org.jlab.coda.cMsg.CADomain

Class CA

java.lang.Object

org.jlab.coda.cMsg.common.cMsgDomainAdapter

org.jlab.coda.cMsg.CADomain.CA

All Implemented Interfaces:

cMsgDomainInterface

public class CA
extends cMsgDomainAdapter

This class implements a client in the cMsg Channel Access (CA) domain.

UDL: cMsg:CA://channelName?addr_list=list.

where addr_list specifies the UDP broadcast address list.

Version:

1.0

Author:

Elliott Wolin

Field Summary

Fields inherited from class org.jlab.coda.cMsg.common.cMsgDomainAdapter

connected, debug, description, domain, host, name, receiving, shutdownHandler, UDL, UDLremainder

Constructor Summary

Constructors

Constructor and Description
CA() Constructor for CA domain.

Method Summary

Modifier and Type	Method and Description
void	connect() Connects to CA channel after parsing UDL.
void	disconnect() Disconnects from CA channel.
void	flush(int timeout) Complete what the "send" method started -- write the double value to channel for real.
void	send(cMsgMessage msg) Set double value of channel from message's text field.
cMsgSubscriptionHandle	subscribe(java.lang.String subject, java.lang.String type, cMsgCallbackInterface cb, java.lang.Object userObj) Does a CA "monitor on" for this channel.
cMsgMessage	subscribeAndGet(java.lang.String subject, java.lang.String type, int timeout) Get the channel's value and place it in the return message's text field.
void	unsubscribe(cMsgSubscriptionHandle obj) Does a CA "monitor off" for this channel.

Methods inherited from class org.jlab.coda.cMsg.common.cMsgDomainAdapter

getCurrentUDL, getDebug, getDescription, getDomain, getHost, getInfo, getName, getServerHost, getServerPort, getShutdownHandler, getUDL, getUDLRemainder, isConnected, isReceiving, monitor, sendAndGet, setDebug, setDescription, setName, setShutdownHandler, setUDL, setUDLRemainder, shutdownClients, shutdownServers, start, stop, syncSend

Methods inherited from class java.lang.Object

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

Constructor Detail

CA

public CA()

Constructor for CA domain.

Method Detail

connect

public void connect()
             throws cMsgException

Connects to CA channel after parsing UDL.

Specified by:

connect in interface cMsgDomainInterface

Overrides:

connect in class cMsgDomainAdapter

Throws:

cMsgException - if there are communication problems

disconnect

public void disconnect()
                throws cMsgException

Disconnects from CA channel.

Specified by:

disconnect in interface cMsgDomainInterface

Overrides:

disconnect in class cMsgDomainAdapter

Throws:

cMsgException - if destroying channel failed

send

public void send(cMsgMessage msg)
          throws cMsgException

Set double value of channel from message's text field.

Specified by:

send in interface cMsgDomainInterface

Overrides:

send in class cMsgDomainAdapter

Parameters:

msg - message containing the text form of a double value

Throws:

cMsgException - if not connected to or cannot write to channel

flush

public void flush(int timeout)
           throws cMsgException

Complete what the "send" method started -- write the double value to channel for real.

Specified by:

flush in interface cMsgDomainInterface

Overrides:

flush in class cMsgDomainAdapter

Parameters:

timeout - time in milliseconds to wait for completion

Throws:

cMsgException - if error in CA flushIO or not connected to channel

subscribeAndGet

public cMsgMessage subscribeAndGet(java.lang.String subject,
                                   java.lang.String type,
                                   int timeout)
                            throws cMsgException

Get the channel's value and place it in the return message's text field.

Specified by:

subscribeAndGet in interface cMsgDomainInterface

Overrides:

subscribeAndGet in class cMsgDomainAdapter

Parameters:

subject - subject of return msg

type - type of return msg

timeout - time in milliseconds to wait for a message

Returns:

message with new double value in text field

Throws:

cMsgException - if not connected to channel or cannot get channel value

subscribe

public cMsgSubscriptionHandle subscribe(java.lang.String subject,
                                        java.lang.String type,
                                        cMsgCallbackInterface cb,
                                        java.lang.Object userObj)
                                 throws cMsgException

Does a CA "monitor on" for this channel. Runs the given callback when the channel's value changes. Subject, type, and userObj are passed right through in message/args sent to callback.

Specified by:

subscribe in interface cMsgDomainInterface

Overrides:

subscribe in class cMsgDomainAdapter

Parameters:

subject - message subject

type - message type

cb - callback object whose single method is called upon receiving a message of subject and type

userObj - any user-supplied object to be given to the callback method as an argument

Returns:

handle object to be used for unsubscribing

Throws:

cMsgException - if channel not connected or "monitor on" failed

unsubscribe

public void unsubscribe(cMsgSubscriptionHandle obj)
                 throws cMsgException

Does a CA "monitor off" for this channel.

Specified by:

unsubscribe in interface cMsgDomainInterface

Overrides:

unsubscribe in class cMsgDomainAdapter

Parameters:

obj - the object returned from a subscribe call

Throws:

cMsgException - if channel not connected or "monitor off" failed