equip.data
Class DataProxyImpl

java.lang.Object
  equip.runtime.Object
      equip.runtime.ValueBase
          equip.net.ServiceProxy
              equip.data.DataProxy
                  equip.data.DataProxyImpl

All Implemented Interfaces:

java.lang.Cloneable, java.lang.Runnable

public class DataProxyImpl

extends DataProxy

implements java.lang.Runnable

The normal implementation of the IDL'd dataspace API, DataProxy; implements a dataspace client, delegating most of the work to an instance of class DataDelegate.

Note 1: you should NOT normally create these directly; use the singleton DataManager to allow sharing of dataspace replicas within a single application.

Note 2: you will probably find the IDataspace API easier to use and more familar in terms of Java idiom (see DataspaceBean).

Nested Class Summary

(package private) class	DataProxyImpl.ActivateThread
(package private) class	DataProxyImpl.MyDeactivateCallback
(package private) class	DataProxyImpl.WaitCallback

Field Summary

(package private) int	ackSeq
(package private) boolean	activateAsyncFlag
(package private) boolean	activeFlag
(package private) DeactivateCallback	callback
(package private) DeactivateCallback	deactivateCallback
(package private) ValueBase	deactivateClosure
(package private) GUID	defaultAgentId
(package private) DataDelegatePeerTCP	driver
(package private) int	lastAckSeq
(package private) boolean	persistFlag
(package private) DataDelegatePeer	serverPeer
(package private) boolean	waitInited
(package private) DataSession	waitSession

Fields inherited from class equip.data.DataProxy

initialItems

Fields inherited from class equip.net.ServiceProxy

serviceMoniker

Constructor Summary

DataProxyImpl()

DataProxyImpl(GUID responsible)

Method Summary

boolean	activate(DeactivateCallback callback, ValueBase closure) Request activation of the service proxy, i.e. connect to server.
void	activateAsync() Create a thread to repeatedly attempt to activate this dataspace (assuming that it is a client) whenever its activation fails.
boolean	activateInternal(DeactivateCallback callback, ValueBase closure, boolean startInputThread)
void	addEvent(Event event) Add a new event into the dataspace.
void	addItem(ItemData item, int locked, boolean processBound, boolean local, Lease itemLease) add item event helper - create and publish an AddEvent.
void	beginBusy() this dangerous internal API lets you suspend the enactment of events; also make a matching call to endBusy().
DataSession	createSession(DataCallback callback, ValueBase closure) Create a new data session in which to express interest in events and data items and to get callbacks/notifications.
void	deactivate() Request deactivation of an (active) service proxy, i.e.
void	deleteItem(GUID id, boolean local) delete item event helper - create and publish an DeleteEvent.
void	deleteSession(DataSession session) Delete a DataSession previously created with createSession(equip.data.DataCallback, equip.runtime.ValueBase); effectively any remaining EventPatterns will be removed.
void	endBusy() this dangerous internal API lets you resume the enactment of events; only call to match a previous call to beginBusy().
double	getConnectionStrength()
ItemData	getItem(GUID id) Get an ItemData from the local dataspace by item GUID.
ItemBinding	getItemBinding(GUID id) Get an ItemBinding from the local dataspace by item GUID.
GUID	getResponsible() get responsible (replica) ID
int	getUnsentEvents() return number of unsent events - connection and outboundEvents
(package private) void	init(GUID responsible)
(package private) void	initWaitForEvents()
(package private) void	jbInit()
void	notifyDeactivate(ServiceProxy proxy, ValueBase closure)
void	queueEvent(Event event) (always) Queued add of a new event into the dataspace.
void	run()
void	setDefaultAgent(GUID defaultAgentId) Set a default GUID to be used as the default owner and/or requestor for locally generated events and data items.
void	setPersist(boolean persistFlag) Whether this dataspace replica should try to associate persistently with its server/peer.
void	terminate() Destroy this dataspace, terminating any communication and threads and (hopefully) allowing all resources to be released/GCed.
void	updateItem(ItemData item, boolean local, boolean reliable) update item event helper - create and publish an UpdateEvent with default priority (0).
void	updateItem2(ItemData item, boolean local, boolean reliable, int priority) update item event helper - create and publish an UpdateEvent.
void	waitForEvents(boolean local) Block and wait for all pending events to be enacted.

