exception as provided by Oracle in the GPL Version 2 section of the License
* file that accompanied this code.
*
* Modifications:
* If applicable, add the following below the License Header, with the fields
* enclosed by brackets [] replaced by your own identifying information:
* "Portions Copyright [year] [name of copyright owner]"
*
* Contributor(s):
* If you wish your version of this file to be governed by only the CDDL or
* only the GPL Version 2, indicate your decision by adding "[Contributor]
* elects to include this software in this distribution under the [CDDL or GPL
* Version 2] license." If you don't indicate a single choice of license, a
* recipient has the option to distribute your version of this file under
* either the CDDL, the GPL Version 2 or to extend the choice of license to
* its licensees as provided above. However, if you add GPL Version 2 code
* and therefore, elected the GPL Version 2 license, then the option applies
* only if the new code is made subject to such option by the copyright
* holder.
*/
package com.sun.xml.ws.policy;
import com.sun.xml.ws.policy.privateutil.PolicyLogger;
import java.util.Collection;
import java.util.LinkedList;
import java.util.List;
import java.util.Queue;
import com.sun.xml.ws.policy.privateutil.LocalizationMessages;
import com.sun.xml.ws.policy.sourcemodel.wspolicy.NamespaceVersion;
import java.util.ArrayList;
/**
* The instance of this class is intended to provide policy intersection mechanism.
*
* @author Marek Potociar (marek.potociar@sun.com)
*/
public final class PolicyIntersector {
static enum CompatibilityMode {
STRICT,
LAX
}
private static final PolicyIntersector STRICT_INTERSECTOR = new PolicyIntersector(CompatibilityMode.STRICT);
private static final PolicyIntersector LAX_INTERSECTOR = new PolicyIntersector(CompatibilityMode.LAX);
private static final PolicyLogger LOGGER = PolicyLogger.getLogger(PolicyIntersector.class);
private CompatibilityMode mode;
/**
* Prevents direct instantiation of this class from outside
* @param intersectionMode intersection mode
*/
private PolicyIntersector(CompatibilityMode intersectionMode) {
this.mode = intersectionMode;
}
/**
* Returns a strict policy intersector that can be used to intersect group of policies.
*
* @return policy intersector instance.
*/
public static PolicyIntersector createStrictPolicyIntersector() {
return PolicyIntersector.STRICT_INTERSECTOR;
}
/**
* Returns a strict policy intersector that can be used to intersect group of policies.
*
* @return policy intersector instance.
*/
public static PolicyIntersector createLaxPolicyIntersector() {
return PolicyIntersector.LAX_INTERSECTOR;
}
/**
* Performs intersection on the input collection of policies and returns the resulting (intersected) policy. If input policy
* collection contains only a single policy instance, no intersection is performed and the instance is directly returned
* as a method call result.
*
* @param policies collection of policies to be intersected. Must not be {@code null} nor empty, otherwise exception is thrown.
* @return intersected policy as a result of perfromed policy intersection. A {@code null} value is never returned.
*
* @throws IllegalArgumentException in case {@code policies} argument is either {@code null} or empty collection.
*/
public Policy intersect(final Policy... policies) {
if (policies == null || policies.length == 0) {
throw LOGGER.logSevereException(new IllegalArgumentException(LocalizationMessages.WSP_0056_NEITHER_NULL_NOR_EMPTY_POLICY_COLLECTION_EXPECTED()));
} else if (policies.length == 1) {
return policies[0];
}
// check for "null" and "empty" policy: if such policy is found return "null" policy,
// or if all policies are "empty", return "empty" policy
boolean found = false;
boolean allPoliciesEmpty = true;
NamespaceVersion latestVersion = null;
for (Policy tested : policies) {
if (tested.isEmpty()) {
found = true;
} else {
if (tested.isNull()) {
found = true;
}
allPoliciesEmpty = false;
}
if (latestVersion == null) {
latestVersion = tested.getNamespaceVersion();
} else if (latestVersion.compareTo(tested.getNamespaceVersion()) < 0) {
latestVersion = tested.getNamespaceVersion();
}
if (found && !allPoliciesEmpty) {
return Policy.createNullPolicy(latestVersion, null, null);
}
}
latestVersion = (latestVersion != null) ? latestVersion : NamespaceVersion.getLatestVersion();
if (allPoliciesEmpty) {
return Policy.createEmptyPolicy(latestVersion, null, null);
}
// simple tests didn't lead to final answer => let's performe some intersecting ;)
final List<AssertionSet> finalAlternatives = new LinkedList<AssertionSet>(policies[0].getContent());
final Queue<AssertionSet> testedAlternatives = new LinkedList<AssertionSet>();
final List<AssertionSet> alternativesToMerge = new ArrayList<AssertionSet>(2);
for (int i = 1; i < policies.length; i++) {
final Collection<AssertionSet> currentAlternatives = policies[i].getContent();
testedAlternatives.clear();
testedAlternatives.addAll(finalAlternatives);
finalAlternatives.clear();
AssertionSet testedAlternative;
while ((testedAlternative = testedAlternatives.poll()) != null) {
for (AssertionSet currentAlternative : currentAlternatives) {
if (testedAlternative.isCompatibleWith(currentAlternative, this.mode)) {
alternativesToMerge.add(testedAlternative);
alternativesToMerge.add(currentAlternative);
finalAlternatives.add(AssertionSet.createMergedAssertionSet(alternativesToMerge));
alternativesToMerge.clear();
}
}
}
}
return Policy.createPolicy(latestVersion, null, null, finalAlternatives);
}
}