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.concepts.ListenerRegistration;
  20 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  21 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  23 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  24 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  25 import org.slf4j.Logger;
  26 import org.slf4j.LoggerFactory;
  27
  28 /**
  29  * Abstract base class for {@link DOMStoreTreeChangePublisher} implementations.
  30  */
  31 public abstract class AbstractDOMStoreTreeChangePublisher extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>> implements DOMStoreTreeChangePublisher {
  32     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMStoreTreeChangePublisher.class);
  33
  34     /**
  35      * Callback for subclass to notify specified registrations of a candidate at a specified path. This method is guaranteed
  36      * to be only called from within {@link #processCandidateTree(DataTreeCandidate)}.
  37      *
  38      * @param registrations Registrations which are affected by the candidate node
  39      * @param path Path of changed candidate node. Guaranteed to match the path specified by the registration
  40      * @param node Candidate node
  41      */
  42     protected abstract void notifyListeners(@Nonnull Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> registrations, @Nonnull YangInstanceIdentifier path, @Nonnull DataTreeCandidateNode node);
  43
  44     /**
  45      * Callback notifying the subclass that the specified registration is being closed and it's user no longer
  46      * wishes to receive notifications. This notification is invoked while the {@link ListenerRegistration#close()}
  47      * method is executing. Subclasses can use this callback to properly remove any delayed notifications pending
  48      * towards the registration.
  49      *
  50      * @param registration Registration which is being closed
  51      */
  52     protected abstract void registrationRemoved(@Nonnull AbstractDOMDataTreeChangeListenerRegistration<?> registration);
  53
  54     /**
  55      * Process a candidate tree with respect to registered listeners.
  56      *
  57      * @param candidate candidate three which needs to be processed
  58      */
  59     protected final void processCandidateTree(@Nonnull final DataTreeCandidate candidate) {
  60         final DataTreeCandidateNode node = candidate.getRootNode();
  61         if (node.getModificationType() == ModificationType.UNMODIFIED) {
  62             LOG.debug("Skipping unmodified candidate {}", candidate);
  63             return;
  64         }
  65
  66         try (final RegistrationTreeSnapshot<AbstractDOMDataTreeChangeListenerRegistration<?>> snapshot = takeSnapshot()) {
  67             final List<PathArgument> toLookup = ImmutableList.copyOf(candidate.getRootPath().getPathArguments());
  68             lookupAndNotify(toLookup, 0, snapshot.getRootNode(), candidate);
  69         }
  70     }
  71
  72     @Override
  73     public final <L extends DOMDataTreeChangeListener> ListenerRegistration<L> registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
  74         // Take the write lock
  75         takeLock();
  76         try {
  77             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node = findNodeFor(treeId.getPathArguments());
  78             final AbstractDOMDataTreeChangeListenerRegistration<L> reg = new AbstractDOMDataTreeChangeListenerRegistration<L>(listener) {
  79                 @Override
  80                 protected void removeRegistration() {
  81                     AbstractDOMStoreTreeChangePublisher.this.removeRegistration(node, this);
  82                     registrationRemoved(this);
  83                 }
  84             };
  85
  86             addRegistration(node, reg);
  87             return reg;
  88         } finally {
  89             // Always release the lock
  90             releaseLock();
  91         }
  92     }
  93
  94     private void lookupAndNotify(final List<PathArgument> args, final int offset, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node, final DataTreeCandidate candidate) {
  95         if (args.size() != offset) {
  96             final PathArgument arg = args.get(offset);
  97
  98             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> exactChild = node.getExactChild(arg);
  99             if (exactChild != null) {
 100                 lookupAndNotify(args, offset + 1, exactChild, candidate);
 101             }
 102
 103             for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> c : node.getInexactChildren(arg)) {
 104                 lookupAndNotify(args, offset + 1, c, candidate);
 105             }
 106         } else {
 107             notifyNode(candidate.getRootPath(), node, candidate.getRootNode());
 108         }
 109     }
 110
 111     private void notifyNode(final YangInstanceIdentifier path, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regNode, final DataTreeCandidateNode candNode) {
 112         if (candNode.getModificationType() == ModificationType.UNMODIFIED) {
 113             LOG.debug("Skipping unmodified candidate {}", path);
 114             return;
 115         }
 116
 117         final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> regs = regNode.getRegistrations();
 118         if (!regs.isEmpty()) {
 119             notifyListeners(regs, path, candNode);
 120         }
 121
 122         for (DataTreeCandidateNode candChild : candNode.getChildNodes()) {
 123             if (candChild.getModificationType() != ModificationType.UNMODIFIED) {
 124                 final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regChild = regNode.getExactChild(candChild.getIdentifier());
 125                 if (regChild != null) {
 126                     notifyNode(path.node(candChild.getIdentifier()), regChild, candChild);
 127                 }
 128
 129                 for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> rc : regNode.getInexactChildren(candChild.getIdentifier())) {
 130                     notifyNode(path.node(candChild.getIdentifier()), rc, candChild);
 131                 }
 132             }
 133         }
 134     }
 135 }