com.google.firebase.database.snapshot.Index 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.

There is a newer version: 9.3.0

Show 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;

import com.google.firebase.database.core.Path;

import java.util.Comparator;

public abstract class Index implements Comparator {

  public static Index fromQueryDefinition(String str) {
    if (str.equals(".value")) {
      return ValueIndex.getInstance();
    } else if (str.equals(".key")) {
      return KeyIndex.getInstance();
    } else if (str.equals(".priority")) {
      throw new IllegalStateException(
          "queryDefinition shouldn't ever be .priority since it's the default");
    } else {
      return new PathIndex(new Path(str));
    }
  }

  public abstract boolean isDefinedOn(Node a);

  public boolean indexedValueChanged(Node oldNode, Node newNode) {
    NamedNode oldWrapped = new NamedNode(ChildKey.getMinName(), oldNode);
    NamedNode newWrapped = new NamedNode(ChildKey.getMinName(), newNode);
    return this.compare(oldWrapped, newWrapped) != 0;
  }

  public abstract NamedNode makePost(ChildKey name, Node value);

  public NamedNode minPost() {
    return NamedNode.getMinNode();
  }

  public abstract NamedNode maxPost();

  public abstract String getQueryDefinition();

  public int compare(NamedNode one, NamedNode two, boolean reverse) {
    if (reverse) {
      return this.compare(two, one);
    } else {
      return this.compare(one, two);
    }
  }
}