Package org.exolab.castor.persist
The Castor persistence engine handles object persistence, object caching, transaction concurrency and locking. This package is not used directly by application developer, and includes the interfaces, implementations and persistence exceptions.
- Version:
- $Revision: 6230 $ $Date: 2004-02-13 14:13:22 -0700 (Fri, 13 Feb 2004) $
- Author:
- Assaf Arkin
The persistence engine API is used by the application APIs (JDO, CMP, DAX) to implement caching, queries, transactions and concurrency, etc. This layer is shared by all persistence engine and exposes a unified interface for use as a persistence engine for EJB CMP.
An application API will use a TransactionContext
in order
to perform operations. All operations against the persistence engine are transactional.
The persistence engine is obtained through the PersistenceEngineFactory
class which returns a LockEngine
. The factory requires
a factory of persistence SPIs (see SPI.
LockEngine
implements a persistence engine that caches
objects in memory for performance, and eliminates the number of persistent storage operations.
In order to speed up interaction between the engines and the object, ClassMolder
is constructed to represent a flat view
of the object graph that is efficient to process.
If the application API supports enlistment as an XA resource, it will use
XAResourceImpl
and implement XAResourceSource
for automatic enlistment/delistment with a
transaction context.
The remainder of this package are persistence exceptions and the concurrency engine implementation.
-
Interface Summary Interface Description DepositBox DepositBox is an interface forClassMolder
to access the dirty checking cache of an object.TxSynchronizable This interface offers some callback hooks for several different stages during a transaction.XAResourceSource A data source that wishes to particiate as an XA resource implements this interface. -
Class Summary Class Description ClassMolder ClassMolder is a 'binder' for one type of data object and its correspondingPersistence
.ClassMolderHelper Utility class that provides (mostly) static methods in relation to the functions required by aClassMolder
.DatingService DataService is a helper class for constructing ClassMolders and pairing up ClassMolders which depends and extends the other.FieldMolder FieldMolder represents a field of a data object class.FieldMolder.CollectionInfo LockEngine LockEngine is a gateway for all the ClassMolders of a persistence storage.ObjectLock Read/write locks and lock synchronization on an object.ObjectLock.LinkedTx Object uses to hold a linked list of transactions holding write locks or waiting for a read/write lock.OID Object identifier.OutputLogInterceptor A simple log interceptor that reports all messages to a writer or an output stream.PersistenceEngineFactory Factory for constructing new persistence engines.PersistenceFactoryRegistry Registry forPersistenceFactory
implementations obtained from the Castor properties file and used by the JDO database configuration file.PersistenceInfoGroup QueryResults The result of a query in the context of a transaction.SQLRelationLoader SQLRelationLoader is a quick hack for creating and removing relation from a many-to-many relation database from ClassMolder.XAResourceImpl AnXAResource
implementation for anXAResourceSource
. -
Enum Summary Enum Description FieldPersistenceType Enumeration for field type in the context of persistence; it is distinguished between primitive fields, serializable fields and relational fields (one-to-one, one-to-many and many-to-many). -
Exception Summary Exception Description ObjectDeletedWaitingForLockException Thrown to indicate that a lock attempt has failed due to object being deleted by a concurrent transaction.