net.sf.eBus.feed.pattern

Class EPatternFeed.AbstractMatchFrame

java.lang.Object

net.sf.eBus.feed.pattern.EPatternFeed.AbstractMatchFrame

Enclosing class:

EPatternFeed

protected abstract static class EPatternFeed.AbstractMatchFrame
extends Object

A match frame tracks an in-progress match. When a frame contains a complete pattern match the frame is used to generate the MatchEvent posted to the subscriber. Match frames are kept until either an event violates the pattern or the match completes.

Base class for EOrderPatternFeed.MatchFrame and EUnorderedPatternFeed.MatchFrame.

Field Summary

Fields

Modifier and Type	Field and Description
protected List<ENotificationMessage>	mAllEvents Contains all events matching the pattern so far.
protected boolean	mIsDefunct Set to true when a match frame is 1) used for an exclusive pattern, 2) the pattern is completely matched, and 3) this frame contains common events with the completely matched frame.
protected boolean	mIsExclusive true if this match frame is for an exclusive pattern.
protected String	mPatternName Match frame created by this pattern.
protected Map<Object,Object>	mUserCache Cache for storing interim, user-defined data calculated while performing a MatchCondition.

Constructor Summary

Constructors

Modifier	Constructor and Description
protected	AbstractMatchFrame(EPatternFeed.AbstractMatchFrame frame) Copies the given frame data into this frame.
protected	AbstractMatchFrame(String patternName, boolean isExclusive) Creates a new match frame for the given pattern and exclusivity flag.

Method Summary

Modifier and Type	Method and Description
List<ENotificationMessage>	allEvents() Returns the "all events" collection as an unmodifiable list.
int	frameId() Returns the unique match frame identifier.
protected abstract Map<String,List<ENotificationMessage>>	groupMap() Returns a read-only copy of the group map.
boolean	isDefunct() Returns true if this match frame is defunct due to a prior exclusive matching and, therefore, may no longer be used.
boolean	isExclusive() Returns true if this is an exclusive feed; false otherwise.
String	patternName() Returns the pattern name.
void	setDefunct() Marks this match frame as defunct.
String	toString()
Map<Object,Object>	userCache() Returns the user-defined match data cache.

Methods inherited from class java.lang.Object

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

Field Detail

mPatternName

protected final String mPatternName

Match frame created by this pattern. Used for logging purposes.

mAllEvents

protected final List<ENotificationMessage> mAllEvents

Contains all events matching the pattern so far. Since these events are repeatedly referenced by the matching algorithm, this list is kept for quick reference.

mUserCache

protected final Map<Object,Object> mUserCache

Cache for storing interim, user-defined data calculated while performing a MatchCondition.

mIsExclusive

protected final boolean mIsExclusive

true if this match frame is for an exclusive pattern. That means events may not be used for multiple matches within the same pattern.

mIsDefunct

protected boolean mIsDefunct

Set to true when a match frame is 1) used for an exclusive pattern, 2) the pattern is completely matched, and 3) this frame contains common events with the completely matched frame. Otherwise, will be false. Marking a match frame as defunct allows for "lazy removal" from the frames queue.

Constructor Detail

AbstractMatchFrame

protected AbstractMatchFrame(String patternName,
                             boolean isExclusive)

Creates a new match frame for the given pattern and exclusivity flag.

Parameters:

patternName - pattern name.

isExclusive - true if the pattern is exclusive.

AbstractMatchFrame

protected AbstractMatchFrame(EPatternFeed.AbstractMatchFrame frame)

Copies the given frame data into this frame.

Parameters:

frame - copy this frame.

Method Detail

groupMap

protected abstract Map<String,List<ENotificationMessage>> groupMap()

Returns a read-only copy of the group map. This is necessary since the returned map is passed to the client-defined match condition and the client is not allowed to modify this map.

Returns:

group map read-only copy.

toString

public String toString()

Overrides:

toString in class Object

patternName

public final String patternName()

Returns the pattern name.

Returns:

pattern name.

frameId

public final int frameId()

Returns the unique match frame identifier.

Returns:

match frame identifier.

isExclusive

public final boolean isExclusive()

Returns true if this is an exclusive feed; false otherwise.

Returns:

true if this is an exclusive feed;

allEvents

public final List<ENotificationMessage> allEvents()

Returns the "all events" collection as an unmodifiable list.

Returns:

unmodifiable all events list.

userCache

public final Map<Object,Object> userCache()

Returns the user-defined match data cache.

Returns:

user match data cache.

isDefunct

public final boolean isDefunct()

Returns true if this match frame is defunct due to a prior exclusive matching and, therefore, may no longer be used.

Returns:

true if defunct.

setDefunct

public final void setDefunct()

Marks this match frame as defunct. Next time this frame is removed from the frame queue, it will be ignored.