| /* |
| * Licensed to the Apache Software Foundation (ASF) under one or more |
| * contributor license agreements. See the NOTICE file distributed with |
| * this work for additional information regarding copyright ownership. |
| * The ASF licenses this file to You 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.apache.jackrabbit.oak.plugins.memory; |
| |
| import static java.util.Collections.emptyList; |
| import static org.apache.jackrabbit.oak.spi.state.AbstractNodeState.checkValidName; |
| |
| import org.apache.jackrabbit.oak.api.PropertyState; |
| import org.apache.jackrabbit.oak.spi.state.ChildNodeEntry; |
| import org.apache.jackrabbit.oak.spi.state.NodeBuilder; |
| import org.apache.jackrabbit.oak.spi.state.NodeState; |
| import org.apache.jackrabbit.oak.spi.state.NodeStateDiff; |
| import org.jetbrains.annotations.NotNull; |
| import org.jetbrains.annotations.Nullable; |
| |
| /** |
| * Singleton instances of empty and non-existent node states, i.e. ones |
| * with neither properties nor child nodes. |
| */ |
| public final class EmptyNodeState implements NodeState { |
| |
| public static final NodeState EMPTY_NODE = new EmptyNodeState(true); |
| |
| public static final NodeState MISSING_NODE = new EmptyNodeState(false); |
| |
| private final boolean exists; |
| |
| private EmptyNodeState(boolean exists) { |
| this.exists = exists; |
| } |
| |
| @Override |
| public boolean exists() { |
| return exists; |
| } |
| |
| @Override |
| public long getPropertyCount() { |
| return 0; |
| } |
| |
| @Override |
| public boolean hasProperty(@NotNull String name) { |
| return false; |
| } |
| |
| @Override @Nullable |
| public PropertyState getProperty(@NotNull String name) { |
| return null; |
| } |
| |
| @Override |
| public boolean getBoolean(@NotNull String name) { |
| return false; |
| } |
| |
| @Override |
| public long getLong(String name) { |
| return 0; |
| } |
| |
| @Override |
| public String getString(String name) { |
| return null; |
| } |
| |
| @NotNull |
| @Override |
| public Iterable<String> getStrings(@NotNull String name) { |
| return emptyList(); |
| } |
| |
| @Override @Nullable |
| public String getName(@NotNull String name) { |
| return null; |
| } |
| |
| @Override @NotNull |
| public Iterable<String> getNames(@NotNull String name) { |
| return emptyList(); |
| } |
| |
| @Override @NotNull |
| public Iterable<? extends PropertyState> getProperties() { |
| return emptyList(); |
| } |
| |
| @Override |
| public long getChildNodeCount(long max) { |
| return 0; |
| } |
| |
| @Override |
| public boolean hasChildNode(@NotNull String name) { |
| return false; |
| } |
| |
| @Override @NotNull |
| public NodeState getChildNode(@NotNull String name) { |
| checkValidName(name); |
| return MISSING_NODE; |
| } |
| |
| @Override |
| public Iterable<String> getChildNodeNames() { |
| return emptyList(); |
| } |
| |
| @Override @NotNull |
| public Iterable<? extends ChildNodeEntry> getChildNodeEntries() { |
| return emptyList(); |
| } |
| |
| @Override @NotNull |
| public NodeBuilder builder() { |
| return new MemoryNodeBuilder(this); |
| } |
| |
| @Override |
| public boolean compareAgainstBaseState(NodeState base, NodeStateDiff diff) { |
| if (base != EMPTY_NODE && base.exists()) { |
| for (PropertyState before : base.getProperties()) { |
| if (!diff.propertyDeleted(before)) { |
| return false; |
| } |
| } |
| for (ChildNodeEntry before : base.getChildNodeEntries()) { |
| if (!diff.childNodeDeleted( |
| before.getName(), before.getNodeState())) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| public static boolean compareAgainstEmptyState( |
| NodeState state, NodeStateDiff diff) { |
| if (state != EMPTY_NODE && state.exists()) { |
| for (PropertyState after : state.getProperties()) { |
| if (!diff.propertyAdded(after)) { |
| return false; |
| } |
| } |
| for (ChildNodeEntry after : state.getChildNodeEntries()) { |
| if (!diff.childNodeAdded(after.getName(), after.getNodeState())) { |
| return false; |
| } |
| } |
| } |
| return true; |
| } |
| |
| public static boolean isEmptyState(NodeState state) { |
| return state == EMPTY_NODE || state == MISSING_NODE; |
| } |
| |
| //------------------------------------------------------------< Object >-- |
| |
| public String toString() { |
| if (exists) { |
| return "{ }"; |
| } else { |
| return "{N/A}"; |
| } |
| } |
| |
| public boolean equals(Object object) { |
| if (object == EMPTY_NODE || object == MISSING_NODE) { |
| return exists == (object == EMPTY_NODE); |
| } else if (object instanceof NodeState) { |
| NodeState that = (NodeState) object; |
| return that.getPropertyCount() == 0 |
| && that.getChildNodeCount(1) == 0 |
| && (exists == that.exists()); |
| } else { |
| return false; |
| } |
| } |
| |
| public int hashCode() { |
| return 0; |
| } |
| |
| } |