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