com.google.firebase.database.snapshot.KeyIndex Maven / Gradle / Ivy

Go to download

Show more of this group Show more artifacts with this name
Show all versions of firebase-admin Show documentation

This is the official Firebase Admin Java SDK. Build extraordinary native JVM apps in minutes with Firebase. The Firebase platform can power your app’s backend, user authentication, static hosting, and more.

The newest version!

/*
 * Copyright 2017 Google Inc.
 *
 * 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 com.google.firebase.database.snapshot;

public class KeyIndex extends Index {

  private static final KeyIndex INSTANCE = new KeyIndex();

  private KeyIndex() {
    // prevent instantiation
  }

  public static KeyIndex getInstance() {
    return INSTANCE;
  }

  @Override
  public boolean isDefinedOn(Node a) {
    return true;
  }

  @Override
  public NamedNode makePost(ChildKey name, Node value) {
    assert value instanceof StringNode;
    // We just use empty node, but it'll never be compared, since our comparator only looks
    // at name
    return new NamedNode(ChildKey.fromString((String) value.getValue()), EmptyNode.Empty());
  }

  @Override
  public NamedNode maxPost() {
    return NamedNode.getMaxNode();
  }

  @Override
  public String getQueryDefinition() {
    return ".key";
  }

  @Override
  public int compare(NamedNode o1, NamedNode o2) {
    return o1.getName().compareTo(o2.getName());
  }

  @Override
  public boolean equals(Object o) {
    return o instanceof KeyIndex;
  }

  @Override
  public int hashCode() {
    // chosen by a fair dice roll. Guaranteed to be random
    return 37;
  }

  @Override
  public String toString() {
    return "KeyIndex";
  }
}