org.datanucleus.store.neodatis
Class NeoDatisManager

java.lang.Object
  org.datanucleus.store.AbstractStoreManager
      org.datanucleus.store.neodatis.NeoDatisManager

All Implemented Interfaces:

org.datanucleus.store.StoreManager

public class NeoDatisManager
extends org.datanucleus.store.AbstractStoreManager

Store Manager for NeoDatis (http://www.neodatis.org/).

DataNucleus will select this StoreManager with URLs of the form "neodatis:...". Support for NeoDatis is for the following URLs

• neodatis:{filename} - uses a local NeoDatis database in the named file
• neodatis:server:{filename} - uses a local NeoDatis database in the named file as an embedded server
• neodatis:{hostname}:{port}/{identifier} - uses a remote NeoDatis database with the specified username/password
These URLs are specific to DataNucleus support since NeoDatis doesn't use URLs to define the datastore.

Object Activation and Field Loading

NeoDatis provides methods to hand out memory versions of the datastore objects. Each object has to be "activated" to have its values accessible. Similarly the object can be "deactivated" when it is no longer needed (freeing up resources, and the link to the disk object). When we retrieve an object from NeoDatis it activates the object. This makes all fields accessible. If however one of the fields is a PC object (or collection, or map, or array etc) that object itself is not activated. Consequently all fields are accessible from the start (unlike with RDBMS), but the StateManager manages the list of fields that are considered "loaded", and this is initially just those in the DFG (even though others are available). When the user accesses one of these "not-loaded" fields NeoDatisManager.fetchObject is called and that field is marked as loaded (if it is a SCO mutable it is wrapped, and if it is a PC object it has a StateManager connected and is activated).

Persistence

Each object is persisted on its own, and we dont use NeoDatis's internal cascade mechanism. Instead the NeoDatisManager.insertObject, or NeoDatisManager.updateObject methods are called for each object that is to be persisted/updated. Each call to insertObject/updateObject provides reachability by use of PersistFieldManager.

Deletion

Currently objects are deleted one by one since NeoDatis doesn't provide its own cascade delete process. We use DeleteFieldManager to navigate through the objec graph according to dependent field metadata.

Transactions and Connections

Refer to ConnectionFactoryImpl. In simple terms each ObjectManager has a NeoDatis ODB associated with it, and this is retained until the end of life of the ObjectManager. With NeoDatis in server mode this allows use of multiple PMs on the same underlying datastore. With NeoDatis in file mode you can only have one PM operating on the same underlying datastore at once. This is a NeoDatis limitation rather than ours.

Field Summary

protected static org.datanucleus.util.Localiser

LOCALISER_NEODATIS Localiser for messages.

Fields inherited from class org.datanucleus.store.AbstractStoreManager

autoStartMechanism, fixedDatastore, LOCALISER, nontxConnectionFactoryName, omfContext, persistenceHandler, readOnlyDatastore, readOnlyDatastoreAction, schemaHandler, starter, starterInitialised, storeDataMgr, storeManagerKey, storeManagerRuntime, txConnectionFactoryName, valueGenerationMgr

Constructor Summary

NeoDatisManager(org.datanucleus.ClassLoaderResolver clr, org.datanucleus.OMFContext omfContext)
Constructor for a new NeoDatis StoreManager.

Method Summary

void	close() Release of resources
void	deregisterODB(org.neodatis.odb.ODB odb) Method to deregister an ODB from this store.
java.util.Date	getDatastoreDate() Get the date/time of the datastore.
org.datanucleus.store.Extent	getExtent(org.datanucleus.ObjectManager om, java.lang.Class c, boolean subclasses) Accessor for an Extent for a class.
org.datanucleus.store.NucleusConnection	getNucleusConnection(org.datanucleus.ObjectManager om) Method to return a DataNucleus Connection for the ObjectManager.
java.lang.Object	getObjectIdForObject(org.datanucleus.ObjectManager om, java.lang.Object pc) Convenience method to get the identity for a Persistable object.
java.util.Collection	getSupportedOptions() Accessor for the supported options in string form
boolean	isStrategyDatastoreAttributed(org.datanucleus.metadata.IdentityStrategy identityStrategy, boolean datastoreIdentityField) Check if the strategy is attributed by the database when the PersistenceCapable object is inserted into the database.
void	notifyObjectIsOutdated(org.datanucleus.StateManager sm) Hook for the StateManager to notify us that an object is outdated (no longer valid).
void	registerODB(org.neodatis.odb.ODB odb) Method to register an ODB as active on this store.
protected void	registerStoreData(org.datanucleus.store.StoreData data) Method to register some data with the store.

