opendaylight/md-sal/sal-dom-broker/src/main/java/org/opendaylight/controller/md/sal/dom/store/impl/MutableDataTree.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 static com.google.common.base.Preconditions.checkState;
  11
  12 import java.util.Map.Entry;
  13 import java.util.concurrent.atomic.AtomicBoolean;
  14
  15 import org.opendaylight.controller.md.sal.dom.store.impl.tree.NodeModification;
  16 import org.opendaylight.controller.md.sal.dom.store.impl.tree.StoreMetadataNode;
  17 import org.opendaylight.controller.md.sal.dom.store.impl.tree.TreeNodeUtils;
  18 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier;
  19 import org.opendaylight.yangtools.yang.data.api.InstanceIdentifier.PathArgument;
  20 import org.opendaylight.yangtools.yang.data.api.schema.NormalizedNode;
  21 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeUtils;
  22 import org.slf4j.Logger;
  23 import org.slf4j.LoggerFactory;
  24
  25 import com.google.common.base.Optional;
  26 import com.google.common.base.Preconditions;
  27
  28 /*
  29  * FIXME: the thread safety of concurrent write/delete/read/seal operations
  30  *        needs to be evaluated.
  31  */
  32 class MutableDataTree {
  33     private static final Logger LOG = LoggerFactory.getLogger(MutableDataTree.class);
  34     private final AtomicBoolean sealed = new AtomicBoolean();
  35     private final ModificationApplyOperation strategyTree;
  36     private final DataAndMetadataSnapshot snapshot;
  37     private final NodeModification rootModification;
  38
  39     private MutableDataTree(final DataAndMetadataSnapshot snapshot, final ModificationApplyOperation strategyTree) {
  40         this.snapshot = snapshot;
  41         this.strategyTree = strategyTree;
  42         this.rootModification = NodeModification.createUnmodified(snapshot.getMetadataTree());
  43     }
  44
  45     public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> value) {
  46         checkSealed();
  47         resolveModificationFor(path).write(value);
  48     }
  49
  50     public void delete(final InstanceIdentifier path) {
  51         checkSealed();
  52         resolveModificationFor(path).delete();
  53     }
  54
  55     public Optional<NormalizedNode<?, ?>> read(final InstanceIdentifier path) {
  56         Entry<InstanceIdentifier, NodeModification> modification = TreeNodeUtils.findClosestsOrFirstMatch(rootModification, path, NodeModification.IS_TERMINAL_PREDICATE);
  57
  58         Optional<StoreMetadataNode> result = resolveSnapshot(modification);
  59         if (result.isPresent()) {
  60             NormalizedNode<?, ?> data = result.get().getData();
  61             return NormalizedNodeUtils.findNode(modification.getKey(), data, path);
  62         }
  63         return Optional.absent();
  64     }
  65
  66     private Optional<StoreMetadataNode> resolveSnapshot(
  67             final Entry<InstanceIdentifier, NodeModification> keyModification) {
  68         InstanceIdentifier path = keyModification.getKey();
  69         NodeModification modification = keyModification.getValue();
  70         return resolveSnapshot(path, modification);
  71     }
  72
  73     private Optional<StoreMetadataNode> resolveSnapshot(final InstanceIdentifier path,
  74             final NodeModification modification) {
  75         try {
  76             Optional<Optional<StoreMetadataNode>> potentialSnapshot = modification.getSnapshotCache();
  77             if(potentialSnapshot.isPresent()) {
  78                 return potentialSnapshot.get();
  79             }
  80             return resolveModificationStrategy(path).apply(modification, modification.getOriginal(),
  81                     StoreUtils.increase(snapshot.getMetadataTree().getSubtreeVersion()));
  82         } catch (Exception e) {
  83             LOG.error("Could not create snapshot for {}:{}", path,modification,e);
  84             throw e;
  85         }
  86     }
  87
  88     private ModificationApplyOperation resolveModificationStrategy(final InstanceIdentifier path) {
  89         LOG.trace("Resolving modification apply strategy for {}", path);
  90         return TreeNodeUtils.findNodeChecked(strategyTree, path);
  91     }
  92
  93     private OperationWithModification resolveModificationFor(final InstanceIdentifier path) {
  94         NodeModification modification = rootModification;
  95         // We ensure strategy is present.
  96         ModificationApplyOperation operation = resolveModificationStrategy(path);
  97         for (PathArgument pathArg : path.getPath()) {
  98             modification = modification.modifyChild(pathArg);
  99         }
 100         return OperationWithModification.from(operation, modification);
 101     }
 102
 103     public static MutableDataTree from(final DataAndMetadataSnapshot snapshot, final ModificationApplyOperation resolver) {
 104         return new MutableDataTree(snapshot, resolver);
 105     }
 106
 107     public void seal() {
 108         final boolean success = sealed.compareAndSet(false, true);
 109         Preconditions.checkState(success, "Attempted to seal an already-sealed Data Tree.");
 110         rootModification.seal();
 111     }
 112
 113     private void checkSealed() {
 114         checkState(!sealed.get(), "Data Tree is sealed. No further modifications allowed.");
 115     }
 116
 117     protected NodeModification getRootModification() {
 118         return rootModification;
 119     }
 120
 121     @Override
 122     public String toString() {
 123         return "MutableDataTree [modification=" + rootModification + "]";
 124     }
 125 }