opendaylight/md-sal/sal-inmemory-datastore/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/ResolveDataChangeEventsTask.java

   1 /*
   2  * Copyright (c) 2014 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.md.sal.dom.store.impl;
   9
  10 import com.google.common.base.Optional;
  11 import com.google.common.base.Preconditions;
  12 import com.google.common.collect.ArrayListMultimap;
  13 import com.google.common.collect.Multimap;
  14 import java.util.Collection;
  15 import java.util.Map.Entry;
  16 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
  17 import org.opendaylight.controller.md.sal.dom.spi.RegistrationTreeSnapshot;
  18 import org.opendaylight.controller.md.sal.dom.store.impl.DOMImmutableDataChangeEvent.Builder;
  19 import org.opendaylight.controller.md.sal.dom.store.impl.DOMImmutableDataChangeEvent.SimpleEventFactory;
  20 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
  21 import org.opendaylight.yangtools.util.concurrent.NotificationManager;
  22 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  23 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  24 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodeContainer;
  25 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  26 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  27 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  28 import org.slf4j.Logger;
  29 import org.slf4j.LoggerFactory;
  30
  31 /**
  32  * Resolve Data Change Events based on modifications and listeners
  33  *
  34  * Computes data change events for all affected registered listeners in data
  35  * tree.
  36  */
  37 final class ResolveDataChangeEventsTask {
  38     private static final Logger LOG = LoggerFactory.getLogger(ResolveDataChangeEventsTask.class);
  39
  40     private final DataTreeCandidate candidate;
  41     private final ListenerTree listenerRoot;
  42
  43     private Multimap<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent> collectedEvents;
  44
  45     public ResolveDataChangeEventsTask(final DataTreeCandidate candidate, final ListenerTree listenerTree) {
  46         this.candidate = Preconditions.checkNotNull(candidate);
  47         this.listenerRoot = Preconditions.checkNotNull(listenerTree);
  48     }
  49
  50     /**
  51      * Resolves and submits notification tasks to the specified manager.
  52      */
  53     public synchronized void resolve(final NotificationManager<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent> manager) {
  54         try (final RegistrationTreeSnapshot<DataChangeListenerRegistration<?>> w = listenerRoot.takeSnapshot()) {
  55             // Defensive: reset internal state
  56             collectedEvents = ArrayListMultimap.create();
  57
  58             // Run through the tree
  59             final ResolveDataChangeState s = ResolveDataChangeState.initial(candidate.getRootPath(), w.getRootNode());
  60             resolveAnyChangeEvent(s, candidate.getRootNode());
  61
  62             /*
  63              * Convert to tasks, but be mindful of multiple values -- those indicate multiple
  64              * wildcard matches, which need to be merged.
  65              */
  66             for (Entry<DataChangeListenerRegistration<?>, Collection<DOMImmutableDataChangeEvent>> e : collectedEvents.asMap().entrySet()) {
  67                 final Collection<DOMImmutableDataChangeEvent> col = e.getValue();
  68                 final DOMImmutableDataChangeEvent event;
  69
  70                 if (col.size() != 1) {
  71                     final Builder b = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE);
  72                     for (DOMImmutableDataChangeEvent i : col) {
  73                         b.merge(i);
  74                     }
  75
  76                     event = b.build();
  77                     LOG.trace("Merged events {} into event {}", col, event);
  78                 } else {
  79                     event = col.iterator().next();
  80                 }
  81
  82                 manager.submitNotification(e.getKey(), event);
  83             }
  84         }
  85     }
  86
  87     /**
  88      * Resolves data change event for supplied node
  89      *
  90      * @param path
  91      *            Path to current node in tree
  92      * @param listeners
  93      *            Collection of Listener registration nodes interested in
  94      *            subtree
  95      * @param modification
  96      *            Modification of current node
  97      * @param before
  98      *            - Original (before) state of current node
  99      * @param after
 100      *            - After state of current node
 101      * @return True if the subtree changed, false otherwise
 102      */
 103     private boolean resolveAnyChangeEvent(final ResolveDataChangeState state, final DataTreeCandidateNode node) {
 104         final Optional<NormalizedNode<?, ?>> maybeBefore = node.getDataBefore();
 105         final Optional<NormalizedNode<?, ?>> maybeAfter = node.getDataAfter();
 106         final ModificationType type = node.getModificationType();
 107
