org.apache.hadoop.hbase.client

Class ResultBoundedCompletionService<V>

java.lang.Object

org.apache.hadoop.hbase.client.ResultBoundedCompletionService<V>

@InterfaceAudience.Private
public class ResultBoundedCompletionService<V>
extends Object

A completion service for the RpcRetryingCallerFactory. Keeps the list of the futures, and allows to cancel them all. This means as well that it can be used for a small set of tasks only.
Implementation is not Thread safe. CompletedTasks is implemented as a queue, the entry is added based on the time order. I.e, when the first task completes (whether it is a success or failure), it is added as a first entry in the queue, the next completed task is added as a second entry in the queue, ... When iterating through the queue, we know it is based on time order. If the first completed task succeeds, it is returned. If it is failure, the iteration goes on until it finds a success.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
(package private) class	ResultBoundedCompletionService.QueueingFuture<T>

Field Summary

Fields

Modifier and Type	Field and Description
private boolean	cancelled
private ArrayList<ResultBoundedCompletionService.QueueingFuture>	completedTasks
private Executor	executor
private static org.slf4j.Logger	LOG
private RpcRetryingCallerFactory	retryingCallerFactory
private ResultBoundedCompletionService.QueueingFuture<V>[]	tasks

Constructor Summary

Constructors

Constructor and Description
ResultBoundedCompletionService(RpcRetryingCallerFactory retryingCallerFactory, Executor executor, int maxTasks)

Method Summary

Modifier and Type	Method and Description
void	cancelAll()
ResultBoundedCompletionService.QueueingFuture<V>	poll(long timeout, TimeUnit unit) Poll for the first completed task whether it is a success or execution exception.
ResultBoundedCompletionService.QueueingFuture<V>	pollForFirstSuccessfullyCompletedTask(long timeout, TimeUnit unit, int startIndex, int endIndex) Poll for the first successfully completed task whose completed order is in startIndex, endIndex(exclusive) range
private ResultBoundedCompletionService.QueueingFuture<V>	pollForSpecificCompletedTask(long timeout, TimeUnit unit, int index) Poll for the Nth completed task (index starts from 0 (the 1st), 1 (the second)...)
void	submit(RetryingCallable<V> task, int callTimeout, int id)
ResultBoundedCompletionService.QueueingFuture<V>	take()

Methods inherited from class java.lang.Object

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

Field Detail

LOG

private static final org.slf4j.Logger LOG

retryingCallerFactory

private final RpcRetryingCallerFactory retryingCallerFactory

executor

private final Executor executor

tasks

private final ResultBoundedCompletionService.QueueingFuture<V>[] tasks

completedTasks

private final ArrayList<ResultBoundedCompletionService.QueueingFuture> completedTasks

cancelled

private volatile boolean cancelled

Constructor Detail

ResultBoundedCompletionService

public ResultBoundedCompletionService(RpcRetryingCallerFactory retryingCallerFactory,
                                      Executor executor,
                                      int maxTasks)

Method Detail

submit

public void submit(RetryingCallable<V> task,
                   int callTimeout,
                   int id)

take

public ResultBoundedCompletionService.QueueingFuture<V> take()
                                                      throws InterruptedException

Throws:

InterruptedException

poll

public ResultBoundedCompletionService.QueueingFuture<V> poll(long timeout,
                                                             TimeUnit unit)
                                                      throws InterruptedException

Poll for the first completed task whether it is a success or execution exception.

Parameters:

timeout - - time to wait before it times out

unit - - time unit for timeout

Throws:

InterruptedException

pollForFirstSuccessfullyCompletedTask

public ResultBoundedCompletionService.QueueingFuture<V> pollForFirstSuccessfullyCompletedTask(long timeout,
                                                                                              TimeUnit unit,
                                                                                              int startIndex,
                                                                                              int endIndex)
                                                                                       throws InterruptedException,
                                                                                              CancellationException,
                                                                                              ExecutionException

Poll for the first successfully completed task whose completed order is in startIndex, endIndex(exclusive) range

Parameters:

timeout - - time to wait before it times out

unit - - time unit for timeout

startIndex - - start index, starting from 0, inclusive

endIndex - - end index, exclusive

Returns:

If within timeout time, there is no successfully completed task, return null; If all tasks get execution exception, it will throw out the last execution exception, otherwise return the first successfully completed task's result.

Throws:

InterruptedException

CancellationException

ExecutionException

pollForSpecificCompletedTask

private ResultBoundedCompletionService.QueueingFuture<V> pollForSpecificCompletedTask(long timeout,
                                                                                      TimeUnit unit,
                                                                                      int index)
                                                                               throws InterruptedException

Poll for the Nth completed task (index starts from 0 (the 1st), 1 (the second)...)

Parameters:

timeout - - time to wait before it times out

unit - - time unit for timeout

index - - the index(th) completed task, index starting from 0

Throws:

InterruptedException

cancelAll

public void cancelAll()