com.bigdata.gom.gpo

Interface IGPO

All Superinterfaces:

IGenericSkin

All Known Implementing Classes:

GPO

public interface IGPO
extends IGenericSkin

A generic object has identity and an extensible, loosely-typed property set. When the value of a property is another generic object, the property models a directed many-to-one association. Many-to-many linking patterns are modeled using intermediate objects and a convenience API. Reverse navigation for associations is automatically aggregated by the association target within a link set. Associations and link sets provide an uniform, efficient and scalable API for object navigation. Link sets may be indexed for efficient search.

Extensible behavior is realized by wrapping up a generic object within some application specific interface. Generic object implementations should be considered as final. Specific backends may support subclassing but use of subclassing will lock an application into a specific GOM platform. Instead applications layer additional behavior onto generic objects using "skins" - see asClass( Class ). A skin delegates the management of persistent state to a backing generic object. The use of skins provides transparent migration of application code across different GOM implementations.

The generic object model provides transparent and scalable persistence when using an appropriate backing store. The backing store is selected and configured using the ObjectManagerFactory.

Method Summary

Methods

Modifier and Type	Method and Description
void	addValue(org.openrdf.model.URI property, org.openrdf.model.Value newValue) Assert (self,p,newValue).
IGenericSkin	asClass(Class theClassOrInterface) Returns an transient object that wraps the same persistent object but exposes the behavior identified by the identified interface.
boolean	equals(Object other) Returns true iff other has the same identity as this generic object and is in the same IObjectManager scope (this is just this == other since the IObjectManager guarantees that IGPOs are canonical for a given Resource within the scope of the IObjectManager).
BigdataResource	getId() Returns the persistent identity of the generic object.
IGPO	getLink(org.openrdf.model.URI property, IGPO target) Return the IGPO modeling the link iff it exists.
Set<IGPO>	getLinksIn() All ?y where (?y,?p,self).
ILinkSet	getLinksIn(org.openrdf.model.URI property) All ?y where (?y,p,self).
Set<IGPO>	getLinksOut() All ?y where (self,?p,?y) and ?y is Resource.
ILinkSet	getLinksOut(org.openrdf.model.URI property) All ?y where (self,p,?y) and ?y is Resource.
IObjectManager	getObjectManager() Return the IObjectManager used to materialize or create this generic object.
Map<org.openrdf.model.URI,Long>	getReverseLinkProperties() Return a map giving the range count for each reverse link property.
Set<org.openrdf.model.Statement>	getStatements() All (self,?p,?o).
IGPO	getType() FIXME: this method will be moved to an as yet unnamed derived class that will become the superclass for alchemist generated subclasses.
org.openrdf.model.Value	getValue(org.openrdf.model.URI property) Return first Value for property or null if no Value for that property.
Set<org.openrdf.model.Value>	getValues(org.openrdf.model.URI property) All ?y where (self,p,?y).
int	hashCode() Return the hash code of the identity of the generic object.
boolean	isBound(org.openrdf.model.URI property) Exists (self,p,?y).
boolean	isMemberOf(ILinkSet linkSet) Exists (?x,linkSet.property,self).
IGPO	materialize() Force the full materialization of the IGPO.
String	pp()
void	remove() Removes the persistent object.
void	removeValue(org.openrdf.model.URI property, org.openrdf.model.Value oldValue) Remove (self,p,oldValue) if found.
void	removeValues(org.openrdf.model.URI property) Remove all (self,p,?).
void	setValue(org.openrdf.model.URI property, org.openrdf.model.Value newValue) Replace (self,p,?x) with (self,p,newValue).

Methods inherited from interface com.bigdata.gom.gpo.IGenericSkin

asGeneric

Method Detail

getId

BigdataResource getId()

Returns the persistent identity of the generic object.

equals

boolean equals(Object other)

Returns true iff other has the same identity as this generic object and is in the same IObjectManager scope (this is just this == other since the IObjectManager guarantees that IGPOs are canonical for a given Resource within the scope of the IObjectManager).

