org.voltdb.task

Class ScheduledAction

java.lang.Object

org.voltdb.task.ScheduledAction

public class ScheduledAction
extends java.lang.Object

Class which describes an interval, an action to perform after that interval and a callback which should be invoked after the action has been performed.

This class also has an optional attachment which can be used to pass state between the initiating class and the callback.

Method Summary

Modifier and Type	Method and Description
static ScheduledAction	callback(long interval, java.util.concurrent.TimeUnit timeUnit, java.util.function.Function<ActionResult,ScheduledAction> callback) Create a ScheduledAction which causes the callback to be invoked after interval .
static ScheduledAction	error(java.lang.String statusMessage) Create a ScheduledAction which indicates that an unrecoverable error has occurred and the scheduler must exit.
static ScheduledAction	exit(java.lang.String statusMessage) Create a ScheduledAction which indicates that the scheduler has reached the end of its life cycle gracefully
<T> T	getAttachment() Retrieve the optional attachment associated with this scheduled action
java.util.function.Function<ActionResult,ScheduledAction>	getCallback()
long	getInterval(java.util.concurrent.TimeUnit timeUnit)
java.lang.String	getProcedure()
java.lang.Object[]	getProcedureParameters()
java.lang.String	getStatusMessage()
ActionType	getType()
static ScheduledAction	of(Action action) Create a ScheduledAction from a Action which is of type stop.
static ScheduledAction	of(Interval interval, Action action) Create a ScheduledAction from a Interval and Action.
static ScheduledAction	procedureCall(long interval, java.util.concurrent.TimeUnit timeUnit, java.util.function.Function<ActionResult,ScheduledAction> callback, java.lang.String procedure, java.lang.Object... procedureParameters) Create a ScheduledAction which executes a procedure with given parameters after interval
ScheduledAction	setAttachment(java.lang.Object attachment) Add an arbitrary attachment to this instance so that it can be retrieved from the ActionResult
ScheduledAction	setStatusMessage(java.lang.String statusMessage) Set the optional status message which will be reported in the statistics for a task and if this is an ActionType.ERROR or ActionType.EXIT action then it will also be logged.
java.lang.String	toString()

Methods inherited from class java.lang.Object

equals, getClass, hashCode, notify, notifyAll, wait, wait, wait

Method Detail

of

public static ScheduledAction of(Action action)

Create a ScheduledAction from a Action which is of type stop.

Parameters:

action - Base Action to get type and message from

Returns:

A new ScheduledAction derived from action

of

public static ScheduledAction of(Interval interval,
                                 Action action)

Create a ScheduledAction from a Interval and Action. The action must not be of type stop.

Parameters:

interval - To wait until performing action

action - To be performed after interval

Returns:

A new ScheduledAction from combining interval and action

error

public static ScheduledAction error(java.lang.String statusMessage)

Create a ScheduledAction which indicates that an unrecoverable error has occurred and the scheduler must exit.

statusMessage is the same status message which is set by calling setStatusMessage(String)

Parameters:

statusMessage - To log indicating the details of the error. May be null

Returns:

A new ActionType.ERROR instance of ScheduledAction

exit

public static ScheduledAction exit(java.lang.String statusMessage)

Create a ScheduledAction which indicates that the scheduler has reached the end of its life cycle gracefully

statusMessage is the same status message which is set by calling setStatusMessage(String)

Parameters:

statusMessage - To log indicating the details of the error. May be null

Returns:

A new ActionType.EXIT instance of ScheduledAction

procedureCall

public static ScheduledAction procedureCall(long interval,
                                            java.util.concurrent.TimeUnit timeUnit,
                                            java.util.function.Function<ActionResult,ScheduledAction> callback,
                                            java.lang.String procedure,
                                            java.lang.Object... procedureParameters)

Create a ScheduledAction which executes a procedure with given parameters after interval

Parameters:

interval - Interval after which the procedure is to be executed

timeUnit - {#link TimeUnit} of interval

callback - That is invoked after procedure completes execution

procedure - Name of procedure to execute

procedureParameters - To pass to procedure during execution

Returns:

A new ActionType.PROCEDURE instance of ScheduledAction

callback

public static ScheduledAction callback(long interval,
                                       java.util.concurrent.TimeUnit timeUnit,
                                       java.util.function.Function<ActionResult,ScheduledAction> callback)

Create a ScheduledAction which causes the callback to be invoked after interval . A ActionResult will be associated with this call however it will have a null procedure and result but an attachment can be used.

Parameters:

interval - Interval until the callback is invoked

timeUnit - TimeUnit of interval

callback - That is invoked after interval has passed

Returns:

A new ActionType.CALLBACK instance of ScheduledAction

getInterval

public long getInterval(java.util.concurrent.TimeUnit timeUnit)

Parameters:

timeUnit - Of the returned interval

Returns:

The time interval until this action should be performed

getType

public ActionType getType()

Returns:

The ActionType of this action

getStatusMessage

public java.lang.String getStatusMessage()

Returns:

Optional status message provided with any action

setStatusMessage

public ScheduledAction setStatusMessage(java.lang.String statusMessage)

Set the optional status message which will be reported in the statistics for a task and if this is an ActionType.ERROR or ActionType.EXIT action then it will also be logged. For ActionType.ERROR or ActionType.EXIT actions this can be provided as part of the factory method.

Parameters:

statusMessage - To be reported

Returns:

this

getProcedure

public java.lang.String getProcedure()

Returns:

Name of procedure to execute. Will be null if this is not a ActionType.PROCEDURE

getProcedureParameters

public java.lang.Object[] getProcedureParameters()

Returns:

The parameters that are to be passed the the procedure returned by getProcedure()

getCallback

public java.util.function.Function<ActionResult,ScheduledAction> getCallback()

Returns:

The callback to invoke after the action has been performed

setAttachment

public ScheduledAction setAttachment(java.lang.Object attachment)

Add an arbitrary attachment to this instance so that it can be retrieved from the ActionResult

Parameters:

attachment - Object to attach. May be null

Returns:

this

getAttachment

public <T> T getAttachment()

Retrieve the optional attachment associated with this scheduled action

Type Parameters:

T - Type of attachment

Returns:

The attachment or null of there was no attachment

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object