IntegerGenerator.java

/**
 * Copyright (c) 2010 Yahoo! Inc. All rights reserved.
 *
 * 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. See accompanying
 * LICENSE file.
 */
package com.googlecode.concurrentlinkedhashmap.generator;

/**
 * A generator that is capable of generating ints as well as strings
 *
 * @author Brian Cooper
 * @see <a href="http://research.yahoo.com/Web_Information_Management/YCSB">YCSB</a>
 */
public abstract class IntegerGenerator extends Generator {
  int lastint;

  /**
   * Set the last value generated. IntegerGenerator subclasses must use this
   * call to properly set the last string value, or the lastString() and
   * lastInt() calls won't work.
   */
  public void setLastInt(int last) {
    lastint = last;
  }

  /**
   * Return the next value as an int. When overriding this method, be sure to
   * call setLastString() properly, or the lastString() call won't work.
   */
  public abstract int nextInt();

  /**
   * Generate the next string in the distribution.
   */
  @Override
  public String nextString() {
    return Integer.toString(nextInt());
  }

  /**
   * Return the previous string generated by the distribution; e.g., returned
   * from the last nextString() call. Calling lastString() should not advance
   * the distribution or have any side effects. If nextString() has not yet been
   * called, lastString() should return something reasonable.
   */
  @Override
  public String lastString() {
    return Integer.toString(lastint);
  }

  /**
   * Return the previous int generated by the distribution. This call is unique
   * to IntegerGenerator subclasses, and assumes IntegerGenerator subclasses
   * always return ints for nextInt() (e.g. not arbitrary strings).
   */
  public int lastInt() {
    return lastint;
  }
}