com.google.api.gax.batching

Class BatcherImpl<ElementT,ElementResultT,RequestT,ResponseT>

java.lang.Object

com.google.api.gax.batching.BatcherImpl<ElementT,ElementResultT,RequestT,ResponseT>

Type Parameters:

ElementT - The type of each individual element to be batched.

ElementResultT - The type of the result for each individual element.

RequestT - The type of the request that will contain the accumulated elements.

ResponseT - The type of the response that will unpack into individual element results.

All Implemented Interfaces:

Batcher<ElementT,ElementResultT>, AutoCloseable

@BetaApi(value="The surface for batching is not stable yet and may change in the future.")
 @InternalApi(value="For google-cloud-java client use only")
public class BatcherImpl<ElementT,ElementResultT,RequestT,ResponseT>
extends Object
implements Batcher<ElementT,ElementResultT>

Queues up the elements until flush() is called; once batching is over, returned future resolves.

This class is not thread-safe, and expects to be used from a single thread.

Constructor Summary

Constructors

Constructor and Description
BatcherImpl(BatchingDescriptor<ElementT,ElementResultT,RequestT,ResponseT> batchingDescriptor, UnaryCallable<RequestT,ResponseT> unaryCallable, RequestT prototype, BatchingSettings batchingSettings, ScheduledExecutorService executor)
BatcherImpl(BatchingDescriptor<ElementT,ElementResultT,RequestT,ResponseT> batchingDescriptor, UnaryCallable<RequestT,ResponseT> unaryCallable, RequestT prototype, BatchingSettings batchingSettings, ScheduledExecutorService executor, FlowController flowController)

Method Summary

Modifier and Type	Method and Description
com.google.api.core.ApiFuture<ElementResultT>	add(ElementT element) 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 flushing the existing 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.

Methods inherited from class java.lang.Object

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

Constructor Detail

BatcherImpl

public BatcherImpl(BatchingDescriptor<ElementT,ElementResultT,RequestT,ResponseT> batchingDescriptor,
                   UnaryCallable<RequestT,ResponseT> unaryCallable,
                   RequestT prototype,
                   BatchingSettings batchingSettings,
                   ScheduledExecutorService executor)

Parameters:

batchingDescriptor - a BatchingDescriptor for transforming individual elements into wrappers request and response

unaryCallable - a UnaryCallable object

prototype - a RequestT object

batchingSettings - a BatchingSettings with configuration of thresholds

BatcherImpl

public BatcherImpl(BatchingDescriptor<ElementT,ElementResultT,RequestT,ResponseT> batchingDescriptor,
                   UnaryCallable<RequestT,ResponseT> unaryCallable,
                   RequestT prototype,
                   BatchingSettings batchingSettings,
                   ScheduledExecutorService executor,
                   @Nullable
                   FlowController flowController)

Parameters:

batchingDescriptor - a BatchingDescriptor for transforming individual elements into wrappers request and response

unaryCallable - a UnaryCallable object

prototype - a RequestT object

batchingSettings - a BatchingSettings with configuration of thresholds

flowController - a FlowController for throttling requests. If it's null, create a FlowController object from BatchingSettings.getFlowControlSettings().

Method Detail

add

public com.google.api.core.ApiFuture<ElementResultT> add(ElementT element)

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.

Specified by:

add in interface Batcher<ElementT,ElementResultT>

flush

public void flush()
           throws InterruptedException

Synchronously sends any pending elements as a batch and waits for all outstanding batches to be complete.

Specified by:

flush in interface Batcher<ElementT,ElementResultT>

Throws:

InterruptedException

sendOutstanding

public void sendOutstanding()

Sends accumulated elements asynchronously for batching.

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

Specified by:

sendOutstanding in interface Batcher<ElementT,ElementResultT>

close

public void close()
           throws InterruptedException

Closes this Batcher by preventing new elements from being added and flushing the existing elements.

Specified by:

close in interface Batcher<ElementT,ElementResultT>

Specified by:

close in interface AutoCloseable

Throws:

InterruptedException