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Diffstat (limited to 'sca-java-1.x/branches/sca-java-1.6.2/modules/policy/src/main/java/org/apache/tuscany/sca/policy/util/PolicyComputationUtils.java')
| -rw-r--r-- | sca-java-1.x/branches/sca-java-1.6.2/modules/policy/src/main/java/org/apache/tuscany/sca/policy/util/PolicyComputationUtils.java | 418 |
1 files changed, 418 insertions, 0 deletions
diff --git a/sca-java-1.x/branches/sca-java-1.6.2/modules/policy/src/main/java/org/apache/tuscany/sca/policy/util/PolicyComputationUtils.java b/sca-java-1.x/branches/sca-java-1.6.2/modules/policy/src/main/java/org/apache/tuscany/sca/policy/util/PolicyComputationUtils.java new file mode 100644 index 0000000000..2e4c6a9d78 --- /dev/null +++ b/sca-java-1.x/branches/sca-java-1.6.2/modules/policy/src/main/java/org/apache/tuscany/sca/policy/util/PolicyComputationUtils.java @@ -0,0 +1,418 @@ +/* + * Licensed to the Apache Software Foundation (ASF) under one + * or more contributor license agreements. See the NOTICE file + * distributed with this work for additional information + * regarding copyright ownership. The ASF licenses this file + * to you under the Apache License, Version 2.0 (the + * "License"); you may not use this file except in compliance + * with the License. You may obtain a copy of the License at + * + * http://www.apache.org/licenses/LICENSE-2.0 + * + * Unless required by applicable law or agreed to in writing, + * software distributed under the License is distributed on an + * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY + * KIND, either express or implied. See the License for the + * specific language governing permissions and limitations + * under the License. + */ + +package org.apache.tuscany.sca.policy.util; + +import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE_NS_URI; + +import java.io.InputStream; +import java.io.StringWriter; +import java.security.AccessController; +import java.security.PrivilegedActionException; +import java.security.PrivilegedExceptionAction; +import java.util.ArrayList; +import java.util.Collection; +import java.util.HashMap; +import java.util.Iterator; +import java.util.List; +import java.util.Map; + +import javax.xml.namespace.NamespaceContext; +import javax.xml.parsers.DocumentBuilder; +import javax.xml.parsers.DocumentBuilderFactory; +import javax.xml.transform.Result; +import javax.xml.transform.Source; +import javax.xml.transform.Transformer; +import javax.xml.transform.TransformerConfigurationException; +import javax.xml.transform.TransformerException; +import javax.xml.transform.TransformerFactory; +import javax.xml.transform.dom.DOMSource; +import javax.xml.transform.stream.StreamResult; +import javax.xml.xpath.XPathConstants; +import javax.xml.xpath.XPathExpression; +import javax.xml.xpath.XPathExpressionException; + +import org.apache.tuscany.sca.policy.Intent; +import org.apache.tuscany.sca.policy.IntentAttachPointType; +import org.apache.tuscany.sca.policy.PolicySet; +import org.apache.tuscany.sca.policy.ProfileIntent; +import org.w3c.dom.Document; +import org.w3c.dom.Element; +import org.w3c.dom.Node; +import org.w3c.dom.NodeList; + +/** + * Utility methods used during computation of PolicyIntents and PolicySets sets + * + * @version $Rev$ $Date$ + */ +public class PolicyComputationUtils { + private static final String POLICYSET_PREFIX = "tp_"; + private static final String APPLICABLE_POLICYSET_ATTR_NS = "http://tuscany.apache.org/xmlns/sca/1.0"; + private static final String APPLICABLE_POLICYSET_ATTR = "applicablePolicySets"; + private static final String POLICY_SETS_ATTR = "policySets"; + private static final String APPLICABLE_POLICYSET_ATTR_PREFIX = "tuscany"; + private static final String SCA10_NS = "http://www.osoa.org/xmlns/sca/1.0"; + + /** + * This method unconditionally adds intents from the source list to the target list. + * It