Package rx.internal.producers

Class QueuedProducer<T>

  • Type Parameters:
    T - the value type
    All Implemented Interfaces:
    java.io.Serializable, Observer<T>, Producer
    public final class QueuedProducer<T>
extends java.util.concurrent.atomic.AtomicLong
implements Producer, Observer<T>
    Producer that holds an unbounded (or custom) queue, handles terminal events, enqueues values and relays them to a child subscriber on request.
    See Also:
    Serialized Form

    • Field Summary

      Fields 
      Modifier and Type Field Description
      (package private) Subscriber<? super T> child  
      (package private) boolean done  
      (package private) java.lang.Throwable error  
      (package private) static java.lang.Object NULL_SENTINEL  
      (package private) java.util.Queue<java.lang.Object> queue  
      private static long serialVersionUID  
      (package private) java.util.concurrent.atomic.AtomicInteger wip  

    • Constructor Summary

      Constructors 
      Constructor Description
      QueuedProducer​(Subscriber<? super T> child)
      Constructs an instance with the target child subscriber and an Spsc Linked (Atomic) Queue as the queue implementation.
      QueuedProducer​(Subscriber<? super T> child, java.util.Queue<java.lang.Object> queue)
      Constructs an instance with the target child subscriber and a custom queue implementation

    • Method Summary

      All Methods Instance Methods Concrete Methods 
      Modifier and Type Method Description
      private boolean checkTerminated​(boolean isDone, boolean isEmpty)  
      private void drain()  
      boolean offer​(T value)
      Offers a value to this producer and tries to emit any queued values if the child requests allow it.
      void onCompleted()
      Notifies the Observer that the Observable has finished sending push-based notifications.
      void onError​(java.lang.Throwable e)
      Notifies the Observer that the Observable has experienced an error condition.
      void onNext​(T value)
      Provides the Observer with a new item to observe.
      void request​(long n)
      Request a certain maximum number of items from this Producer.

      • Methods inherited from class java.util.concurrent.atomic.AtomicLong

        accumulateAndGet, addAndGet, compareAndExchange, compareAndExchangeAcquire, compareAndExchangeRelease, compareAndSet, decrementAndGet, doubleValue, floatValue, get, getAcquire, getAndAccumulate, getAndAdd, getAndDecrement, getAndIncrement, getAndSet, getAndUpdate, getOpaque, getPlain, incrementAndGet, intValue, lazySet, longValue, set, setOpaque, setPlain, setRelease, toString, updateAndGet, weakCompareAndSet, weakCompareAndSetAcquire, weakCompareAndSetPlain, weakCompareAndSetRelease, weakCompareAndSetVolatile

      • Methods inherited from class java.lang.Number

        byteValue, shortValue

      • Methods inherited from class java.lang.Object

        clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

    • Field Detail

      • queue

        final java.util.Queue<java.lang.Object> queue

      • wip

        final java.util.concurrent.atomic.AtomicInteger wip

      • error

        java.lang.Throwable error

      • done

        volatile boolean done

      • NULL_SENTINEL

        static final java.lang.Object NULL_SENTINEL

    • Constructor Detail

      • QueuedProducer

        public QueuedProducer​(Subscriber<? super T> child)
        Constructs an instance with the target child subscriber and an Spsc Linked (Atomic) Queue as the queue implementation.
        Parameters:
        child - the target child subscriber

      • QueuedProducer

        public QueuedProducer​(Subscriber<? super T> child,
                      java.util.Queue<java.lang.Object> queue)
        Constructs an instance with the target child subscriber and a custom queue implementation
        Parameters:
        child - the target child subscriber
        queue - the queue to use

    • Method Detail

      • request

        public void request​(long n)
        Description copied from interface: Producer
        Request a certain maximum number of items from this Producer. This is a way of requesting backpressure. To disable backpressure, pass Long.MAX_VALUE to this method.

        Requests are additive but if a sequence of requests totals more than Long.MAX_VALUE then Long.MAX_VALUE requests will be actioned and the extras may be ignored. Arriving at Long.MAX_VALUE by addition of requests cannot be assumed to disable backpressure. For example, the code below may result in Long.MAX_VALUE requests being actioned only. 

         request(100);
 request(Long.MAX_VALUE-1);
        Specified by:
        request in interface Producer
        Parameters:
        n - the maximum number of items you want this Producer to produce, or Long.MAX_VALUE if you want the Producer to produce items at its own pace

      • offer

        public boolean offer​(T value)
        Offers a value to this producer and tries to emit any queued values if the child requests allow it.
        Parameters:
        value - the value to enqueue and attempt to drain
        Returns:
        true if the queue accepted the offer, false otherwise

      • checkTerminated

        private boolean checkTerminated​(boolean isDone,
                                boolean isEmpty)

      • drain

        private void drain()