BatchRequestService

public class BatchRequestService extends AbstractIdleService

Batch multiple requests. Use add(AsyncRequest) to batch requests. Caller can use returned ListenableFuture to get result of batched request. Use isRunning() to determine if more requests can be batched. Set BatchPolicy to specify max batch request size or batching delay. Requests will be automatically flushed once flush policy is satisfied. Use flush() to flush current batched requests.

TODO(tvartak) : Use executor service to set values or exceptions on settable future with timeout. Caller can potentially add long running callback or listener with newDirectExecutorService(). These should not block other threads.

Nested Class Summary

class	BatchRequestService.Builder		Builder object for creating an instance of BatchRequestService
interface	BatchRequestService.ExecutorFactory		Factory for obtaining ExecutorService instance.
class	BatchRequestService.ExecutorFactoryImpl		BatchRequestService.ExecutorFactory implementation to get ExecutorService and ScheduledExecutorService instances used by BatchRequestService.
class	BatchRequestService.SystemTimeProvider		BatchRequestService.TimeProvider implementation to get current system time.
interface	BatchRequestService.TimeProvider		Interface for classes that can provide the current time.

Public Constructor Summary

BatchRequestService(BatchRequestService.Builder builder) Create an instance of BatchRequestService

Public Method Summary

<T> void	add(AsyncRequest<T> request) Adds an request to batch request.
ListenableFuture<Integer>	flush() Flushes all enqueued requests for batched execution.
int	getCurrentBatchSize() Returns number of elements enqueued for batched execution.

Inherited Method Summary

From class com.google.common.util.concurrent.AbstractIdleService

final void	addListener(Service.Listener arg0, Executor arg1)
final void	awaitRunning()
final void	awaitRunning(long arg0, TimeUnit arg1)
final void	awaitTerminated(long arg0, TimeUnit arg1)
final void	awaitTerminated()
final Throwable	failureCause()
final boolean	isRunning()
final Service	startAsync()
final Service.State	state()
final Service	stopAsync()
String	toString()

From class java.lang.Object

boolean	equals(Object arg0)
final Class<?>	getClass()
int	hashCode()
final void	notify()
final void	notifyAll()
String	toString()
final void	wait(long arg0, int arg1)
final void	wait(long arg0)
final void	wait()

From interface com.google.common.util.concurrent.Service

abstract void	addListener(Service.Listener arg0, Executor arg1)
abstract void	awaitRunning()
abstract void	awaitRunning(long arg0, TimeUnit arg1)
abstract void	awaitTerminated(long arg0, TimeUnit arg1)
abstract void	awaitTerminated()
abstract Throwable	failureCause()
abstract boolean	isRunning()
abstract Service	startAsync()
abstract Service.State	state()
abstract Service	stopAsync()

Public Constructors

public BatchRequestService (BatchRequestService.Builder builder)

Create an instance of BatchRequestService

Parameters

builder	for creating BatchRequestService

Public Methods

public void add (AsyncRequest<T> request)

Adds an request to batch request. If current batch size is greater than or equal to getMaxBatchSize(), current batched requests will be automatically flushed. Operation might block if BatchRequestService can not accept more request immediately.

Parameters

request	to be batched

Throws

InterruptedException

public ListenableFuture<Integer> flush ()

Flushes all enqueued requests for batched execution.

Returns

• number of requests flushed for batched execution.

Throws

InterruptedException	if interrupted while executing batch requests.

public int getCurrentBatchSize ()

Returns number of elements enqueued for batched execution.

Returns

• number of elements enqueued for batched execution.