content: /**
   * 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 com.datatorrent.apps.logstream.PropertyRegistry;
  
  /**
   * Interface for property registry which can be implemented and shared across the dag
   * Properties can be added to the registry during dag setup and then be accessible in all
   * interested operators to look them up.
   *
   * @param <T>
   * @since 0.9.4
   */
  public interface PropertyRegistry<T>
  {
    /**
     * binds a given name and value, assigns a unique index to the name value pair and returns it
     * @param name
     * @param value
     * @return
     */
    public int bind(T name, T value);
  
    /**
     * Returns the index of name value pair if exists, else returns -1
     * @param name
     * @param value
     * @return
     */
    public int getIndex(T name, T value);
  
    /**
     * Returns the name associated with given index
     * @param register
     * @return
     */
    public T lookupName(int register);
  
    /**
     * Returns the value associated with given index
     * @param register
     * @return
     */
    public T lookupValue(int register);
  
    /**
     * Returns a list of values associated with given name
     * @param name
     * @return
     */
    public T[] list(String name);
  }
  