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
  15 import java.util.Collection;
  16 import java.util.Map.Entry;
  17
  18 import org.opendaylight.controller.md.sal.common.api.data.AsyncDataBroker.DataChangeScope;
  19 import org.opendaylight.controller.md.sal.dom.store.impl.DOMImmutableDataChangeEvent.Builder;
  20 import org.opendaylight.controller.md.sal.dom.store.impl.DOMImmutableDataChangeEvent.SimpleEventFactory;
  21 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree;
  22 import org.opendaylight.controller.md.sal.dom.store.impl.tree.ListenerTree.Walker;
  23 import org.opendaylight.yangtools.util.concurrent.NotificationManager;
  24 import org.opendaylight.yangtools.yang.data.api.YangInstanceIdentifier.PathArgument;
  25 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  26 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNodeContainer;
  27 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidate;
  28 import org.opendaylight.yangtools.yang.data.api.schema.tree.DataTreeCandidateNode;
  29 import org.opendaylight.yangtools.yang.data.api.schema.tree.ModificationType;
  30 import org.slf4j.Logger;
  31 import org.slf4j.LoggerFactory;
  32
  33 /**
  34  * Resolve Data Change Events based on modifications and listeners
  35  *
  36  * Computes data change events for all affected registered listeners in data
  37  * tree.
  38  */
  39 final class ResolveDataChangeEventsTask {
  40     private static final Logger LOG = LoggerFactory.getLogger(ResolveDataChangeEventsTask.class);
  41
  42     private final DataTreeCandidate candidate;
  43     private final ListenerTree listenerRoot;
  44
  45     private Multimap<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent> collectedEvents;
  46
  47     public ResolveDataChangeEventsTask(final DataTreeCandidate candidate, final ListenerTree listenerTree) {
  48         this.candidate = Preconditions.checkNotNull(candidate);
  49         this.listenerRoot = Preconditions.checkNotNull(listenerTree);
  50     }
  51
  52     /**
  53      * Resolves and submits notification tasks to the specified manager.
  54      */
  55     public synchronized void resolve(final NotificationManager<DataChangeListenerRegistration<?>, DOMImmutableDataChangeEvent> manager) {
  56         try (final Walker w = listenerRoot.getWalker()) {
  57             // Defensive: reset internal state
  58             collectedEvents = ArrayListMultimap.create();
  59
  60             // Run through the tree
  61             final ResolveDataChangeState s = ResolveDataChangeState.initial(candidate.getRootPath(), w.getRootNode());
  62             resolveAnyChangeEvent(s, candidate.getRootNode());
  63
  64             /*
  65              * Convert to tasks, but be mindful of multiple values -- those indicate multiple
  66              * wildcard matches, which need to be merged.
  67              */
  68             for (Entry<DataChangeListenerRegistration<?>, Collection<DOMImmutableDataChangeEvent>> e : collectedEvents.asMap().entrySet()) {
  69                 final Collection<DOMImmutableDataChangeEvent> col = e.getValue();
  70                 final DOMImmutableDataChangeEvent event;
  71
  72                 if (col.size() != 1) {
  73                     final Builder b = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE);
  74                     for (DOMImmutableDataChangeEvent i : col) {
  75                         b.merge(i);
  76                     }
  77
  78                     event = b.build();
  79                     LOG.trace("Merged events {} into event {}", col, event);
  80                 } else {
  81                     event = col.iterator().next();
  82                 }
  83
  84                 manager.submitNotification(e.getKey(), event);
  85             }
  86         }
  87     }
  88
  89     /**
  90      * Resolves data change event for supplied node
  91      *
  92      * @param path
  93      *            Path to current node in tree
  94      * @param listeners
  95      *            Collection of Listener registration nodes interested in
  96      *            subtree
  97      * @param modification
  98      *            Modification of current node
  99      * @param before
 100      *            - Original (before) state of current node
 101      * @param after
 102      *            - After state of current node
 103      * @return True if the subtree changed, false otherwise
 104      */
 105     private boolean resolveAnyChangeEvent(final ResolveDataChangeState state, final DataTreeCandidateNode node) {
 106         if (node.getModificationType() != ModificationType.UNMODIFIED &&
 107                 !node.getDataAfter().isPresent() && !node.getDataBefore().isPresent()) {
 108             LOG.debug("Modification at {} has type {}, but no before- and after-data. Assuming unchanged.",
 109                     state.getPath(), node.getModificationType());
 110             return false;
 111         }
 112
 113         // no before and after state is present
 114
 115         switch (node.getModificationType()) {
 116         case SUBTREE_MODIFIED:
 117             return resolveSubtreeChangeEvent(state, node);
 118         case MERGE:
 119         case WRITE:
 120             Preconditions.checkArgument(node.getDataAfter().isPresent(),
