Package es.bsc.dataclay.storagelocation

Class StorageLocationService

java.lang.Object

es.bsc.dataclay.storagelocation.StorageLocationService

public final class StorageLocationService
extends Object

This class is responsible to manage data of the objects stored in the system.

Constructor Summary

Constructors

Constructor	Description
StorageLocationService(DBHandlerConf dbHandlerconf)	Constructor

Method Summary

Modifier and Type	Method	Description
void	associateExecutionEnvironment(ExecutionEnvironmentID executionEnvironmentID)	Associate execution environment id to this SL
void	closeDbHandler(ExecutionEnvironmentID eeID)	Close DbHandler
void	delete(ExecutionEnvironmentID eeID, ObjectID objectID)	Deletes and object from the database.
boolean	exists(ExecutionEnvironmentID eeID, ObjectID objectID)	Check if object exists in DB
boolean	exists(ObjectID objectID)	Check if the object exists in SL or in any EE memory associated to current SL
byte[]	get(ExecutionEnvironmentID eeID, ObjectID objectID)	Get from DB
Set<ExecutionEnvironmentID>	getAssociateExecutionEnvironments()	Get associated execution environments id to this SL
DBHandler	getDbHandler(ExecutionEnvironmentID eeID)	Get DbHandler.
int	getNumObjects()	Return number of objects in current SL and associated EEs
int	getNumReferencesTo(ObjectID objectID)	Return number of references pointing to object.
void	initialize(DataServiceRuntime theruntime, ExecutionEnvironmentID associatedEEID)	Initialize
void	shutDownGarbageCollector()	Shutdown storage location
void	store(ExecutionEnvironmentID eeID, ObjectID objectID, byte[] bytes)	Store the object.
void	update(ExecutionEnvironmentID eeID, ObjectID objectID, byte[] newbytes, boolean dirty)	Updates an object identified by the ID provided with the new values provided.
void	updateRefs(Map<ObjectID,Integer> updateCounterRefs)	Update counters of references.
void	vacuum(ExecutionEnvironmentID eeID)	Vacuum database.

Methods inherited from class java.lang.Object

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

Constructor Detail

StorageLocationService

public StorageLocationService(DBHandlerConf dbHandlerconf)

Constructor

Parameters:

dbHandlerconf - Configuration for the db handler

Method Detail

initialize

public void initialize(DataServiceRuntime theruntime,
                       ExecutionEnvironmentID associatedEEID)

Initialize

Parameters:

theruntime - Runtime to be used in Storage Location.

associatedEEID - Associated EE ID.

store

public void store(ExecutionEnvironmentID eeID,
                  ObjectID objectID,
                  byte[] bytes)

Store the object.

Parameters:

eeID - ID of the EE triggering the call

objectID - ID of the object

bytes - Bytes of the object

get

public byte[] get(ExecutionEnvironmentID eeID,
                  ObjectID objectID)

Get from DB

Parameters:

eeID - ID of the EE triggering the call

objectID - ID of the object

Returns:

Bytes of object

exists

public boolean exists(ExecutionEnvironmentID eeID,
                      ObjectID objectID)

Check if object exists in DB

Parameters:

eeID - ID of the EE triggering the call

objectID - ID of the object

Returns:

TRUE if object exists. FALSE otherwise.

update

public void update(ExecutionEnvironmentID eeID,
                   ObjectID objectID,
                   byte[] newbytes,
                   boolean dirty)

Updates an object identified by the ID provided with the new values provided.

Parameters:

eeID - ID of the EE triggering the call

objectID - ID of the object.

newbytes - New byte values

dirty - Indicates object has been modified. If false, it means that bytes only contains reference counting information. DESIGN NOTE: in order to be able to find out which references where removed in complex objects (arrays, collections) GlobalGc decreases all pointed references in a Get procedure and increase them again (except removed ones) during update. While in EE, objects have memory references so they cannot be removed neither.

delete

public void delete(ExecutionEnvironmentID eeID,
                   ObjectID objectID)

Deletes and object from the database.

Parameters:

eeID - ID of the EE triggering the call

objectID - ID of the object to delete

vacuum

public void vacuum(ExecutionEnvironmentID eeID)

Vacuum database.

Parameters:

eeID - ID of the EE to vacuum

updateRefs

public void updateRefs(Map<ObjectID,Integer> updateCounterRefs)

Update counters of references.

Parameters:

updateCounterRefs - Update counter of references.

getDbHandler

public DBHandler getDbHandler(ExecutionEnvironmentID eeID)

Get DbHandler. Used for testing purposes.

Parameters:

eeID - ID of EE

Returns:

DbHandler.

associateExecutionEnvironment

public void associateExecutionEnvironment(ExecutionEnvironmentID executionEnvironmentID)

Associate execution environment id to this SL

Parameters:

executionEnvironmentID - ID to associate

getAssociateExecutionEnvironments

public Set<ExecutionEnvironmentID> getAssociateExecutionEnvironments()

Get associated execution environments id to this SL

Returns:

associated execution environments

closeDbHandler

public void closeDbHandler(ExecutionEnvironmentID eeID)

Close DbHandler

shutDownGarbageCollector

public void shutDownGarbageCollector()

Shutdown storage location

getNumReferencesTo

public int getNumReferencesTo(ObjectID objectID)

Return number of references pointing to object.

Parameters:

objectID - ID of object

Returns:

Number of references pointing to object

getNumObjects

public int getNumObjects()

Return number of objects in current SL and associated EEs

Returns:

Number of objects in current SL and associated EEs

exists

public boolean exists(ObjectID objectID)

Check if the object exists in SL or in any EE memory associated to current SL

Parameters:

objectID - ID of the object to check

Returns:

TRUE if the object either exists in SL disk or in EE memory.