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/**
 * This class contains all logical related to process records from a broadcast stream and a
 * non-broadcast stream.
 */
public interface BroadcastTwoInputStreamProcessFunction<IN1, IN2, OUT> extends ProcessFunction {
    /**
     * Process record from non-broadcast input and emit data through {@link Collector}.
     *
     * @param record to process.
     * @param output to emit processed records.
     * @param ctx, runtime context in which this function is executed.
     */
    void processRecordFromNonBroadcastInput(IN1 record, Collector<OUT> output, RuntimeContext ctx)
            throws Exception;

    /**
     * Process record from broadcast input.In general, the broadcast side is not allowed to
     * manipulate state and output data because it corresponds to all partitions instead of a single
     * partition. But you could use broadcast context to process all the partitions at once.
     *
     * @param record to process.
     * @param ctx, the context in which this function is executed.
     */
    void processRecordFromBroadcastInput(IN2 record, BroadcastContext<OUT> ctx) throws Exception;

    /**
     * This is a life-cycle method indicates that this function will no longer receive any data from
     * the non-broadcast input. This allowing the ProcessFunction to emit results at once rather
     * than upon each record.
     *
     * @param output to emit record.
     * @param ctx, runtime context in which this function is executed.
     */
    default void endNonBroadcastInput(Collector<OUT> output, RuntimeContext ctx) {}

    /**
     * This is a life-cycle method indicates that this function will no longer receive any data from
     * the broadcast input.
     *
     * @param ctx, the context in which this function is executed.
     */
    default void endBroadcastInput(BroadcastContext<OUT> ctx) {}
}


/** This interface represents the context associated with broadcasting. */
public interface BroadcastContext<OUT> {
    /**
     * Apply a function to all partitions. For keyed stream, it will apply to all keys. For
     * non-keyed stream, it will apply to single partition.
     */
    void applyToAllPartitions(ApplyPartitionFunction<OUT> applyPartitionFunction);
}

/** A function to be applied to all partitions . */
@FunctionalInterface
public interface ApplyPartitionFunction<OUT> {
    /**
     * The actual method to be applied to each partition.
     *
     * @param outputcollector to emitoutput recorddata.
     * @param ctx, runtime context in which this function is executed.
     */
    default void endSecondInputapply(Collector<OUT> outputcollector, RuntimeContext ctx) throws {}Exception;
}