Add a builder to calculate whether policy sets apply to the element to which they are attached.

git-svn-id: http://svn.us.apache.org/repos/asf/tuscany@924993 13f79535-47bb-0310-9956-ffa450edef68

2 files changed, 183 insertions, 96 deletions

diff --git a/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAppliesToBuilderImpl.java b/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAppliesToBuilderImpl.java
new file mode 100644
index 0000000000..2417940b1c
--- /dev/null
+++ b/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAppliesToBuilderImpl.java
@@ -0,0 +1,171 @@
+/*
+ * 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.builder.impl;
+
+
+import java.util.ArrayList;
+import java.util.HashMap;
+import java.util.List;
+import java.util.Map;
+
+import javax.xml.xpath.XPathConstants;
+import javax.xml.xpath.XPathExpression;
+
+import org.apache.tuscany.sca.assembly.Component;
+import org.apache.tuscany.sca.assembly.ComponentReference;
+import org.apache.tuscany.sca.assembly.ComponentService;
+import org.apache.tuscany.sca.assembly.Composite;
+import org.apache.tuscany.sca.assembly.Endpoint;
+import org.apache.tuscany.sca.assembly.EndpointReference;
+import org.apache.tuscany.sca.assembly.Implementation;
+import org.apache.tuscany.sca.assembly.builder.BuilderContext;
+import org.apache.tuscany.sca.assembly.builder.CompositeBuilderException;
+
+import org.apache.tuscany.sca.core.ExtensionPointRegistry;
+import org.apache.tuscany.sca.policy.PolicySet;
+import org.apache.tuscany.sca.policy.PolicySubject;
+import org.w3c.dom.Document;
+import org.w3c.dom.Node;
+import org.w3c.dom.NodeList;
+
+/**
+ * A builder that checks that policy sets apply to the elements to which they are attached. 
+ * Any that don't are removed. It first creates a DOM model for the composite so that the xpath
+ * expression can be evaluated. For each element that holds a policy set is calculates the 
+ * appliesTo nodes and checks that the current element is in the set. If not the policySet is
+ * removed from the element   
+ *
+ * @version $Rev$ $Date$
+ */
+public class PolicyAppliesToBuilderImpl extends PolicyAttachmentBuilderImpl {
+
+    public PolicyAppliesToBuilderImpl(ExtensionPointRegistry registry) {
+        super(registry);
+    }
+
+    public String getID() {
+        return "org.apache.tuscany.sca.policy.builder.PolicyAppliesToBuilder";
+    }
+
+    public Composite build(Composite composite, BuilderContext context)
+        throws CompositeBuilderException {
+        try {
+            // create a DOM for the Domain Composite Infoset
+            Document document = saveAsDOM(composite);
+            
+            // create a cache of evaluated node against each policy set so we don't
+            // have to keep evaluating policy sets that appear in multiple places
+            Map<PolicySet, List<PolicySubject>> appliesToSubjects = new HashMap<PolicySet, List<PolicySubject>>();
+            
+            // for all implementations, endpoint and endpoint references check that 
+            // the policy sets validly apply
+            return checkAppliesTo(document, appliesToSubjects, composite, context);
+           
+        } catch (Exception e) {
+            throw new CompositeBuilderException(e);
+        }
+    }
+    
+    private Composite checkAppliesTo(Document document, Map<PolicySet, List<PolicySubject>> appliesToSubjects, Composite composite, BuilderContext context) throws Exception {
+        // look at policies recursively
+        for (Component component : composite.getComponents()) {
+            Implementation implementation = component.getImplementation();
+            if (implementation instanceof Composite) {
+                checkAppliesTo(document, appliesToSubjects, (Composite)implementation, context);
+            }
+        }
+
+        for (Component component : composite.getComponents()) {
+
+            for (ComponentService componentService : component.getServices()) {
+                for (Endpoint ep : componentService.getEndpoints()) {
+                    if (ep.getBinding() instanceof PolicySubject) {
+                        checkAppliesToSubject(document, appliesToSubjects, composite, (PolicySubject)ep.getBinding(), ep.getPolicySets());
+                    }
+                }
+            }
+
+            for (ComponentReference componentReference : component.getReferences()) {
+                for (EndpointReference epr : componentReference.getEndpointReferences()) {
+                    if (epr.getBinding() instanceof PolicySubject) {
+                        checkAppliesToSubject(document, appliesToSubjects, composite, (PolicySubject)epr.getBinding(), epr.getPolicySets());
+                    }
+                }
+            }
+
+            Implementation implementation = component.getImplementation();
+            if (implementation != null && 
+                implementation instanceof PolicySubject) {
+                checkAppliesToSubject(document, appliesToSubjects, composite, implementation, implementation.getPolicySets());
+            }
+        }
+        
+        return composite;
+    }
+    
+    /**
+     * Checks that all the provided policy sets apply to the provided policy subject
+     * 
+     * @param document
+     * @param appliesToSubjects
+     * @param policySubject
+     * @param policySets
+     * @return
+     * @throws Exception
+     */
+    private void checkAppliesToSubject(Document document, Map<PolicySet, List<PolicySubject>> appliesToSubjects, Composite composite, PolicySubject policySubject, List<PolicySet> policySets) throws Exception {
+        List<PolicySet> policySetsToRemove = new ArrayList<PolicySet>();
+        
+        for (PolicySet policySet : policySets){
+            List<PolicySubject> subjects = appliesToSubjects.get(policySet);
+            
+            if (subjects == null){
+                XPathExpression appliesTo = policySet.getAppliesToXPathExpression();
+                if (appliesTo != null) {
+                    NodeList nodes = (NodeList)appliesTo.evaluate(document, XPathConstants.NODESET);
+                    
+                    if (nodes.getLength() > 0){
+                        subjects = new ArrayList<PolicySubject>();
+                        appliesToSubjects.put(policySet, subjects);
+                    }
+                    
+                    for (int i = 0; i < nodes.getLength(); i++) {
+                        Node node = nodes.item(i);
+                        String index = getStructuralURI(node);
+                        PolicySubject subject = lookup(composite, index);
+                        subjects.add(subject);
+                    }
+                }
+            }
+            
+            if (subjects != null){
+                if (!subjects.contains(policySubject)){
+                    policySetsToRemove.add(policySet);
+                }
+            } 
+            
+            // TODO - If no "appliesTo" is provided does the policy set apply to 
+            //        everything or nothing?
+
+        }
+        
+        policySets.removeAll(policySetsToRemove);      
+    }    
+}
diff --git a/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAttachmentBuilderImpl.java b/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAttachmentBuilderImpl.java
index c8f4461cdd..e9a49c8842 100644
--- a/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAttachmentBuilderImpl.java
+++ b/sca-java-2.x/trunk/modules/builder/src/main/java/org/apache/tuscany/sca/builder/impl/PolicyAttachmentBuilderImpl.java
@@ -19,14 +19,9 @@
 
