javax.batch.api.partition.PartitionPlan Maven / Gradle / Ivy
/*
* Copyright 2012 International Business Machines Corp.
*
* See the NOTICE file distributed with this work for additional information
* regarding copyright ownership. 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 javax.batch.api.partition;
import java.util.Properties;
/**
*
* PartitionPlan is a helper class that carries partition processing
* information set by the @PartitionMapper method.
*
* A PartitionPlan contains:
*
* - number of partition instances
* - number of threads on which to execute the partitions
* - substitution properties for each Partition (which can be
* referenced using the #{partitionPlan['propertyName']}
* syntax.
*
*/
public interface PartitionPlan {
/**
* Set number of partitions.
* @param count specifies the partition count
*/
public void setPartitions(int count);
/**
* Specify whether or not to override the partition
* count from the previous job execution. This applies
* only to step restart.
*
* When false is specified, the
* partition count from the previous job execution is used
* and any new value set for partition count in the current run
* is ignored. In addition, partition results from the previous
* job execution are remembered, and only incomplete partitions
* are reprocessed.
*
* When true is specified, the partition count from the current run
* is used and all results from past partitions are discarded. Any
* resource cleanup or back out of work done in the previous run is the
* responsibility of the application. The PartitionReducer artifact's
* rollbackPartitionedStep method is invoked during restart before any
* partitions begin processing to provide a cleanup hook.
*
* @param override See method description
*/
public void setPartitionsOverride(boolean override);
/**
* Return current value of partition override setting.
* @return override setting.
* @see PartitionPlan#setPartitionsOverride(boolean)
*/
public boolean getPartitionsOverride();
/**
* Set maximum number of threads requested to use to run
* partitions for this step. A value of '0' requests the batch
* implementation to use the partition count as the thread
* count. Note the batch runtime is not required to use
* this full number of threads; it may not have this many
* available, and may use less.
*
* @param count specifies the requested thread count
*/
public void setThreads(int count);
/**
* Sets array of substitution Properties objects for the set of Partitions.
* @param props specifies the Properties object array
* @see PartitionPlan#getPartitionProperties()
*/
public void setPartitionProperties(Properties[] props);
/**
* Gets count of Partitions.
* @return Partition count
*/
public int getPartitions();
/**
* Gets maximum number of threads requested to use to run
* partitions for this step. A value of '0' requests the batch
* implementation to use the partition count as the thread
* count. Note the batch runtime is not required to use
* this full number of threads; it may not have this many
* available, and may use less.
*
* @return requested thread count
*/
public int getThreads();
/**
* Gets array of Partition Properties objects for Partitions.
*
* These can be used in Job XML substitution using
* substitution expressions with the syntax:
* #{partitionPlan['propertyName']}
*
* Each element of the Properties array returned can
* be used to resolving substitutions for a single partition.
* In the typical use case, each Properties element will
* have a similar set of property names, with a
* substitution potentially resolving to the corresponding
* value for each partition.
*
* @return Partition Properties object array
*/
public Properties[] getPartitionProperties();
}