com.sun.sgs.impl.service.data.store
Class DataStoreProfileProducer

java.lang.Object
  com.sun.sgs.impl.service.data.store.DataStoreProfileProducer

All Implemented Interfaces:

DataStore, TransactionParticipant

public class DataStoreProfileProducer
extends Object
implements DataStore, TransactionParticipant

Implements a DataStore that reports profiling information about data store operations under the name "com.sun.sgs.impl.service.data.store.DataStore", implementing DataStore operations and transaction participant methods by delegating them to another data store.

Constructor Summary

DataStoreProfileProducer(DataStore dataStore, ProfileCollector collector)
Creates an instance that delegates all DataStore and TransactionParticipant methods to dataStore.

Method Summary

void	abort(Transaction txn) Tells the participant to abort its involvement with the given transaction.
void	commit(Transaction txn) Tells the participant to commit its state associated with the given transaction.
long	createObject(Transaction txn) Reserves an object ID for a new object.
long	getBinding(Transaction txn, String name) Obtains the object ID bound to a name.
int	getClassId(Transaction txn, byte[] classInfo) Returns the class ID to represent classes with the specified class information.
byte[]	getClassInfo(Transaction txn, int classId) Returns the class information associated with the specified class ID.
DataStore	getDataStore() Returns the DataStore that this instance delegates to.
long	getLocalNodeId() Returns the node ID for the local node.
byte[]	getObject(Transaction txn, long oid, boolean forUpdate) Obtains the data associated with an object ID.
String	getTypeName() Returns the fully qualified type name of the participant.
void	markForUpdate(Transaction txn, long oid) Notifies the DataStore that an object is going to be modified.
String	nextBoundName(Transaction txn, String name) Returns the next name after the specified name that has a binding, or null if there are no more bound names.
long	nextObjectId(Transaction txn, long oid) Returns the object ID for the next object after the object with the specified ID, or -1 if there are no more objects.
boolean	prepare(Transaction txn) Tells the participant to prepare for commiting its state associated with the given transaction.
void	prepareAndCommit(Transaction txn) Tells the participant to both prepare and commit its state associated with the given transaction.
void	ready() Notifies the data store that services associated with the application have been successfully created.
void	removeBinding(Transaction txn, String name) Removes the binding for a name.
void	removeObject(Transaction txn, long oid) Removes the object with the specified object ID.
void	setBinding(Transaction txn, String name, long oid) Binds an object ID to a name.
void	setBindingDescription(Transaction txn, String name, Object description) Associates a description with a bound name, for use in describing name accesses.
void	setObject(Transaction txn, long oid, byte[] data) Specifies data to associate with an object ID.
void	setObjectDescription(Transaction txn, long oid, Object description) Associates a description with an object ID, for use in describing object accesses.
void	setObjects(Transaction txn, long[] oids, byte[][] dataArray) Specifies data to associate with a series of object IDs.
void	shutdown() Shuts down this data store.
String	toString() Returns a string representation of this object.

Methods inherited from class java.lang.Object

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

Constructor Detail

DataStoreProfileProducer

public DataStoreProfileProducer(DataStore dataStore,
                                ProfileCollector collector)

Creates an instance that delegates all DataStore and TransactionParticipant methods to dataStore.

Parameters:

dataStore - the object for delegating operations

collector - the object for collecting profile data

Throws:

IllegalArgumentException - if dataStore does not implement TransactionParticipant

Method Detail

ready

public void ready()
           throws Exception

Notifies the data store that services associated with the application have been successfully created. If the method throws an exception, then the application should be shutdown.

Specified by:

ready in interface DataStore

Throws:

Exception - if an error occurs

getLocalNodeId

public long getLocalNodeId()

Returns the node ID for the local node.

Specified by:

getLocalNodeId in interface DataStore

Returns:

the node ID for the local node

createObject

public long createObject(Transaction txn)

Reserves an object ID for a new object. Note that calling other operations using this ID are not required to find the object until setObject or setObjects is called. Aborting a transaction is also not required to unassign the ID so long as other operations treat it as a non-existent object.

Specified by:

createObject in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

Returns:

the new object ID

markForUpdate

public void markForUpdate(Transaction txn,
                          long oid)

Notifies the DataStore that an object is going to be modified. The implementation can use this information to obtain an exclusive lock on the object in order to avoid contention when the object is modified. This method does nothing if the object does not exist.

Specified by:

markForUpdate in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oid - the object ID

getObject

public byte[] getObject(Transaction txn,
                        long oid,
                        boolean forUpdate)

Obtains the data associated with an object ID. If the forUpdate parameter is true, the caller is stating its intention to modify the object. The implementation can use that information to obtain an exclusive lock on the object in order avoid contention when the object is modified.

Specified by:

getObject in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oid - the object ID

forUpdate - whether the caller intends to modify the object

Returns:

the data associated with the object ID

setObject

public void setObject(Transaction txn,
                      long oid,
                      byte[] data)

Specifies data to associate with an object ID.

Specified by:

setObject in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oid - the object ID

data - the data

setObjects

public void setObjects(Transaction txn,
                       long[] oids,
                       byte[][] dataArray)

Specifies data to associate with a series of object IDs.

Specified by:

setObjects in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oids - the object IDs

dataArray - the associated data values

removeObject

public void removeObject(Transaction txn,
                         long oid)

Removes the object with the specified object ID. The implementation will make an effort to flag subsequent references to the removed object by throwing ObjectNotFoundException, although this behavior is not guaranteed. The implementation is not required to check that the object is an externally visible object rather than one used internally by the implementation.

