ai.grakn.engine.tasks.mock

Class MockBackgroundTask

java.lang.Object

ai.grakn.engine.tasks.mock.MockBackgroundTask

All Implemented Interfaces:

BackgroundTask

Direct Known Subclasses:

EndlessExecutionMockTask, FailingMockTask, LongExecutionMockTask, ShortExecutionMockTask

public abstract class MockBackgroundTask
extends Object
implements BackgroundTask

Main task Mock class- keeps track of completed and failed tasks

Author:

alexandraorth, Felix Chapman

Field Summary

Fields

Modifier and Type	Field and Description
protected AtomicBoolean	cancelled
protected Object	sync

Constructor Summary

Constructors

Constructor and Description
MockBackgroundTask()

Method Summary

Modifier and Type	Method and Description
static com.google.common.collect.ImmutableMultiset<ai.grakn.engine.TaskId>	cancelledTasks()
static void	clearTasks()
static com.google.common.collect.ImmutableMultiset<ai.grakn.engine.TaskId>	completedTasks()
protected abstract void	executeResumeInner(TaskCheckpoint checkpoint)
protected abstract void	executeStartInner(ai.grakn.engine.TaskId id)
boolean	resume(java.util.function.Consumer<TaskCheckpoint> saveCheckpoint, TaskCheckpoint lastCheckpoint) This method may be called when resuming from a paused state or recovering from a crash or failure of any kind.
boolean	start(java.util.function.Consumer<TaskCheckpoint> saveCheckpoint, TaskConfiguration configuration, TaskSubmitter taskSubmitter) Called to start execution of the task, may be called on a newly scheduled or previously stopped task.
boolean	stop() Called to stop execution of the task, may be called on a running or paused task.
static void	whenTaskFinishes(java.util.function.Consumer<ai.grakn.engine.TaskId> onTaskFinish)
static void	whenTaskResumes(java.util.function.Consumer<TaskCheckpoint> onTaskResume)
static void	whenTaskStarts(java.util.function.Consumer<ai.grakn.engine.TaskId> beforeTaskStarts)

Methods inherited from class java.lang.Object

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

Methods inherited from interface ai.grakn.engine.tasks.BackgroundTask

pause

Field Detail

cancelled

protected final AtomicBoolean cancelled

sync

protected final Object sync

Constructor Detail

MockBackgroundTask

public MockBackgroundTask()

Method Detail

completedTasks

public static com.google.common.collect.ImmutableMultiset<ai.grakn.engine.TaskId> completedTasks()

cancelledTasks

public static com.google.common.collect.ImmutableMultiset<ai.grakn.engine.TaskId> cancelledTasks()

whenTaskStarts

public static void whenTaskStarts(java.util.function.Consumer<ai.grakn.engine.TaskId> beforeTaskStarts)

whenTaskFinishes

public static void whenTaskFinishes(java.util.function.Consumer<ai.grakn.engine.TaskId> onTaskFinish)

whenTaskResumes

public static void whenTaskResumes(java.util.function.Consumer<TaskCheckpoint> onTaskResume)

clearTasks

public static void clearTasks()

start

public final boolean start(java.util.function.Consumer<TaskCheckpoint> saveCheckpoint,
                           TaskConfiguration configuration,
                           TaskSubmitter taskSubmitter)

Description copied from interface: BackgroundTask

Called to start execution of the task, may be called on a newly scheduled or previously stopped task.

Specified by:

start in interface BackgroundTask

Parameters:

saveCheckpoint - Consumer which can be called at any time to save a state checkpoint that would allow the task to resume from this point should it crash.

configuration - The configuration needed to execute the task

taskSubmitter - Allows followup tasks to be submitted for processing

Returns:

true if the task successfully completed, or false if it was stopped.

stop

public final boolean stop()

Description copied from interface: BackgroundTask

Called to stop execution of the task, may be called on a running or paused task. Task should stop gracefully.

Specified by:

stop in interface BackgroundTask

Returns:

true if the task was successfully stopped, or false if it could not be stopped. TODO: Should we allow start() to be called after stop()?

resume

public final boolean resume(java.util.function.Consumer<TaskCheckpoint> saveCheckpoint,
                            TaskCheckpoint lastCheckpoint)

Description copied from interface: BackgroundTask

This method may be called when resuming from a paused state or recovering from a crash or failure of any kind.

Specified by:

resume in interface BackgroundTask

Parameters:

saveCheckpoint - Consumer which can be called at any time to save a state checkpoint that would allow the task to resume from this point should it crash.

lastCheckpoint - The last checkpoint as sent to saveCheckpoint.

executeStartInner

protected abstract void executeStartInner(ai.grakn.engine.TaskId id)

executeResumeInner

protected abstract void executeResumeInner(TaskCheckpoint checkpoint)