Methods inherited from class org.datanucleus.store.AbstractStoreManager

addClass, addClasses, assertReadOnlyForUpdateOfObject, clearAutoStarter, deregisterAllStoreData, getApiAdapter, getAutoStartMechanism, getBackingStoreForField, getClassNameForObjectID, getConnection, getConnection, getConnection, getMetaDataManager, getNucleusSequence, getOMFContext, getPersistenceHandler, getPropertiesForGenerator, getRuntimeManager, getSchemaHandler, getStoreManagerKey, getStrategyForNative, getStrategyValue, getStrategyValueForGenerator, getSubClassesForClass, getValueGenerationManager, initialiseAutoStart, logConfiguration, manageClassForIdentity, managesClass, newStoreData, performVersionCheck, printInformation, removeAllClasses, supportsQueryLanguage, supportsValueStrategy

Methods inherited from class java.lang.Object

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

Field Detail

LOCALISER_NEODATIS

protected static final org.datanucleus.util.Localiser LOCALISER_NEODATIS

Localiser for messages.

Constructor Detail

NeoDatisManager

public NeoDatisManager(org.datanucleus.ClassLoaderResolver clr,
                       org.datanucleus.OMFContext omfContext)

Constructor for a new NeoDatis StoreManager. Stores the basic information required for the datastore management.

Parameters:

clr - the ClassLoaderResolver

omfContext - The corresponding ObjectManagerFactory omfContext.

Method Detail

close

public void close()

Release of resources

Specified by:

close in interface org.datanucleus.store.StoreManager

Overrides:

close in class org.datanucleus.store.AbstractStoreManager

getDatastoreDate

public java.util.Date getDatastoreDate()

Get the date/time of the datastore.

Specified by:

getDatastoreDate in interface org.datanucleus.store.StoreManager

Specified by:

getDatastoreDate in class org.datanucleus.store.AbstractStoreManager

Returns:

Date/time of the datastore

getNucleusConnection

public org.datanucleus.store.NucleusConnection getNucleusConnection(org.datanucleus.ObjectManager om)

Method to return a DataNucleus Connection for the ObjectManager.

Specified by:

getNucleusConnection in interface org.datanucleus.store.StoreManager

Specified by:

getNucleusConnection in class org.datanucleus.store.AbstractStoreManager

Parameters:

om - ObjectManager

Returns:

The DataNucleusConnection

registerStoreData

protected void registerStoreData(org.datanucleus.store.StoreData data)

Method to register some data with the store. This will also register the data with the starter process.

Overrides:

registerStoreData in class org.datanucleus.store.AbstractStoreManager

Parameters:

data - The StoreData to add

registerODB

public void registerODB(org.neodatis.odb.ODB odb)

Method to register an ODB as active on this store. Will load up all known class mapping information into the datastore container.

Parameters:

odb - ODB

deregisterODB

public void deregisterODB(org.neodatis.odb.ODB odb)

Method to deregister an ODB from this store. ODB are deregistered when about to be closed and hence not interested in more class mapping information.

Parameters:

odb - ODB

notifyObjectIsOutdated

public void notifyObjectIsOutdated(org.datanucleus.StateManager sm)

Hook for the StateManager to notify us that an object is outdated (no longer valid). With NeoDatis we have no activate/deactivate mechanism so we do nothing.

Specified by:

notifyObjectIsOutdated in interface org.datanucleus.store.StoreManager

Overrides:

notifyObjectIsOutdated in class org.datanucleus.store.AbstractStoreManager

Parameters:

sm - StateManager of object

isStrategyDatastoreAttributed

public boolean isStrategyDatastoreAttributed(org.datanucleus.metadata.IdentityStrategy identityStrategy,
                                             boolean datastoreIdentityField)

Check if the strategy is attributed by the database when the PersistenceCapable object is inserted into the database. "datastore-identity" cases will be datastore attributed (since we can't store the id anywhere). "application-identity" cases will be datastore attributed if using "IDENTITY" strategy.

Specified by:

isStrategyDatastoreAttributed in interface org.datanucleus.store.StoreManager

Overrides:

isStrategyDatastoreAttributed in class org.datanucleus.store.AbstractStoreManager

Parameters:

identityStrategy - the identityStrategy

datastoreIdentityField - Whether this is for the surrogate datastore identity field

Returns:

if the object for the strategy is attributed by the database

getObjectIdForObject

public java.lang.Object getObjectIdForObject(org.datanucleus.ObjectManager om,
                                             java.lang.Object pc)

Convenience method to get the identity for a Persistable object.

Parameters:

om - The Object Manager

pc - The object

Returns:

The identity

getExtent

public org.datanucleus.store.Extent getExtent(org.datanucleus.ObjectManager om,
                                              java.lang.Class c,
                                              boolean subclasses)

Accessor for an Extent for a class.

Specified by:

getExtent in interface org.datanucleus.store.StoreManager

Specified by:

getExtent in class org.datanucleus.store.AbstractStoreManager

Parameters:

om - The Object Manager

c - The class requiring the Extent

subclasses - Whether to include subclasses of 'c'

Returns:

The Extent.

getSupportedOptions

public java.util.Collection getSupportedOptions()

Accessor for the supported options in string form

Specified by:

getSupportedOptions in interface org.datanucleus.store.StoreManager

Overrides:

getSupportedOptions in class org.datanucleus.store.AbstractStoreManager