org.apache.cayenne.access
Class ObjectStore

java.lang.Object
  org.apache.cayenne.access.ObjectStore

All Implemented Interfaces:

java.io.Serializable, java.util.EventListener, SnapshotEventListener, GraphChangeHandler, GraphManager

public class ObjectStore
extends java.lang.Object
implements java.io.Serializable, SnapshotEventListener, GraphManager

ObjectStore stores objects using their ObjectId as a key. It works as a dedicated object cache for a DataContext. Users rarely need to access ObjectStore directly, as DataContext serves as a facade, providing cover methods for most ObjectStore operations.

Since:

1.0

Author:

Andrus Adamchik

See Also:

Serialized Form

Field Summary

protected java.util.Map	changes
protected DataContext	context The DataContext that owns this ObjectStore.
protected DataRowStore	dataRowCache Stores a reference to the DataRowStore.
protected java.util.Map	newObjectsMap
protected java.util.Map	objectMap
protected java.util.Map	queryResultMap

Constructor Summary

ObjectStore()

ObjectStore(DataRowStore dataRowCache)

Method Summary

void	addObject(DataObject object) Deprecated. since 1.2 as a different change tracking algorithm is used.
void	arcCreated(java.lang.Object nodeId, java.lang.Object targetNodeId, java.lang.Object arcId) Does nothing.
void	arcDeleted(java.lang.Object nodeId, java.lang.Object targetNodeId, java.lang.Object arcId) Does nothing.
int	cachedQueriesCount() Returns a number of query results cached by this object store.
void	cacheQueryResult(java.lang.String name, java.util.List results) Caches a list of query results.
java.util.List	getCachedQueryResult(java.lang.String name) Returns cached query results for a given query, or null if no results are cached.
DataRow	getCachedSnapshot(ObjectId oid) Returns a snapshot for ObjectId from the underlying snapshot cache.
DataContext	getContext()
DataRowStore	getDataRowCache() Returns a DataRowStore associated with this ObjectStore.
java.lang.Object	getNode(java.lang.Object nodeId) Returns a registered DataObject or null of no object exists for the ObjectId.
DataObject	getObject(ObjectId id) Deprecated. since 1.2 a GraphManager getNode(Object) method should be used.
java.util.Iterator	getObjectIterator() Returns an iterator over the registered objects.
java.util.List	getObjects() Deprecated. since 1.2 use GraphManager method registeredNodes().
DataRow	getSnapshot(ObjectId oid) Returns a snapshot for ObjectId from the underlying snapshot cache.
DataRow	getSnapshot(ObjectId oid, QueryEngine engine) Deprecated. since 1.2. Use getSnapshot(ObjectId) instead.
void	graphCommitAborted() Does nothing.
void	graphCommitStarted() Does nothing.
void	graphCommitted() Does nothing.
void	graphRolledback() Does nothing.
boolean	hasChanges() Returns true if there are any modified, deleted or new objects registered with this ObjectStore, false otherwise.
void	nodeCreated(java.lang.Object nodeId) Does nothing.
void	nodeIdChanged(java.lang.Object nodeId, java.lang.Object newId) Does nothing.
void	nodePropertyChanged(java.lang.Object nodeId, java.lang.String property, java.lang.Object oldValue, java.lang.Object newValue) Does nothing.
void	nodeRemoved(java.lang.Object nodeId) Does nothing.
void	objectRelationshipSet(DataObject source, DataObject target, ObjRelationship relationship, boolean processFlattened) Deprecated. since 1.2 use recordArcCreated(Persistent, ObjectId, String).
void	objectRelationshipUnset(DataObject source, DataObject target, ObjRelationship relationship, boolean processFlattened) Deprecated. since 1.2 use recordArcDeleted(Persistent, ObjectId, String).
void	objectsCommitted() Deprecated. since 1.2 unused.
java.util.List	objectsInState(int state) Return a subset of registered objects that are in a certian persistence state.
void	objectsInvalidated(java.util.Collection objects) Invalidates a collection of DataObjects.
void	objectsRolledBack() Reverts changes to all stored uncomitted objects.
void	objectsUnregistered(java.util.Collection objects) Evicts a collection of DataObjects from the ObjectStore, invalidates the underlying cache snapshots.
void	recordArcCreated(Persistent object, ObjectId targetId, java.lang.String relationshipName) Performs tracking of object relationship changes.
void	recordArcDeleted(Persistent object, ObjectId targetId, java.lang.String relationshipName) Performs tracking of object relationship changes.
java.util.Collection	registeredNodes() Returns all registered DataObjects.
int	registeredObjectsCount() Returns a number of objects currently registered with this ObjectStore.
void	registerNode(java.lang.Object nodeId, java.lang.Object nodeObject) "Registers" a graph node, usually striong the node in some internal map using its id as a key.
void	resolveHollow(DataObject object) Initializes object with data from cache or from the database, if this object is not fully resolved.
void	setContext(DataContext context)
void	setDataRowCache(DataRowStore dataRowCache) Sets parent DataRowStore.
void	snapshotsChanged(SnapshotEvent event) SnapshotEventListener implementation that processes snapshot change event, updating DataObjects that have the changes.
void	snapshotsUpdatedForObjects(java.util.List objects, java.util.List snapshots, boolean refresh) Updates snapshots in the underlying DataRowStore.
void	startTrackingNewObjects() Starts tracking the registration of new objects from this ObjectStore.
void	unregisterNewObjects() Unregisters the newly registered DataObjects from this objectStore.
java.lang.Object	unregisterNode(java.lang.Object nodeId) "Unregisters" a graph node, forgetting any information associated with nodeId.
void	validateUncommittedObjects() Deprecated. since 1.2 - This method is no longer used in Cayenne internally.