 121                     "Modification at {} has type {} but no after-data", state.getPath(), node.getModificationType());
 122             if (!node.getDataBefore().isPresent()) {
 123                 resolveCreateEvent(state, node.getDataAfter().get());
 124                 return true;
 125             }
 126
 127             return resolveReplacedEvent(state, node.getDataBefore().get(), node.getDataAfter().get());
 128         case DELETE:
 129             Preconditions.checkArgument(node.getDataBefore().isPresent(),
 130                     "Modification at {} has type {} but no before-data", state.getPath(), node.getModificationType());
 131             resolveDeleteEvent(state, node.getDataBefore().get());
 132             return true;
 133         case UNMODIFIED:
 134             return false;
 135         }
 136
 137         throw new IllegalStateException(String.format("Unhandled node state %s at %s", node.getModificationType(), state.getPath()));
 138     }
 139
 140     private boolean resolveReplacedEvent(final ResolveDataChangeState state,
 141             final NormalizedNode<?, ?> beforeData, final NormalizedNode<?, ?> afterData) {
 142
 143         if (beforeData instanceof NormalizedNodeContainer<?, ?, ?>) {
 144             /*
 145              * Node is a container (contains a child) and we have interested
 146              * listeners registered for it, that means we need to do
 147              * resolution of changes on children level and can not
 148              * shortcut resolution.
 149              */
 150             LOG.trace("Resolving subtree replace event for {} before {}, after {}", state.getPath(), beforeData, afterData);
 151             @SuppressWarnings("unchecked")
 152             NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> beforeCont = (NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>>) beforeData;
 153             @SuppressWarnings("unchecked")
 154             NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> afterCont = (NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>>) afterData;
 155             return resolveNodeContainerReplaced(state, beforeCont, afterCont);
 156         }
 157
 158         // Node is a Leaf type (does not contain child nodes)
 159         // so normal equals method is sufficient for determining change.
 160         if (beforeData.equals(afterData)) {
 161             LOG.trace("Skipping equal leaf {}", state.getPath());
 162             return false;
 163         }
 164
 165         LOG.trace("Resolving leaf replace event for {} , before {}, after {}", state.getPath(), beforeData, afterData);
 166         DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE).addUpdated(state.getPath(), beforeData, afterData).build();
 167         state.addEvent(event);
 168         state.collectEvents(beforeData, afterData, collectedEvents);
 169         return true;
 170     }
 171
 172     private boolean resolveNodeContainerReplaced(final ResolveDataChangeState state,
 173             final NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> beforeCont,
 174                     final NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> afterCont) {
 175         if (!state.needsProcessing()) {
 176             LOG.trace("Not processing replaced container {}", state.getPath());
 177             return true;
 178         }
 179
 180         // We look at all children from before and compare it with after state.
 181         boolean childChanged = false;
 182         for (NormalizedNode<PathArgument, ?> beforeChild : beforeCont.getValue()) {
 183             final PathArgument childId = beforeChild.getIdentifier();
 184
 185             if (resolveNodeContainerChildUpdated(state.child(childId), beforeChild, afterCont.getChild(childId))) {
 186                 childChanged = true;
 187             }
 188         }
 189
 190         for (NormalizedNode<PathArgument, ?> afterChild : afterCont.getValue()) {
 191             final PathArgument childId = afterChild.getIdentifier();
 192
 193             /*
 194              * We have already iterated of the before-children, so have already
 195              * emitted modify/delete events. This means the child has been
 196              * created.
 197              */
 198             if (!beforeCont.getChild(childId).isPresent()) {
 199                 resolveSameEventRecursivelly(state.child(childId), afterChild, DOMImmutableDataChangeEvent.getCreateEventFactory());
 200                 childChanged = true;
 201             }
 202         }
 203
 204         if (childChanged) {
 205             DOMImmutableDataChangeEvent event = DOMImmutableDataChangeEvent.builder(DataChangeScope.BASE)
 206                     .addUpdated(state.getPath(), beforeCont, afterCont).build();
 207             state.addEvent(event);
 208         }
 209
 210         state.collectEvents(beforeCont, afterCont, collectedEvents);
 211         return childChanged;
 212     }
 213
 214     private boolean resolveNodeContainerChildUpdated(final ResolveDataChangeState state,
 215             final NormalizedNode<PathArgument, ?> before, final Optional<NormalizedNode<PathArgument, ?>> after) {
 216         if (after.isPresent()) {
 217             // REPLACE or SUBTREE Modified
 218             return resolveReplacedEvent(state, before, after.get());
 219         }
 220
 221         // AFTER state is not present - child was deleted.
