Package org.apache.flink.cep.nfa.aftermatch

Class AfterMatchSkipStrategy

java.lang.Object

org.apache.flink.cep.nfa.aftermatch.AfterMatchSkipStrategy

All Implemented Interfaces:

Serializable

Direct Known Subclasses:

NoSkipStrategy, SkipPastLastStrategy, SkipToFirstStrategy, SkipToLastStrategy, SkipToNextStrategy

public abstract class AfterMatchSkipStrategy
extends Object
implements Serializable

Indicate the skip strategy after a match process.

See Also:

• Serialized Form

Method Summary

Modifier and Type	Method	Description
Optional<String>	getPatternName()	Name of pattern that processing will be skipped to.
protected abstract EventId	getPruningId(Collection<Map<String,List<EventId>>> match)	Retrieves event id of the pruning element from the given match based on the strategy.
abstract boolean	isSkipStrategy()	Tells if the strategy may skip some matches.
static NoSkipStrategy	noSkip()	Every possible match will be emitted.
void	prune(Collection<ComputationState> matchesToPrune, Collection<Map<String,List<EventId>>> matchedResult, SharedBufferAccessor<?> sharedBufferAccessor)	Prunes matches/partial matches based on the chosen strategy.
protected abstract boolean	shouldPrune(EventId startEventID, EventId pruningId)	Tells if the partial/completed match starting at given id should be prunned by given pruningId.
static SkipPastLastStrategy	skipPastLastEvent()	Discards every partial match that started before emitted match ended.
static SkipToFirstStrategy	skipToFirst(String patternName)	Discards every partial match that started before the first event of emitted match mapped to *PatternName*.
static SkipToLastStrategy	skipToLast(String patternName)	Discards every partial match that started before the last event of emitted match mapped to *PatternName*.
static AfterMatchSkipStrategy	skipToNext()	Discards every partial match that started with the same event, emitted match was started.

Methods inherited from class java.lang.Object

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

Method Details

skipToFirst

public static SkipToFirstStrategy skipToFirst(String patternName)

Discards every partial match that started before the first event of emitted match mapped to *PatternName*.

Parameters:

patternName - the pattern name to skip to

Returns:

the created AfterMatchSkipStrategy

skipToLast

public static SkipToLastStrategy skipToLast(String patternName)

Discards every partial match that started before the last event of emitted match mapped to *PatternName*.

Parameters:

patternName - the pattern name to skip to

Returns:

the created AfterMatchSkipStrategy

skipPastLastEvent

public static SkipPastLastStrategy skipPastLastEvent()

Discards every partial match that started before emitted match ended.

Returns:

the created AfterMatchSkipStrategy

skipToNext

public static AfterMatchSkipStrategy skipToNext()

Discards every partial match that started with the same event, emitted match was started.

Returns:

the created AfterMatchSkipStrategy

noSkip

public static NoSkipStrategy noSkip()

Every possible match will be emitted.

Returns:

the created AfterMatchSkipStrategy

isSkipStrategy

public abstract boolean isSkipStrategy()

Tells if the strategy may skip some matches.

Returns:

false if the strategy is NO_SKIP strategy

prune

public void prune(Collection<ComputationState> matchesToPrune,
 Collection<Map<String,List<EventId>>> matchedResult,
 SharedBufferAccessor<?> sharedBufferAccessor)
           throws Exception

Prunes matches/partial matches based on the chosen strategy.

Parameters:

matchesToPrune - current partial matches

matchedResult - already completed matches

sharedBufferAccessor - accessor to corresponding shared buffer

Throws:

Exception - thrown if could not access the state

shouldPrune

protected abstract boolean shouldPrune(EventId startEventID,
 EventId pruningId)

Tells if the partial/completed match starting at given id should be prunned by given pruningId.

Parameters:

startEventID - starting event id of a partial/completed match

pruningId - pruningId calculated by this strategy

Returns:

true if the match should be pruned

getPruningId

protected abstract EventId getPruningId(Collection<Map<String,List<EventId>>> match)

Retrieves event id of the pruning element from the given match based on the strategy.

Parameters:

match - match corresponding to which should the pruning happen

Returns:

pruning event id

getPatternName

public Optional<String> getPatternName()

Name of pattern that processing will be skipped to.