Interface Dequeuer


  • public interface Dequeuer
    A Dequeuer is used for dequeueing tuples from a specific stream.
    Since:
    6.6
    • Method Detail

      • getSchema

        Schema getSchema()
        Get the Schema for the associated stream.
        Equivalent to getStreamProperties().getSchema()
        Returns:
        Schema
      • dequeue

        List<Tuple> dequeue​(int numTuples)
                     throws StreamBaseException
        Try to dequeue tuples with the DEFAULT_TIMEOUT and DEFAULT_TIMEOUT_UNIT
        • if numTuples == 0 will return immediately
        • if numTuples < 0 will wait the maximum timeout before returning
        Parameters:
        numTuples - the number of tuples to dequeue
        Returns:
        all of the tuples dequeued before the timeout, possibly an empty list
        Throws:
        StreamBaseException - Dequeue failed
      • dequeue

        List<Tuple> dequeue​(int numTuples,
                            long timeout,
                            TimeUnit timeUnit)
                     throws StreamBaseException
        Try to dequeue tuples within a provided timeout.
        • if numTuples == 0 will return immediately
        • if numTuples < 0 will wait the maximum timeout before returning
        Parameters:
        numTuples - the number of tuples to dequeue
        timeout - the maximum time to wait
        timeUnit - the time unit of timeout argument
        Returns:
        all of the tuples dequeued before the timeout, possibly an empty list
        Throws:
        StreamBaseException - Dequeue failed
      • drain

        void drain()
            throws StreamBaseException
        Drain any tuples that are currently in flight in the server. This method should not normally be called, but is provided to speed up things that expect no output.
        Throws:
        StreamBaseException - Drain failed