Specified by:

removeObject in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oid - the object ID

getBinding

public long getBinding(Transaction txn,
                       String name)

Obtains the object ID bound to a name.

Specified by:

getBinding in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

name - the name

Returns:

the object ID

setBinding

public void setBinding(Transaction txn,
                       String name,
                       long oid)

Binds an object ID to a name.

Specified by:

setBinding in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

name - the name

oid - the object ID

removeBinding

public void removeBinding(Transaction txn,
                          String name)

Removes the binding for a name.

Specified by:

removeBinding in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

name - the name

nextBoundName

public String nextBoundName(Transaction txn,
                            String name)

Returns the next name after the specified name that has a binding, or null if there are no more bound names. If name is null, then the search starts at the beginning.

Specified by:

nextBoundName in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

name - the name to search after, or null to start at the beginning

Returns:

the next name with a binding following name, or null if there are no more bound names

shutdown

public void shutdown()

Shuts down this data store. This method will block until the shutdown is complete.

Specified by:

shutdown in interface DataStore

getClassId

public int getClassId(Transaction txn,
                      byte[] classInfo)

Returns the class ID to represent classes with the specified class information. Obtains an existing ID for the class information if present; otherwise, stores the information and returns the new ID associated with it. Class IDs are always greater than 0. The class information is the serialized form of the ObjectStreamClass instance that serialization uses to represent the class.

Specified by:

getClassId in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

classInfo - the class information

Returns:

the associated class ID

getClassInfo

public byte[] getClassInfo(Transaction txn,
                           int classId)
                    throws ClassInfoNotFoundException

Returns the class information associated with the specified class ID. The class information is the serialized form of the ObjectStreamClass instance that serialization uses to represent the class.

Specified by:

getClassInfo in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

classId - the class ID

Returns:

the associated class information

Throws:

ClassInfoNotFoundException - if the ID is not found

nextObjectId

public long nextObjectId(Transaction txn,
                         long oid)

Returns the object ID for the next object after the object with the specified ID, or -1 if there are no more objects. If objectId is -1, then returns the ID of the first object. The IDs returned by this method will not include ones for objects that have already been removed, and may not include identifiers for objects created after an iteration has begun. It is not an error for the object associated with the specified identifier to have already been removed.

Applications should not assume that objects associated with the IDs returned by this method, but which cannot be reached by traversing object field references starting with an object associated with a name binding, will continue to be retained by the data store.

Specified by:

nextObjectId in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oid - the identifier of the object to search after, or -1 to request the first object

Returns:

the identifier of the next object following the object with identifier oid, or -1 if there are no more objects

setBindingDescription

public void setBindingDescription(Transaction txn,
                                  String name,
                                  Object description)

Associates a description with a bound name, for use in describing name accesses. The description should provide a meaningful toString method.

Specified by:

setBindingDescription in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

name - the name

description - the description

See Also:

AccessReporter.setObjectDescription

setObjectDescription

public void setObjectDescription(Transaction txn,
                                 long oid,
                                 Object description)

Associates a description with an object ID, for use in describing object accesses. The description should provide a meaningful toString method.

Specified by:

setObjectDescription in interface DataStore

Parameters:

txn - the transaction under which the operation should take place

oid - the object ID

description - the description

See Also:

AccessReporter.setObjectDescription

prepare

public boolean prepare(Transaction txn)
                throws Exception

Tells the participant to prepare for commiting its state associated with the given transaction. This method returns a boolean flag stating whether the prepared state is read-only, meaning that no external state is modified by this participant. If this method returns true, then neither commit nor abort will be called.

If this method throws an exception, then the preparation failed, and the transaction will be aborted. If this method completes successfully, then the participant is required to be able to commit the transaction without failure.

Specified by:

prepare in interface TransactionParticipant

Parameters:

txn - the Transaction object

Returns:

true if this participant is read-only, false otherwise

Throws:

Exception - if there are any failures in preparing

IllegalStateException - if this participant has already been prepared, committed, or aborted, or if this participant is not participating in the given transaction

commit

public void commit(Transaction txn)

Tells the participant to commit its state associated with the given transaction.

Specified by:

commit in interface TransactionParticipant

Parameters:

txn - the Transaction object

prepareAndCommit

public void prepareAndCommit(Transaction txn)
                      throws Exception

Tells the participant to both prepare and commit its state associated with the given transaction.

Specified by:

prepareAndCommit in interface TransactionParticipant

Parameters:

txn - the Transaction object

Throws:

Exception - if there are any failures in preparing

IllegalStateException - if this participant has already been prepared, committed, or aborted, or if this participant is not participating in the given transaction

abort

public void abort(Transaction txn)

Tells the participant to abort its involvement with the given transaction.

Specified by:

abort in interface TransactionParticipant

Parameters:

txn - the Transaction object

getTypeName

public String getTypeName()

Returns the fully qualified type name of the participant. If this participant is acting as a proxy for a Service, this will typically be the Service's type name.

Specified by:

getTypeName in interface TransactionParticipant

Returns:

the name of the participant

toString

public String toString()

Returns a string representation of this object.

Overrides:

toString in class Object

Returns:

a string representation of this object

getDataStore

public DataStore getDataStore()

Returns the DataStore that this instance delegates to.

Returns:

the DataStore that this instance delegates to