 package org.apache.tuscany.sca.builder.impl;
 
-import static javax.xml.XMLConstants.DEFAULT_NS_PREFIX;
-import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE;
-import static javax.xml.XMLConstants.XMLNS_ATTRIBUTE_NS_URI;
-
 import java.io.IOException;
 import java.io.StringWriter;
 import java.util.Set;
-import java.util.StringTokenizer;
 
 import javax.xml.namespace.QName;
 import javax.xml.stream.XMLStreamException;
@@ -56,7 +51,6 @@ import org.apache.tuscany.sca.definitions.Definitions;
 import org.apache.tuscany.sca.monitor.Monitor;
 import org.apache.tuscany.sca.policy.PolicySet;
 import org.apache.tuscany.sca.policy.PolicySubject;
-import org.w3c.dom.Attr;
 import org.w3c.dom.Document;
 import org.w3c.dom.Element;
 import org.w3c.dom.Node;
@@ -66,18 +60,18 @@ import org.xml.sax.SAXException;
 /**
  * A builder that attaches policy sets to the domain composite using the xpath defined by
  * the attachTo attribute. It first creates a DOM model for the composite so that the xpath
- * expression can be evaluated. For the nodes selected by the xpath, add the policySets attribute
- * to the subject element. Then reload the patched DOM into a Composite model again.  
+ * expression can be evaluated. For the nodes selected by the xpath, caluclate the element
+ * URI and add the policy set into the composite model  
  *
  * @version $Rev$ $Date$
  */
 public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
-    private static final String BUILDER_VALIDATION_BUNDLE = "org.apache.tuscany.sca.builder.builder-validation-messages";
+    protected static final String BUILDER_VALIDATION_BUNDLE = "org.apache.tuscany.sca.builder.builder-validation-messages";
     
-    private StAXHelper staxHelper;
-    private DOMHelper domHelper;
-    private ExtensionPointRegistry registry;
-    private StAXArtifactProcessor<Composite> processor;
+    protected StAXHelper staxHelper;
+    protected DOMHelper domHelper;
+    protected ExtensionPointRegistry registry;
+    protected StAXArtifactProcessor<Composite> processor;
 
     public PolicyAttachmentBuilderImpl(ExtensionPointRegistry registry) {
         this.registry = registry;
@@ -197,7 +191,7 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
         }            
     }
 