is used for intermediate intent inheritance between promotion levels + * (e.g. between a composite service and a component service). It does not check + * whether there are conflicting (mutually exclusive) intents. This is because + * promotion cannot override intents. If the resulting target list has conflicting + * intents, this will be detected later during policy computation. + */ + public static void addInheritedIntents(List<Intent> sourceList, List<Intent> targetList) { + if (sourceList != null) { + targetList.addAll(sourceList); + } + } + + public static void addInheritedPolicySets(List<PolicySet> sourceList, + List<PolicySet> targetList, + boolean checkOverrides) { + // check overrides is true when policysets are to be copied from + // componentType to component level + if (checkOverrides) { + // aggregate all the provided intents present in the target + List<Intent> targetProvidedIntents = new ArrayList<Intent>(); + for (PolicySet policySet : targetList) { + targetProvidedIntents.addAll(policySet.getProvidedIntents()); + } + + // for every policy set in the source check if it provides one of + // the intents that is + // already provided by the policysets in the destination and do not + // copy them. + for (PolicySet policySet : sourceList) { + for (Intent sourceProvidedIntent : policySet.getProvidedIntents()) { + if (!targetProvidedIntents.contains(sourceProvidedIntent)) { + targetList.add(policySet); + } + } + } + } else { + targetList.addAll(sourceList); + } + } + + /** + * This method is used to inherit intents and policy sets between hierarchical levels + * within the same composite (e.g. between a component and its services and references). + * In this case the source intents and policy sets provide defaults which are inherited + * into the target lists only when there is no conflict. For example consider a component + * with 3 references. The component level requires intent 'propagatesTransaction'. + * Reference 1 and 2 do not specify an intent, but reference 3 requires 'suspendsTransaction'. + * In this case the 'propagatesTransaction' intent is inherited by reference 1 and 2 + * but not by reference 3. + */ + public static void addDefaultPolicies(List<Intent> sourceIntents, + List<PolicySet> sourcePolicySets, + List<Intent> targetIntents, + List<PolicySet> targetPolicySets) + { + // form a list of all intents required by the target + List<Intent> combinedTargetIntents = new ArrayList<Intent>(); + combinedTargetIntents.addAll(findAndExpandProfileIntents(targetIntents)); + for (PolicySet targetPolicySet : targetPolicySets) { + combinedTargetIntents.addAll(findAndExpandProfileIntents(targetPolicySet.getProvidedIntents())); + } + + // inherit intents in the source list that do not conflict with intents already in the target list + for (Intent sourceIntent : findAndExpandProfileIntents(sourceIntents)) { + boolean conflict = false; + for (Intent excluded : sourceIntent.getExcludedIntents()) { + if (combinedTargetIntents.contains(excluded)) { + conflict = true; + break; + } + } + if (!conflict) { + targetIntents.add(sourceIntent); + } + } + + // inherit policy sets in the source list that do not conflict with policy sets or intents + // in the target list + for (PolicySet sourcePolicySet : sourcePolicySets) { + boolean conflict = false; + List<Intent> providedIntents = findAndExpandProfileIntents(sourcePolicySet.getProvidedIntents()); + checkConflict: for (Intent intent : providedIntents) { + for (Intent excluded : intent.getExcludedIntents()) { + if (combinedTargetIntents.contains(excluded)) { + conflict = true; + break checkConflict; + } + } + } + if (!conflict) + targetPolicySets.add(sourcePolicySet); + } + + } + + public static void checkForMutuallyExclusiveIntents( + List<Intent> intents, + List<PolicySet> policySets, + IntentAttachPointType intentAttachPointType, + String id) throws