com.db4o.internal

Class ObjectReference

java.lang.Object

com.db4o.internal.Identifiable

com.db4o.internal.ObjectReference

All Implemented Interfaces:

Activator, ObjectInfo

public class ObjectReference
extends Identifiable
implements ObjectInfo, Activator

A weak reference to an known object. "Known" ~ has been stored and/or retrieved within a transaction. References the corresponding ClassMetaData along with further metadata: internal id, UUID/version information, ...

Field Summary

Fields

Modifier and Type	Field and Description
int	_hcHashcode

Fields inherited from class com.db4o.internal.Identifiable

_id, _state

Constructor Summary

Constructors

Constructor and Description
ObjectReference()
ObjectReference(ClassMetadata classMetadata, int id)
ObjectReference(int id)

Method Summary

Methods

Modifier and Type	Method and Description
void	activate(ActivationPurpose purpose) Method to be called to activate the host object.
void	activate(Transaction ta, java.lang.Object obj, ActivationDepth depth)
void	activateOn(Transaction transaction, ActivationPurpose purpose)
ClassMetadata	classMetadata()
void	classMetadata(ClassMetadata classMetadata)
ObjectContainerBase	container()
void	deactivate(Transaction trans, ActivationDepth depth)
void	flagAsHandled(int callId)
void	flagForDelete(int callId)
long	getCommitTimestamp() The serial timestamp the object is assigned to when it is commited. You need to enable this feature before using it in FileConfiguration.generateCommitTimestamps(boolean). All the objects commited within the same transaction will receive the same commitTimestamp. db4o replication system (dRS) relies on this feature.
byte	getIdentifier()
long	getInternalID() returns the internal db4o ID.
java.lang.Object	getObject() returns the object that is referenced.
java.lang.Object	getObjectReference()
Db4oUUID	getUUID() returns a UUID representation of the referenced object.
long	getVersion() returns the transaction serial number ("version") the referenced object was stored with last.
ObjectReference	hc_add(ObjectReference newRef) HCTREE
ObjectReference	hc_find(java.lang.Object obj)
static int	hc_getCode(java.lang.Object obj)
ObjectReference	hc_remove(ObjectReference findRef)
void	hc_traverse(Visitor4 visitor)
ObjectReference	id_add(ObjectReference newRef) IDTREE
ObjectReference	id_find(int id)
ObjectReference	id_remove(ObjectReference ref)
boolean	isFlaggedAsHandled(int callID)
boolean	isFlaggedForDelete()
boolean	isValid()
static boolean	isValidId(int id)
protected boolean	objectCanUpdate(Transaction transaction, java.lang.Object obj)
int	ownLength()
VirtualAttributes	produceVirtualAttributes()
java.lang.Object	read(Transaction trans, ByteArrayBuffer buffer, java.lang.Object obj, ActivationDepth instantiationDepth, int addToIDTree, boolean checkIDTree)
java.lang.Object	readPrefetch(Transaction trans, ByteArrayBuffer buffer, int addToIDTree)
void	readThis(Transaction trans, ByteArrayBuffer buffer)
void	ref_init()
void	setObject(java.lang.Object obj)
void	setObjectWeak(ObjectContainerBase container, java.lang.Object obj)
void	setVirtualAttributes(VirtualAttributes at)
java.lang.String	toString()
Transaction	transaction()
VirtualAttributes	virtualAttributes()
VirtualAttributes	virtualAttributes(Transaction trans)
VirtualAttributes	virtualAttributes(Transaction trans, boolean lastCommitted)
void	writeThis(Transaction trans, ByteArrayBuffer buffer)
void	writeUpdate(Transaction transaction, UpdateDepth updatedepth)

Methods inherited from class com.db4o.internal.Identifiable

beginProcessing, endProcessing, getID, hashCode, isActive, isDirty, isNew, setID, setStateClean, setStateDeactivated, setStateDirty

Methods inherited from class java.lang.Object

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

Field Detail

_hcHashcode

public int _hcHashcode

Constructor Detail

ObjectReference

public ObjectReference()

ObjectReference

public ObjectReference(int id)

ObjectReference

public ObjectReference(ClassMetadata classMetadata,
               int id)

Method Detail

activate

public void activate(ActivationPurpose purpose)

Description copied from interface: Activator

Method to be called to activate the host object.

Specified by:

activate in interface Activator

Parameters:

purpose - for which purpose is the object being activated? ActivationPurpose.WRITE will cause the object to be saved on the next ObjectContainer.commit() operation.

activateOn

public void activateOn(Transaction transaction,
              ActivationPurpose purpose)

activate

public void activate(Transaction ta,
            java.lang.Object obj,
            ActivationDepth depth)

deactivate

public void deactivate(Transaction trans,
              ActivationDepth depth)

getIdentifier

public byte getIdentifier()

getInternalID

public long getInternalID()

Description copied from interface: ObjectInfo

returns the internal db4o ID.

