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.Multimap;
  12 import com.google.common.collect.Multimaps;
  13 import java.util.ArrayList;
  14 import java.util.Collection;
  15 import java.util.IdentityHashMap;
  16 import java.util.List;
  17 import java.util.Map;
  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.mdsal.dom.spi.RegistrationTreeSnapshot;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier;
  25 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  26 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  27 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  28 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates;
  29 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 /**
  34  * Abstract base class for {@link DOMStoreTreeChangePublisher} implementations.
  35  */
  36 public abstract class AbstractDOMStoreTreeChangePublisher
  37     extends AbstractRegistrationTree<AbstractDOMDataTreeChangeListenerRegistration<?>>
  38         implements DOMStoreTreeChangePublisher {
  39     private static final Logger LOG = LoggerFactory.getLogger(AbstractDOMStoreTreeChangePublisher.class);
  40
  41     /**
  42      * Callback for subclass to notify a specified registration of a list of candidates. This method is guaranteed
  43      * to be only called from within {@link #processCandidateTree(DataTreeCandidate)}.
  44      * @param registration the registration to notify
  45      * @param changes the list of DataTreeCandidate changes
  46      */
  47     protected abstract void notifyListener(@NonNull AbstractDOMDataTreeChangeListenerRegistration<?> registration,
  48             @NonNull Collection<DataTreeCandidate> changes);
  49
  50     /**
  51      * Callback notifying the subclass that the specified registration is being
  52      * closed and it's user no longer
  53      * wishes to receive notifications. This notification is invoked while
  54      * the {@link org.opendaylight.yangtools.concepts.ListenerRegistration#close()}
  55      * method is executing. Subclasses can use this callback to properly
  56      * remove any delayed notifications pending
  57      * towards the registration.
  58      *
  59      * @param registration Registration which is being closed
  60      */
  61     protected abstract void registrationRemoved(
  62             @NonNull AbstractDOMDataTreeChangeListenerRegistration<?> registration);
  63
  64     /**
  65      * Process a candidate tree with respect to registered listeners.
  66      *
  67      * @param candidate candidate three which needs to be processed
  68      * @return true if at least one listener was notified or false.
  69      */
  70     protected final boolean processCandidateTree(final @NonNull DataTreeCandidate candidate) {
  71         final DataTreeCandidateNode node = candidate.getRootNode();
  72         if (node.getModificationType() == ModificationType.UNMODIFIED) {
  73             LOG.debug("Skipping unmodified candidate {}", candidate);
  74             return false;
  75         }
  76
  77         try (RegistrationTreeSnapshot<AbstractDOMDataTreeChangeListenerRegistration<?>> snapshot
  78                 = takeSnapshot()) {
  79             final List<PathArgument> toLookup = ImmutableList.copyOf(candidate.getRootPath().getPathArguments());
  80             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges =
  81                     Multimaps.newListMultimap(new IdentityHashMap<>(), ArrayList::new);
  82             lookupAndNotify(toLookup, 0, snapshot.getRootNode(), candidate, listenerChanges);
  83
  84             for (Map.Entry<AbstractDOMDataTreeChangeListenerRegistration<?>, Collection<DataTreeCandidate>> entry:
  85                     listenerChanges.asMap().entrySet()) {
  86                 notifyListener(entry.getKey(), entry.getValue());
  87             }
  88
  89             return !listenerChanges.isEmpty();
  90         }
  91     }
  92
  93     @Override
  94     public <L extends DOMDataTreeChangeListener> AbstractDOMDataTreeChangeListenerRegistration<L>
  95         registerTreeChangeListener(final YangInstanceIdentifier treeId, final L listener) {
  96         // Take the write lock
  97         takeLock();
  98         try {
  99             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node =
 100                     findNodeFor(treeId.getPathArguments());
 101             final AbstractDOMDataTreeChangeListenerRegistration<L> reg =
 102                     new AbstractDOMDataTreeChangeListenerRegistration<L>(listener) {
 103                 @Override
 104                 protected void removeRegistration() {
 105                     AbstractDOMStoreTreeChangePublisher.this.removeRegistration(node, this);
 106                     registrationRemoved(this);
 107                 }
 108             };
 109
 110             addRegistration(node, reg);
 111             return reg;
 112         } finally {
 113             // Always release the lock
 114             releaseLock();
 115         }
 116     }
 117
 118     private void lookupAndNotify(final List<PathArgument> args,
 119             final int offset, final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> node,
 120             final DataTreeCandidate candidate,
 121             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges) {
 122         if (args.size() != offset) {
 123             final PathArgument arg = args.get(offset);
 124
 125             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> exactChild
 126                 = node.getExactChild(arg);
 127             if (exactChild != null) {
 128                 lookupAndNotify(args, offset + 1, exactChild, candidate, listenerChanges);
 129             }
 130
 131             for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> c :
 132                     node.getInexactChildren(arg)) {
 133                 lookupAndNotify(args, offset + 1, c, candidate, listenerChanges);
 134             }
 135         } else {
 136             notifyNode(candidate.getRootPath(), node, candidate.getRootNode(), listenerChanges);
 137         }
 138     }
 139
 140     private void notifyNode(final YangInstanceIdentifier path,
 141             final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regNode,
 142             final DataTreeCandidateNode candNode,
 143             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges) {
 144         if (candNode.getModificationType() == ModificationType.UNMODIFIED) {
 145             LOG.debug("Skipping unmodified candidate {}", path);
 146             return;
 147         }
 148
 149         final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> regs = regNode.getRegistrations();
 150         if (!regs.isEmpty()) {
 151             addToListenerChanges(regs, path, candNode, listenerChanges);
 152         }
 153
 154         for (DataTreeCandidateNode candChild : candNode.getChildNodes()) {
 155             if (candChild.getModificationType() != ModificationType.UNMODIFIED) {
 156                 final RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> regChild =
 157                         regNode.getExactChild(candChild.getIdentifier());
 158                 if (regChild != null) {
 159                     notifyNode(path.node(candChild.getIdentifier()), regChild, candChild, listenerChanges);
 160                 }
 161
 162                 for (RegistrationTreeNode<AbstractDOMDataTreeChangeListenerRegistration<?>> rc :
 163                     regNode.getInexactChildren(candChild.getIdentifier())) {
 164                     notifyNode(path.node(candChild.getIdentifier()), rc, candChild, listenerChanges);
 165                 }
 166             }
 167         }
 168     }
 169
 170     private static void addToListenerChanges(
 171             final Collection<AbstractDOMDataTreeChangeListenerRegistration<?>> registrations,
 172             final YangInstanceIdentifier path, final DataTreeCandidateNode node,
 173             final Multimap<AbstractDOMDataTreeChangeListenerRegistration<?>, DataTreeCandidate> listenerChanges) {
 174         final DataTreeCandidate dataTreeCandidate = DataTreeCandidates.newDataTreeCandidate(path, node);
 175
 176         for (AbstractDOMDataTreeChangeListenerRegistration<?> reg : registrations) {
 177             listenerChanges.put(reg, dataTreeCandidate);
 178         }
 179     }
 180 }