/*
* Licensed to the Apache Software Foundation (ASF) under one or more
* contributor license agreements. See the NOTICE file distributed with
* this work for additional information regarding copyright ownership.
* The ASF licenses this file to You 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 gobblin.source;
import gobblin.configuration.SourceState;
import gobblin.source.workunit.WorkUnitStream;
/**
* A {@link Source} that produces a {@link WorkUnitStream}.
*
* Streamed sources may offer certain advantages over non-streamed sources if the job launcher supports them:
* * Low memory usage: If the {@link WorkUnitStream} is backed by a generator, the job launcher may optimize memory
* usage by never materializing all work units in memory.
* * Eager processing of slow sources: If the source is slow at producing work units, the job launcher may start
* processing available work units while future work units are still being computed.
* * Infinite work unit streams: in the future, some job launchers will support infinite streams of work units.
*/
public interface WorkUnitStreamSource<S, D> extends Source<S, D> {
/**
* Get the {@link WorkUnitStream} to process.
*/
WorkUnitStream getWorkunitStream(SourceState state);
}