PriorityUtilities.java

/*
 * 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.DatabaseException;

public class PriorityUtilities {

  // CSOFF: MethodName
  public static Node NullPriority() {
    return EmptyNode.Empty();
  }
  // CSON: MethodName

  public static boolean isValidPriority(Node priority) {
    return priority.getPriority().isEmpty()
        && (priority.isEmpty()
            || priority instanceof DoubleNode
            || priority instanceof StringNode
            || priority instanceof DeferredValueNode);
  }

  public static Node parsePriority(Object value) {
    Node priority = NodeUtilities.NodeFromJSON(value);
    if (priority instanceof LongNode) {
      priority =
          new DoubleNode(
              Double.valueOf((Long) priority.getValue()), PriorityUtilities.NullPriority());
    }
    if (!isValidPriority(priority)) {
      throw new DatabaseException(
          "Invalid Firebase Database priority (must be a string, double, ServerValue, or null)");
    }
    return priority;
  }
}