Package com.swiftmq.impl.streams.comp.memory

Class MemoryGroup

java.lang.Object

com.swiftmq.impl.streams.comp.memory.MemoryGroup

public class MemoryGroup
extends Object

A MemoryGroup groups incoming Messages on base of the values of a Message Property (Group Property). Scripts register a MemoryCreateCallback that is called for each new value of this Property so that a Memory exists for each distinct Property value. The MemoryCreateCallback may also chose to not create a Memory and may return null. In that case the value will not be respected.

A MemoryGroup may be used to implement session windows.

Author:

IIT Software GmbH, Muenster/Germany, (c) 2017, All Rights Reserved

Constructor Summary

Constructors

Constructor	Description
MemoryGroup(StreamContext ctx, String name, String groupPropName)	Internal use only.

Method Summary

Modifier and Type	Method	Description
MemoryGroup	add(Message message)	Adds a Message to this MemoryGroup.
MemoryGroup	checkLimit()	Checks inactivity and calls checkLimit() on each Memory of this MemoryGroup
void	close()	Closes this MemoryGroup.
void	deferredClose()	Internal Use.
void	forEach(ForEachMemoryCallback callback)	Executes the Callback for each Memory in this MemoryGroup
String	groupPropertyName()	Returns the name of the group Property.
GroupInactivityTimeout	inactivityTimeout()	Sets and returns the GroupInactivityTimeout for this Memory.
boolean	isMarkedAsClose()	Internal Use.
String	name()	Returns the name of this MemoryGroup
MemoryGroup	onCreate(MemoryCreateCallback callback)	Registers a MemoryCreateCallback (mandatory)
MemoryGroup	onRemove(MemoryRemoveCallback callback)	Registers a MemoryRemoveCallback (optional)
MemoryGroup	removeMemory(Comparable key)	Removes a Memory from this MemoryGroup.
String	toString()

Methods inherited from class java.lang.Object

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

Constructor Details

MemoryGroup

public MemoryGroup(StreamContext ctx,
 String name,
 String groupPropName)

Internal use only.

Method Details

name

public String name()

Returns the name of this MemoryGroup

Returns:

name

groupPropertyName

public String groupPropertyName()

Returns the name of the group Property.

Returns:

group Property name

inactivityTimeout

public GroupInactivityTimeout inactivityTimeout()

Sets and returns the GroupInactivityTimeout for this Memory. A GroupInactivityTimeout can be attached to a MemoryGroup and specifies a time of inactivity (no adds to attached Memory) after which all Messages in that Memory will retire and the Memory will be closed and removed from the MemoryGroup. Inactivity is checked during MemoryGroup.checkLimit() and thus needs to be regularly called from a Timer.

Returns:

GroupInactivityTimeout

add

public MemoryGroup add(Message message)
                throws Exception

Adds a Message to this MemoryGroup. If the value of the group Property is detected for the first time, MemoryCreateCallback.create is called.

Parameters:

message - Message

Returns:

this

Throws:

Exception

onCreate

public MemoryGroup onCreate(MemoryCreateCallback callback)

Registers a MemoryCreateCallback (mandatory)

Parameters:

callback - MemoryCreateCallback

Returns:

this

onRemove

public MemoryGroup onRemove(MemoryRemoveCallback callback)

Registers a MemoryRemoveCallback (optional)

Parameters:

callback - MemoryRemoveCallback

Returns:

this

removeMemory

public MemoryGroup removeMemory(Comparable key)

Removes a Memory from this MemoryGroup.

Parameters:

key - Value of the group Property

Returns:

this

checkLimit

public MemoryGroup checkLimit()

Checks inactivity and calls checkLimit() on each Memory of this MemoryGroup

Returns:

this

forEach

public void forEach(ForEachMemoryCallback callback)

Executes the Callback for each Memory in this MemoryGroup

Parameters:

callback - Callback

Throws:

Exception

deferredClose

public void deferredClose()

Internal Use.

isMarkedAsClose

public boolean isMarkedAsClose()

Internal Use.

close

public void close()

Closes this MemoryGroup. It closes also all Memories attached to this MemoryGroup

toString

public String toString()

Overrides:

toString in class Object