PolicyValidationException + { + // gather all intents (keeping track of where they come from) + Map<Intent, PolicySet> combinedIntents = new HashMap<Intent,PolicySet>(); + for (PolicySet policySet : policySets) { + for (Intent providedIntent : findAndExpandProfileIntents(policySet.getProvidedIntents())) { + combinedIntents.put(providedIntent, policySet); + } + } + for (Intent intent : intents) { + combinedIntents.put(intent, null); + } + + // check for conflicts + for (Intent intent : combinedIntents.keySet()) { + for (Intent excluded : intent.getExcludedIntents()) { + if (combinedIntents.keySet().contains(excluded)) { + String sIntent1, sIntent2; + if (combinedIntents.get(intent) == null) + sIntent1 = intent.getName().toString(); + else + sIntent1 = intent.getName().toString() + " in policy set " + combinedIntents.get(intent).getName().toString(); + if (combinedIntents.get(excluded) == null) + sIntent2 = excluded.getName().toString(); + else + sIntent2 = excluded.getName().toString() + " in policy set " + combinedIntents.get(excluded).getName().toString(); + throw new PolicyValidationException( + intentAttachPointType.getName() + " for " + id + + " uses mutually-exclusive intents " + sIntent1 + " and " + sIntent2); + } + } + } + } + + public static void expandProfileIntents(List<Intent> intents) { + List<Intent> expandedIntents = null; + if ( intents.size() > 0 ) { + expandedIntents = findAndExpandProfileIntents(intents); + intents.clear(); + intents.addAll(expandedIntents); + } + } + + public static List<Intent> findAndExpandProfileIntents(List<Intent> intents) { + List<Intent> expandedIntents = new ArrayList<Intent>(); + for ( Intent intent : intents ) { + if ( intent instanceof ProfileIntent ) { + ProfileIntent profileIntent = (ProfileIntent)intent; + List<Intent> requiredIntents = profileIntent.getRequiredIntents(); + expandedIntents.addAll(findAndExpandProfileIntents(requiredIntents)); + } else { + expandedIntents.add(intent); + } + } + return expandedIntents; + } + + private static byte[] addApplicablePolicySets(Document doc, Collection<PolicySet> policySets) + throws XPathExpressionException, TransformerConfigurationException, TransformerException { + + for (PolicySet policySet : policySets) { + if (policySet.getAppliesTo() != null) { + addApplicablePolicySets(policySet, doc); + } + + if (policySet.getAlwaysAppliesTo() != null) { + addAlwaysApplicablePolicySets(policySet, doc); + } + } + + StringWriter sw = new StringWriter(); + final Source domSource = new DOMSource(doc); + final Result finalResult = new StreamResult(sw); + final Transformer transformer = TransformerFactory.newInstance().newTransformer(); + // transformer.setOutputProperty("omit-xml-declaration", "yes"); + // Allow priviledged access to let transformers read property files. Requires + // PropertyPermission in security policy. + try { + AccessController.doPrivileged(new PrivilegedExceptionAction<Object>() { + public Object run() throws TransformerException { + transformer.transform(domSource, finalResult); + return null; + } + }); + } catch (PrivilegedActionException e) { + throw (TransformerException)e.getException(); + } + + return sw.toString().getBytes(); + } + + private static void addAlwaysApplicablePolicySets(PolicySet policySet, + Document doc) throws XPathExpressionException { + XPathExpression expression = policySet.getAlwaysAppliesToXPathExpression(); + NodeList result = (NodeList)expression.evaluate(doc, XPathConstants.NODESET); + + if (result != null) { + for (int counter = 0; counter < result.getLength(); ++counter) { + Node aResultNode = result.item(counter); + + String alwaysApplicablePolicySets = null; + + String policySetPrefix = + declareNamespace((Element)aResultNode, policySet.getName().getNamespaceURI()); + String policySetsAttrPrefix = + declareNamespace((Element)aResultNode, SCA10_NS); + if (aResultNode.getAttributes().getNamedItem(POLICY_SETS_ATTR) != null) { + alwaysApplicablePolicySets = + aResultNode.getAttributes().getNamedItem(POLICY_SETS_ATTR).getNodeValue(); + } + + if (alwaysApplicablePolicySets != null && alwaysApplicablePolicySets.length() > 0) { + alwaysApplicablePolicySets = + alwaysApplicablePolicySets + " " + + policySetPrefix + + ":" + + policySet.getName().getLocalPart(); + } else { + alwaysApplicablePolicySets = + policySetPrefix + ":" + policySet.getName().getLocalPart(); + } + + ((Element)aResultNode).setAttribute(POLICY_SETS_ATTR, alwaysApplicablePolicySets); + } + } + } + + private static void addApplicablePolicySets(PolicySet policySet, + Document doc) throws XPathExpressionException { + XPathExpression expression = policySet.getAppliesToXPathExpression(); + NodeList result = (NodeList)expression.evaluate(doc, XPathConstants.NODESET); + + if (result != null) { + for (int counter = 0; counter < result.getLength(); ++counter) { + Node aResultNode = result.item(counter); + + String applicablePolicySets = null; + + String policySetPrefix = + declareNamespace((Element)aResultNode, policySet.getName().getNamespaceURI()); + String appPolicyAttrPrefix = + declareNamespace((Element)aResultNode, + APPLICABLE_POLICYSET_ATTR_NS); + if (aResultNode.getAttributes().getNamedItemNS(APPLICABLE_POLICYSET_ATTR_NS, + APPLICABLE_POLICYSET_ATTR) != null) { + applicablePolicySets = + aResultNode.getAttributes().getNamedItemNS(APPLICABLE_POLICYSET_ATTR_NS, + APPLICABLE_POLICYSET_ATTR) + .getNodeValue(); + } + + if (applicablePolicySets != null && applicablePolicySets.length() > 0) { + applicablePolicySets = + applicablePolicySets + " " + + policySetPrefix + + ":" + + policySet.getName().getLocalPart(); + } else { + applicablePolicySets = + policySetPrefix + ":" + policySet.getName().getLocalPart(); + } + + ((Element)aResultNode).setAttributeNS(APPLICABLE_POLICYSET_ATTR_NS, + appPolicyAttrPrefix + ":" + + APPLICABLE_POLICYSET_ATTR, + applicablePolicySets); + } + } + } + + public static byte[] addApplicablePolicySets(InputStream is, Collection<PolicySet> domainPolicySets, DocumentBuilderFactory documentBuilderFactory) throws Exception { + documentBuilderFactory.setNamespaceAware(true); + DocumentBuilder db = documentBuilderFactory.newDocumentBuilder(); + Document doc = db.parse(is); + is.close(); + return addApplicablePolicySets(doc, domainPolicySets); + } + + private static class DOMNamespaceContext implements NamespaceContext { + private Node node; + + /** + * @param node + */ + public DOMNamespaceContext(Node node) { + super(); + this.node = node; + } + + public String getNamespaceURI(String prefix) { + return node.lookupNamespaceURI(prefix); + } + + public String getPrefix(String namespaceURI) { + return node.lookupPrefix(namespaceURI); + } + + public Iterator<?> getPrefixes(String namespaceURI) { + return null; + } + + } + + private static String declareNamespace(Element element, String ns) { + if (ns == null) { + ns = ""; + } + Node node = element; + String prefix = ""; + boolean declared = false; + while (node != null && node.getNodeType() == Node.ELEMENT_NODE) { + if ( node.lookupPrefix(ns) != null ) { + prefix = node.lookupPrefix(ns); + declared = true; + break; + } else { + /*NamedNodeMap attrs = node.getAttributes(); + if (attrs == null) { + break; + } + Node attr = attrs.getNamedItem(qname); + if (attr != null) { + declared = ns.equals(attr.getNodeValue()); + break; + }*/ + node = node.getParentNode(); + } + } + if (!declared) { + // Find an available prefix + for (int i=1; ; i++) { + prefix = POLICYSET_PREFIX + i; + if (element.lookupNamespaceURI(prefix) == null) { + break; + } + } + String qname = "xmlns:" + prefix; + org.w3c.dom.Attr attr = element.getOwnerDocument().createAttributeNS(XMLNS_ATTRIBUTE_NS_URI, qname); + attr.setValue(ns); + element.setAttributeNodeNS(attr); + } + return prefix; + } + +} |