org.datanucleus.store.mapped.scostore
Class ElementContainerStore

java.lang.Object
  org.datanucleus.store.mapped.scostore.BaseContainerStore
      org.datanucleus.store.mapped.scostore.ElementContainerStore

Direct Known Subclasses:

AbstractArrayStore, AbstractCollectionStore

public abstract class ElementContainerStore
extends BaseContainerStore

Representation of the store of an element-based container. This is used to represent either a collection or an array. There are the following types of situation that we try to cater for with respect to elements.

• element-type is PC with "new-table" or "superclass-table" inheritance. In this case we will have elementInfo with 1 entry.
• element-type is PC with "subclass-table" inheritance. In this case we will have elementInfo with "n" entries (1 for each subclass type with its own table). We also have emd being the MetaData for the element-type.
• element-type is Reference type. In this case we will have elementInfo with "n" entries (1 for each implementation type).
• element-type is non-PC. In this case we have no elementInfo and no emd

Nested Class Summary

class

ElementContainerStore.ElementInfo Inner class wrapping the information required for a valid element type.

Field Summary

protected ClassLoaderResolver	clr ClassLoader resolver.
protected DatastoreContainerObject	containerTable Table containing the link between owner and element.
protected ElementContainerStore.ElementInfo[]	elementInfo Information for the elements of this container.
protected boolean	elementIsPersistentInterface Whether the element is of a persistent-interface (defined using "") type.
protected JavaTypeMapping	elementMapping Mapping for the element.
protected boolean	elementsAreEmbedded Whether the elements are embedded.
protected boolean	elementsAreSerialised Whether the elements are serialised.
protected java.lang.String	elementType Type of the element.
protected AbstractClassMetaData	emd MetaData for the "element-type" class.
protected boolean	iterateUsingDiscriminator Flag to set whether the iterator statement will use a discriminator or not.
protected JavaTypeMapping	orderMapping Mapping for an ordering column to allow for duplicates in the container.
protected JavaTypeMapping	relationDiscriminatorMapping Optional mapping to distinguish elements of one collection from another when sharing the join table.
protected java.lang.String	relationDiscriminatorValue Value to use to discriminate between elements of this collection from others using the same join table.
protected ElementContainerStoreSpecialization	specialization Specialization.

Fields inherited from class org.datanucleus.store.mapped.scostore.BaseContainerStore

allowsNull, dba, LOCALISER, ownerMapping, ownerMemberMetaData, relationType, storeMgr

Constructor Summary

protected

ElementContainerStore(StoreManager storeMgr, ClassLoaderResolver clr, ElementContainerStoreSpecialization elementContainerStoreSpecialization) Constructor.

Method Summary

void	clear(StateManager ownerSM) Clear the association from owner to all elements.
DatastoreContainerObject	getContainerTable()
ElementContainerStore.ElementInfo[]	getElementInfo()
protected ElementContainerStore.ElementInfo[]	getElementInformationForClass() Convenience method to find the element information relating to the element type.
JavaTypeMapping	getElementMapping()
java.lang.String	getElementType() Accessor for the element type stored in this container.
AbstractClassMetaData	getEmd()
JavaTypeMapping	getOrderMapping()
JavaTypeMapping	getRelationDiscriminatorMapping()
java.lang.String	getRelationDiscriminatorValue()
boolean	hasOrderMapping() Accessor for whether the store has an order mapping, to allow for duplicates or ordering.
boolean	isElementsAreEmbedded()
boolean	isElementsAreSerialised()
abstract java.util.Iterator	iterator(StateManager ownerSM) Accessor for an iterator through the container elements.
int	size(StateManager sm) Method to return the size of the container.
protected boolean	validateElementForReading(StateManager sm, java.lang.Object element) Method to check if an element is already persistent or is persistent but managed by a different persistence manager.
protected boolean	validateElementForWriting(StateManager sm, java.lang.Object element, FieldValues fieldValues) Method to check if an element is already persistent, or is managed by a different Persistencemanager.
protected boolean	validateElementType(ClassLoaderResolver clr, java.lang.Object element) Method to validate an element against the accepted type.

