org.planx.xmlstore.stores
Class LocalXMLStore

java.lang.Object
  org.planx.xmlstore.stores.AbstractXMLStore
      org.planx.xmlstore.stores.LocalXMLStore

All Implemented Interfaces:

XMLStore

Direct Known Subclasses:

WriteBufferXMLStore

public class LocalXMLStore
extends AbstractXMLStore

A local XMLStore that only operates on location dependent References, that is, LocalLocators. Thus, it is fast but unable to resolve ValueReferences. In order to do this, wrap the LocalXMLStore in a TranslatorXMLStore.

A LocalXMLStore will run a Sharer in the background that compacts redundant on-disk data and performs garbage collection.

Author:

Thomas Ambus

Field Summary

Fields inherited from class org.planx.xmlstore.stores.AbstractXMLStore

xmlstore

Constructor Summary

LocalXMLStore(String name)
Creates a new LocalXMLStore with the specified on-disk name.

LocalXMLStore(String name, RegionConfiguration conf)
Creates a new LocalXMLStore with the specified on-disk name.

Method Summary

void	addReferenceListener(ReferenceListener listener) Adds the specified ReferenceListener for receiving Reference events.
protected void	checkClosed()
void	close() The method is used to let the XMLStore properly commit all data to the underlying ressource, release resources, and so forth.
NameServer	getNameServer() Returns a NameServer for this store.
RegionManager	getRegionManager() Access to the RegionManager is provided merely for testing purposes and for accessing the managers statistics.
void	release(Reference ref) Informs the XMLStore that the data referenced by the specified Reference is no longer needed.
void	removeReferenceListener(ReferenceListener listener) Removes the specified ReferenceListener previously added with addReferenceListener.
protected Node	resolvedLoad(Reference vref) Only accepts LocalLocators.
void	retain(Reference ref) Informs the XMLStore that the data referenced by the specified Reference should be kept permanently.
Reference	save(Node node) Saves the specified Node and returns a LocalLocator to it.
long	size() Returns the disk size of this LocalXMLStore.
String	toString()

Methods inherited from class org.planx.xmlstore.stores.AbstractXMLStore

load

Methods inherited from class java.lang.Object

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

Constructor Detail

LocalXMLStore

public LocalXMLStore(String name)
              throws IOException

Creates a new LocalXMLStore with the specified on-disk name.

Parameters:

name - the on-disk file name to use as base for persistent data

Throws:

IOException - if an error occurred initializing the XMLStore using the specified name

LocalXMLStore

public LocalXMLStore(String name,
                     RegionConfiguration conf)
              throws IOException

Creates a new LocalXMLStore with the specified on-disk name.

Parameters:

name - the on-disk file name to use as base for persistent data

Throws:

IOException - if an error occurred initializing the XMLStore using the specified name

Method Detail

save

public Reference save(Node node)
               throws IOException

Saves the specified Node and returns a LocalLocator to it.

Specified by:

save in interface XMLStore

Overrides:

save in class AbstractXMLStore

Parameters:

node - representing XML data in the form of semi-structured tree data

Returns:

a reference to the saved node/tree

Throws:

IOException - if an error occurs during disk, network, etc access

resolvedLoad

protected Node resolvedLoad(Reference vref)
                     throws IOException,
                            UnknownReferenceException

Only accepts LocalLocators.

Overrides:

resolvedLoad in class AbstractXMLStore

Parameters:

vref - the resolved Reference

Throws:

IOException

UnknownReferenceException

getNameServer

public NameServer getNameServer()

Returns a NameServer for this store.

getRegionManager

public RegionManager getRegionManager()

Access to the RegionManager is provided merely for testing purposes and for accessing the managers statistics.

retain

public void retain(Reference ref)
            throws UnknownReferenceException

Informs the XMLStore that the data referenced by the specified Reference should be kept permanently. Implementations may assume that the Reference is one previously obtained from this XMLStore. When the data referenced is no longer needed the XMLStore should be informed of this be calling release(Reference).

Parameters:

ref - the Reference to retain

Throws:

UnknownReferenceException

release

public void release(Reference ref)
             throws UnknownReferenceException

Informs the XMLStore that the data referenced by the specified Reference is no longer needed. The XMLStore should previously have been informed to retain the data using the retain(Reference) method. More specifically, implementations may assume that the argument of this method, or one equal to it, has previously been an argument to retain.

Parameters:

ref - the Reference to release

Throws:

UnknownReferenceException

addReferenceListener

public void addReferenceListener(ReferenceListener listener)

Adds the specified ReferenceListener for receiving Reference events.

Parameters:

listener - the listener to add

removeReferenceListener

public void removeReferenceListener(ReferenceListener listener)

Removes the specified ReferenceListener previously added with addReferenceListener.

Parameters:

listener - the listener to remove

size

public long size()
          throws IOException

Returns the disk size of this LocalXMLStore.

Throws:

IOException

close

public void close()
           throws IOException

Description copied from interface: XMLStore

The method is used to let the XMLStore properly commit all data to the underlying ressource, release resources, and so forth. Once close has been issued on an XMLStore, the store is no longer available for handling requests. Any subsequent request to the store will result in an exception being thrown. An XMLStore implementation has to ensure that this happens.

Specified by:

close in interface XMLStore

Overrides:

close in class AbstractXMLStore

Throws:

IOException - if it is not possible to properly close the store

toString

public String toString()

Overrides:

toString in class AbstractXMLStore

checkClosed

protected void checkClosed()

Overrides:

checkClosed in class AbstractXMLStore