org.lsst.ccs.gconsole.plugins.trending

Class RestSource

java.lang.Object

org.lsst.ccs.gconsole.plugins.trending.RestSource

public class RestSource
extends Object

Source of trending data based on a REST server. Provides getters for retrieving the list of known trending channels and the data for specified channels.

This sources watches for external events that can change the list of known channels, and notifies listeners on EDT when this happens.

Current implementation note. This class maintains a map of paths to DataChannel, but only the list of paths is externally available. Metadata provided by DataChannel is unused. Accordingly, whenever the map is updated (due to time window or REST server change), listeners are not notified unless the set of available paths changes.

Author:

onoprien

Method Summary

Modifier and Type	Method and Description
void	addListener(ChangeListener listener) Registers a listener to be notified if the list of channels available from this trending source changes.
protected void	fireEvent() Notifies listeners of changes in this source.
ArrayList<TrendData>	get(List<Trend> trends, long begin, long end, Boolean raw, Integer bins) Retrieves from the REST server and processes historical data for the specified trending channel.
List<String>	getChannels() Returns the list of known data channel paths.
void	refresh() Refreshes the list of channels by retrieving them from the REST server.
void	removeAllListeners() Removes all listeners.
void	removeListener(ChangeListener listener) Removes a listener.

Methods inherited from class java.lang.Object

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

Method Detail

refresh

public void refresh()

Refreshes the list of channels by retrieving them from the REST server.

addListener

public void addListener(ChangeListener listener)

Registers a listener to be notified if the list of channels available from this trending source changes. This method can be called on any thread. The listeners are notified on the EDT.

Parameters:

listener - Listener to be added.

removeListener

public void removeListener(ChangeListener listener)

Removes a listener. This method can be called on any thread.

Parameters:

listener - Listener to be removed.

removeAllListeners

public void removeAllListeners()

Removes all listeners. This method can be called on any thread.

fireEvent

protected void fireEvent()

Notifies listeners of changes in this source. Can be called on any thread. Listeners are notified on EDT.

getChannels

public List<String> getChannels()

Returns the list of known data channel paths. Calling this method does not retrieve data from the REST server.

Returns:

List of channel paths.

get

public ArrayList<TrendData> get(List<Trend> trends,
                                long begin,
                                long end,
                                Boolean raw,
                                Integer bins)

Retrieves from the REST server and processes historical data for the specified trending channel. If the supplied trends contain previously retrieved data, some of that data can be re-used, reducing the amount of data that needs to be retrieved from the REST server.

Parameters:

trends - List of trends for which the data has to be retrieved.

begin - Beginning of time window.

end - End of time window

raw - TRUE or FALSE depending on whether raw or statistical data should be retrieved; if null, current application preferences will be consulted.

bins - Approximate desired number of bins in the resulting dataset; if null, current application preferences will be consulted.

Returns:

List of newly created datasets, in the trends order. Note that this list will never be null, but individual elements can be null if data retrieval for corresponding trends fails for any reason.