Methods inherited from class org.datanucleus.store.mapped.scostore.BaseContainerStore

allowsBatching, getDatastoreAdapter, getOwnerMapping, getOwnerMemberMetaData, getRelationType, getStateManagerForEmbeddedPCObject, getStoreManager, isEmbeddedMapping, setOwner

Methods inherited from class java.lang.Object

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

Field Detail

iterateUsingDiscriminator

protected boolean iterateUsingDiscriminator

Flag to set whether the iterator statement will use a discriminator or not.

elementInfo

protected ElementContainerStore.ElementInfo[] elementInfo

Information for the elements of this container. When the "element-type" table is new-table, or superclass-table then there is 1 value here. When the "element-type" table uses subclass-table, or when it is a reference type then there can be multiple.

emd

protected AbstractClassMetaData emd

MetaData for the "element-type" class. Not used for reference types since no metadata is present for the declared type.

containerTable

protected DatastoreContainerObject containerTable

Table containing the link between owner and element. Not set when using FK relations.

elementMapping

protected JavaTypeMapping elementMapping

Mapping for the element.

elementType

protected java.lang.String elementType

Type of the element.

elementsAreEmbedded

protected boolean elementsAreEmbedded

Whether the elements are embedded.

elementsAreSerialised

protected boolean elementsAreSerialised

Whether the elements are serialised.

elementIsPersistentInterface

protected boolean elementIsPersistentInterface

Whether the element is of a persistent-interface (defined using "") type.

orderMapping

protected JavaTypeMapping orderMapping

Mapping for an ordering column to allow for duplicates in the container. Can also be used for ordering elements in a List/array. Can also be used where we have an embedded object and so need to form the PK with something.

relationDiscriminatorMapping

protected JavaTypeMapping relationDiscriminatorMapping

Optional mapping to distinguish elements of one collection from another when sharing the join table.

relationDiscriminatorValue

protected java.lang.String relationDiscriminatorValue

Value to use to discriminate between elements of this collection from others using the same join table.

clr

protected ClassLoaderResolver clr

ClassLoader resolver.

specialization

protected final ElementContainerStoreSpecialization specialization

Specialization.

Constructor Detail

ElementContainerStore

protected ElementContainerStore(StoreManager storeMgr,
                                ClassLoaderResolver clr,
                                ElementContainerStoreSpecialization elementContainerStoreSpecialization)

Constructor.

Parameters:

storeMgr - Manager for the store

clr - ClassLoader resolver

Method Detail

getElementInfo

public ElementContainerStore.ElementInfo[] getElementInfo()

getElementMapping

public JavaTypeMapping getElementMapping()

getOrderMapping

public JavaTypeMapping getOrderMapping()

getRelationDiscriminatorMapping

public JavaTypeMapping getRelationDiscriminatorMapping()

getRelationDiscriminatorValue

public java.lang.String getRelationDiscriminatorValue()

getContainerTable

public DatastoreContainerObject getContainerTable()

getEmd

public AbstractClassMetaData getEmd()

isElementsAreSerialised

public boolean isElementsAreSerialised()

isElementsAreEmbedded

public boolean isElementsAreEmbedded()

getElementInformationForClass

protected ElementContainerStore.ElementInfo[] getElementInformationForClass()

Convenience method to find the element information relating to the element type. Used specifically for the "element-type" of a collection/array to find the elements which have table information. Not used for reference types.

Returns:

Element information relating to the element type

hasOrderMapping

public boolean hasOrderMapping()

Accessor for whether the store has an order mapping, to allow for duplicates or ordering.

Returns:

Whether an order mapping is present.

getElementType

public java.lang.String getElementType()

Accessor for the element type stored in this container.

Returns:

The element type.

validateElementType

protected boolean validateElementType(ClassLoaderResolver clr,
                                      java.lang.Object element)

Method to validate an element against the accepted type.

Parameters:

clr - The ClassLoaderResolver

element - The element to validate

Returns:

Whether it is valid.

validateElementForReading

protected boolean validateElementForReading(StateManager sm,
                                            java.lang.Object element)

Method to check if an element is already persistent or is persistent but managed by a different persistence manager.

Parameters:

sm - The state manager of this owner

element - The element

Returns:

Whether it is valid for reading.

validateElementForWriting

protected boolean validateElementForWriting(StateManager sm,
                                            java.lang.Object element,
                                            FieldValues fieldValues)

Method to check if an element is already persistent, or is managed by a different Persistencemanager. If not persistent, this will persist it.

Parameters:

sm - The state manager of this owner

element - The element

fieldValues - any initial field values to use if persisting the element

Returns:

Whether the element was persisted during this call

iterator

public abstract java.util.Iterator iterator(StateManager ownerSM)

Accessor for an iterator through the container elements.

Parameters:

ownerSM - State Manager for the container.

Returns:

The Iterator

clear

public void clear(StateManager ownerSM)

Clear the association from owner to all elements. Provides cascade-delete when the elements being deleted are PC types.

Parameters:

ownerSM - State Manager for the container.

size

public int size(StateManager sm)

Method to return the size of the container.

Parameters:

sm - The state manager.

Returns:

The size.