org.axonframework.eventhandling

Class TrackerStatus

java.lang.Object

org.axonframework.eventhandling.TrackerStatus

All Implemented Interfaces:

EventTrackerStatus

public final class TrackerStatus
extends Object
implements EventTrackerStatus

Implementation of the EventTrackerStatus, providing simply modification methods to switch from one EventTrackerStatus value object to another.

Since:

3.0

Author:

Allard Buijze

Constructor Summary

Constructors

Constructor and Description
TrackerStatus(Segment segment, boolean caughtUp, TrackingToken trackingToken, Throwable errorState) Construct a EventTrackerStatus to portray the status of the given segment and trackingToken.
TrackerStatus(Segment segment, TrackingToken trackingToken) Construct a EventTrackerStatus to portray the status of the given segment and trackingToken.

Method Summary

Modifier and Type	Method and Description
TrackerStatus	advancedTo(TrackingToken trackingToken) Advance this TrackerStatus' TrackingToken towards the given trackingToken.
TrackerStatus	caughtUp() Returns this TrackerStatus if it is caught up, otherwise return a new instance with the caught up flag set to true.
boolean	equals(Object o)
OptionalLong	getCurrentPosition() Return the estimated relative current token position this Segment represents.
Throwable	getError() Returns the exception that caused processing to fail, if present.
TrackingToken	getInternalTrackingToken() Return the TrackingToken this EventTrackerStatus portrays the status of.
OptionalLong	getResetPosition() Return the relative position at which a reset was triggered for this Segment.
Segment	getSegment() The segment for which this status is valid.
TrackingToken	getTrackingToken() The tracking token of the last event that has been seen by this Segment.
int	hashCode()
boolean	isCaughtUp() Whether the Segment of this status has caught up with the head of the event stream.
boolean	isErrorState() Indicates whether this status represents an error.
boolean	isMerging() Indicates whether this Segment is still merging two (or more) Segments.
boolean	isReplaying() Indicates whether this Segment is still replaying previously processed Events.
TrackerStatus	markError(Throwable error) Return a new TrackerStatus based on this status, setting the given error as the errorState.
OptionalLong	mergeCompletedPosition() Return the estimated relative token position this Segment will have after a merge operation is complete.
TrackerStatus[]	split() Splits the current status object to reflect the status of their underlying segments being split.
static TrackerStatus[]	split(Segment segment, TrackingToken trackingToken) Split the given segment and trackingToken in two.
String	toString()
TrackerStatus	unmarkError() Return a new TrackerStatus based on this status, removing the errorState.

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

Methods inherited from interface org.axonframework.eventhandling.EventTrackerStatus

isDifferent, isDifferent, matchPositions, matchStates, trackerAdded, trackerRemoved

Constructor Detail

TrackerStatus

public TrackerStatus(Segment segment,
                     TrackingToken trackingToken)

Construct a EventTrackerStatus to portray the status of the given segment and trackingToken.

Parameters:

segment - the Segment this EventTrackerStatus shares the status of

trackingToken - the TrackingToken this EventTrackerStatus shares the status of

TrackerStatus

public TrackerStatus(Segment segment,
                     boolean caughtUp,
                     TrackingToken trackingToken,
                     Throwable errorState)

Construct a EventTrackerStatus to portray the status of the given segment and trackingToken. The caughtUp boolean specifies whether the trackingToken reached the head of the stream at least once. A Throwable can be provided to signal this EventTrackerStatus is in an error state

Parameters:

segment - the Segment this EventTrackerStatus shares the status of

caughtUp - a boolean specifying whether this EventTrackerStatus reached the head of the stream at least once.

trackingToken - the TrackingToken this EventTrackerStatus shares the status of

errorState - a Throwable defining the error status of this EventTrackerStatus. If null, the status is not in an error state

Method Detail

caughtUp

public TrackerStatus caughtUp()

Returns this TrackerStatus if it is caught up, otherwise return a new instance with the caught up flag set to true.

Returns:

this TrackerStatus if it is caught up, otherwise return a new instance with the caught up flag set to true

advancedTo

public TrackerStatus advancedTo(TrackingToken trackingToken)

Advance this TrackerStatus' TrackingToken towards the given trackingToken. If this status' token is identical to the given token, return this. Otherwise create a new TrackerStatus instance using the given trackingToken.

Parameters:

trackingToken - the TrackingToken to advance this TrackerStatus' token towards, if they are not the same

Returns:

this TrackerStatus if the given trackingToken is identical to the current one, otherwise a new TrackerStatus instance with the given trackingToken

markError

public TrackerStatus markError(Throwable error)

Return a new TrackerStatus based on this status, setting the given error as the errorState.

Parameters:

error - the Throwable used to define the errorState

Returns:

a new TrackerStatus based on this status, setting the given error as the errorState

unmarkError

public TrackerStatus unmarkError()

Return a new TrackerStatus based on this status, removing the errorState.

