wt.vc.views
Class ViewCache

java.lang.Object
  java.rmi.server.RemoteObject
      java.rmi.server.RemoteServer
          wt.util.RMIServer
              wt.cache.CacheManager
                  wt.vc.views.ViewCache

All Implemented Interfaces:

CacheServer, Remote, Serializable, Unreferenced

public class ViewCache

extends CacheManager

A cache of all View and ViewAssociation objects.

See Also:

Serialized Form

Field Summary

private Hashtable	children
private static String	CHILDREN_CACHE_KEY
private boolean	initialized
private Hashtable	parents
private static String	PARENTS_CACHE_KEY
private static boolean	VERBOSE
private View[]	views
private static String	VIEWS_BY_NAME_CACHE_KEY
private static String	VIEWS_BY_OID_CACHE_KEY
private static String	VIEWS_CACHE_KEY
private static String	VIEWS_TRANSACTION_CACHE
private Hashtable	viewsByName
private Hashtable	viewsByOid

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

Fields inherited from interface wt.cache.CacheServer

versionID

Constructor Summary

ViewCache()
Construct an empty view cache.

Method Summary

protected void	addParentChildToContextCache(View parent, View child)
private Object[]	addToArray(Object[] array, Object element)
protected void	addViewChangeToContextCache(View view)
private void	clear()
protected void	clearContextCache()
View[]	getAllViews() Get all views.
ObjectIdentifier[]	getChildren(ObjectIdentifier parent_key) Get children of a view.
private Hashtable	getContextCache()
int	getDefaultSize() Get desired size of the managed cache.
ObjectIdentifier	getParent(ObjectIdentifier child_key) Get parent of a view.
View	getView(Object key) Get the View object corresponding to a object identifier or name.
private void	init()
private void	initializeContextCache()
private boolean	isContextCacheInitialized()
void	put(Object key, Object value) Signal a new or updated View or ViewAssociation object.
void	remove(Object key) Signal a removed View or ViewAssociation object.
protected void	removeEntry(Object key) Protected method called to remove an entry of the managed cache.
private Object[]	removeFromArray(Object[] array, Object element)
protected void	removeParentChildInContextCache(View parent, View child)
void	reset() Method called when connection to master cache is broken and recovered indicating that a notification from another view cache might have been missed.

Methods inherited from class wt.cache.CacheManager

checkAccess, get, getDefaultName, getEntry, isCacheHost, overflow, ping, putEntry, putEntry, reference, registerSlave, 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

VIEWS_TRANSACTION_CACHE

private static final String VIEWS_TRANSACTION_CACHE

See Also:

Constant Field Values

VIEWS_CACHE_KEY

private static final String VIEWS_CACHE_KEY

See Also:

Constant Field Values

views

private View[] views

VIEWS_BY_OID_CACHE_KEY

private static final String VIEWS_BY_OID_CACHE_KEY

See Also:

Constant Field Values

viewsByOid

private Hashtable viewsByOid

VIEWS_BY_NAME_CACHE_KEY

private static final String VIEWS_BY_NAME_CACHE_KEY

See Also:

Constant Field Values

viewsByName

private Hashtable viewsByName

PARENTS_CACHE_KEY

private static final String PARENTS_CACHE_KEY

See Also:

Constant Field Values

parents

private Hashtable parents

CHILDREN_CACHE_KEY

private static final String CHILDREN_CACHE_KEY

See Also:

Constant Field Values

children

private Hashtable children

initialized

private boolean initialized

VERBOSE

private static final boolean VERBOSE

See Also:

Constant Field Values

Constructor Detail

ViewCache

public ViewCache()
          throws RemoteException

Construct an empty view cache. Cache is registered as a slave of master cache at this time. Cache will be initialized when first used.

Method Detail

getDefaultSize

public int getDefaultSize()

Get desired size of the managed cache. The view cache uses the managed class only as a signalling mechanism, so the default size is 1.

Supported API: false

Overrides:

getDefaultSize in class CacheManager

init

private void init()
           throws WTException

Throws:

WTException

clear

private void clear()

put

public void put(Object key,
                Object value)

Signal a new or updated View or ViewAssociation object. Currently, this just causes the current cache to be cleared and reinitialized later, but it could actively maintain the cache in the future.

Overrides:

put in class CacheManager

Parameters:

key - an ObjectIdentifier

value - the new or changed object

removeEntry

protected void removeEntry(Object key)

Protected method called to remove an entry of the managed cache. This signals a new or updated View or ViewAssociation object. Currently, this just causes the current cache to be cleared and reinitialized later, but it could actively maintain the cache in the future.

Overrides:

removeEntry in class CacheManager

Parameters:

key - an ObjectIdentifier

reset

public void reset()

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

Overrides:

reset in class CacheManager

remove

public void remove(Object key)

Signal a removed View or ViewAssociation object. Currently, this just causes the current cache to be cleared and reinitialized later, but it could actively maintain the cache in the future.

Overrides:

remove in class CacheManager

Parameters:

key - an ObjectIdentifier

getView

public View getView(Object key)
             throws WTException

Get the View object corresponding to a object identifier or name. If the key is a String, it is assumed to be the name of the View, otherwise it is expected to be the object identifier of the View.

Parameters:

key - an ObjectIdentifier or View name

Returns:

the View object or null if not found

Throws:

WTException

getParent

public ObjectIdentifier getParent(ObjectIdentifier child_key)
                           throws WTException

Get parent of a view.

Parameters:

child_key - ObjectIdentifier of the child view

Returns:

the ObjectIdentifier of the parent view or null if no parent view

Throws:

WTException

getChildren

public ObjectIdentifier[] getChildren(ObjectIdentifier parent_key)
                               throws WTException

Get children of a view.

Parameters:

parent_key - ObjectIdentifier of the parent view

Returns:

array of child ObjectIdentifier or null if no children

Throws:

WTException

getAllViews

public View[] getAllViews()
                   throws WTException

Get all views.

Returns:

array of all view objects

Throws:

WTException

isContextCacheInitialized

private boolean isContextCacheInitialized()

initializeContextCache

private void initializeContextCache()
                             throws WTException

Throws:

WTException

getContextCache

private Hashtable getContextCache()
                           throws WTException

Throws:

WTException

clearContextCache

protected void clearContextCache()

addToArray

private Object[] addToArray(Object[] array,
                            Object element)

removeFromArray

private Object[] removeFromArray(Object[] array,
                                 Object element)

addViewChangeToContextCache

protected void addViewChangeToContextCache(View view)
                                    throws WTException

Throws:

WTException

addParentChildToContextCache

protected void addParentChildToContextCache(View parent,
                                            View child)
                                     throws WTException

Throws:

WTException

removeParentChildInContextCache

protected void removeParentChildInContextCache(View parent,
                                               View child)
                                        throws WTException

Throws:

WTException