 108         if (type != ModificationType.UNMODIFIED && !maybeAfter.isPresent() && !maybeBefore.isPresent()) {
 109             LOG.debug("Modification at {} has type {}, but no before- and after-data. Assuming unchanged.",
 110                     state.getPath(), type);
 111             return false;
 112         }
 113
 114         // no before and after state is present
 115
 116         switch (type) {
 117         case SUBTREE_MODIFIED:
 118             return resolveSubtreeChangeEvent(state, node);
 119         case MERGE:
 120         case WRITE:
 121             Preconditions.checkArgument(maybeAfter.isPresent(),
 122                     "Modification at {} has type {} but no after-data", state.getPath(), type);
 123             if (!maybeBefore.isPresent()) {
 124                 @SuppressWarnings({ "unchecked", "rawtypes" })
 125                 final NormalizedNode<PathArgument, ?> afterNode = (NormalizedNode)maybeAfter.get();
 126                 resolveSameEventRecursivelly(state, afterNode, DOMImmutableDataChangeEvent.getCreateEventFactory());
 127                 return true;
 128             }
 129
 130             return resolveReplacedEvent(state, maybeBefore.get(), maybeAfter.get());
 131         case DELETE:
 132             Preconditions.checkArgument(maybeBefore.isPresent(),
 133                     "Modification at {} has type {} but no before-data", state.getPath(), type);
 134
 135             @SuppressWarnings({ "unchecked", "rawtypes" })
 136             final NormalizedNode<PathArgument, ?> beforeNode = (NormalizedNode)maybeBefore.get();
 137             resolveSameEventRecursivelly(state, beforeNode, DOMImmutableDataChangeEvent.getRemoveEventFactory());
 138             return true;
 139         case UNMODIFIED:
 140             return false;
 141         }
 142
 143         throw new IllegalStateException(String.format("Unhandled node state %s at %s", type, state.getPath()));
 144     }
 145
 146     private boolean resolveReplacedEvent(final ResolveDataChangeState state,
 147             final NormalizedNode<?, ?> beforeData, final NormalizedNode<?, ?> afterData) {
 148
 149         if (beforeData instanceof NormalizedNodeContainer<?, ?, ?>) {
 150             /*
 151              * Node is a container (contains a child) and we have interested
 152              * listeners registered for it, that means we need to do
 153              * resolution of changes on children level and can not
 154              * shortcut resolution.
 155              */
 156             LOG.trace("Resolving subtree replace event for {} before {}, after {}", state.getPath(), beforeData, afterData);
 157             @SuppressWarnings("unchecked")
 158             NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> beforeCont = (NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>>) beforeData;
 159             @SuppressWarnings("unchecked")
 160             NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> afterCont = (NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>>) afterData;
 161             return resolveNodeContainerReplaced(state, beforeCont, afterCont);
 162         }
 163
 164         // Node is a Leaf type (does not contain child nodes)
 165         // so normal equals method is sufficient for determining change.
 166         if (beforeData.equals(afterData)) {
 167             LOG.trace("Skipping equal leaf {}", state.getPath());
 168             return false;
 169         }
 170
 171         LOG.trace("Resolving leaf replace event for {} , before {}, after {}", state.getPath(), beforeData, afterData);
 172         DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE).addUpdated(state.getPath(), beforeData, afterData).build();
 173         state.addEvent(event);
 174         state.collectEvents(beforeData, afterData, collectedEvents);
 175         return true;
 176     }
 177
 178     private boolean resolveNodeContainerReplaced(final ResolveDataChangeState state,
 179             final NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> beforeCont,
 180                     final NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> afterCont) {
 181         if (!state.needsProcessing()) {
 182             LOG.trace("Not processing replaced container {}", state.getPath());
 183             return true;
 184         }
 185
 186         // We look at all children from before and compare it with after state.
 187         boolean childChanged = false;
 188         for (NormalizedNode<PathArgument, ?> beforeChild : beforeCont.getValue()) {
 189             final PathArgument childId = beforeChild.getIdentifier();
 190
 191             if (resolveNodeContainerChildUpdated(state.child(childId), beforeChild, afterCont.getChild(childId))) {
 192                 childChanged = true;
 193             }
 194         }
 195
 196         for (NormalizedNode<PathArgument, ?> afterChild : afterCont.getValue()) {
 197             final PathArgument childId = afterChild.getIdentifier();
 198
 199             /*
 200              * We have already iterated of the before-children, so have already
 201              * emitted modify/delete events. This means the child has been
 202              * created.
