ai.grakn.redisq

Interface Queue<T>

All Known Implementing Classes:

Redisq

public interface Queue<T>

Method Summary

Modifier and Type	Method and Description
void	close() Sets a flag and waits for all the running threads to terminate
QueueConsumer<T>	getConsumer() Getter for the consumer being used
Future<Void>	getFutureForDocumentStateWait(Set<State> state, String id) It returns a future that waits for a document to reach a certain state Note that this works for DONE and FAILED since they are terminal states.
Future<Void>	getFutureForDocumentStateWait(Set<State> state, String id, long timeout, TimeUnit unit, redis.clients.util.Pool<redis.clients.jedis.Jedis> pool)
String	getName() Getter for the name of the queue
Optional<StateInfo>	getState(String id) Retrieves the state for the given id
java.util.stream.Stream<Optional<ExtendedStateInfo>>	getStates() Retrieves all the states.
void	push(T document) Put a document in the queue
void	pushAndWait(T document, long waitTimeout, TimeUnit waitTimeoutUnit) Same as push but it waits for the state of the document to be DONE i.e.
default void	setState(String id, State state)
void	setState(String id, State state, String info) Sets a state "manually"
void	startConsumer() Starts the comsumer for this queue.

Method Detail

push

void push(T document)

Put a document in the queue

Parameters:

document - Document to be pushed to the queue. It must be serialisable.

pushAndWait

void pushAndWait(T document,
                 long waitTimeout,
                 TimeUnit waitTimeoutUnit)
          throws WaitException

Same as push but it waits for the state of the document to be DONE i.e. the consumer successfully completed working on it.

Parameters:

document - Document to be pushed to the queue. It must be serialisable.

waitTimeout - Timeout for the wait. A WaitException is thrown when expired

waitTimeoutUnit - Unit for the timeout

Throws:

WaitException - Thrown if a timeout occurs while waiting for the consumer to be acknowledged in Redis or if the waitTimeout expires

getFutureForDocumentStateWait

Future<Void> getFutureForDocumentStateWait(Set<State> state,
                                           String id)
                                    throws StateFutureInitializationException

It returns a future that waits for a document to reach a certain state Note that this works for DONE and FAILED since they are terminal states.

Parameters:

state - Desired state

id - Id of the document we are watching

Returns:

A future that blocks on the state being equal to the given state

Throws:

StateFutureInitializationException - Thrown if it fails to subscribe to the state

getFutureForDocumentStateWait

Future<Void> getFutureForDocumentStateWait(Set<State> state,
                                           String id,
                                           long timeout,
                                           TimeUnit unit,
                                           redis.clients.util.Pool<redis.clients.jedis.Jedis> pool)
                                    throws StateFutureInitializationException

Parameters:

timeout - How long to wait until failing the subscription

unit - Unit of the timeout

Throws:

StateFutureInitializationException

See Also:

Also takes a jedis pool

startConsumer

void startConsumer()

Starts the comsumer for this queue. The consumer takes care of the whole lifecycle, so e.g. in the Redisq implementation this includes a thread that consumes the elements in the queue and a thread that makes sure there are no dead jobs in the inflight queue.

close

void close()
    throws InterruptedException

Sets a flag and waits for all the running threads to terminate

Throws:

InterruptedException - if the operation is interrupted

getName

String getName()

Getter for the name of the queue

Returns:

The name of the queue

setState

default void setState(String id,
                      State state)

See Also:

setState(String, State, String)

setState

void setState(String id,
              State state,
              String info)

Sets a state "manually"

Parameters:

id - Id of the document

state - State (e.g. DONE, FAILED)

info - Extra info to be stored (e.g. the exception message for the failure)

getState

Optional<StateInfo> getState(String id)

Retrieves the state for the given id

Parameters:

id - Id of the document

Returns:

Current state of the document. Empty if not available

getStates

java.util.stream.Stream<Optional<ExtendedStateInfo>> getStates()

Retrieves all the states. It gives a snapshot of the keys at the time the method is called. If the returned state is empty it means it's not available any longer (the key was available when first invoked though).

Returns:

A stream with all the states currently stored. The stream is null if finished.

getConsumer

QueueConsumer<T> getConsumer()

Getter for the consumer being used

Returns:

The comsumer