org.dmd.dmp.server.servlet.base.cache

Interface CacheIF

All Superinterfaces:

org.dmd.dmc.DmcNameResolverIF

All Known Implementing Classes:

BasicCachePlugin

public interface CacheIF
extends org.dmd.dmc.DmcNameResolverIF

The CacheIF defines an entity that manages a collection of named Dark Matter Objects. The cache provides notification of creations, deletions and modifications associated with the objects it manages. Generally speaking, a cache implementation will be run in a separate thread and change requests will be queued for servicing in the order in which they arrive.

The interface methods are broken down into the following areas:

• Direct access methods: these methods are used internally by plugins to directly manipulate the contents of the cache.
• Asynchronous operation processing: these methods are used to queue requests to be processed against the cache.
• Listener support: these methods are used to add listeners against the cache and the operations being performed against it.

Method Summary

Modifier and Type	Method and Description
Collection<org.dmd.dmw.DmwNamedObjectWrapper>	addListener(CacheListener listener) Adds the specified listener to the cache.
void	addNameGenerator(NameGeneratorIF ng) Adds the specified name generator to the cache.
void	addObject(org.dmd.dmw.DmwNamedObjectWrapper obj) This method is used to add a new object to the cache during the initialization phase of the plugins.
void	create(org.dmd.dmw.DmwNamedObjectWrapper obj, org.dmd.dmp.server.extended.Request request)
void	createAndNotify(org.dmd.dmw.DmwNamedObjectWrapper obj)
void	delete(org.dmd.dmc.DmcObjectName name, org.dmd.dmp.server.extended.Request request)
void	delete(org.dmd.dmw.DmwNamedObjectWrapper obj)
void	deleteAndNotify(org.dmd.dmc.DmcObjectName name)
void	deleteAndNotify(org.dmd.dmw.DmwNamedObjectWrapper obj)
void	dumpObjects(PrintStream ps) Dumps all cached objects to the specified PrintStream.
org.dmd.dmw.DmwNamedObjectWrapper	get(org.dmd.dmc.DmcObjectName name) Returns the specified object if it exists.
Collection<org.dmd.dmw.DmwHierarchicObjectWrapper>	getAll(org.dmd.dmc.DmcHierarchicObjectName name)
Collection<org.dmd.dmw.DmwNamedObjectWrapper>	getIndex(org.dmd.dmc.DmcClassInfo ci)
int	getIndexSize(org.dmd.dmc.DmcClassInfo ci)
Collection<org.dmd.dmw.DmwHierarchicObjectWrapper>	getNext(org.dmd.dmc.DmcHierarchicObjectName name)
long	getNextListenerID() This method is called when a new CacheListener is instantiated.
boolean	hasIndex(org.dmd.dmc.DmcClassInfo dci)
void	maintainIndex(org.dmd.dmc.DmcClassInfo cd) Indexing is a generally useful mechanism that allows for rapid access to objects of a particular type.
void	queueCreateRequest(org.dmd.dmp.server.extended.CreateRequest request) Queues a CreateRequest for processing in the order in which it arrived.
void	queueDeleteRequest(org.dmd.dmp.server.extended.DeleteRequest request) Queues a DeleteRequest for processing in the order in which it arrived.
void	queueEvent(org.dmd.dmp.server.extended.DMPEvent event) Queues an event from a remote source for processing by the cache.
void	queueSetRequest(org.dmd.dmp.server.extended.SetRequest request) Queues a SetRequest for processing in the order in which it arrived.
CacheRegistration	register(SessionIF session) If you are going to perform operations against a cache, you will need a unique registration against that cache.
void	removeListener(CacheListener listener) Removes the specified listener from the cache.
void	removeListenersForSession(SessionIF session) Removes all cache listeners associated with the specified session.
void	set(org.dmd.dmc.DmcObjectName name, org.dmd.dms.generated.types.DmcTypeModifierMV modifier, org.dmd.dmp.server.extended.Request request)
void	set(org.dmd.dmw.DmwNamedObjectWrapper obj)
void	setAndNotify(org.dmd.dmw.DmwNamedObjectWrapper obj)

Methods inherited from interface org.dmd.dmc.DmcNameResolverIF

findNamedDMO, findNamedObject, findNamedObject

Method Detail

register

CacheRegistration register(SessionIF session)

If you are going to perform operations against a cache, you will need a unique registration against that cache.

Parameters:

session - the session that's registering against the cache

Returns:

a registration against the cache.

addObject

void addObject(org.dmd.dmw.DmwNamedObjectWrapper obj)
        throws org.dmd.util.exceptions.ResultException

This method is used to add a new object to the cache during the initialization phase of the plugins. The object is added to either a flat name space or the hierarchic namespace, depending on whether the name is hierarchic or not.

Parameters:

obj - the object to be added.