 203              */
 204             if (!beforeCont.getChild(childId).isPresent()) {
 205                 resolveSameEventRecursivelly(state.child(childId), afterChild, DOMImmutableDataChangeEvent.getCreateEventFactory());
 206                 childChanged = true;
 207             }
 208         }
 209
 210         if (childChanged) {
 211             DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE)
 212                     .addUpdated(state.getPath(), beforeCont, afterCont).build();
 213             state.addEvent(event);
 214         }
 215
 216         state.collectEvents(beforeCont, afterCont, collectedEvents);
 217         return childChanged;
 218     }
 219
 220     private boolean resolveNodeContainerChildUpdated(final ResolveDataChangeState state,
 221             final NormalizedNode<PathArgument, ?> before, final Optional<NormalizedNode<PathArgument, ?>> after) {
 222         if (after.isPresent()) {
 223             // REPLACE or SUBTREE Modified
 224             return resolveReplacedEvent(state, before, after.get());
 225         }
 226
 227         // AFTER state is not present - child was deleted.
 228         resolveSameEventRecursivelly(state, before, DOMImmutableDataChangeEvent.getRemoveEventFactory());
 229         return true;
 230     }
 231
 232     private void resolveSameEventRecursivelly(final ResolveDataChangeState state,
 233             final NormalizedNode<PathArgument, ?> node, final SimpleEventFactory eventFactory) {
 234         if (!state.needsProcessing()) {
 235             LOG.trace("Skipping child {}", state.getPath());
 236             return;
 237         }
 238
 239         // We have listeners for this node or it's children, so we will try
 240         // to do additional processing
 241         if (node instanceof NormalizedNodeContainer<?, ?, ?>) {
 242             LOG.trace("Resolving subtree recursive event for {}, type {}", state.getPath(), eventFactory);
 243
 244             // Node has children, so we will try to resolve it's children
 245             // changes.
 246             @SuppressWarnings("unchecked")
 247             NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> container = (NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>>) node;
 248             for (NormalizedNode<PathArgument, ?> child : container.getValue()) {
 249                 final PathArgument childId = child.getIdentifier();
 250
 251                 LOG.trace("Resolving event for child {}", childId);
 252                 resolveSameEventRecursivelly(state.child(childId), child, eventFactory);
 253             }
 254         }
 255
 256         final DOMImmutableDataChangeEvent event = eventFactory.create(state.getPath(), node);
 257         LOG.trace("Adding event {} at path {}", event, state.getPath());
 258         state.addEvent(event);
 259         state.collectEvents(event.getOriginalSubtree(), event.getUpdatedSubtree(), collectedEvents);
 260     }
 261
 262     private boolean resolveSubtreeChangeEvent(final ResolveDataChangeState state, final DataTreeCandidateNode modification) {
 263         final Optional<NormalizedNode<?, ?>> maybeBefore = modification.getDataBefore();
 264         final Optional<NormalizedNode<?, ?>> maybeAfter = modification.getDataAfter();
 265
 266         Preconditions.checkArgument(maybeBefore.isPresent(), "Subtree change with before-data not present at path %s", state.getPath());
 267         Preconditions.checkArgument(maybeAfter.isPresent(), "Subtree change with after-data not present at path %s", state.getPath());
 268
 269         if (!state.needsProcessing()) {
 270             LOG.trace("Not processing modified subtree {}", state.getPath());
 271             return true;
 272         }
 273
 274         DataChangeScope scope = null;
 275         for (DataTreeCandidateNode childMod : modification.getChildNodes()) {
 276             final ResolveDataChangeState childState = state.child(childMod.getIdentifier());
 277
 278             switch (childMod.getModificationType()) {
 279             case WRITE:
 280             case MERGE:
 281             case DELETE:
 282                 if (resolveAnyChangeEvent(childState, childMod)) {
 283                     scope = DataChangeScope.ONE;
 284                 }
 285                 break;
 286             case SUBTREE_MODIFIED:
 287                 if (resolveSubtreeChangeEvent(childState, childMod) && scope == null) {
 288                     scope = DataChangeScope.SUBTREE;
 289                 }
 290                 break;
 291             case UNMODIFIED:
 292                 // no-op
 293                 break;
 294             }
 295         }
 296
 297         final NormalizedNode<?, ?> before = maybeBefore.get();
 298         final NormalizedNode<?, ?> after = maybeAfter.get();
 299
 300         if (scope != null) {
 301             DOMImmutableDataChangeEvent one = DOMImmutableDataChangeEvent.builder(scope).addUpdated(state.getPath(), before, after).build();
 302             state.addEvent(one);
 303         }
 304
 305         state.collectEvents(before, after, collectedEvents);
 306         return scope != null;
 307     }
 308
 309     public static ResolveDataChangeEventsTask create(final DataTreeCandidate candidate, final ListenerTree listenerTree) {
 310         return new ResolveDataChangeEventsTask(candidate, listenerTree);
 311     }
 312 }