org.apache.flink.streaming.api.functions.co.BaseBroadcastProcessFunction Maven / Gradle / Ivy
/*
* 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.co;
import org.apache.flink.annotation.PublicEvolving;
import org.apache.flink.api.common.functions.AbstractRichFunction;
import org.apache.flink.api.common.state.BroadcastState;
import org.apache.flink.api.common.state.MapStateDescriptor;
import org.apache.flink.api.common.state.ReadOnlyBroadcastState;
import org.apache.flink.util.OutputTag;
/**
* The base class containing the functionality available to all broadcast process function.
* These include the {@link BroadcastProcessFunction} and the {@link KeyedBroadcastProcessFunction}.
*/
@PublicEvolving
public abstract class BaseBroadcastProcessFunction extends AbstractRichFunction {
private static final long serialVersionUID = -131631008887478610L;
/**
* The base context available to all methods in a broadcast process function. This
* include {@link BroadcastProcessFunction BroadcastProcessFunctions} and
* {@link KeyedBroadcastProcessFunction KeyedBroadcastProcessFunctions}.
*/
abstract class BaseContext {
/**
* Timestamp of the element currently being processed or timestamp of a firing timer.
*
* This might be {@code null}, for example if the time characteristic of your program
* is set to {@link org.apache.flink.streaming.api.TimeCharacteristic#ProcessingTime}.
*/
public abstract Long timestamp();
/**
* Emits a record to the side output identified by the {@link OutputTag}.
*
* @param outputTag the {@code OutputTag} that identifies the side output to emit to.
* @param value The record to emit.
*/
public abstract void output(final OutputTag outputTag, final X value);
/** Returns the current processing time. */
public abstract long currentProcessingTime();
/** Returns the current event-time watermark. */
public abstract long currentWatermark();
}
/**
* A base {@link BaseContext context} available to the broadcasted stream side of
* a {@link org.apache.flink.streaming.api.datastream.BroadcastConnectedStream BroadcastConnectedStream}.
*
* Apart from the basic functionality of a {@link BaseContext context},
* this also allows to get and update the elements stored in the
* {@link BroadcastState broadcast state}.
* In other words, it gives read/write access to the broadcast state.
*/
public abstract class Context extends BaseContext {
/**
* Fetches the {@link BroadcastState} with the specified name.
*
* @param stateDescriptor the {@link MapStateDescriptor} of the state to be fetched.
* @return The required {@link BroadcastState broadcast state}.
*/
public abstract BroadcastState getBroadcastState(final MapStateDescriptor stateDescriptor);
}
/**
* A {@link BaseContext context} available to the non-broadcasted stream side of
* a {@link org.apache.flink.streaming.api.datastream.BroadcastConnectedStream BroadcastConnectedStream}.
*
* Apart from the basic functionality of a {@link BaseContext context},
* this also allows to get a read-only {@link Iterable} over the elements stored in the
* broadcast state.
*/
public abstract class ReadOnlyContext extends BaseContext {
/**
* Fetches a read-only view of the broadcast state with the specified name.
*
* @param stateDescriptor the {@link MapStateDescriptor} of the state to be fetched.
* @return The required read-only view of the broadcast state.
*/
public abstract ReadOnlyBroadcastState getBroadcastState(final MapStateDescriptor stateDescriptor);
}
}