Methods inherited from class equip.data.DataProxy

_equals_helper, _matches_helper, equals, getModuleName, matches, readObject, writeObject

Methods inherited from class equip.net.ServiceProxy

_equals_helper, _matches_helper

Methods inherited from class equip.runtime.ValueBase

_equals_helper, _matches_helper, clone

Methods inherited from class java.lang.Object

finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

defaultAgentId

GUID defaultAgentId

serverPeer

DataDelegatePeer serverPeer

driver

DataDelegatePeerTCP driver

persistFlag

boolean persistFlag

activeFlag

boolean activeFlag

activateAsyncFlag

boolean activateAsyncFlag

callback

DeactivateCallback callback

deactivateCallback

DeactivateCallback deactivateCallback

deactivateClosure

ValueBase deactivateClosure

waitInited

boolean waitInited

waitSession

DataSession waitSession

ackSeq

int ackSeq

lastAckSeq

int lastAckSeq

Constructor Detail

DataProxyImpl

public DataProxyImpl()

DataProxyImpl

public DataProxyImpl(GUID responsible)

Method Detail

init

void init(GUID responsible)

setPersist

public void setPersist(boolean persistFlag)

Description copied from class: DataProxy

Whether this dataspace replica should try to associate persistently with its server/peer. A persistent association will not be garbage collected when the underlying network connection is removed or fails. This option is largely untested at the moment, and should really have a Lease mechanism to handle garbage collection: use with care.

Note that replicas are identified to each other by the responsible GUID of each.

Specified by:

setPersist in class DataProxy

Parameters:

persistFlag - Whether to connect persistently.

addEvent

public void addEvent(Event event)

Description copied from class: DataProxy

Add a new event into the dataspace. Note that if the dataspace is already busy (e.g. in an event notification callback) then the event will be queued internally for subsequent asynchronous delivery.

Specified by:

addEvent in class DataProxy

Parameters:

event - The event to published.

queueEvent

public void queueEvent(Event event)

(always) Queued add of a new event into the dataspace.

Specified by:

queueEvent in class DataProxy

Parameters:

event - The event to published.

getItemBinding

public ItemBinding getItemBinding(GUID id)

Description copied from class: DataProxy

Get an ItemBinding from the local dataspace by item GUID.

Specified by:

getItemBinding in class DataProxy

Parameters:

id - The item's GUID.

Returns:

The item's binding to the dataspace replica, or null if unknown.

getItem

public ItemData getItem(GUID id)

Description copied from class: DataProxy

Get an ItemData from the local dataspace by item GUID.

Specified by:

getItem in class DataProxy

Parameters:

id - The item's GUID.

Returns:

The item's value in the dataspace replica, or null if unknown.

setDefaultAgent

public void setDefaultAgent(GUID defaultAgentId)

Description copied from class: DataProxy

Set a default GUID to be used as the default owner and/or requestor for locally generated events and data items.

Specified by:

setDefaultAgent in class DataProxy

Parameters:

defaultAgentId - GUID to use as default owner/requestor

addItem

public void addItem(ItemData item,
                    int locked,
                    boolean processBound,
                    boolean local,
                    Lease itemLease)

Description copied from class: DataProxy

add item event helper - create and publish an AddEvent.

Specified by:

addItem in class DataProxy

Parameters:

item - The value of the new item (including id).

locked - See ItemBindingInfo.locked.

processBound - See ItemBindingInfo.processBound.

local - See ItemBindingInfo.local.

itemLease - See ItemBindingInfo.itemLease.

updateItem

public void updateItem(ItemData item,
                       boolean local,
                       boolean reliable)

Description copied from class: DataProxy

update item event helper - create and publish an UpdateEvent with default priority (0). NOTE: if this is an item with a lease and you want the lease to be renewed then use an addItem repeatedly instead (with the new Lease value in the ItemBinding).

Specified by:

updateItem in class DataProxy

Parameters:

item - The new value of the item (including original id).

local - See EventMetadata.local.

reliable - See EventMetadata.reliable.

updateItem2

public void updateItem2(ItemData item,
                        boolean local,
                        boolean reliable,
                        int priority)

Description copied from class: DataProxy

update item event helper - create and publish an UpdateEvent. NOTE: if this is an item with a lease and you want the lease to be renewed then use an addItem repeatedly instead (with the new Lease value in the ItemBinding).