 222         resolveSameEventRecursivelly(state, before, DOMImmutableDataChangeEvent.getRemoveEventFactory());
 223         return true;
 224     }
 225
 226     /**
 227      * Resolves create events deep down the interest listener tree.
 228      *
 229      * @param path
 230      * @param listeners
 231      * @param afterState
 232      * @return
 233      */
 234     private void resolveCreateEvent(final ResolveDataChangeState state, final NormalizedNode<?, ?> afterState) {
 235         @SuppressWarnings({ "unchecked", "rawtypes" })
 236         final NormalizedNode<PathArgument, ?> node = (NormalizedNode) afterState;
 237         resolveSameEventRecursivelly(state, node, DOMImmutableDataChangeEvent.getCreateEventFactory());
 238     }
 239
 240     private void resolveDeleteEvent(final ResolveDataChangeState state, final NormalizedNode<?, ?> beforeState) {
 241         @SuppressWarnings({ "unchecked", "rawtypes" })
 242         final NormalizedNode<PathArgument, ?> node = (NormalizedNode) beforeState;
 243         resolveSameEventRecursivelly(state, node, DOMImmutableDataChangeEvent.getRemoveEventFactory());
 244     }
 245
 246     private void resolveSameEventRecursivelly(final ResolveDataChangeState state,
 247             final NormalizedNode<PathArgument, ?> node, final SimpleEventFactory eventFactory) {
 248         if (!state.needsProcessing()) {
 249             LOG.trace("Skipping child {}", state.getPath());
 250             return;
 251         }
 252
 253         // We have listeners for this node or it's children, so we will try
 254         // to do additional processing
 255         if (node instanceof NormalizedNodeContainer<?, ?, ?>) {
 256             LOG.trace("Resolving subtree recursive event for {}, type {}", state.getPath(), eventFactory);
 257
 258             // Node has children, so we will try to resolve it's children
 259             // changes.
 260             @SuppressWarnings("unchecked")
 261             NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>> container = (NormalizedNodeContainer<?, PathArgument, NormalizedNode<PathArgument, ?>>) node;
 262             for (NormalizedNode<PathArgument, ?> child : container.getValue()) {
 263                 final PathArgument childId = child.getIdentifier();
 264
 265                 LOG.trace("Resolving event for child {}", childId);
 266                 resolveSameEventRecursivelly(state.child(childId), child, eventFactory);
 267             }
 268         }
 269
 270         final DOMImmutableDataChangeEvent event = eventFactory.create(state.getPath(), node);
 271         LOG.trace("Adding event {} at path {}", event, state.getPath());
 272         state.addEvent(event);
 273         state.collectEvents(event.getOriginalSubtree(), event.getUpdatedSubtree(), collectedEvents);
 274     }
 275
 276     private boolean resolveSubtreeChangeEvent(final ResolveDataChangeState state, final DataTreeCandidateNode modification) {
 277         Preconditions.checkArgument(modification.getDataBefore().isPresent(), "Subtree change with before-data not present at path %s", state.getPath());
 278         Preconditions.checkArgument(modification.getDataAfter().isPresent(), "Subtree change with after-data not present at path %s", state.getPath());
 279
 280         DataChangeScope scope = null;
 281         for (DataTreeCandidateNode childMod : modification.getChildNodes()) {
 282             final ResolveDataChangeState childState = state.child(childMod.getIdentifier());
 283
 284             switch (childMod.getModificationType()) {
 285             case WRITE:
 286             case MERGE:
 287             case DELETE:
 288                 if (resolveAnyChangeEvent(childState, childMod)) {
 289                     scope = DataChangeScope.ONE;
 290                 }
 291                 break;
 292             case SUBTREE_MODIFIED:
 293                 if (resolveSubtreeChangeEvent(childState, childMod) && scope == null) {
 294                     scope = DataChangeScope.SUBTREE;
 295                 }
 296                 break;
 297             case UNMODIFIED:
 298                 // no-op
 299                 break;
 300             }
 301         }
 302
 303         final NormalizedNode<?, ?> before = modification.getDataBefore().get();
 304         final NormalizedNode<?, ?> after = modification.getDataAfter().get();
 305
 306         if (scope != null) {
 307             DOMImmutableDataChangeEvent one = DOMImmutableDataChangeEvent.builder(scope).addUpdated(state.getPath(), before, after).build();
 308             state.addEvent(one);
 309         }
 310
 311         state.collectEvents(before, after, collectedEvents);
 312         return scope != null;
 313     }
 314
 315     public static ResolveDataChangeEventsTask create(final DataTreeCandidate candidate, final ListenerTree listenerTree) {
 316         return new ResolveDataChangeEventsTask(candidate, listenerTree);
 317     }
 318 }