api/src/main/java/com/datatorrent/api/annotation/OperatorAnnotation.java

/**
 * Copyright (C) 2015 DataTorrent, 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.datatorrent.api.annotation;

import java.lang.annotation.Documented;
import java.lang.annotation.ElementType;
import java.lang.annotation.Retention;
import java.lang.annotation.RetentionPolicy;
import java.lang.annotation.Target;

/**
 * Annotation to specify characteristics of an operator.
 *
 * @since 0.3.5
 */
@Documented
@Target(ElementType.TYPE)
@Retention(RetentionPolicy.RUNTIME)
public @interface OperatorAnnotation
{
  /**
   * Element specifying whether operator can be partitioned or not.
   * Default value is true indicating operator can be partitioned.
   * @return Whether operator can be partitioned or not
   */
  public boolean partitionable() default true;

  /**
   * Element specifying whether an operator can be check-pointed in the middle of an application window.
   * Default value is true indicating that it can be. When false the checkpoint window count should be a multiple of
   * application window count otherwise the dag validation will fail.
   *
   * @return whether operator can be checkpointed in middle of an application window.
   */
  public boolean checkpointableWithinAppWindow() default true;
}