-    private Document saveAsDOM(Composite composite) throws XMLStreamException, ContributionWriteException, IOException,
+    protected Document saveAsDOM(Composite composite) throws XMLStreamException, ContributionWriteException, IOException,
         SAXException {
         // First write the composite into a DOM document so that we can apply the xpath
         StringWriter sw = new StringWriter();
@@ -218,7 +212,7 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
     private static final QName SERVICE = new QName(Base.SCA11_NS, "service");
     private static final QName REFERENCE = new QName(Base.SCA11_NS, "reference");
 
-    private static String getStructuralURI(Node node) {
+    protected static String getStructuralURI(Node node) {
         if (node != null) {
             QName name = new QName(node.getNamespaceURI(), node.getLocalName());
             if (COMPONENT.equals(name)) {
@@ -253,7 +247,7 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
         return null;
     }
 
-    private Binding getBinding(Contract contract, String name) {
+    protected Binding getBinding(Contract contract, String name) {
         for (Binding binding : contract.getBindings()) {
             if (name.equals(binding.getName())) {
                 return binding;
@@ -262,7 +256,7 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
         return null;
     }
 
-    private PolicySubject lookup(Composite composite, String structuralURI) {
+    protected PolicySubject lookup(Composite composite, String structuralURI) {
         if (structuralURI == null) {
             return null;
         }
@@ -287,7 +281,7 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
                     int pos = path.indexOf('/');
                     if (pos != -1) {
                         binding = path.substring(pos + 1);
-                        path = path.substring(0, index);
+                        path = path.substring(0, pos);
                         if ("service-binding".equals(prefix)) {
                             service = path;
                         } else if ("reference-binding".equals(prefix)) {
@@ -339,82 +333,4 @@ public class PolicyAttachmentBuilderImpl implements CompositeBuilder {
         }
         return null;
     }
-
-    /**
-     * Attach the policySet to the given DOM node 
-     * @param node The DOM node (should be an element)
-     * @param policySet The policy set to be attached
-     * @return true if the element is changed, false if the element already contains the same policy set
-     * and no change is made
-     */
-    private boolean attach(Node node, PolicySet policySet) {
-        Element element = (Element)node;
-        Document document = element.getOwnerDocument();
-
-        QName qname = policySet.getName();
-        String prefix = DOMHelper.getPrefix(element, qname.getNamespaceURI());
-        if (prefix == null) {
-            // Find the a non-conflicting prefix
-            int i = 0;
-            while (true) {
-                prefix = "ns" + i;
-                String ns = DOMHelper.getNamespaceURI(element, prefix);
-                if (ns == null) {
-                    break;
-                }
-            }
-            // Declare the namespace
-            Attr nsAttr = document.createAttributeNS(XMLNS_ATTRIBUTE_NS_URI, XMLNS_ATTRIBUTE + ":" + prefix);
-            nsAttr.setValue(qname.getNamespaceURI());
-            element.setAttributeNodeNS(nsAttr);
-        }
-        // Form the value as a qualified name
-        String qvalue = null;
-        if (DEFAULT_NS_PREFIX.equals(prefix)) {
-            qvalue = qname.getLocalPart();
-        } else {
-            qvalue = prefix + ":" + qname.getLocalPart();
-        }
-
-        // Check if the attribute exists
-        Attr attr = element.getAttributeNode("policySets");
-        if (attr == null) {
-            // Create the policySets attr
-            attr = document.createAttributeNS(null, "policySets");
-            attr.setValue(qvalue);
-            element.setAttributeNodeNS(attr);
-            return true;
-        } else {
-            // Append to the existing value
-            boolean duplicate = false;
-            String value = attr.getValue();
-            StringTokenizer tokenizer = new StringTokenizer(value);
-            while (tokenizer.hasMoreTokens()) {
-                String ps = tokenizer.nextToken();
-                int index = ps.indexOf(':');
-                String ns = null;
-                String localName = null;
-                if (index == -1) {
-                    ns = DOMHelper.getNamespaceURI(element, DEFAULT_NS_PREFIX);
-                    localName = ps;
-                } else {
-                    ns = DOMHelper.getNamespaceURI(element, ps.substring(0, index));
-                    localName = ps.substring(index + 1);
-                }
-                QName psName = new QName(ns, localName);
-                if (qname.equals(psName)) {
-                    duplicate = true;
-                    break;
-                }
-            }
-            if (!duplicate) {
-                // REVIEW: [rfeng] How to comply to POL40012?
-                value = value + " " + qvalue;
-                attr.setValue(value.trim());
-                return true;
-            }
-            return false;
-        }
-    }
-
 }