Updates to DocumentTreeNode + Simple implementation of DocumentTree interface
Change-Id: Icc162201a50de8ae48abdb8e769fb6ed86138a03
diff --git a/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/DefaultDocumentTree.java b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/DefaultDocumentTree.java
new file mode 100644
index 0000000..fdfe9dd
--- /dev/null
+++ b/core/store/primitives/src/main/java/org/onosproject/store/primitives/resources/impl/DefaultDocumentTree.java
@@ -0,0 +1,175 @@
+/*
+ * Copyright 2016-present Open Networking Laboratory
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ * http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package org.onosproject.store.primitives.resources.impl;
+
+import java.util.Iterator;
+import java.util.Map;
+import java.util.Objects;
+import java.util.concurrent.atomic.AtomicInteger;
+
+import org.onosproject.store.service.DocumentPath;
+import org.onosproject.store.service.DocumentTree;
+import org.onosproject.store.service.DocumentTreeListener;
+import org.onosproject.store.service.DocumentTreeNode;
+import org.onosproject.store.service.IllegalDocumentModificationException;
+import org.onosproject.store.service.NoSuchDocumentPathException;
+import org.onosproject.store.service.Versioned;
+
+import com.google.common.base.Preconditions;
+import com.google.common.collect.Maps;
+
+/**
+ * Simple implementation of a {@link DocumentTree}.
+ *
+ * @param <V> tree node value type
+ */
+public class DefaultDocumentTree<V> implements DocumentTree<V> {
+
+ private static final DocumentPath ROOT_PATH = DocumentPath.from("root");
+ private final DefaultDocumentTreeNode<V> root;
+ private final AtomicInteger versionCounter = new AtomicInteger(0);
+
+ public DefaultDocumentTree() {
+ root = new DefaultDocumentTreeNode<V>(ROOT_PATH, null, nextVersion(), null);
+ }
+
+ @Override
+ public DocumentPath root() {
+ return ROOT_PATH;
+ }
+
+ @Override
+ public Map<String, Versioned<V>> getChildren(DocumentPath path) {
+ DocumentTreeNode<V> node = getNode(path);
+ if (node != null) {
+ Map<String, Versioned<V>> childrenValues = Maps.newHashMap();
+ node.children().forEachRemaining(n -> childrenValues.put(simpleName(n.path()), n.value()));
+ return childrenValues;
+ }
+ throw new NoSuchDocumentPathException();
+ }
+
+ @Override
+ public Versioned<V> get(DocumentPath path) {
+ DocumentTreeNode<V> currentNode = getNode(path);
+ return currentNode != null ? currentNode.value() : null;
+ }
+
+ @Override
+ public Versioned<V> set(DocumentPath path, V value) {
+ checkRootModification(path);
+ DefaultDocumentTreeNode<V> node = getNode(path);
+ if (node != null) {
+ return node.update(value, nextVersion());
+ } else {
+ create(path, value);
+ return null;
+ }
+ }
+
+ @Override
+ public boolean create(DocumentPath path, V value) {
+ checkRootModification(path);
+ DocumentTreeNode<V> node = getNode(path);
+ if (node != null) {
+ return false;
+ }
+ DocumentPath parentPath = path.parent();
+ DefaultDocumentTreeNode<V> parentNode = getNode(parentPath);
+ if (parentNode == null) {
+ throw new IllegalDocumentModificationException();
+ }
+ parentNode.addChild(simpleName(path), value, nextVersion());
+ return true;
+ }
+
+ @Override
+ public boolean replace(DocumentPath path, V newValue, long version) {
+ checkRootModification(path);
+ DocumentTreeNode<V> node = getNode(path);
+ if (node != null && node.value() != null && node.value().version() == version) {
+ if (!Objects.equals(newValue, node.value().value())) {
+ set(path, newValue);
+ return true;
+ }
+ }
+ return false;
+ }
+
+ @Override
+ public boolean replace(DocumentPath path, V newValue, V currentValue) {
+ checkRootModification(path);
+ if (Objects.equals(newValue, currentValue)) {
+ return false;
+ }
+ DocumentTreeNode<V> node = getNode(path);
+ if (node != null && Objects.equals(Versioned.valueOrNull(node.value()), currentValue)) {
+ set(path, newValue);
+ return true;
+ }
+ return false;
+ }
+
+ @Override
+ public Versioned<V> removeNode(DocumentPath path) {
+ checkRootModification(path);
+ DefaultDocumentTreeNode<V> nodeToRemove = getNode(path);
+ if (nodeToRemove == null) {
+ throw new NoSuchDocumentPathException();
+ }
+ if (nodeToRemove.hasChildren()) {
+ throw new IllegalDocumentModificationException();
+ }
+ DefaultDocumentTreeNode<V> parent = (DefaultDocumentTreeNode<V>) nodeToRemove.parent();
+ parent.removeChild(simpleName(path));
+ return nodeToRemove.value();
+ }
+
+ @Override
+ public void addListener(DocumentPath path, DocumentTreeListener<V> listener) {
+ // TODO Auto-generated method stub
+ }
+
+ @Override
+ public void removeListener(DocumentTreeListener<V> listener) {
+ // TODO Auto-generated method stub
+ }
+
+ private DefaultDocumentTreeNode<V> getNode(DocumentPath path) {
+ Iterator<String> pathElements = path.pathElements().iterator();
+ DefaultDocumentTreeNode<V> currentNode = root;
+ Preconditions.checkState("root".equals(pathElements.next()), "Path should start with root");
+ while (pathElements.hasNext() && currentNode != null) {
+ currentNode = (DefaultDocumentTreeNode<V>) currentNode.child(pathElements.next());
+ }
+ return currentNode;
+ }
+
+ private long nextVersion() {
+ return versionCounter.incrementAndGet();
+ }
+
+ private String simpleName(DocumentPath path) {
+ return path.pathElements().get(path.pathElements().size() - 1);
+ }
+
+ private void checkRootModification(DocumentPath path) {
+ if (ROOT_PATH.equals(path)) {
+ throw new IllegalDocumentModificationException();
+ }
+ }
+}