org.apache.flink.streaming.api.functions.source.datagen.DataGenerator Maven / Gradle / Ivy
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* 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 org.apache.flink.streaming.api.functions.source.datagen;
import org.apache.flink.annotation.Experimental;
import org.apache.flink.api.common.functions.RuntimeContext;
import org.apache.flink.runtime.state.FunctionInitializationContext;
import org.apache.flink.runtime.state.FunctionSnapshotContext;
import org.apache.flink.streaming.api.checkpoint.CheckpointedFunction;
import java.io.Serializable;
import java.util.Iterator;
/** Stateful and re-scalable data generator. */
@Experimental
public interface DataGenerator extends Serializable, Iterator {
/**
* Open and initialize state for {@link DataGenerator}. See {@link
* CheckpointedFunction#initializeState}.
*
* @param name The state of {@link DataGenerator} should related to this name, make sure the
* name of state is different.
*/
void open(String name, FunctionInitializationContext context, RuntimeContext runtimeContext)
throws Exception;
/** Snapshot state for {@link DataGenerator}. See {@link CheckpointedFunction#snapshotState}. */
default void snapshotState(FunctionSnapshotContext context) throws Exception {}
}