Package org.datanucleus.cache

Class CachedPC

java.lang.Object

org.datanucleus.cache.CachedPC

All Implemented Interfaces:

java.io.Serializable, java.lang.Comparable<CachedPC>

public class CachedPC
extends java.lang.Object
implements java.io.Serializable, java.lang.Comparable<CachedPC>

An object that is stored in the Level2 Cache keyed by the identity of the persistable object. Comprises a map of the field values keyed by the absolute field number in the class, the loaded fields array, and the version of the object that is represented with these values.

• Where the field is a relation field (PC, Map, Collection, array) we store the id of any referenced persistable object. This is used when regenerating the object, and recreating its relations. Note that the "id" is the DatastoreId or SingleFieldId etc where applicable otherwise is CachedId (ensuring that the class of the related object is stored).
• Where the field contains an embedded/serialised persistable object, we store a nested CachedPC object representing that object (since it doesn't exist in its own right).

See Also:

Serialized Form

Nested Class Summary

Nested Classes

Modifier and Type	Class	Description
static class	CachedPC.CachedId

Field Summary

Fields

Modifier and Type	Field	Description
private java.lang.Class	cls	Class of the object being cached.
private java.util.Map<java.lang.Integer,java.lang.Object>	fieldValues	Values for the fields, keyed by the absolute field number.
private java.lang.Object	id	Identity of the object being cached.
private boolean[]	loadedFields	The loaded fields array.
private static long	serialVersionUID
private java.lang.Object	version	Version of the cached object (if any) - Long, Timestamp etc.

Constructor Summary

Constructors

Constructor	Description
CachedPC(java.lang.Class cls, boolean[] loadedFields, java.lang.Object vers, java.lang.Object id)	Constructor.

Method Summary

Modifier and Type	Method	Description
int	compareTo(CachedPC other)
CachedPC	getCopy()
java.lang.Object	getFieldValue(java.lang.Integer fieldNumber)
java.lang.Object	getId()
int[]	getLoadedFieldNumbers()
boolean[]	getLoadedFields()	Accessor for the loaded fields of this object.
java.lang.Class	getObjectClass()
java.lang.Object	getVersion()
void	setFieldValue(java.lang.Integer fieldNumber, java.lang.Object value)
void	setLoadedField(int fieldNumber, boolean loaded)
void	setVersion(java.lang.Object ver)
java.lang.String	toString()	Method to return a sting form of the cached object.
java.lang.String	toString(java.lang.String indent, boolean debug)	Method to return a string form of the cached object.

Methods inherited from class java.lang.Object

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

Field Detail

serialVersionUID

private static final long serialVersionUID

See Also:

Constant Field Values

cls

private java.lang.Class cls

Class of the object being cached.

id

private java.lang.Object id

Identity of the object being cached. This is to allow recreation of the object when using uniqueKey lookup. This will be null if embedded/serialised.

fieldValues

private java.util.Map<java.lang.Integer,java.lang.Object> fieldValues

Values for the fields, keyed by the absolute field number.

version

private java.lang.Object version

Version of the cached object (if any) - Long, Timestamp etc.

loadedFields

private boolean[] loadedFields

The loaded fields array. TODO Note that this could be interpreted from the keys of fieldValues.

Constructor Detail

CachedPC

public CachedPC(java.lang.Class cls,
                boolean[] loadedFields,
                java.lang.Object vers,
                java.lang.Object id)

Constructor.

Parameters:

cls - The class of the object

loadedFields - The loaded fields

vers - Version of the object (optional)

id - Identity of the object

Method Detail

getObjectClass

public java.lang.Class getObjectClass()

getId

public java.lang.Object getId()

setFieldValue

public void setFieldValue(java.lang.Integer fieldNumber,
                          java.lang.Object value)

getFieldValue

public java.lang.Object getFieldValue(java.lang.Integer fieldNumber)

setVersion

public void setVersion(java.lang.Object ver)

getVersion

public java.lang.Object getVersion()

getLoadedFields

public boolean[] getLoadedFields()

Accessor for the loaded fields of this object. Use setLoadedField() if you want to update a flag.

Returns:

The loaded fields flags

getLoadedFieldNumbers

public int[] getLoadedFieldNumbers()

setLoadedField

public void setLoadedField(int fieldNumber,
                           boolean loaded)

getCopy

public CachedPC getCopy()

compareTo

public int compareTo(CachedPC other)

Specified by:

compareTo in interface java.lang.Comparable<CachedPC>

toString

public java.lang.String toString()

Method to return a sting form of the cached object. Returns something like

 CachedPC : cls=mydomain.MyClass version=1 loadedFlags=[YY]
 

Overrides:

toString in class java.lang.Object

Returns:

The string form

toString

public java.lang.String toString(java.lang.String indent,
                                 boolean debug)

Method to return a string form of the cached object. Returns something like

 CachedPC : cls=mydomain.MyClass version=1 loadedFlags=[YY] numValues=2
     field=0 value=101 type=class java.lang.Long
     field=1 value=Home type=class java.lang.String
 

when debug is enabled, and omits the "field=..." parts when not using debug.

Parameters:

indent - Indent for this CachedPC

debug - Whether to include the field values in the return

Returns:

The string form