se.esss.ics.rbac.logic.evaluation

Class CachedPVProvider

java.lang.Object

se.esss.ics.rbac.logic.evaluation.CachedPVProvider

All Implemented Interfaces:

Serializable

public class CachedPVProvider
extends Object
implements Serializable

CachedPVProvider is a singleton that provides PVs by PV name. PVs retrieved through CachedPVProvider are cached and the connection is kept open, so that there is no need to reconnect them on subsequent uses. CachedPVProvider also offers capability of automatically connecting and caching PVs on startup. PVs that should take advantage of this must be declared in "autoconnect.xml" file, which must in turn be located somewhere in the classpath.

Author:

Jaka Bobnar

See Also:

Serialized Form

Field Summary

Fields

Modifier and Type	Field and Description
static String	FILE_AUTOCONNECT The name of the file that defines the PVs that RBAC automatically connects to at startup

Constructor Summary

Constructors

Constructor and Description
CachedPVProvider()

Method Summary

Modifier and Type	Method and Description
PV	getPV(String pvName) Returns a PV connection by the specified name from cache or creates a new one, if on does not already exist.
PV	getPV(String pvName, boolean waitForValue) Returns a PV connection by the specified name from cache or creates a new one, if on does not already exist.

Methods inherited from class java.lang.Object

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

Field Detail

FILE_AUTOCONNECT

public static final String FILE_AUTOCONNECT

The name of the file that defines the PVs that RBAC automatically connects to at startup

See Also:

Constant Field Values

Constructor Detail

CachedPVProvider

public CachedPVProvider()

Method Detail

getPV

public PV getPV(String pvName,
                boolean waitForValue)
         throws PVException

Returns a PV connection by the specified name from cache or creates a new one, if on does not already exist. Returned PV is already connected.

Parameters:

pvName - name of the PV

waitForValue - if true the calling thread will be blocked, until the PV receives the first value, but no longer than 2 seconds

Returns:

PV by the specified name

Throws:

PVException - if there is a problem connecting the PV or if the parameter is null

See Also:

PV.blockUntilFirstUpdate(int)

getPV

public PV getPV(String pvName)
         throws PVException

Returns a PV connection by the specified name from cache or creates a new one, if on does not already exist. Returned PV is already connected.

Parameters:

pvName - name of the PV

Returns:

PV by the specified name

Throws:

PVException - if there is a problem connecting the PV or parameter is null