dom/mdsal-dom-spi/src/main/java/org/opendaylight/mdsal/dom/spi/shard/DOMDataTreeChangeListenerAggregator.java

   1 /*
   2  * Copyright (c) 2017 Pantheon Technologies, s.ro. 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.shard;
   9
  10 import com.google.common.base.Preconditions;
  11 import com.google.common.base.Stopwatch;
  12 import com.google.common.collect.ImmutableList;
  13 import com.google.common.collect.ImmutableMap;
  14 import com.google.common.collect.Iterables;
  15 import com.google.common.collect.Iterators;
  16 import java.util.ArrayList;
  17 import java.util.Collection;
  18 import java.util.HashMap;
  19 import java.util.Iterator;
  20 import java.util.List;
  21 import java.util.Map;
  22 import java.util.Optional;
  23 import javax.annotation.concurrent.GuardedBy;
  24 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  26 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  27 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  28 import org.opendaylight.yangtools.concepts.Identifiable;
  29 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  30 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  31 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  32 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  33 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates;
  34 import org.slf4j.Logger;
  35 import org.slf4j.LoggerFactory;
  36
  37 /**
  38  * A compatibility class for bridging DOMDataTreeChangeListener, which can listen on only single subtree with
  39  * {@link DOMDataTreeListener} interface.
  40  *
  41  * @author Robert Varga
  42  * @deprecated This class is scheduled for removal when we remove compatibility with dom.spi.store APIs.
  43  */
  44 @Deprecated
  45 final class DOMDataTreeChangeListenerAggregator
  46         extends AbstractStateAggregator<DOMDataTreeChangeListenerAggregator.State> {
  47
  48     static final class State extends AbstractStateAggregator.State implements Identifiable<DOMDataTreeIdentifier> {
  49         private final DOMDataTreeIdentifier identifier;
  50         final List<DataTreeCandidate> changes;
  51
  52         State(final DOMDataTreeIdentifier identifier, final List<DataTreeCandidate> changes) {
  53             this.identifier = Preconditions.checkNotNull(identifier);
  54             this.changes = Preconditions.checkNotNull(changes);
  55         }
  56
  57         @Override
  58         public DOMDataTreeIdentifier getIdentifier() {
  59             return identifier;
  60         }
  61     }
  62
  63     private static final class StateBuilder extends AbstractStateAggregator.StateBuilder<State> {
  64         @GuardedBy("this")
  65         private final List<DataTreeCandidate> changes = new ArrayList<>();
  66         private final DOMDataTreeIdentifier identifier;
  67
  68         StateBuilder(final DOMDataTreeIdentifier identifier) {
  69             this.identifier = Preconditions.checkNotNull(identifier);
  70         }
  71
  72         @Override
  73         protected synchronized void append(final State state) {
  74             changes.addAll(state.changes);
  75         }
  76
  77         @Override
  78         protected synchronized void appendInitial(final State state) {
  79             // We are still starting up, so all we need to do is squash reported changes to an initial write event
  80             final DataTreeCandidate last = Iterables.getLast(state.changes);
  81             changes.clear();
  82             final Optional<NormalizedNode<?, ?>> lastData = last.getRootNode().getDataAfter();
  83             if (lastData.isPresent()) {
  84                 changes.add(DataTreeCandidates.fromNormalizedNode(last.getRootPath(), lastData.get()));
  85             }
  86         }
  87
  88         @Override
  89         public synchronized State build() {
  90             final State ret = new State(identifier, ImmutableList.copyOf(changes));
  91             changes.clear();
  92             return ret;
  93         }
  94     }
  95
  96     private static final class Operational extends AbstractStateAggregator.Operational<State> {
  97         private final Map<DOMDataTreeIdentifier, NormalizedNode<?, ?>> subtrees = new HashMap<>();
  98         private final DOMDataTreeListener listener;
  99
 100         Operational(final Collection<AbstractStateAggregator.StateBuilder<State>> builders,
 101                 final DOMDataTreeListener listener) {
 102             super(builders);
 103             this.listener = Preconditions.checkNotNull(listener);
 104         }
 105
 106         @Override
 107         protected void notifyListener(final Iterator<State> iterator) {
 108             final Stopwatch clock = Stopwatch.createStarted();
 109             final List<DataTreeCandidate> changes = new ArrayList<>();
 110             while (iterator.hasNext()) {
 111                 final State state = iterator.next();
 112                 final List<DataTreeCandidate> candidates = state.changes;
 113                 if (!candidates.isEmpty()) {
 114                     // Update current subtree snapshot based on last candidate node
 115                     final DataTreeCandidateNode lastRoot = candidates.get(candidates.size() - 1).getRootNode();
 116                     final Optional<NormalizedNode<?, ?>> optData = lastRoot.getDataAfter();
 117                     if (optData.isPresent()) {
 118                         subtrees.put(state.getIdentifier(), optData.get());
 119                     } else {
 120                         subtrees.remove(state.getIdentifier());
 121                     }
 122
 123                     // Append changes
 124                     changes.addAll(candidates);
 125                 }
 126             }
 127
 128             final int size = changes.size();
 129             if (size != 0) {
 130                 // Note: it is okay to leak changes, we must never leak mutable subtrees.
 131                 listener.onDataTreeChanged(changes, ImmutableMap.copyOf(subtrees));
 132                 LOG.trace("Listener {} processed {} changes in {}", listener, clock);
 133             }
 134         }
 135     }
 136
 137     private static final Logger LOG = LoggerFactory.getLogger(DOMDataTreeChangeListenerAggregator.class);
 138
 139     private final boolean allowRxMerges;
 140
 141     DOMDataTreeChangeListenerAggregator(final int sizeHint, final boolean allowRxMerges) {
 142         super(sizeHint);
 143         this.allowRxMerges = allowRxMerges;
 144     }
 145
 146     DOMDataTreeChangeListener createListener(final DOMDataTreeIdentifier treeId) {
 147         // TODO: do not ignore allowRxMerges, but rather create a dedicated subclass or something
 148         final StateBuilder builder = new StateBuilder(treeId);
 149         addBuilder(builder);
 150
 151         return changes -> receiveState(builder, new State(treeId, ImmutableList.copyOf(changes)));
 152     }
 153
 154     <L extends DOMDataTreeListener> ListenerRegistration<L> start(final L listener,
 155             final Collection<ListenerRegistration<?>> regs) {
 156         start(builders -> {
 157             final Operational ret = new Operational(builders, listener);
 158             ret.notifyListener(Iterators.transform(builders.iterator(), AbstractStateAggregator.StateBuilder::build));
 159             return ret;
 160         });
 161
 162         return new AbstractListenerRegistration<L>(listener) {
 163             @Override
 164             protected void removeRegistration() {
 165                 regs.forEach(ListenerRegistration::close);
 166             }
 167         };
 168     }
 169 }