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 static java.util.Objects.requireNonNull;
  11
  12 import com.google.common.base.Stopwatch;
  13 import com.google.common.collect.ImmutableList;
  14 import com.google.common.collect.ImmutableMap;
  15 import com.google.common.collect.Iterables;
  16 import com.google.common.collect.Iterators;
  17 import java.util.ArrayList;
  18 import java.util.Collection;
  19 import java.util.HashMap;
  20 import java.util.Iterator;
  21 import java.util.List;
  22 import java.util.Map;
  23 import java.util.Optional;
  24 import org.checkerframework.checker.lock.qual.GuardedBy;
  25 import org.opendaylight.mdsal.dom.api.DOMDataTreeChangeListener;
  26 import org.opendaylight.mdsal.dom.api.DOMDataTreeIdentifier;
  27 import org.opendaylight.mdsal.dom.api.DOMDataTreeListener;
  28 import org.opendaylight.yangtools.concepts.AbstractListenerRegistration;
  29 import org.opendaylight.yangtools.concepts.Identifiable;
  30 import org.opendaylight.yangtools.concepts.ListenerRegistration;
  31 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  32 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  33 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  34 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidates;
  35 import org.slf4j.Logger;
  36 import org.slf4j.LoggerFactory;
  37
  38 /**
  39  * A compatibility class for bridging DOMDataTreeChangeListener, which can listen on only single subtree with
  40  * {@link DOMDataTreeListener} interface.
  41  *
  42  * @author Robert Varga
  43  * @deprecated This class is scheduled for removal when we remove compatibility with dom.spi.store APIs.
  44  */
  45 @Deprecated(forRemoval = true)
  46 final class DOMDataTreeChangeListenerAggregator
  47         extends AbstractStateAggregator<DOMDataTreeChangeListenerAggregator.State> {
  48
  49     static final class State extends AbstractStateAggregator.State implements Identifiable<DOMDataTreeIdentifier> {
  50         private final DOMDataTreeIdentifier identifier;
  51         final List<DataTreeCandidate> changes;
  52
  53         State(final DOMDataTreeIdentifier identifier, final List<DataTreeCandidate> changes) {
  54             this.identifier = requireNonNull(identifier);
  55             this.changes = requireNonNull(changes);
  56         }
  57
  58         @Override
  59         public DOMDataTreeIdentifier getIdentifier() {
  60             return identifier;
  61         }
  62     }
  63
  64     private static final class StateBuilder extends AbstractStateAggregator.StateBuilder<State> {
  65         @GuardedBy("this")
  66         private final List<DataTreeCandidate> changes = new ArrayList<>();
  67         private final DOMDataTreeIdentifier identifier;
  68
  69         StateBuilder(final DOMDataTreeIdentifier identifier) {
  70             this.identifier = requireNonNull(identifier);
  71         }
  72
  73         @Override
  74         protected synchronized void append(final State state) {
  75             changes.addAll(state.changes);
  76         }
  77
  78         @Override
  79         protected synchronized void appendInitial(final State state) {
  80             // We are still starting up, so all we need to do is squash reported changes to an initial write event
  81             final DataTreeCandidate last = Iterables.getLast(state.changes);
  82             changes.clear();
  83             final Optional<NormalizedNode<?, ?>> lastData = last.getRootNode().getDataAfter();
  84             if (lastData.isPresent()) {
  85                 changes.add(DataTreeCandidates.fromNormalizedNode(last.getRootPath(), lastData.get()));
  86             }
  87         }
  88
  89         @Override
  90         public synchronized State build() {
  91             final State ret = new State(identifier, ImmutableList.copyOf(changes));
  92             changes.clear();
  93             return ret;
  94         }
  95     }
  96
  97     private static final class Operational extends AbstractStateAggregator.Operational<State> {
  98         private final Map<DOMDataTreeIdentifier, NormalizedNode<?, ?>> subtrees = new HashMap<>();
  99         private final DOMDataTreeListener listener;
 100
 101         Operational(final Collection<AbstractStateAggregator.StateBuilder<State>> builders,
 102                 final DOMDataTreeListener listener) {
 103             super(builders);
 104             this.listener = requireNonNull(listener);
 105         }
 106
 107         @Override
 108         protected void notifyListener(final Iterator<State> iterator) {
 109             final Stopwatch clock = Stopwatch.createStarted();
 110             final List<DataTreeCandidate> changes = new ArrayList<>();
 111             while (iterator.hasNext()) {
 112                 final State state = iterator.next();
 113                 final List<DataTreeCandidate> candidates = state.changes;
 114                 if (!candidates.isEmpty()) {
 115                     // Update current subtree snapshot based on last candidate node
 116                     final DataTreeCandidateNode lastRoot = candidates.get(candidates.size() - 1).getRootNode();
 117                     final Optional<NormalizedNode<?, ?>> optData = lastRoot.getDataAfter();
 118                     if (optData.isPresent()) {
 119                         subtrees.put(state.getIdentifier(), optData.get());
 120                     } else {
 121                         subtrees.remove(state.getIdentifier());
 122                     }
 123
 124                     // Append changes
 125                     changes.addAll(candidates);
 126                 }
 127             }
 128
 129             final int size = changes.size();
 130             if (size != 0) {
 131                 // Note: it is okay to leak changes, we must never leak mutable subtrees.
 132                 listener.onDataTreeChanged(changes, ImmutableMap.copyOf(subtrees));
 133                 LOG.trace("Listener {} processed {} changes in {}", listener, size, clock);
 134             }
 135         }
 136     }
 137
 138     private static final Logger LOG = LoggerFactory.getLogger(DOMDataTreeChangeListenerAggregator.class);
 139
 140     private final boolean allowRxMerges;
 141
 142     DOMDataTreeChangeListenerAggregator(final int sizeHint, final boolean allowRxMerges) {
 143         super(sizeHint);
 144         this.allowRxMerges = allowRxMerges;
 145     }
 146
 147     DOMDataTreeChangeListener createListener(final DOMDataTreeIdentifier treeId) {
 148         // TODO: do not ignore allowRxMerges, but rather create a dedicated subclass or something
 149         final StateBuilder builder = new StateBuilder(treeId);
 150         addBuilder(builder);
 151
 152         return changes -> receiveState(builder, new State(treeId, ImmutableList.copyOf(changes)));
 153     }
 154
 155     <L extends DOMDataTreeListener> ListenerRegistration<L> start(final L listener,
 156             final Collection<ListenerRegistration<?>> regs) {
 157         start(builders -> {
 158             final Operational ret = new Operational(builders, listener);
 159             ret.notifyListener(Iterators.transform(builders.iterator(), AbstractStateAggregator.StateBuilder::build));
 160             return ret;
 161         });
 162
 163         return new AbstractListenerRegistration<>(listener) {
 164             @Override
 165             protected void removeRegistration() {
 166                 regs.forEach(ListenerRegistration::close);
 167             }
 168         };
 169     }
 170 }