ERXDatabaseContextDelegate Class Reference

Collaboration diagram for ERXDatabaseContextDelegate:

[legend]

List of all members.

Classes
interface	AutoBatchFaultingEnterpriseObject
interface	BatchHandler
class	ObjectNotAvailableException
class	ReentranceProtector
Public Member Functions
ERXArrayFaultCache	arrayFaultCache ()
void	databaseContextDidFetchObjects (EODatabaseContext dbc, NSArray eos, EOFetchSpecification fs, EOEditingContext ec)
void	databaseContextDidSelectObjects (EODatabaseContext dc, EOFetchSpecification fs, EODatabaseChannel channel)
boolean	databaseContextFailedToFetchObject (EODatabaseContext context, Object object, EOGlobalID gid)
NSDictionary	databaseContextNewPrimaryKey (EODatabaseContext databaseContext, Object object, EOEntity entity)
boolean	databaseContextShouldFetchArrayFault (EODatabaseContext dbc, Object obj)
boolean	databaseContextShouldFetchObjectFault (EODatabaseContext dbc, Object obj)
NSArray	databaseContextShouldFetchObjects (EODatabaseContext dbc, EOFetchSpecification fs, EOEditingContext ec)
boolean	databaseContextShouldHandleDatabaseException (EODatabaseContext dbc, Exception e) throws Throwable
boolean	databaseContextShouldHandleDatabaseException (EODatabaseContext databaseContext, Throwable throwable)
NSArray	databaseContextWillPerformAdaptorOperations (EODatabaseContext dbCtxt, NSArray adaptorOps, EOAdaptorChannel adChannel)
ERXFetchResultCache	fetchResultCache ()
void	setArrayFaultCache (ERXArrayFaultCache value)
void	setBatchHandler (BatchHandler handler)
void	setFetchResultCache (ERXFetchResultCache value)
Static Public Member Functions
static int	autoBatchFetchSize ()
static ERXDatabaseContextDelegate	defaultDelegate ()
static void	setCurrentBatchObjects (NSArray arr)
static void	setDefaultDelegate (ERXDatabaseContextDelegate delegate)
Static Public Attributes
static int	autoBatchFetchSize = -1
static final Logger	batchLog = Logger.getLogger("er.transaction.adaptor.Batching")
static final String	DatabaseContextFailedToFetchObject = "DatabaseContextFailedToFetchObject"
static final Logger	dbLog = Logger.getLogger("er.transaction.adaptor.FaultFiring")
static final Logger	exLog = Logger.getLogger("er.transaction.adaptor.Exceptions")
static final Logger	log = Logger.getLogger(ERXDatabaseContextDelegate.class)
static final String	THREAD_KEY = "ERXBatching"
Private Member Functions
boolean	batchFetchToManyFault (EODatabaseContext dbc, Object obj)
synchronized boolean	batchFetchToOneFault (EODatabaseContext dbc, AutoBatchFaultingEnterpriseObject eo)
void	doFetch (EODatabaseContext dbc, EOEditingContext ec, EORelationship relationship, NSArray eos)
void	freshenFetchTimestamps (NSArray eos, long timestamp)
void	markEnd (String type, EOEnterpriseObject eo, String key)
void	markStart (String type, EOEnterpriseObject eo, String key)
Private Attributes
ERXArrayFaultCache	_arrayFaultCache = null
ERXFetchResultCache	_fetchResultCache = null
BatchHandler	_handler = DEFAULT
BatchHandler	DEFAULT
ReentranceProtector	fetchingToMany = new ReentranceProtector()
ReentranceProtector	fetchingToOne = new ReentranceProtector()
ReentranceProtector	reportingError = new ReentranceProtector()
Static Private Attributes
static ERXDatabaseContextDelegate	_defaultDelegate = new ERXDatabaseContextDelegate()

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Detailed Description

This delegate implements several methods from the formal interface EODatabaseContext.Delegate. Of special note this class adds the ability for enterprise objects to generate their own primary keys, correctly throws an exception when a toOne relationship object is not found in the database and adds debugging abilities to tracking down when faults are fired. It also supports a cache for array fault that is checked before they are fetched from the database.

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Member Function Documentation

ERXArrayFaultCache arrayFaultCache

(

)

static int autoBatchFetchSize

(

)

[static]

Returns the batch size for automatic batch faulting from the System property er.extensions.ERXDatabaseContextDelegate.autoBatchFetchSize. Default is 0, meaning it's disabled.

