opendaylight/md-sal/sal-dom-spi/src/main/java/org/opendaylight/controller/sal/core/spi/data/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.controller.sal.core.spi.data;
   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.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  15 import org.opendaylight.controller.md.sal.dom.spi.AbstractDOMDataTreeChangeListenerRegistration;
  16 import org.opendaylight.controller.md.sal.dom.spi.AbstractRegistrationTree;
  17 import org.opendaylight.controller.md.sal.dom.spi.RegistrationTreeNode;
  18 import org.opendaylight.controller.md.sal.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 extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>> implements DOMStoreTreeChangePublisher {
  31     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMStoreTreeChangePublisher.class);
  32
  33     /**
  34      * Callback for subclass to notify specified registrations of a candidate at a specified path. This method is guaranteed
  35      * to be only called from within {@link #processCandidateTree(DataTreeCandidate)}.
  36      *
  37      * @param registrations Registrations which are affected by the candidate node
  38      * @param path Path of changed candidate node. Guaranteed to match the path specified by the registration
  39      * @param node Candidate node
  40      */
  41     protected abstract void notifyListeners(@Nonnull Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> registrations, @Nonnull YangInstanceIdentifier path, @Nonnull DataTreeCandidateNode node);
  42
  43     /**
  44      * Callback notifying the subclass that the specified registration is being closed and it's user no longer
  45      * wishes to receive notifications. This notification is invoked while the {@link org.opendaylight.yangtools.concepts.ListenerRegistration#close()}
  46      * method is executing. Subclasses can use this callback to properly remove any delayed notifications pending
  47      * towards the registration.
  48      *
  49      * @param registration Registration which is being closed
  50      */
  51     protected abstract void registrationRemoved(@Nonnull AbstractDOMDataTreeChangeListenerRegistration<?> registration);
  52
  53     /**
  54      * Process a candidate tree with respect to registered listeners.
  55      *
  56      * @param candidate candidate three which needs to be processed
  57      */
  58     protected final void processCandidateTree(@Nonnull final DataTreeCandidate candidate) {
  59         final DataTreeCandidateNode node = candidate.getRootNode();
  60         if (node.getModificationType() == ModificationType.UNMODIFIED) {
  61             LOG.debug("Skipping unmodified candidate {}", candidate);
  62             return;
  63         }
  64
  65         try (final RegistrationTreeSnapshot<AbstractDOMDataTreeChangeListenerRegistration<?>> snapshot = takeSnapshot()) {
  66             final List<PathArgument> toLookup = ImmutableList.copyOf(candidate.getRootPath().getPathArguments());
  67             lookupAndNotify(toLookup, 0, snapshot.getRootNode(), candidate);
  68         }
  69     }
  70
  71     @Override
  72     public final <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L> registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
  73         // Take the write lock
  74         takeLock();
  75         try {
  76             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node = findNodeFor(treeId.getPathArguments());
  77             final AbstractDOMDataTreeChangeListenerRegistration<L> reg = new AbstractDOMDataTreeChangeListenerRegistration<L>(listener) {
  78                 @Override
  79                 protected void removeRegistration() {
  80                     AbstractDOMStoreTreeChangePublisher.this.removeRegistration(node, this);
  81                     registrationRemoved(this);
  82                 }
  83             };
  84
  85             addRegistration(node, reg);
  86             return reg;
  87         } finally {
  88             // Always release the lock
  89             releaseLock();
  90         }
  91     }
  92
  93     private void lookupAndNotify(final List<PathArgument> args, final int offset, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node, final DataTreeCandidate candidate) {
  94         if (args.size() != offset) {
  95             final PathArgument arg = args.get(offset);
  96
  97             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> exactChild = node.getExactChild(arg);
  98             if (exactChild != null) {
  99                 lookupAndNotify(args, offset + 1, exactChild, candidate);
 100             }
 101
 102             for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> c : node.getInexactChildren(arg)) {
 103                 lookupAndNotify(args, offset + 1, c, candidate);
 104             }
 105         } else {
 106             notifyNode(candidate.getRootPath(), node, candidate.getRootNode());
 107         }
 108     }
 109
 110     private void notifyNode(final YangInstanceIdentifier path, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regNode, final DataTreeCandidateNode candNode) {
 111         if (candNode.getModificationType() == ModificationType.UNMODIFIED) {
 112             LOG.debug("Skipping unmodified candidate {}", path);
 113             return;
 114         }
 115
 116         final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> regs = regNode.getRegistrations();
 117         if (!regs.isEmpty()) {
 118             notifyListeners(regs, path, candNode);
 119         }
 120
 121         for (DataTreeCandidateNode candChild : candNode.getChildNodes()) {
 122             if (candChild.getModificationType() != ModificationType.UNMODIFIED) {
 123                 final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regChild = regNode.getExactChild(candChild.getIdentifier());
 124                 if (regChild != null) {
 125                     notifyNode(path.node(candChild.getIdentifier()), regChild, candChild);
 126                 }
 127
 128                 for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> rc : regNode.getInexactChildren(candChild.getIdentifier())) {
 129                     notifyNode(path.node(candChild.getIdentifier()), rc, candChild);
 130                 }
 131             }
 132         }
 133     }
 134 }