Class StreamFileContainerHandle

java.lang.Object

org.apache.derby.impl.store.raw.data.StreamFileContainerHandle

All Implemented Interfaces:

DerbyObserver, StreamContainerHandle

final class StreamFileContainerHandle
extends Object
implements StreamContainerHandle, DerbyObserver

A handle to an open stream container, implememts StreamContainerHandle.

This class is an Observer to observe RawTransactions
MT - Mutable - Immutable identity - Thread Aware

Field Summary

Fields

Modifier and Type	Field	Description
protected boolean	active	Is this StreamContainerHandle active.
protected StreamFileContainer	container	The actual container we are accessing.
private boolean	hold	Whether this container should be held open across commit.
protected final ContainerKey	identity	Container identifier MT - Immutable
private final UUID	rawStoreId	Raw Store identifier MT - Immutable
protected RawTransaction	xact	our transaction.

Fields inherited from interface StreamContainerHandle

TEMPORARY_SEGMENT

Constructor Summary

Constructors

Constructor	Description
StreamFileContainerHandle(UUID rawStoreId, RawTransaction xact, ContainerKey identity, boolean hold)
StreamFileContainerHandle(UUID rawStoreId, RawTransaction xact, StreamFileContainer container, boolean hold)

Method Summary

Modifier and Type	Method	Description
void	close()	Close me.
boolean	fetchNext(DataValueDescriptor[] row)	fetch a row from the container.
void	getContainerProperties(Properties prop)	Request the system properties associated with a container.
ContainerKey	getId()	get the container key for the stream container
final RawTransaction	getTransaction()	Return the RawTransaction this object was opened in.
void	removeContainer()	remove the stream container
String	toString()
void	update(DerbyObservable obj, Object arg)	Called when the transaction is about to complete.
boolean	useContainer()	Attach me to a container.

Methods inherited from class Object

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

Field Details

rawStoreId

private final UUID rawStoreId

Raw Store identifier
MT - Immutable

identity

protected final ContainerKey identity

Container identifier
MT - Immutable

active

protected boolean active

Is this StreamContainerHandle active.
MT - Mutable : scoped

container

protected StreamFileContainer container

The actual container we are accessing. Only valid when active is true.
MT - Mutable : scoped

xact

protected RawTransaction xact

our transaction. Only valid when active is true.
MT - Mutable : scoped

hold

private boolean hold

Whether this container should be held open across commit. Only valid when active is true.
MT - Mutable : scoped

Constructor Details

StreamFileContainerHandle

public StreamFileContainerHandle(UUID rawStoreId,
 RawTransaction xact,
 ContainerKey identity,
 boolean hold)

StreamFileContainerHandle

public StreamFileContainerHandle(UUID rawStoreId,
 RawTransaction xact,
 StreamFileContainer container,
 boolean hold)

Method Details

getContainerProperties

public void getContainerProperties(Properties prop)
                            throws StandardException

Request the system properties associated with a container.

Specified by:

getContainerProperties in interface StreamContainerHandle

Parameters:

prop - Property list to fill in.

Throws:

StandardException - Standard exception policy.

See Also:

• StreamContainerHandle.getContainerProperties(Properties)

fetchNext

public boolean fetchNext(DataValueDescriptor[] row)
                  throws StandardException

fetch a row from the container.

Specified by:

fetchNext in interface StreamContainerHandle

Parameters:

row - Row to be filled in with information from the record.

Throws:

StandardException - Standard exception policy.

close

public void close()

Description copied from interface: StreamContainerHandle

Close me. After using this method the caller must throw away the reference to the Container object, e.g.

        ref.close();
        ref = null;

The container will be closed automatically at the commit or abort of the transaction if this method is not called explictly.

Specified by:

close in interface StreamContainerHandle

Throws:

StandardException - Standard exception policy.

See Also:

• StreamContainerHandle.close()

removeContainer

public void removeContainer()
                     throws StandardException

remove the stream container

Specified by:

removeContainer in interface StreamContainerHandle

Throws:

StandardException - Standard Derby error policy

See Also:

• StreamContainerHandle.removeContainer()

getId

public ContainerKey getId()

get the container key for the stream container

Specified by:

getId in interface StreamContainerHandle

update

public void update(DerbyObservable obj,
 Object arg)

Called when the transaction is about to complete.

Specified by:

update in interface DerbyObserver

Parameters:

obj - The object which is being observed

arg - Extra information being passed to the callback

See Also:

• DerbyObserver.update(DerbyObservable, Object)

useContainer

public boolean useContainer()
                     throws StandardException

Attach me to a container. If this method returns false then I cannot be used anymore, and any reference to me must be discarded.

Throws:

StandardException - Standard Derby error policy

getTransaction

public final RawTransaction getTransaction()

Return the RawTransaction this object was opened in.

toString

public String toString()

Overrides:

toString in class Object