Specified by:

getInternalID in interface ObjectInfo

getObject

public java.lang.Object getObject()

Description copied from interface: ObjectInfo

returns the object that is referenced.

This method may return null, if the object has been garbage collected.

Specified by:

getObject in interface ObjectInfo

Returns:

the referenced object or null, if the object has been garbage collected.

getObjectReference

public java.lang.Object getObjectReference()

container

public ObjectContainerBase container()

transaction

public Transaction transaction()

getUUID

public Db4oUUID getUUID()

Description copied from interface: ObjectInfo

returns a UUID representation of the referenced object. UUID generation has to be turned on, in order to be able to use this feature: com.db4o.config.Configuration#generateUUIDs(int)

Specified by:

getUUID in interface ObjectInfo

Returns:

the UUID of the referenced object.

getVersion

public long getVersion()

Description copied from interface: ObjectInfo

returns the transaction serial number ("version") the referenced object was stored with last. Version number generation has to be turned on, in order to be able to use this feature: com.db4o.config.Configuration#generateVersionNumbers(int)
This feature was replaced by ObjectInfo.getCommitTimestamp(). The main difference is that the old version mechamism used to assign a serial timestamp to the object upon storing time, and the new commiTimestamp approach, assigns it upon commit time.

Specified by:

getVersion in interface ObjectInfo

Returns:

the version number.

getCommitTimestamp

public long getCommitTimestamp()

Description copied from interface: ObjectInfo

The serial timestamp the object is assigned to when it is commited.

You need to enable this feature before using it in FileConfiguration.generateCommitTimestamps(boolean).

All the objects commited within the same transaction will receive the same commitTimestamp.

db4o replication system (dRS) relies on this feature.

Specified by:

getCommitTimestamp in interface ObjectInfo

Returns:

the serial timestamp that was given to the object upon commit.

See Also:

FileConfiguration.generateCommitTimestamps(boolean)

classMetadata

public final ClassMetadata classMetadata()

classMetadata

public void classMetadata(ClassMetadata classMetadata)

ownLength

public int ownLength()

produceVirtualAttributes

public VirtualAttributes produceVirtualAttributes()

read

public final java.lang.Object read(Transaction trans,
                    ByteArrayBuffer buffer,
                    java.lang.Object obj,
                    ActivationDepth instantiationDepth,
                    int addToIDTree,
                    boolean checkIDTree)

readPrefetch

public java.lang.Object readPrefetch(Transaction trans,
                            ByteArrayBuffer buffer,
                            int addToIDTree)

readThis

public final void readThis(Transaction trans,
            ByteArrayBuffer buffer)

setObjectWeak

public void setObjectWeak(ObjectContainerBase container,
                 java.lang.Object obj)

setObject

public void setObject(java.lang.Object obj)

flagForDelete

public void flagForDelete(int callId)

isFlaggedForDelete

public boolean isFlaggedForDelete()

flagAsHandled

public void flagAsHandled(int callId)

isFlaggedAsHandled

public final boolean isFlaggedAsHandled(int callID)

isValid

public final boolean isValid()

isValidId

public static final boolean isValidId(int id)

virtualAttributes

public VirtualAttributes virtualAttributes()

virtualAttributes

public VirtualAttributes virtualAttributes(Transaction trans,
                                  boolean lastCommitted)

virtualAttributes

public VirtualAttributes virtualAttributes(Transaction trans)

setVirtualAttributes

public void setVirtualAttributes(VirtualAttributes at)

writeThis

public void writeThis(Transaction trans,
             ByteArrayBuffer buffer)

writeUpdate

public void writeUpdate(Transaction transaction,
               UpdateDepth updatedepth)

objectCanUpdate

protected boolean objectCanUpdate(Transaction transaction,
                      java.lang.Object obj)

ref_init

public void ref_init()

hc_add

public ObjectReference hc_add(ObjectReference newRef)

HCTREE

hc_find

public ObjectReference hc_find(java.lang.Object obj)

hc_getCode

public static int hc_getCode(java.lang.Object obj)

hc_remove

public ObjectReference hc_remove(ObjectReference findRef)

hc_traverse

public void hc_traverse(Visitor4 visitor)

id_add

public ObjectReference id_add(ObjectReference newRef)

IDTREE

id_find

public ObjectReference id_find(int id)

id_remove

public ObjectReference id_remove(ObjectReference ref)

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object