Methods inherited from class java.lang.Object

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

Field Detail

newObjectsMap

protected transient java.util.Map newObjectsMap

objectMap

protected java.util.Map objectMap

queryResultMap

protected java.util.Map queryResultMap

changes

protected java.util.Map changes

dataRowCache

protected transient DataRowStore dataRowCache

Stores a reference to the DataRowStore.

Serialization note: It is up to the owner of this ObjectStore to initialize DataRowStore after deserialization of this object. ObjectStore will not know how to restore the DataRowStore by itself.

context

protected DataContext context

The DataContext that owns this ObjectStore.

Constructor Detail

ObjectStore

public ObjectStore()

ObjectStore

public ObjectStore(DataRowStore dataRowCache)

Method Detail

recordArcCreated

public void recordArcCreated(Persistent object,
                             ObjectId targetId,
                             java.lang.String relationshipName)

Performs tracking of object relationship changes.

Since:

1.2

recordArcDeleted

public void recordArcDeleted(Persistent object,
                             ObjectId targetId,
                             java.lang.String relationshipName)

Performs tracking of object relationship changes.

Since:

1.2

registeredObjectsCount

public int registeredObjectsCount()

Returns a number of objects currently registered with this ObjectStore.

Since:

1.2

cachedQueriesCount

public int cachedQueriesCount()

Returns a number of query results cached by this object store. Note that each result is a list and can possibly contain a large number of entries.

Since:

1.2

getDataRowCache

public DataRowStore getDataRowCache()

Returns a DataRowStore associated with this ObjectStore.

setDataRowCache

public void setDataRowCache(DataRowStore dataRowCache)

Sets parent DataRowStore. Registers to receive SnapshotEvents if the cache is configured to allow ObjectStores to receive such events.

objectsInvalidated

public void objectsInvalidated(java.util.Collection objects)

Invalidates a collection of DataObjects. Changes objects state to HOLLOW.

See Also:

objectsUnregistered(Collection)

objectsUnregistered

public void objectsUnregistered(java.util.Collection objects)

Evicts a collection of DataObjects from the ObjectStore, invalidates the underlying cache snapshots. Changes objects state to TRANSIENT. This method can be used for manual cleanup of Cayenne cache.

See Also:

objectsInvalidated(Collection)

objectsRolledBack

public void objectsRolledBack()

Reverts changes to all stored uncomitted objects.

Since:

1.1

objectRelationshipUnset

public void objectRelationshipUnset(DataObject source,
                                    DataObject target,
                                    ObjRelationship relationship,
                                    boolean processFlattened)

Deprecated. since 1.2 use recordArcDeleted(Persistent, ObjectId, String).