Overrides:

equals in class Object

hashCode

int hashCode()

Return the hash code of the identity of the generic object. (The hash code is NOT based on the internal state of the generic object.)

Overrides:

hashCode in class Object

getObjectManager

IObjectManager getObjectManager()

Return the IObjectManager used to materialize or create this generic object.

getValue

org.openrdf.model.Value getValue(org.openrdf.model.URI property)

Return first Value for property or null if no Value for that property.

setValue

void setValue(org.openrdf.model.URI property,
            org.openrdf.model.Value newValue)

Replace (self,p,?x) with (self,p,newValue).

addValue

void addValue(org.openrdf.model.URI property,
            org.openrdf.model.Value newValue)

Assert (self,p,newValue).

getLink

IGPO getLink(org.openrdf.model.URI property,
           IGPO target)

Return the IGPO modeling the link iff it exists.

removeValue

void removeValue(org.openrdf.model.URI property,
               org.openrdf.model.Value oldValue)

Remove (self,p,oldValue) if found.

removeValues

void removeValues(org.openrdf.model.URI property)

Remove all (self,p,?).

getStatements

Set<org.openrdf.model.Statement> getStatements()

All (self,?p,?o).

getValues

Set<org.openrdf.model.Value> getValues(org.openrdf.model.URI property)

All ?y where (self,p,?y).

getLinksIn

Set<IGPO> getLinksIn()

All ?y where (?y,?p,self).

getLinksIn

ILinkSet getLinksIn(org.openrdf.model.URI property)

All ?y where (?y,p,self).

getLinksOut

Set<IGPO> getLinksOut()

All ?y where (self,?p,?y) and ?y is Resource.

getLinksOut

ILinkSet getLinksOut(org.openrdf.model.URI property)

All ?y where (self,p,?y) and ?y is Resource.

isMemberOf

boolean isMemberOf(ILinkSet linkSet)

Exists (?x,linkSet.property,self).

isBound

boolean isBound(org.openrdf.model.URI property)

Exists (self,p,?y).

getReverseLinkProperties

Map<org.openrdf.model.URI,Long> getReverseLinkProperties()

Return a map giving the range count for each reverse link property.

 SELECT ?p, COUNT(*) WHERE { ?o ?p  } GROUP BY ?p
 

remove

void remove()

Removes the persistent object. Any links to this generic object are also removed. Any link sets collected by this generic object are removed.

While this clears all link sets held by the generic object, the members of those link sets are NOT explicitly removed since they may participate in other associations.

The IGPO interface may no longer be used for this object if this operation is successful.

asClass

IGenericSkin asClass(Class theClassOrInterface)

Returns an transient object that wraps the same persistent object but exposes the behavior identified by the identified interface. The interface effectively names the behavior that will be wrapped around the persistent data. If the current object already implements the desired interface, then it is simply returned. If a suitable IGenericSkin has already been minted for this generic object, then it is simply returned. Otherwise an implementation class for the interface MUST have been registered with the runtime and MUST implement a constructor accepting a single IGenericSkin argument.

The life cycle of a skin object returned by this method MUST be no less than the in-memory life cycle of the generic object for which the skin was minted. This constraint makes it possible to have transient yet expensive initialization, such as caches, on skin objects.

Returns:

An object that wraps the same persistent data but implements the desired interface.

Throws:

UnsupportedOperationException - If the runtime is unable to identify an implementation class for the specified interface.

See Also:

IGenericSkin, GenericSkinRegistry

materialize

IGPO materialize()

Force the full materialization of the IGPO.

Returns:

This IGPO.

pp

String pp()

Returns:

a pretty printed representation of the GPO

getType

IGPO getType()

FIXME: this method will be moved to an as yet unnamed derived class that will become the superclass for alchemist generated subclasses.