org.helenus.driver.impl

Class ListenableFutureImpl<T>

java.lang.Object

com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

org.helenus.driver.impl.ListenableFutureImpl<T>

Type Parameters:

T - The type of POJO associated with the future object set

All Implemented Interfaces:

com.google.common.util.concurrent.ListenableFuture<ObjectSet<T>>, Future<ObjectSet<T>>

Direct Known Subclasses:

ObjectSetFutureImpl

public class ListenableFutureImpl<T>
extends com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

The ListenableFutureImpl class extends Cassandra's ResultSetFuture in order to provide support for POJOs.

Since:

1.0

Version:

1 - Jan 4, 2017 - paouelle - abstracted out from ObjectSetFutureImpl

Author:

The Helenus Driver Project Authors

Copyright:

2015-2017 The Helenus Driver Project Authors

Field Summary

Fields

Modifier and Type	Field and Description
protected StatementManager.Context<T>	context Holds the statement context associated with this object set.

Method Summary

Modifier and Type	Method and Description
void	addListener(Runnable listener, Executor exec)
boolean	cancel(boolean mayInterruptIfRunning) Attempts to cancel the execution of the request corresponding to this future.
ObjectSet<T>	get()
ObjectSet<T>	get(long timeout, TimeUnit unit)
boolean	isCancelled()
boolean	isDone()
protected void	postProcess(com.datastax.driver.core.ResultSet result) Post-process the result set.

Methods inherited from class com.google.common.util.concurrent.AbstractFuture

interruptTask, set, setException, wasInterrupted

Methods inherited from class java.lang.Object

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

Field Detail

context

protected final StatementManager.Context<T> context

Holds the statement context associated with this object set.

Method Detail

postProcess

protected void postProcess(com.datastax.driver.core.ResultSet result)

Post-process the result set. The returned ObjectSetImpl will be based on what is left off in the result set after post-processing.

Parameters:

result - the non-null result set to be post processed

get

public ObjectSet<T> get(long timeout,
                        TimeUnit unit)
                 throws InterruptedException,
                        TimeoutException,
                        ExecutionException

Specified by:

get in interface Future<ObjectSet<T>>

Overrides:

get in class com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

Throws:

com.datastax.driver.core.exceptions.NoHostAvailableException - if no host in the cluster can be contacted successfully to execute this query.

com.datastax.driver.core.exceptions.QueryExecutionException - if the query triggered an execution exception, that is an exception thrown by Cassandra when it cannot execute the query with the requested consistency level successfully.

ObjectNotFoundException - if the statement is a select and the keyspace specified doesn't exist

com.datastax.driver.core.exceptions.QueryValidationException - if the query is invalid (syntax error, unauthorized or any other validation problem).

InterruptedException

TimeoutException

ExecutionException

See Also:

AbstractFuture.get(long, java.util.concurrent.TimeUnit)

get

public ObjectSet<T> get()
                 throws InterruptedException,
                        ExecutionException

Specified by:

get in interface Future<ObjectSet<T>>

Overrides:

get in class com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

Throws:

com.datastax.driver.core.exceptions.NoHostAvailableException - if no host in the cluster can be contacted successfully to execute this query.

com.datastax.driver.core.exceptions.QueryExecutionException - if the query triggered an execution exception, that is an exception thrown by Cassandra when it cannot execute the query with the requested consistency level successfully.

ObjectNotFoundException - if the statement is a select and the keyspace specified doesn't exist

com.datastax.driver.core.exceptions.QueryValidationException - if the query is invalid (syntax error, unauthorized or any other validation problem).

InterruptedException

ExecutionException

See Also:

AbstractFuture.get()

cancel

public boolean cancel(boolean mayInterruptIfRunning)

Attempts to cancel the execution of the request corresponding to this future. This attempt will fail if the request has already returned.

Please note that this only cancel the request driver side, but nothing is done to interrupt the execution of the request Cassandra side (and that even if mayInterruptIfRunning is true) since Cassandra does not support such interruption.

This method can be used to ensure no more work is performed driver side (which, while it doesn't include stopping a request already submitted to a Cassandra node, may include not retrying another Cassandra host on failure/timeout) if the object set is not going to be retried. Typically, the code to wait for a request result for a maximum of 1 second could look like:

   final ObjectSetFuture<T> future = statement.executeAsync();

   try {
       final ObjectSet<T> result = future.get(1, TimeUnit.SECONDS);
       ... process result ...
   } catch (TimeoutException e) {
       future.cancel(true); // Ensure any ressource used by this query driver
                            // side is released immediately
       ... handle timeout ...
   }
 

Specified by:

cancel in interface Future<ObjectSet<T>>

Overrides:

cancel in class com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

Parameters:

mayInterruptIfRunning - the value of this parameter is currently ignored.

Returns:

false if the future could not be cancelled (it has already completed normally); true otherwise.

See Also:

AbstractFuture.cancel(boolean)

isDone

public boolean isDone()

Specified by:

isDone in interface Future<ObjectSet<T>>

Overrides:

isDone in class com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

See Also:

AbstractFuture.isDone()

isCancelled

public boolean isCancelled()

Specified by:

isCancelled in interface Future<ObjectSet<T>>

Overrides:

isCancelled in class com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

See Also:

AbstractFuture.isCancelled()

addListener

public void addListener(Runnable listener,
                        Executor exec)

Specified by:

addListener in interface com.google.common.util.concurrent.ListenableFuture<ObjectSet<T>>

Overrides:

addListener in class com.google.common.util.concurrent.AbstractFuture<ObjectSet<T>>

See Also:

AbstractFuture.addListener(Runnable, java.util.concurrent.Executor)