com.streamsets.pipeline.api.Processor Maven / Gradle / Ivy
/*
* Copyright 2017 StreamSets 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.streamsets.pipeline.api;
import java.util.List;
/**
* A Processor is a Data Collector processor stage. Processor stages receive records from an origin
* ({@link Source}) or other processors stages, perform operations on the records and write them out so they can be
* processed by another processor or destination ({@link Target}) stages.
*
* @see Source
* @see Target
*/
public interface Processor extends Stage {
/**
* Processor stage context.
*/
public interface Context extends Stage.Context, ToErrorContext, ToEventContext, ProcessedContext {
/**
* Returns the output lane names (stream names) of the Source.
*
* @return the output lane names (stream names) of the Source.
*/
public List getOutputLanes();
/**
* Creates an empty record indicating another record as its source.
*
* @param originatorRecord the original record.
* @return an empty record with the specified ID and raw data.
*/
public Record createRecord(Record originatorRecord);
/**
* Creates an empty record indicating another record as its source.
*
* @param originatorRecord the original record.
* @param sourceIdPostfix the sourceId postfix
* @return an empty record with the specified ID and raw data.
* The sourceIdPostFix will be appended to the sourceId of originator record.
*/
public Record createRecord(Record originatorRecord, String sourceIdPostfix);
/**
* Creates an empty record indicating another record as its source, including the original raw data of the record.
*
* @param originatorRecord the original record.
* @param raw the record raw data.
* @param rawMime the MIME type of the raw data.
* @return an empty record with the specified ID and raw data.
*/
public Record createRecord(Record originatorRecord, byte[] raw, String rawMime);
/**
* Clones a record.
*
* @param record the record to clone.
* @return the cloned record. The cloned record is a share-nothing deep-copy of the original record.
*/
public Record cloneRecord(Record record);
/**
* Clones a record.
*
* @param record the record to clone.
* @param sourceIdPostfix the sourceId postfix
* @return the cloned record. The cloned record is a share-nothing deep-copy of the original record.
* The sourceIdPostFix will be appended to the sourceId of original record being cloned.
*/
public Record cloneRecord(Record record, String sourceIdPostfix);
}
/**
* When running a pipeline, the Data Collector calls this method from the Processor stage with a
* batch of records to process.
*
* @param batch the batch of records to process.
* @param batchMaker records created by the Processor stage must be added to the BatchMaker
* for them to be available to the rest of the pipeline.
* @throws StageException if the Processor had an error while processing records.
*/
public void process(Batch batch, BatchMaker batchMaker) throws StageException;
}