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 java.util.Collection;
  11 import java.util.List;
  12 import javax.annotation.Nonnull;
  13 import org.opendaylight.controller.md.sal.dom.api.DOMDataTreeChangeListener;
  14 import org.opendaylight.controller.md.sal.dom.spi.AbstractDOMDataTreeChangeListenerRegistration;
  15 import org.opendaylight.mdsal.dom.spi.AbstractRegistrationTree;
  16 import org.opendaylight.mdsal.dom.spi.RegistrationTreeNode;
  17 import org.opendaylight.mdsal.dom.spi.RegistrationTreeSnapshot;
  18 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  19 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  20 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  21 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  22 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  23 import org.slf4j.Logger;
  24 import org.slf4j.LoggerFactory;
  25
  26 /**
  27  * Abstract base class for {@link DOMStoreTreeChangePublisher} implementations.
  28  */
  29 public abstract class AbstractDOMStoreTreeChangePublisher
  30         extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>>
  31         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
  36      * guaranteed 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<?>>
  43             registrations, @Nonnull YangInstanceIdentifier path, @Nonnull DataTreeCandidateNode node);
  44
  45     /**
  46      * Callback notifying the subclass that the specified registration is being closed and it's user no longer
  47      * wishes to receive notifications. This notification is invoked while the
  48      * {@link org.opendaylight.yangtools.concepts.ListenerRegistration#close()}
  49      * method is executing. Subclasses can use this callback to properly remove any delayed notifications pending
  50      * towards the registration.
  51      *
  52      * @param registration Registration which is being closed
  53      */
  54     protected abstract void registrationRemoved(@Nonnull AbstractDOMDataTreeChangeListenerRegistration<?> registration);
  55
  56     /**
  57      * Process a candidate tree with respect to registered listeners.
  58      *
  59      * @param candidate candidate three which needs to be processed
  60      */
  61     protected final void processCandidateTree(@Nonnull final DataTreeCandidate candidate) {
  62         final DataTreeCandidateNode node = candidate.getRootNode();
  63         if (node.getModificationType() == ModificationType.UNMODIFIED) {
  64             LOG.debug("Skipping unmodified candidate {}", candidate);
  65             return;
  66         }
  67
  68         try (RegistrationTreeSnapshot<AbstractDOMDataTreeChangeListenerRegistration<?>> snapshot = takeSnapshot()) {
  69             lookupAndNotify(candidate.getRootPath().getPathArguments(), 0, snapshot.getRootNode(), candidate);
  70         }
  71     }
  72
  73     @Override
  74     public final <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
  75             registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
  76         // Take the write lock
  77         takeLock();
  78         try {
  79             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node =
  80                     findNodeFor(treeId.getPathArguments());
  81             final AbstractDOMDataTreeChangeListenerRegistration<L> reg =
  82                 new AbstractDOMDataTreeChangeListenerRegistration<L>(listener) {
  83                     @Override
  84                     protected void removeRegistration() {
  85                         AbstractDOMStoreTreeChangePublisher.this.removeRegistration(node, this);
  86                         registrationRemoved(this);
  87                     }
  88             };
  89
  90             addRegistration(node, reg);
  91             return reg;
  92         } finally {
  93             // Always release the lock
  94             releaseLock();
  95         }
  96     }
  97
  98     private void lookupAndNotify(final List<PathArgument> args, final int offset,
  99             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node,
 100             final DataTreeCandidate candidate) {
 101         if (args.size() != offset) {
 102             final PathArgument arg = args.get(offset);
 103
 104             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> exactChild =
 105                     node.getExactChild(arg);
 106             if (exactChild != null) {
 107                 lookupAndNotify(args, offset + 1, exactChild, candidate);
 108             }
 109
 110             for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> c :
 111                     node.getInexactChildren(arg)) {
 112                 lookupAndNotify(args, offset + 1, c, candidate);
 113             }
 114         } else {
 115             notifyNode(candidate.getRootPath(), node, candidate.getRootNode());
 116         }
 117     }
 118
 119     private void notifyNode(final YangInstanceIdentifier path,
 120             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regNode,
 121             final DataTreeCandidateNode candNode) {
 122         if (candNode.getModificationType() == ModificationType.UNMODIFIED) {
 123             LOG.debug("Skipping unmodified candidate {}", path);
 124             return;
 125         }
 126
 127         final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> regs = regNode.getRegistrations();
 128         if (!regs.isEmpty()) {
 129             notifyListeners(regs, path, candNode);
 130         }
 131
 132         for (DataTreeCandidateNode candChild : candNode.getChildNodes()) {
 133             if (candChild.getModificationType() != ModificationType.UNMODIFIED) {
 134                 final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regChild =
 135                         regNode.getExactChild(candChild.getIdentifier());
 136                 if (regChild != null) {
 137                     notifyNode(path.node(candChild.getIdentifier()), regChild, candChild);
 138                 }
 139
 140                 for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> rc :
 141                         regNode.getInexactChildren(candChild.getIdentifier())) {
 142                     notifyNode(path.node(candChild.getIdentifier()), rc, candChild);
 143                 }
 144             }
 145         }
 146     }
 147 }