wt.units.dbService
Class UnitCache

java.lang.Object
  java.rmi.server.RemoteObject
      java.rmi.server.RemoteServer
          wt.util.RMIServer
              wt.cache.CacheManager
                  wt.units.dbService.UnitCache

All Implemented Interfaces:

CacheServer, Remote, Serializable, Unreferenced

public class UnitCache

extends CacheManager

This class implements a IBA Units cache service. It follows the 2-level cache paradigm. Creation and updates to IBA Measurment Systems and QOMs must be communicated to the cache by the Services manager.

See Also:

Serialized Form

Field Summary

private static UnitCache	cache
private static int	CACHESIZE
private static HashMap	currentThreads
private static Object	dataLock
private static Object	flushLock
private static HashMap	measurementSystems
private static boolean	populated
private static HashMap	quantityOfMeasures
private static boolean	VERBOSE
private static String	versionID

Fields inherited from class wt.cache.CacheManager

MASTER

Fields inherited from class wt.util.RMIServer

csf, ssf

Fields inherited from class java.rmi.server.RemoteServer

Fields inherited from class java.rmi.server.RemoteObject

ref

Constructor Summary

UnitCache()
Do not directly invoke this constructor! Use getUnitCache instead.

Method Summary

private Object	aquireLock()
private void	blockOnLock()
protected void	clear()
int	getDefaultSize() Get desired size of this cache.
MeasurementSystem	getMeasurementSystem(String name)
String[]	getMeasurementSystemNames()
MeasurementSystem[]	getMeasurementSystems()
QuantityOfMeasure	getQuantityOfMeasure(String name)
String[]	getQuantityOfMeasureNames()
QuantityOfMeasure[]	getQuantityOfMeasures()
static UnitCache	getUnitCache() Contruct a new Unit cache.
void	populateCache()
void	Print()
void	putEntry(Object key, Object value) Overrides CacheManager.putEntry to do nothing so that no entries are added to the wt.util.Cache object contained in CacheManager.
private void	releaseLock(Object localLock)
protected void	removeEntry(Object target) Simply clear local cache when signalled.
void	reset() Method called when connection to master cache is broken and recovered indicating that a notification from another IBADefinition cache might have been missed.

Methods inherited from class wt.cache.CacheManager

checkAccess, get, getDefaultName, getEntry, isCacheHost, overflow, ping, put, putEntry, reference, registerSlave, remove, remove, removeEntry, unreferenced, update, updateEntry, updateEntry

Methods inherited from class wt.util.RMIServer

clone, exportObject, exportObject, exportObject, getClientSocketFactory, getPort, getServerSocketFactory, getStub, isHostInList, isLocalHost, setPort, writeReplace

Methods inherited from class java.rmi.server.RemoteServer

getClientHost, getLog, setLog

Methods inherited from class java.rmi.server.RemoteObject

equals, getRef, hashCode, toString, toStub

Methods inherited from class java.lang.Object

finalize, getClass, notify, notifyAll, wait, wait, wait

Field Detail

versionID

private static final String versionID

See Also:

Constant Field Values

dataLock

private static Object dataLock

flushLock

private static Object flushLock

currentThreads

private static HashMap currentThreads

quantityOfMeasures

private static HashMap quantityOfMeasures

measurementSystems

private static HashMap measurementSystems

populated

private static boolean populated

cache

private static UnitCache cache

VERBOSE

private static final boolean VERBOSE

CACHESIZE

private static int CACHESIZE

Constructor Detail

UnitCache

public UnitCache()
          throws RemoteException

Do not directly invoke this constructor! Use getUnitCache instead. The constructor is public so that the ServerManager can create an instance of this class for use as the master cache.

However, since the master cache is only being used to signal slave caches, we don't want to construct any of the internal cache objects.

Method Detail

getUnitCache

public static UnitCache getUnitCache()

Contruct a new Unit cache.

removeEntry

protected void removeEntry(Object target)

Simply clear local cache when signalled. Will be repopulated on subsequent requests

Overrides:

removeEntry in class CacheManager

Parameters:

target - the key object (null = clear entire cache)

putEntry

public void putEntry(Object key,
                     Object value)

Overrides CacheManager.putEntry to do nothing so that no entries are added to the wt.util.Cache object contained in CacheManager.

Overrides:

putEntry in class CacheManager

Parameters:

key - the key object

value - the value object

getDefaultSize

public int getDefaultSize()

Description copied from class: CacheManager

Get desired size of this cache. This method attemps to find a size property called wt.cache.size.CacheName where cacheName is the name of this cache. Subclasses can override this method to control cache size in some other way. If no property is found, the default size is 100.

Supported API: true

Overrides:

getDefaultSize in class CacheManager

clear

protected void clear()

reset

public void reset()

Method called when connection to master cache is broken and recovered indicating that a notification from another IBADefinition cache might have been missed. The current cache is cleared and reinitialized later.

Overrides:

reset in class CacheManager

populateCache

public void populateCache()
                   throws WTException

Throws:

WTException

Print

public void Print()

getMeasurementSystem

public MeasurementSystem getMeasurementSystem(String name)
                                       throws WTException

Throws:

WTException

getMeasurementSystemNames

public String[] getMeasurementSystemNames()
                                   throws WTException

Throws:

WTException

getMeasurementSystems

public MeasurementSystem[] getMeasurementSystems()
                                          throws WTException

Throws:

WTException

getQuantityOfMeasure

public QuantityOfMeasure getQuantityOfMeasure(String name)
                                       throws WTException

Throws:

WTException

getQuantityOfMeasureNames

public String[] getQuantityOfMeasureNames()
                                   throws WTException

Throws:

WTException

getQuantityOfMeasures

public QuantityOfMeasure[] getQuantityOfMeasures()
                                          throws WTException

Throws:

WTException

aquireLock

private Object aquireLock()

releaseLock

private void releaseLock(Object localLock)

blockOnLock

private void blockOnLock()