Returns:

batch size

boolean batchFetchToManyFault	(	EODatabaseContext	dbc,
		Object	obj
	)			[private]

Fetches the to-many fault and the faults of all other objects in the EC that have the same relationship, the fetch timestamp and the same class description.

Parameters:

	dbc	database context
	obj	to-many fault

Returns:

true if it's still a fault.

synchronized boolean batchFetchToOneFault	(	EODatabaseContext	dbc,
		AutoBatchFaultingEnterpriseObject	eo
	)			[private]

Fetches the to-one fault and the faults of all other objects in the EC that have the same relationship, the fetch timestamp and the same class description.

Parameters:

	dbc	database context
	obj	to-one fault

Returns:

true if it's still a fault.

void databaseContextDidFetchObjects	(	EODatabaseContext	dbc,
		NSArray	eos,
		EOFetchSpecification	fs,
		EOEditingContext	ec
	)

Sets the cache entry for the fetched objects and refreshes the timestamps for fetched objects if batch faulting is enabled.

Parameters:

	dbc
	eos
	fs
	ec

void databaseContextDidSelectObjects	(	EODatabaseContext	dc,
		EOFetchSpecification	fs,
		EODatabaseChannel	channel
	)

This delegate method is called every time a fault is fired that needs to go to the database. All we have added is logging statement of the debug priority. This way during runtime a developer can toggle the logger priority settting on and off to see what faults are firing. Also note that when using ERXPatternLayout one can set the option to see full backtraces to the calling method. With this option specified a developer can see exactly which methods are firing faults.

Parameters:

	dc	the databasecontext
	fs	the fetchspecification
	channel	the databasechannel

boolean databaseContextFailedToFetchObject	(	EODatabaseContext	context,
		Object	object,
		EOGlobalID	gid
	)

This is Kelly Hawks' fix for the missing to one relationship. Delegate on EODatabaseContext that gets called when a to-one fault cannot find its data in the database. The object that is returned is a cleared fault. We raise here to restore the functionality that existed prior to WebObjects 4.5. Whenever a fault fails for a globalID (i.e. the object is NOT found in the database), we raise an EOObjectNotAvailableException.
If you have entities you don't really care about, you can set the system property er.extensions.ERXDatabaseContextDelegate.tolerantEntityPattern to a regular expression that will be tested against the GID entity name. If it matches, then only an error will be logged but no exception will be thrown.

Parameters:

	context	database context
	object	object that is firing the fault for a given to-one relationship
	gid	global id that wasn't found in the database.

NSDictionary databaseContextNewPrimaryKey	(	EODatabaseContext	databaseContext,
		Object	object,
		EOEntity	entity
	)

Provides the ability for new enterprise objects that implement the interface ERXGeneratesPrimaryKeyInterface to provide their own primary key dictionary. If the enterprise object implements the above interface then the method primaryKeyDictionary(true) will be called on the object. If the object returns null then a primary key will be generated for the object in the usual fashion.

Parameters:

	databaseContext	databasecontext
	object	the new enterprise object
	entity	the entity of the object

Returns:

primary key dictionary to be used or null if a primary key should be generated for the object.

boolean databaseContextShouldFetchArrayFault	(	EODatabaseContext	dbc,
		Object	obj
	)

This delegate method first checks the arrayFaultCache if it is set before trying to resolve the fault from the DB. It can be a severe performance optimization depending on your setup. Also, it support batch fetching of to-many relationships of EOs that were fetched at the "same" time.

Parameters:

	dbc
	obj

boolean databaseContextShouldFetchObjectFault	(	EODatabaseContext	dbc,
		Object	obj
	)

Batch fetches to one relationships if enabled.

Parameters:

	dbc
	obj

Returns:

true if the fault should get fetched

NSArray databaseContextShouldFetchObjects	(	EODatabaseContext	dbc,
		EOFetchSpecification	fs,
		EOEditingContext	ec
	)

Returns an array of already fetched objects or null if they were not already fetched.

Parameters:

	dbc
	fs
	ec

boolean databaseContextShouldHandleDatabaseException	(	EODatabaseContext	dbc,
		Exception	e
	)			throws Throwable

Allows custom handling of dropped connection exceptions. This was needed in WebObjects 4.5 because the OracleEOAdaptor wouldn't correctly handle all exceptions of dropped connections. This may not be needed now.