Returns:

a new TrackerStatus based on this status, removing the errorState

getInternalTrackingToken

public TrackingToken getInternalTrackingToken()

Return the TrackingToken this EventTrackerStatus portrays the status of.

Returns:

the TrackingToken this EventTrackerStatus portrays the status of

split

public TrackerStatus[] split()

Splits the current status object to reflect the status of their underlying segments being split.

Returns:

an array with two status objects, representing the status of the split segments

split

public static TrackerStatus[] split(Segment segment,
                                    TrackingToken trackingToken)

Split the given segment and trackingToken in two. Constructs an array containing two TrackerStatuss objects based on the split.

Parameters:

segment - the Segment to split in two

trackingToken - the TrackingToken to split in two

Returns:

an array of two TrackerStatuss objects based on the split of the given segment and trackingToken

getSegment

public Segment getSegment()

Description copied from interface: EventTrackerStatus

The segment for which this status is valid.

Specified by:

getSegment in interface EventTrackerStatus

Returns:

segment for which this status is valid

isCaughtUp

public boolean isCaughtUp()

Description copied from interface: EventTrackerStatus

Whether the Segment of this status has caught up with the head of the event stream. Note that this is no guarantee that this segment is still processing at (or near) real-time events. It merely indicates that this segment has been at the head of the stream since it started processing. It may have fallen back since then.

Specified by:

isCaughtUp in interface EventTrackerStatus

Returns:

whether the Segment of this status has caught up with the head of the event stream

isReplaying

public boolean isReplaying()

Description copied from interface: EventTrackerStatus

Indicates whether this Segment is still replaying previously processed Events.

Note that this method will only recognize a replay if the tokens have been reset using TrackingEventProcessor.resetTokens(). Removing tokens directly from the underlying TokenStore will not be recognized as a replay.

Specified by:

isReplaying in interface EventTrackerStatus

Returns:

true if this segment is replaying historic events after a reset, otherwise false

isMerging

public boolean isMerging()

Description copied from interface: EventTrackerStatus

Indicates whether this Segment is still merging two (or more) Segments. The merging process will be done once all Segments have reached the same position.

Specified by:

isMerging in interface EventTrackerStatus

Returns:

true if this segment is merging Segments, otherwise false

mergeCompletedPosition

public OptionalLong mergeCompletedPosition()

Description copied from interface: EventTrackerStatus

Return the estimated relative token position this Segment will have after a merge operation is complete. Will return a non-empty result as long as EventTrackerStatus.isMerging() } returns true. In case no estimation can be given or no merge in progress, an OptionalLong.empty() will be returned.

Specified by:

mergeCompletedPosition in interface EventTrackerStatus

Returns:

return the estimated relative position this Segment will reach after a merge operation is complete.

getTrackingToken

public TrackingToken getTrackingToken()

Description copied from interface: EventTrackerStatus

The tracking token of the last event that has been seen by this Segment.

The returned tracking token represents the position of this segment in the event stream. In case of a recent merge of segments, the token represents the lowest position of the two merged segments.

Specified by:

getTrackingToken in interface EventTrackerStatus

Returns:

tracking token of the last event that has been seen by this Segment

isErrorState

public boolean isErrorState()

Description copied from interface: EventTrackerStatus

Indicates whether this status represents an error. When this method return true, the EventTrackerStatus.getError() will return the exception that caused the failure.

Specified by:

isErrorState in interface EventTrackerStatus

Returns:

true if an error was reported, otherwise false

getError

public Throwable getError()

Description copied from interface: EventTrackerStatus

Returns the exception that caused processing to fail, if present. If the segment is being processed normally, this method returns null.

Specified by:

getError in interface EventTrackerStatus

Returns:

the exception that caused processing to fail, or null when processing normally

getCurrentPosition

public OptionalLong getCurrentPosition()

Description copied from interface: EventTrackerStatus

Return the estimated relative current token position this Segment represents. In case of replay is active, return the estimated relative position reached by merge operation. In case of merge is active, return the estimated relative position reached by merge operation. In case no estimation can be given, or no replay or merge in progress, an OptionalLong.empty() will be returned.

Specified by:

getCurrentPosition in interface EventTrackerStatus

Returns:

return the estimated relative current token position this Segment represents

getResetPosition

public OptionalLong getResetPosition()

Description copied from interface: EventTrackerStatus

Return the relative position at which a reset was triggered for this Segment. In case a replay finished or no replay is active, an OptionalLong.empty() will be returned.

Specified by:

getResetPosition in interface EventTrackerStatus

Returns:

the relative position at which a reset was triggered for this Segment

equals

public boolean equals(Object o)

Overrides:

equals in class Object

hashCode

public int hashCode()

Overrides:

hashCode in class Object

toString

public String toString()

Overrides:

toString in class Object