Performs tracking of object relationship changes.

Since:

1.1

objectRelationshipSet

public void objectRelationshipSet(DataObject source,
                                  DataObject target,
                                  ObjRelationship relationship,
                                  boolean processFlattened)

Deprecated. since 1.2 use recordArcCreated(Persistent, ObjectId, String).

Performs tracking of object relationship changes.

Since:

1.1

snapshotsUpdatedForObjects

public void snapshotsUpdatedForObjects(java.util.List objects,
                                       java.util.List snapshots,
                                       boolean refresh)

Updates snapshots in the underlying DataRowStore. If refresh is true, all snapshots in snapshots will be loaded into DataRowStore, regardless of the existing cache state. If refresh is false, only missing snapshots are loaded. This method is normally called internally by the DataContext owning the ObjectStore to update the caches after a select query.

Parameters:

objects - a list of object whose snapshots need to be updated.

snapshots - a list of snapshots. Must be of the same length and use the same order as objects list.

refresh - controls whether existing cached snapshots should be replaced with the new ones.

Since:

1.1

objectsCommitted

public void objectsCommitted()

Deprecated. since 1.2 unused.

Processes internal objects after the parent DataContext was committed. Changes object persistence state and handles snapshot updates.

Since:

1.1

addObject

public void addObject(DataObject object)

Deprecated. since 1.2 as a different change tracking algorithm is used.

Adds a new object to the ObjectStore.

startTrackingNewObjects

public void startTrackingNewObjects()

Starts tracking the registration of new objects from this ObjectStore. Used in conjunction with unregisterNewObjects() to control garbage collection when an instance of ObjectStore is used over a longer time for batch processing.

See Also:

unregisterNewObjects()

unregisterNewObjects

public void unregisterNewObjects()

Unregisters the newly registered DataObjects from this objectStore. Used in conjunction with startTrackingNewObjects() to control garbage collection when an instance of ObjectStore is used over a longer time for batch processing.

See Also:

startTrackingNewObjects()

getObject

public DataObject getObject(ObjectId id)

Deprecated. since 1.2 a GraphManager getNode(Object) method should be used.

Returns a DataObject registered for a given ObjectId, or null if no such object exists. This method does not do a database fetch.

getCachedSnapshot

public DataRow getCachedSnapshot(ObjectId oid)

Returns a snapshot for ObjectId from the underlying snapshot cache. If cache contains no snapshot, a null is returned.

Since:

1.1

getCachedQueryResult

public java.util.List getCachedQueryResult(java.lang.String name)

Returns cached query results for a given query, or null if no results are cached. Note that ObjectStore will only lookup results in its local cache, and not the shared cache associated with the underlying DataRowStore.

Since:

1.1

cacheQueryResult

public void cacheQueryResult(java.lang.String name,
                             java.util.List results)

Caches a list of query results.

Since:

1.1

getSnapshot

public DataRow getSnapshot(ObjectId oid,
                           QueryEngine engine)

Deprecated. since 1.2. Use getSnapshot(ObjectId) instead.

Returns a snapshot for ObjectId from the underlying snapshot cache. If cache contains no snapshot, it will attempt fetching it using provided QueryEngine. If fetch attempt fails or inconsistent data is returned, underlying cache will throw a CayenneRuntimeException.

Since:

1.1

getSnapshot

public DataRow getSnapshot(ObjectId oid)

Returns a snapshot for ObjectId from the underlying snapshot cache. If cache contains no snapshot, it will attempt fetching it using provided QueryEngine. If fetch attempt fails or inconsistent data is returned, underlying cache will throw a CayenneRuntimeException.

Since:

1.2

getObjects

public java.util.List getObjects()

Deprecated. since 1.2 use GraphManager method registeredNodes().

