Meters
The base class for meters is the class
Meter.
The classes derived from
Meter either measure at one point or
between two points and thus are called
OnePointMeter and
TwoPointMeter, respectively. It is the meters
responsibility to derive a metric from each message or from the flow of
messages, and provide the values of this metric to a statistic.
- The class
OnePointMeter provides the method
attachInput() which connects a
PortMonitor to a port. Whenever a message travels
accross that port, the abstract method evaluateMessage() in the
meter is called.
- The class
TwoPointMeter provides the methods
attachFromPort() and attachToPort() each of which
connects a PortMonitor to the specified port.
Whenever a message travels accross one of those ports, the abstract method
evaluateMessageFromPort() or
evaluateMessageToPort(), respectively, in the meter is called.