Package com.google.api.gax.batching

Interface Batcher<ElementT,​ElementResultT>

  • Type Parameters:
    ElementT - The type of each individual element to be batched.
    ElementResultT - The type of the result for each individual element.
    All Superinterfaces:
    java.lang.AutoCloseable
    All Known Implementing Classes:
    BatcherImpl
    @InternalExtensionOnly
public interface Batcher<ElementT,​ElementResultT>
extends java.lang.AutoCloseable
    Represents a batching context where individual elements will be accumulated and flushed in a large batch request at some point in the future. The buffered elements can be flushed manually or when triggered by an internal threshold. This is intended to be used for high throughput scenarios at the cost of latency.

    Batcher instances are not thread safe. To use across different threads, create a new Batcher instance per thread.

    • Method Summary

      All Methods Instance Methods Abstract Methods 
      Modifier and Type Method Description
      com.google.api.core.ApiFuture<ElementResultT> add​(ElementT entry)
      Queues the passed in element to be sent at some point in the future.
      void close()
      Closes this Batcher by preventing new elements from being added, and then flushing the existing elements.
      com.google.api.core.ApiFuture<java.lang.Void> closeAsync()
      Closes this Batcher by preventing new elements from being added, and then sending outstanding elements.
      void flush()
      Synchronously sends any pending elements as a batch and waits for all outstanding batches to be complete.
      void sendOutstanding()
      Sends accumulated elements asynchronously for batching.

    • Method Detail

      • add

        com.google.api.core.ApiFuture<ElementResultT> add​(ElementT entry)
        Queues the passed in element to be sent at some point in the future.

        The element will be sent as part of a larger batch request at some point in the future. The returned ApiFuture will be resolved once the result for the element has been extracted from the batch response.

        Note: Cancelling returned result simply marks the future cancelled, It would not stop the batch request.

      • flush

        void flush()
    throws java.lang.InterruptedException
        Synchronously sends any pending elements as a batch and waits for all outstanding batches to be complete.
        Throws:
        java.lang.InterruptedException

      • sendOutstanding

        void sendOutstanding()
        Sends accumulated elements asynchronously for batching.

        Note: This method can be invoked concurrently unlike add(ElementT) and close(), which can only be called from a single user thread. Please take caution to avoid race condition.

      • close

        void close()
    throws java.lang.InterruptedException
        Closes this Batcher by preventing new elements from being added, and then flushing the existing elements.
        Specified by:
        close in interface java.lang.AutoCloseable
        Throws:
        java.lang.InterruptedException

      • closeAsync

        com.google.api.core.ApiFuture<java.lang.Void> closeAsync()
        Closes this Batcher by preventing new elements from being added, and then sending outstanding elements. The returned future will be resolved when the last element completes