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 com.google.common.collect.ListMultimap;
  12 import com.google.common.collect.Multimap;
  13 import com.google.common.collect.Multimaps;
  14 import java.util.ArrayList;
  15 import java.util.Collection;
  16 import java.util.IdentityHashMap;
  17 import java.util.List;
  18 import org.eclipse.jdt.annotation.NonNull;
  19 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  20 import org.opendaylight.mdsal.dom.spi.AbstractDOMDataTreeChangeListenerRegistration;
  21 import org.opendaylight.mdsal.dom.spi.AbstractRegistrationTree;
  22 import org.opendaylight.mdsal.dom.spi.RegistrationTreeNode;
  23 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  25 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidate;
  26 import org.opendaylight.yangtools.yang.data.tree.api.DataTreeCandidateNode;
  27 import org.opendaylight.yangtools.yang.data.tree.api.ModificationType;
  28 import org.opendaylight.yangtools.yang.data.tree.spi.DataTreeCandidates;
  29 import org.slf4j.Logger;
  30 import org.slf4j.LoggerFactory;
  31
  32 /**
  33  * Abstract base class for {@link DOMStoreTreeChangePublisher} implementations.
  34  */
  35 public abstract class AbstractDOMStoreTreeChangePublisher
  36     extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>>
  37         implements DOMStoreTreeChangePublisher {
  38     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMStoreTreeChangePublisher.class);
  39
  40     /**
  41      * Callback for subclass to notify a specified registration of a list of candidates. This method is guaranteed
  42      * to be only called from within {@link #processCandidateTree(DataTreeCandidate)}.
  43      * @param registration the registration to notify
  44      * @param changes the list of DataTreeCandidate changes
  45      */
  46     protected abstract void notifyListener(@NonNull AbstractDOMDataTreeChangeListenerRegistration<?> registration,
  47             @NonNull List<DataTreeCandidate> changes);
  48
  49     /**
  50      * Callback notifying the subclass that the specified registration is being
  51      * closed and it's user no longer
  52      * wishes to receive notifications. This notification is invoked while
  53      * the {@link org.opendaylight.yangtools.concepts.ListenerRegistration#close()}
  54      * method is executing. Subclasses can use this callback to properly
  55      * remove any delayed notifications pending
  56      * towards the registration.
  57      *
  58      * @param registration Registration which is being closed
  59      */
  60     protected abstract void registrationRemoved(
  61             @NonNull AbstractDOMDataTreeChangeListenerRegistration<?> registration);
  62
  63     /**
  64      * Process a candidate tree with respect to registered listeners.
  65      *
  66      * @param candidate candidate three which needs to be processed
  67      * @return true if at least one listener was notified or false.
  68      */
  69     protected final boolean processCandidateTree(final @NonNull DataTreeCandidate candidate) {
  70         final DataTreeCandidateNode node = candidate.getRootNode();
  71         if (node.getModificationType() == ModificationType.UNMODIFIED) {
  72             LOG.debug("Skipping unmodified candidate {}", candidate);
  73             return false;
  74         }
  75
  76         try (var snapshot = takeSnapshot()) {
  77             final List<PathArgument> toLookup = ImmutableList.copyOf(candidate.getRootPath().getPathArguments());
  78             final ListMultimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges =
  79                     Multimaps.newListMultimap(new IdentityHashMap<>(), ArrayList::new);
  80             lookupAndNotify(toLookup, 0, snapshot.getRootNode(), candidate, listenerChanges);
  81
  82             for (var entry : Multimaps.asMap(listenerChanges).entrySet()) {
  83                 notifyListener(entry.getKey(), entry.getValue());
  84             }
  85
  86             return !listenerChanges.isEmpty();
  87         }
  88     }
  89
  90     @Override
  91     public <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
  92         registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
  93         // Take the write lock
  94         takeLock();
  95         try {
  96             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node =
  97                     findNodeFor(treeId.getPathArguments());
  98             final var reg = new AbstractDOMDataTreeChangeListenerRegistration<>(listener) {
  99                 @Override
 100                 protected void removeRegistration() {
 101                     AbstractDOMStoreTreeChangePublisher.this.removeRegistration(node, this);
 102                     registrationRemoved(this);
 103                 }
 104             };
 105
 106             addRegistration(node, reg);
 107             return reg;
 108         } finally {
 109             // Always release the lock
 110             releaseLock();
 111         }
 112     }
 113
 114     private void lookupAndNotify(final List<PathArgument> args,
 115             final int offset, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node,
 116             final DataTreeCandidate candidate,
 117             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges) {
 118         if (args.size() != offset) {
 119             final PathArgument arg = args.get(offset);
 120
 121             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> exactChild
 122                 = node.getExactChild(arg);
 123             if (exactChild != null) {
 124                 lookupAndNotify(args, offset + 1, exactChild, candidate, listenerChanges);
 125             }
 126
 127             for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> c :
 128                     node.getInexactChildren(arg)) {
 129                 lookupAndNotify(args, offset + 1, c, candidate, listenerChanges);
 130             }
 131         } else {
 132             notifyNode(candidate.getRootPath(), node, candidate.getRootNode(), listenerChanges);
 133         }
 134     }
 135
 136     private void notifyNode(final YangInstanceIdentifier path,
 137             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regNode,
 138             final DataTreeCandidateNode candNode,
 139             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges) {
 140         if (candNode.getModificationType() == ModificationType.UNMODIFIED) {
 141             LOG.debug("Skipping unmodified candidate {}", path);
 142             return;
 143         }
 144
 145         final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> regs = regNode.getRegistrations();
 146         if (!regs.isEmpty()) {
 147             addToListenerChanges(regs, path, candNode, listenerChanges);
 148         }
 149
 150         for (DataTreeCandidateNode candChild : candNode.getChildNodes()) {
 151             if (candChild.getModificationType() != ModificationType.UNMODIFIED) {
 152                 final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regChild =
 153                         regNode.getExactChild(candChild.getIdentifier());
 154                 if (regChild != null) {
 155                     notifyNode(path.node(candChild.getIdentifier()), regChild, candChild, listenerChanges);
 156                 }
 157
 158                 for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> rc :
 159                     regNode.getInexactChildren(candChild.getIdentifier())) {
 160                     notifyNode(path.node(candChild.getIdentifier()), rc, candChild, listenerChanges);
 161                 }
 162             }
 163         }
 164     }
 165
 166     private static void addToListenerChanges(
 167             final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> registrations,
 168             final YangInstanceIdentifier path, final DataTreeCandidateNode node,
 169             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges) {
 170         final DataTreeCandidate dataTreeCandidate = DataTreeCandidates.newDataTreeCandidate(path, node);
 171
 172         for (AbstractDOMDataTreeChangeListenerRegistration<?> reg : registrations) {
 173             listenerChanges.put(reg, dataTreeCandidate);
 174         }
 175     }
 176 }