2 * Copyright (c) 2014 Cisco Systems, Inc. and others. All rights reserved.
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
8 package org.opendaylight.controller.md.sal.dom.store.impl;
10 import static com.google.common.base.Preconditions.checkState;
12 import java.util.Map.Entry;
13 import java.util.concurrent.atomic.AtomicIntegerFieldUpdater;
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.api.schema.NormalizedNodeContainer;
22 import org.opendaylight.yangtools.yang.data.impl.schema.NormalizedNodeUtils;
23 import org.slf4j.Logger;
24 import org.slf4j.LoggerFactory;
26 import com.google.common.base.Optional;
27 import com.google.common.base.Preconditions;
30 * Class encapsulation of set of modifications to a base tree. This tree is backed
31 * by a read-only snapshot and tracks modifications on top of that. The modification
32 * has the ability to rebase itself on a new snapshot.
34 class DataTreeModification {
35 private static final Logger LOG = LoggerFactory.getLogger(DataTreeModification.class);
38 * FIXME: the thread safety of concurrent write/delete/read/seal operations
39 * needs to be evaluated.
41 private static final AtomicIntegerFieldUpdater<DataTreeModification> SEALED_UPDATER =
42 AtomicIntegerFieldUpdater.newUpdater(DataTreeModification.class, "sealed");
43 private volatile int sealed = 0;
45 private final ModificationApplyOperation strategyTree;
46 private final DataTree.Snapshot snapshot;
47 private final NodeModification rootNode;
49 private DataTreeModification(final DataTree.Snapshot snapshot, final ModificationApplyOperation strategyTree) {
50 this.snapshot = Preconditions.checkNotNull(snapshot);
51 this.strategyTree = Preconditions.checkNotNull(strategyTree);
52 this.rootNode = NodeModification.createUnmodified(snapshot.getRootNode());
55 public void write(final InstanceIdentifier path, final NormalizedNode<?, ?> value) {
57 resolveModificationFor(path).write(value);
60 public void merge(final InstanceIdentifier path, final NormalizedNode<?, ?> data) {
62 mergeImpl(resolveModificationFor(path),data);
65 private void mergeImpl(final OperationWithModification op,final NormalizedNode<?,?> data) {
67 if(data instanceof NormalizedNodeContainer<?,?,?>) {
68 @SuppressWarnings({ "rawtypes", "unchecked" })
69 NormalizedNodeContainer<?,?,NormalizedNode<PathArgument, ?>> dataContainer = (NormalizedNodeContainer) data;
70 for(NormalizedNode<PathArgument, ?> child : dataContainer.getValue()) {
71 PathArgument childId = child.getIdentifier();
72 mergeImpl(op.forChild(childId), child);
78 public void delete(final InstanceIdentifier path) {
80 resolveModificationFor(path).delete();
83 public Optional<NormalizedNode<?, ?>> read(final InstanceIdentifier path) {
84 Entry<InstanceIdentifier, NodeModification> modification = TreeNodeUtils.findClosestsOrFirstMatch(rootNode, path, NodeModification.IS_TERMINAL_PREDICATE);
86 Optional<StoreMetadataNode> result = resolveSnapshot(modification);
87 if (result.isPresent()) {
88 NormalizedNode<?, ?> data = result.get().getData();
89 return NormalizedNodeUtils.findNode(modification.getKey(), data, path);
91 return Optional.absent();
94 private Optional<StoreMetadataNode> resolveSnapshot(
95 final Entry<InstanceIdentifier, NodeModification> keyModification) {
96 InstanceIdentifier path = keyModification.getKey();
97 NodeModification modification = keyModification.getValue();
98 return resolveSnapshot(path, modification);
101 private Optional<StoreMetadataNode> resolveSnapshot(final InstanceIdentifier path,
102 final NodeModification modification) {
104 Optional<Optional<StoreMetadataNode>> potentialSnapshot = modification.getSnapshotCache();
105 if(potentialSnapshot.isPresent()) {
106 return potentialSnapshot.get();
108 return resolveModificationStrategy(path).apply(modification, modification.getOriginal(),
109 StoreUtils.increase(snapshot.getRootNode().getSubtreeVersion()));
110 } catch (Exception e) {
111 LOG.error("Could not create snapshot for {}:{}", path,modification,e);
116 private ModificationApplyOperation resolveModificationStrategy(final InstanceIdentifier path) {
117 LOG.trace("Resolving modification apply strategy for {}", path);
118 return TreeNodeUtils.findNodeChecked(strategyTree, path);
121 private OperationWithModification resolveModificationFor(final InstanceIdentifier path) {
122 NodeModification modification = rootNode;
123 // We ensure strategy is present.
124 ModificationApplyOperation operation = resolveModificationStrategy(path);
125 for (PathArgument pathArg : path.getPath()) {
126 modification = modification.modifyChild(pathArg);
128 return OperationWithModification.from(operation, modification);
131 public static DataTreeModification from(final DataTree.Snapshot snapshot, final ModificationApplyOperation resolver) {
132 return new DataTreeModification(snapshot, resolver);
136 final boolean success = SEALED_UPDATER.compareAndSet(this, 0, 1);
137 Preconditions.checkState(success, "Attempted to seal an already-sealed Data Tree.");
141 private void checkSealed() {
142 checkState(sealed == 0, "Data Tree is sealed. No further modifications allowed.");
146 protected NodeModification getRootModification() {
151 public String toString() {
152 return "MutableDataTree [modification=" + rootNode + "]";