org.apache.flink.streaming.api.datastream.BroadcastStream 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.datastream;
import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.api.common.state.MapStateDescriptor;
import org.apache.flink.api.common.typeinfo.TypeInformation;
import org.apache.flink.api.dag.Transformation;
import org.apache.flink.streaming.api.environment.StreamExecutionEnvironment;
import java.util.Arrays;
import java.util.List;
import static java.util.Objects.requireNonNull;
/**
* A {@code BroadcastStream} is a stream with {@link
* org.apache.flink.api.common.state.BroadcastState broadcast state(s)}. This can be created by any
* stream using the {@link DataStream#broadcast(MapStateDescriptor[])} method and implicitly creates
* states where the user can store elements of the created {@code BroadcastStream}. (see {@link
* BroadcastConnectedStream}).
*
* Note that no further operation can be applied to these streams. The only available option is
* to connect them with a keyed or non-keyed stream, using the {@link
* KeyedStream#connect(BroadcastStream)} and the {@link DataStream#connect(BroadcastStream)}
* respectively. Applying these methods will result it a {@link BroadcastConnectedStream} for
* further processing.
*
* @param The type of input/output elements.
*/
@PublicEvolving
public class BroadcastStream {
private final StreamExecutionEnvironment environment;
private final DataStream inputStream;
/**
* The {@link org.apache.flink.api.common.state.StateDescriptor state descriptors} of the
* registered {@link org.apache.flink.api.common.state.BroadcastState broadcast states}. These
* states have {@code key-value} format.
*/
private final List> broadcastStateDescriptors;
protected BroadcastStream(
final StreamExecutionEnvironment env,
final DataStream input,
final MapStateDescriptor... broadcastStateDescriptors) {
this.environment = requireNonNull(env);
this.inputStream = requireNonNull(input);
this.broadcastStateDescriptors = Arrays.asList(requireNonNull(broadcastStateDescriptors));
}
public TypeInformation getType() {
return inputStream.getType();
}
public F clean(F f) {
return environment.clean(f);
}
public Transformation getTransformation() {
return inputStream.getTransformation();
}
public List> getBroadcastStateDescriptors() {
return broadcastStateDescriptors;
}
public StreamExecutionEnvironment getEnvironment() {
return environment;
}
}