Specified by:

updateItem2 in class DataProxy

Parameters:

item - The new value of the item (including original id).

local - See EventMetadata.local.

reliable - See EventMetadata.reliable.

priority - See EventMetadata.priority.

deleteItem

public void deleteItem(GUID id,
                       boolean local)

Description copied from class: DataProxy

delete item event helper - create and publish an DeleteEvent.

Specified by:

deleteItem in class DataProxy

Parameters:

id - The GUID of the item to be deleted.

local - See EventMetadata.local.

createSession

public DataSession createSession(DataCallback callback,
                                 ValueBase closure)

Description copied from class: DataProxy

Create a new data session in which to express interest in events and data items and to get callbacks/notifications. See also information about DataCallback and (usually easier to use) DataCallbackPost.

Specified by:

createSession in class DataProxy

Parameters:

callback - Event-handling subclass of DataCallback or DataCallbackPost, notified about events matching any EventPatterns that are added to new session.

closure - Optional application parameter provided to the callback notification (can be null).

Returns:

A new DataSession to which EventPatterns can be added to cause replication and/or notifications of events and items.

deleteSession

public void deleteSession(DataSession session)

Description copied from class: DataProxy

Delete a DataSession previously created with DataProxy.createSession(equip.data.DataCallback, equip.runtime.ValueBase); effectively any remaining EventPatterns will be removed.

In C++ the caller will still hold the last reference to the data session object, which must be released in order for the session object to actually be deleted.

Specified by:

deleteSession in class DataProxy

Parameters:

session - The DataSession object returned from DataProxy.createSession(equip.data.DataCallback, equip.runtime.ValueBase) to be deleted from the dataspace.

activateAsync

public void activateAsync()

Description copied from class: DataProxy

Create a thread to repeatedly attempt to activate this dataspace (assuming that it is a client) whenever its activation fails. This is an alternative to ServiceProxy.activate(equip.net.DeactivateCallback, equip.runtime.ValueBase) and ServiceProxy.deactivate() which are also implemented for direct control over activation.

Specified by:

activateAsync in class DataProxy

activate

public boolean activate(DeactivateCallback callback,
                        ValueBase closure)

Description copied from class: ServiceProxy

Request activation of the service proxy, i.e. connect to server.

Specified by:

activate in class ServiceProxy

Returns:

success (true = ok). If true, and callback!=null then if the communication fails before deactivate is intiated then callback will be notified.

activateInternal

public boolean activateInternal(DeactivateCallback callback,
                                ValueBase closure,
                                boolean startInputThread)

deactivate

public void deactivate()

Description copied from class: ServiceProxy

Request deactivation of an (active) service proxy, i.e. disconnect from server.

Specified by:

deactivate in class ServiceProxy

notifyDeactivate

public void notifyDeactivate(ServiceProxy proxy,
                             ValueBase closure)

run

public void run()

Specified by:

run in interface java.lang.Runnable

getConnectionStrength

public double getConnectionStrength()

getUnsentEvents

public int getUnsentEvents()

return number of unsent events - connection and outboundEvents

initWaitForEvents

void initWaitForEvents()

waitForEvents

public void waitForEvents(boolean local)

Description copied from class: DataProxy

Block and wait for all pending events to be enacted. Be careful or this will deadlock, so make sure nothing else is going on in that thread!. Only in Java, at the moment (2003-10-16).

Specified by:

waitForEvents in class DataProxy

Parameters:

local - Wait only for local events (if false, then also send a message to the server dataspace and wait for it to come back as well).

jbInit

void jbInit()

beginBusy

public void beginBusy()

Description copied from class: DataProxy

this dangerous internal API lets you suspend the enactment of events; also make a matching call to DataProxy.endBusy(). Easy to deadlock with unmatched calls!

Specified by:

beginBusy in class DataProxy

endBusy

public void endBusy()

Description copied from class: DataProxy

this dangerous internal API lets you resume the enactment of events; only call to match a previous call to DataProxy.beginBusy(). Easy to deadlock - or break synchronization - with unmatched calls!

Specified by:

endBusy in class DataProxy

getResponsible

public GUID getResponsible()

get responsible (replica) ID

Specified by:

getResponsible in class DataProxy

Returns:

The dataspace replica's own GUID.

terminate

public void terminate()

Destroy this dataspace, terminating any communication and threads and (hopefully) allowing all resources to be released/GCed.

Specified by:

terminate in class DataProxy