Parameters:

	dbc	current database context
	e	throw exception

Returns:

if the exception is one of the bad ones that isn't handled then the method handleDroppedConnection is called directly on the database object of the context and false is returned otherwise true.

boolean databaseContextShouldHandleDatabaseException	(	EODatabaseContext	databaseContext,
		Throwable	throwable
	)

Provides for a hook to get at the original exceptions from the JDBC driver, as opposed to the cooked EOGeneralAdaptorException you get from EOF. To see the exceptions trace, set the logger er.transaction.adaptor.Exceptions to DEBUG.

Parameters:

	databaseContext
	throwable

NSArray databaseContextWillPerformAdaptorOperations	(	EODatabaseContext	dbCtxt,
		NSArray	adaptorOps,
		EOAdaptorChannel	adChannel
	)

Overridden to remove inserts and deletes of the "same" row. When you delete from a join table and then re-add the same object, then the order of operations would be insert, then delete and you will get an error because the delete would try to also delete the newly inserted row. Here we just check every insert and see if the deleted contains the same object. If they do, we just skip both operations,

Author:

chello team!

Parameters:

	dbCtxt
	adaptorOps
	adChannel

static ERXDatabaseContextDelegate defaultDelegate

(

)

[static]

Returns the singleton of the database context delegate

void doFetch	(	EODatabaseContext	dbc,
		EOEditingContext	ec,
		EORelationship	relationship,
		NSArray	eos
	)			[private]

ERXFetchResultCache fetchResultCache

(

)

void freshenFetchTimestamps	(	NSArray	eos,
		long	timestamp
	)			[private]

Refreshes the fetch timestamp for the fetched objects.

Parameters:

	eos
	ec

void markEnd	(	String	type,
		EOEnterpriseObject	eo,
		String	key
	)			[private]

void markStart	(	String	type,
		EOEnterpriseObject	eo,
		String	key
	)			[private]

void setArrayFaultCache

(

ERXArrayFaultCache

value

)

void setBatchHandler

(

BatchHandler

handler

)

Sets the batch handler.

Parameters:

handler

static void setCurrentBatchObjects

(

NSArray

arr

)

[static]

static void setDefaultDelegate

(

ERXDatabaseContextDelegate

delegate

)

[static]

Parameters:

delegate

- the singleton database context delegate to set

void setFetchResultCache

(

ERXFetchResultCache

value

)

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Member Data Documentation

ERXArrayFaultCache _arrayFaultCache = null [private]

ERXDatabaseContextDelegate _defaultDelegate = new ERXDatabaseContextDelegate() [static, private]

Holds onto the singleton of the default delegate

ERXFetchResultCache _fetchResultCache = null [private]

BatchHandler _handler = DEFAULT [private]

int autoBatchFetchSize = -1 [static]

Holds the auto batch fetch size.

final Logger batchLog = Logger.getLogger("er.transaction.adaptor.Batching") [static]

Faulting logging support, logging category: er.transaction.adaptor.Batching

final String DatabaseContextFailedToFetchObject = "DatabaseContextFailedToFetchObject" [static]

final Logger dbLog = Logger.getLogger("er.transaction.adaptor.FaultFiring") [static]

Faulting logging support, logging category: er.transaction.adaptor.FaultFiring

BatchHandler DEFAULT [private]

Initial value:

 new BatchHandler() {
                public int batchSizeForRelationship(EOEditingContext ec, EORelationship relationship) {
                        return autoBatchFetchSize();
                }
                
        }

final Logger exLog = Logger.getLogger("er.transaction.adaptor.Exceptions") [static]

Faulting logging support, logging category: er.transaction.adaptor.Exceptions

ReentranceProtector fetchingToMany = new ReentranceProtector() [private]

The delegate is not reentrant, so this marks whether we are already batch faulting a to-many relationship.

ReentranceProtector fetchingToOne = new ReentranceProtector() [private]

The delegate is not reentrant, so this marks whether we are already batch faulting a to-one relationship.

final Logger log = Logger.getLogger(ERXDatabaseContextDelegate.class) [static]

Basic logging support

ReentranceProtector reportingError = new ReentranceProtector() [private]

The delegate is not reentrant, so this marks whether we are already reporting an error (most probably due to a logging pattern)

final String THREAD_KEY = "ERXBatching" [static]

Batching thread key

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The documentation for this class was generated from the following file:

• /opt/source/Wonder/Frameworks/Core/ERExtensions/Sources/er/extensions/eof/ERXDatabaseContextDelegate.java