org.lsst.ccs.gconsole.services.aggregator

Interface AgentChannel

All Known Implementing Classes:

BasicChannel, StaticChannel

public interface AgentChannel

Encapsulates static properties and current status of a data channel. Each channel has a central value (an Object) and optional attributes identified by string keys. A channel is identified by a unique path (slash-separated string, with the subsystem name as the first element).

Implementations should ensure that the path is used to establish channel equality and hash code.

Author:

onoprien

Nested Class Summary

Nested Classes

Modifier and Type	Interface and Description
static interface	AgentChannel.Key Enumeration of standard attributes.

Method Summary

Modifier and Type	Method and Description
<T> T	get() Returns the current central value of this channel.
<T> T	get(Object key) Returns the value of the channel attribute identified by the key.
org.lsst.ccs.bus.data.AgentInfo	getAgent() Returns the descriptor of the Agent this channel belongs to.
String	getAgentName() Returns the name of the Agent this channel belongs to.
List<String>	getAttributes() Returns the list of keys of attributes this channel has.
String	getLocalPath() Returns the path of this channel with the agent name and the following slash stripped.
String	getPath() Return the unique path of this channel.
boolean	set(Object value) Sets the value of this channel.
boolean	set(Object key, Object value) Sets the value of the specified attribute.

Method Detail

getPath

String getPath()

Return the unique path of this channel.

Returns:

Channel path in (agent name)/(local path) form.

getAgentName

String getAgentName()

Returns the name of the Agent this channel belongs to.

Returns:

Agent name.

getAgent

org.lsst.ccs.bus.data.AgentInfo getAgent()

Returns the descriptor of the Agent this channel belongs to.

Returns:

Agent descriptor.

getLocalPath

String getLocalPath()

Returns the path of this channel with the agent name and the following slash stripped. Local paths are unique inside an agent.

Returns:

Local path.

get

<T> T get(Object key)

Returns the value of the channel attribute identified by the key.

Type Parameters:

T - Type of the attribute value.

Parameters:

key - The attribute is identified by the string returned by toString() method of the key object. If key is null or evaluates to AgentChannel.Key.VALUE, the central value is returned.

Returns:

Attribute value, or null if this channel does not have the specified attribute.

get

<T> T get()

Returns the current central value of this channel.

Type Parameters:

T - Type of the central value.

Returns:

Current value.

getAttributes

List<String> getAttributes()

Returns the list of keys of attributes this channel has.

Returns:

List of existing attribute keys.

set

boolean set(Object key,
            Object value)

Sets the value of the specified attribute. The attribute value does not change if the new value is equal to the old one.

Parameters:

key - The attribute is identified by the string returned by toString() method of the key object. If key is null or evaluates to AgentChannel.Key.VALUE, the central value is set.

value - The new value.

Returns:

true if the attribute value has changed as a result of this call.

set

boolean set(Object value)

Sets the value of this channel. The value will not change if the new value is equal to the old one.

Parameters:

value - New value.

Returns:

true if the value has changed as a result of this call.