Throws:

org.dmd.util.exceptions.ResultException

create

void create(org.dmd.dmw.DmwNamedObjectWrapper obj,
            org.dmd.dmp.server.extended.Request request)
     throws org.dmd.util.exceptions.ResultException

Throws:

org.dmd.util.exceptions.ResultException

createAndNotify

void createAndNotify(org.dmd.dmw.DmwNamedObjectWrapper obj)
              throws org.dmd.util.exceptions.ResultException

Throws:

org.dmd.util.exceptions.ResultException

delete

void delete(org.dmd.dmw.DmwNamedObjectWrapper obj)

deleteAndNotify

void deleteAndNotify(org.dmd.dmw.DmwNamedObjectWrapper obj)

delete

void delete(org.dmd.dmc.DmcObjectName name,
            org.dmd.dmp.server.extended.Request request)
     throws org.dmd.util.exceptions.ResultException

Throws:

org.dmd.util.exceptions.ResultException

deleteAndNotify

void deleteAndNotify(org.dmd.dmc.DmcObjectName name)

set

void set(org.dmd.dmw.DmwNamedObjectWrapper obj)
  throws org.dmd.util.exceptions.ResultException

Throws:

org.dmd.util.exceptions.ResultException

set

void set(org.dmd.dmc.DmcObjectName name,
         org.dmd.dms.generated.types.DmcTypeModifierMV modifier,
         org.dmd.dmp.server.extended.Request request)
  throws org.dmd.util.exceptions.ResultException

Throws:

org.dmd.util.exceptions.ResultException

setAndNotify

void setAndNotify(org.dmd.dmw.DmwNamedObjectWrapper obj)
           throws org.dmd.util.exceptions.ResultException

Throws:

org.dmd.util.exceptions.ResultException

queueSetRequest

void queueSetRequest(org.dmd.dmp.server.extended.SetRequest request)

Queues a SetRequest for processing in the order in which it arrived.

Parameters:

request - the request to be processed

queueCreateRequest

void queueCreateRequest(org.dmd.dmp.server.extended.CreateRequest request)

Queues a CreateRequest for processing in the order in which it arrived.

Parameters:

request - the request to be processed

queueDeleteRequest

void queueDeleteRequest(org.dmd.dmp.server.extended.DeleteRequest request)

Queues a DeleteRequest for processing in the order in which it arrived.

Parameters:

request - the request to be processed

queueEvent

void queueEvent(org.dmd.dmp.server.extended.DMPEvent event)

Queues an event from a remote source for processing by the cache. This is required in cases where the web server is acting has a front for one or more other data sources.

Parameters:

event - the event to be processed

getNextListenerID

long getNextListenerID()

This method is called when a new CacheListener is instantiated.

Returns:

the next unique identifier for a newly created CacheListener.

addListener

Collection<org.dmd.dmw.DmwNamedObjectWrapper> addListener(CacheListener listener)

Adds the specified listener to the cache. The exact behaviour of the listener is cache implementation specific.

Parameters:

listener - the cache listener

Returns:

a set of objects that meet the listener criteria

removeListener

void removeListener(CacheListener listener)

Removes the specified listener from the cache.

Parameters:

listener - the listener to be removed.

removeListenersForSession

void removeListenersForSession(SessionIF session)

Removes all cache listeners associated with the specified session.

Parameters:

sessionID - the session

get

org.dmd.dmw.DmwNamedObjectWrapper get(org.dmd.dmc.DmcObjectName name)

Returns the specified object if it exists.

Parameters:

name - the name of the object to be retrieved.

Returns:

the specified object or null if it doesn't exist.

getNext

Collection<org.dmd.dmw.DmwHierarchicObjectWrapper> getNext(org.dmd.dmc.DmcHierarchicObjectName name)

Parameters:

name - the name of the parent object.

Returns:

the children of the specified object

getAll

Collection<org.dmd.dmw.DmwHierarchicObjectWrapper> getAll(org.dmd.dmc.DmcHierarchicObjectName name)

Parameters:

name - the root of the tree to be retrieved

Returns:

the entire tree of hierarchic objects, include the root object.

maintainIndex

void maintainIndex(org.dmd.dmc.DmcClassInfo cd)

Indexing is a generally useful mechanism that allows for rapid access to objects of a particular type. This method should be overloaded to add an index for the specified class. This mechanism should work for both concrete and abstract classes since it is easy to determine if a DMO is an instance of a particular base class using the DmcClassInfo.isInstanceOf() method.

Parameters:

cd - The class info of the class from the DMSAG

hasIndex

boolean hasIndex(org.dmd.dmc.DmcClassInfo dci)

Parameters:

dci - the class to check for.

Returns:

true if there's an index for the class and false otherwise.

getIndexSize

int getIndexSize(org.dmd.dmc.DmcClassInfo ci)

Parameters:

ci - the class whose index you want to check.

Returns:

The number of entries in the index.

getIndex

Collection<org.dmd.dmw.DmwNamedObjectWrapper> getIndex(org.dmd.dmc.DmcClassInfo ci)

Parameters:

ci - the class for which you want the indexed values.

Returns:

the value in the index.

addNameGenerator

void addNameGenerator(NameGeneratorIF ng)

Adds the specified name generator to the cache. Generators are used to set the unique name of objects that are created via the cache.

Parameters:

ng -

dumpObjects

void dumpObjects(PrintStream ps)

Dumps all cached objects to the specified PrintStream.