Returns a list of objects that are registered with this DataContext, regardless of their persistence state. List is returned by copy and can be modified by the caller.

getObjectIterator

public java.util.Iterator getObjectIterator()

Returns an iterator over the registered objects.

hasChanges

public boolean hasChanges()

Returns true if there are any modified, deleted or new objects registered with this ObjectStore, false otherwise. This method will treat "phantom" modifications are real ones. I.e. if you "change" an object property to an equivalent value, this method will still think such object is modified. Phantom modifications are only detected and discarded during commit.

objectsInState

public java.util.List objectsInState(int state)

Return a subset of registered objects that are in a certian persistence state. Collection is returned by copy.

snapshotsChanged

public void snapshotsChanged(SnapshotEvent event)

SnapshotEventListener implementation that processes snapshot change event, updating DataObjects that have the changes.

Implementation note: This method should not attempt to alter the underlying DataRowStore, since it is normally invoked *AFTER* the DataRowStore was modified as a result of some external interaction.

Specified by:

snapshotsChanged in interface SnapshotEventListener

Since:

1.1

validateUncommittedObjects

public void validateUncommittedObjects()
                                throws ValidationException

Deprecated. since 1.2 - This method is no longer used in Cayenne internally.

Performs validation of all uncommitted objects in the ObjectStore. If validation fails, a ValidationException is thrown, listing all encountered failures. This is a utility method for the users to call. Cayenne itself uses a different mechanism to validate objects on commit.

Throws:

ValidationException

Since:

1.1

resolveHollow

public void resolveHollow(DataObject object)

Initializes object with data from cache or from the database, if this object is not fully resolved.

Since:

1.1

getContext

public DataContext getContext()

Since:

1.2

setContext

public void setContext(DataContext context)

Since:

1.2

getNode

public java.lang.Object getNode(java.lang.Object nodeId)

Returns a registered DataObject or null of no object exists for the ObjectId.

Specified by:

getNode in interface GraphManager

Since:

1.2

registeredNodes

public java.util.Collection registeredNodes()

Returns all registered DataObjects. List is returned by copy and can be modified by the caller.

Specified by:

registeredNodes in interface GraphManager

Since:

1.2

registerNode

public void registerNode(java.lang.Object nodeId,
                         java.lang.Object nodeObject)

Description copied from interface: GraphManager

"Registers" a graph node, usually striong the node in some internal map using its id as a key.

Specified by:

registerNode in interface GraphManager

Since:

1.2

unregisterNode

public java.lang.Object unregisterNode(java.lang.Object nodeId)

Description copied from interface: GraphManager

"Unregisters" a graph node, forgetting any information associated with nodeId.

Specified by:

unregisterNode in interface GraphManager

Since:

1.2

graphCommitAborted

public void graphCommitAborted()

Does nothing.

Since:

1.2

graphCommitStarted

public void graphCommitStarted()

Does nothing.

Since:

1.2

graphCommitted

public void graphCommitted()

Does nothing.

Since:

1.2

graphRolledback

public void graphRolledback()

Does nothing.

Since:

1.2

nodeIdChanged

public void nodeIdChanged(java.lang.Object nodeId,
                          java.lang.Object newId)

Does nothing.

Specified by:

nodeIdChanged in interface GraphChangeHandler

Since:

1.2

nodeCreated

public void nodeCreated(java.lang.Object nodeId)

Does nothing.

Specified by:

nodeCreated in interface GraphChangeHandler

Since:

1.2

nodeRemoved

public void nodeRemoved(java.lang.Object nodeId)

Does nothing.

Specified by:

nodeRemoved in interface GraphChangeHandler

Since:

1.2

nodePropertyChanged

public void nodePropertyChanged(java.lang.Object nodeId,
                                java.lang.String property,
                                java.lang.Object oldValue,
                                java.lang.Object newValue)

Does nothing.

Specified by:

nodePropertyChanged in interface GraphChangeHandler

Since:

1.2

arcCreated

public void arcCreated(java.lang.Object nodeId,
                       java.lang.Object targetNodeId,
                       java.lang.Object arcId)

Does nothing.

Specified by:

arcCreated in interface GraphChangeHandler

Since:

1.2

arcDeleted

public void arcDeleted(java.lang.Object nodeId,
                       java.lang.Object targetNodeId,
                       java.lang.Object arcId)

Does nothing.

Specified by:

arcDeleted in interface GraphChangeHandler

Since:

1.2