dom/mdsal-dom-spi/src/main/java/org/opendaylight/mdsal/dom/spi/store/AbstractDOMStoreTreeChangePublisher.java

   1 /*
   2  * Copyright (c) 2015 Cisco Systems, Inc. and others.  All rights reserved.
   3  *
   4  * This program and the accompanying materials are made available under the
   5  * terms of the Eclipse Public License v1.0 which accompanies this distribution,
   6  * and is available at http://www.eclipse.org/legal/epl-v10.html
   7  */
   8 package org.opendaylight.mdsal.dom.spi.store;
   9
  10 import com.google.common.collect.ImmutableList;
  11 import java.util.Collection;
  12 import java.util.List;
  13 import javax.annotation.Nonnull;
  14 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  15 import org.opendaylight.mdsal.dom.spi.AbstractDOMDataTreeChangeListenerRegistration;
  16 import org.opendaylight.mdsal.dom.spi.AbstractRegistrationTree;
  17 import org.opendaylight.mdsal.dom.spi.RegistrationTreeNode;
  18 import org.opendaylight.mdsal.dom.spi.RegistrationTreeSnapshot;
  19 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  20 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  24 import org.slf4j.Logger;
  25 import org.slf4j.LoggerFactory;
  26
  27 /**
  28  * Abstract base class for {@link DOMStoreTreeChangePublisher} implementations.
  29  */
  30 public abstract class AbstractDOMStoreTreeChangePublisher
  31     extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>>
  32         implements DOMStoreTreeChangePublisher {
  33     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMStoreTreeChangePublisher.class);
  34
  35     /**
  36      * Callback for subclass to notify specified registrations
  37      * of a candidate at a specified path. This method is guaranteed
  38      * to be only called from within {@link #processCandidateTree(DataTreeCandidate)}.
  39      * @param registrations Registrations which are affected by the candidate node
  40      * @param path Path of changed candidate node. Guaranteed to match the path specified by the registration
  41      * @param node Candidate node
  42      */
  43     protected abstract void notifyListeners(
  44             @Nonnull Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> registrations,
  45             @Nonnull YangInstanceIdentifier path, @Nonnull DataTreeCandidateNode node);
  46
  47     /**
  48      * Callback notifying the subclass that the specified registration is being
  49      * closed and it's user no longer
  50      * wishes to receive notifications. This notification is invoked while
  51      * the {@link org.opendaylight.yangtools.concepts.ListenerRegistration#close()}
  52      * method is executing. Subclasses can use this callback to properly
  53      * remove any delayed notifications pending
  54      * towards the registration.
  55      *
  56      * @param registration Registration which is being closed
  57      */
  58     protected abstract void registrationRemoved(
  59             @Nonnull AbstractDOMDataTreeChangeListenerRegistration<?> registration);
  60
  61     /**
  62      * Process a candidate tree with respect to registered listeners.
  63      *
  64      * @param candidate candidate three which needs to be processed
  65      */
  66     protected final void processCandidateTree(@Nonnull final DataTreeCandidate candidate) {
  67         final DataTreeCandidateNode node = candidate.getRootNode();
  68         if (node.getModificationType() == ModificationType.UNMODIFIED) {
  69             LOG.debug("Skipping unmodified candidate {}", candidate);
  70             return;
  71         }
  72
  73         try (final RegistrationTreeSnapshot<AbstractDOMDataTreeChangeListenerRegistration<?>> snapshot
  74                 = takeSnapshot()) {
  75             final List<PathArgument> toLookup
  76                 = ImmutableList.copyOf(candidate.getRootPath().getPathArguments());
  77             lookupAndNotify(toLookup, 0, snapshot.getRootNode(), candidate);
  78         }
  79     }
  80
  81     @Override
  82     public <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
  83         registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
  84         // Take the write lock
  85         takeLock();
  86         try {
  87             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node =
  88                     findNodeFor(treeId.getPathArguments());
  89             final AbstractDOMDataTreeChangeListenerRegistration<L> reg =
  90                     new AbstractDOMDataTreeChangeListenerRegistration<L>(listener) {
  91                 @Override
  92                 protected void removeRegistration() {
  93                     AbstractDOMStoreTreeChangePublisher.this.removeRegistration(node, this);
  94                     registrationRemoved(this);
  95                 }
  96             };
  97
  98             addRegistration(node, reg);
  99             return reg;
 100         } finally {
 101             // Always release the lock
 102             releaseLock();
 103         }
 104     }
 105
 106     private void lookupAndNotify(final List<PathArgument> args,
 107             final int offset, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node,
 108                     final DataTreeCandidate candidate) {
 109         if (args.size() != offset) {
 110             final PathArgument arg = args.get(offset);
 111
 112             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> exactChild
 113                 = node.getExactChild(arg);
 114             if (exactChild != null) {
 115                 lookupAndNotify(args, offset + 1, exactChild, candidate);
 116             }
 117
 118             for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> c :
 119                     node.getInexactChildren(arg)) {
 120                 lookupAndNotify(args, offset + 1, c, candidate);
 121             }
 122         } else {
 123             notifyNode(candidate.getRootPath(), node, candidate.getRootNode());
 124         }
 125     }
 126
 127     private void notifyNode(final YangInstanceIdentifier path,
 128             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regNode,
 129             final DataTreeCandidateNode candNode) {
 130         if (candNode.getModificationType() == ModificationType.UNMODIFIED) {
 131             LOG.debug("Skipping unmodified candidate {}", path);
 132             return;
 133         }
 134
 135         final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> regs = regNode.getRegistrations();
 136         if (!regs.isEmpty()) {
 137             notifyListeners(regs, path, candNode);
 138         }
 139
 140         for (DataTreeCandidateNode candChild : candNode.getChildNodes()) {
 141             if (candChild.getModificationType() != ModificationType.UNMODIFIED) {
 142                 final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regChild =
 143                         regNode.getExactChild(candChild.getIdentifier());
 144                 if (regChild != null) {
 145                     notifyNode(path.node(candChild.getIdentifier()), regChild, candChild);
 146                 }
 147
 148                 for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> rc :
 149                     regNode.getInexactChildren(candChild.getIdentifier())) {
 150                     notifyNode(path.node(candChild.getIdentifier()), rc, candChild);
 151                 }
 152             }
 153         }
 154     }
 155 }