Package ch.psi.wica.controlsystem.epics.monitor

Class EpicsChannelMonitorSubscriber

java.lang.Object

ch.psi.wica.controlsystem.epics.monitor.EpicsChannelMonitorSubscriber

@Immutable
@Component
class EpicsChannelMonitorSubscriber
extends Object

Provides the functionality to monitor the specified EPICS channel and to publish updating channel value information to listening consumers.

Constructor Summary

Constructors

Constructor	Description
EpicsChannelMonitorSubscriber(WicaChannelValueCreator wicaChannelValueCreator)	Returns a new instance that will work with the specified value builder object.

Method Summary

Modifier and Type	Method	Description
(package private) void	subscribe(org.epics.ca.Channel<Object> channel, Consumer<WicaChannelValue> valueChangeHandler)	Establishes a monitor on the supplied EPICS channel and registers a handler which should subsequently be informed when the channel value changes.

Methods inherited from class java.lang.Object

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

Constructor Details

EpicsChannelMonitorSubscriber

public EpicsChannelMonitorSubscriber(@Autowired
 WicaChannelValueCreator wicaChannelValueCreator)

Returns a new instance that will work with the specified value builder object.

Parameters:

wicaChannelValueCreator - the builder.

Method Details

subscribe

void subscribe(org.epics.ca.Channel<Object> channel,
 Consumer<WicaChannelValue> valueChangeHandler)

Establishes a monitor on the supplied EPICS channel and registers a handler which should subsequently be informed when the channel value changes.

This method operates synchronously and incurs the cost of a network round trip to establish the monitor on the remote data source.

Precondition: the channel should have been connected at least once. Postcondition: the state of the channel will remain unaffected.

Parameters:

channel - the EPICS channel.

valueChangeHandler - the event consumer.

Throws:

NullPointerException - if the channel argument was null.

IllegalStateException - if the channel state was not as expected.