content: /*
   * Copyright (c) 2013 - 2014, Allen A. George <allen dot george at gmail dot com>
   *
   * All rights reserved.
   *
   * Redistribution and use in source and binary forms, with or without
   * modification, are permitted provided that the following conditions are met:
   *     * Redistributions of source code must retain the above copyright
   *       notice, this list of conditions and the following disclaimer.
   *     * Redistributions in binary form must reproduce the above copyright
   *       notice, this list of conditions and the following disclaimer in the
   *       documentation and/or other materials provided with the distribution.
   *     * Neither the name of libraft nor the
   *       names of its contributors may be used to endorse or promote products
   *       derived from this software without specific prior written permission.
   *
   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
   * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
   * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
   * DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE LIABLE FOR
   * ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
   * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
   * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
   * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
   * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
   * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
   */
  
  package io.libraft.kayvee.store;
  
  import javax.annotation.Nullable;
  
  /**
   * Thrown when a key exists in the key-value store
   * but its value does not match the excepted value
   * in a {@code CAS} operation.
   * <p/>
   * This exception <strong>should not</strong> be thrown
   * if the key does not exist - use {@link KeyNotFoundException}
   * instead.
   */
  public final class ValueMismatchException extends KayVeeException {
  
      private static final long serialVersionUID = -8419273931405391504L;
  
      private final String key;
  
      @Nullable private final String expectedValue;
      @Nullable private final String existingValue;
  
      /**
       * Constructor.
       *
       * @param key non-null, non-empty key for which the CAS operation failed
       * @param expectedValue expected value (may be null) the caller specified for the CAS operation on the key
       * @param existingValue current value for the key, or null if the key does not exist
       */
      public ValueMismatchException(String key, @Nullable String expectedValue, @Nullable String existingValue) {
          super(String.format("key:%s - mismatched value: expected:%s existing:%s", key, expectedValue, existingValue));
          this.key = key;
          this.expectedValue = expectedValue;
          this.existingValue = existingValue;
      }
  
      /**
       * Get the key for which the CAS operation failed.
       *
       * @return non-null, non-empty key for which the CAS operation failed
       */
      public String getKey() {
          return key;
      }
  
      /**
       * Get the expected value the caller specified for the CAS operation on the key.
       *
       * @return expected value (may be null) the caller specified for the CAS operation on the key
       */
      public @Nullable String getExpectedValue() {
          return expectedValue;
      }
  
      /**
       * Get the current value for the key.
       *
       * @return current value for the key, or null if the key does not exist
       */
      public @Nullable String getExistingValue() {
          return existingValue;
      }
  }
  