org.opentripplanner.routing.edgetype

Class TimetableSnapshot

java.lang.Object

org.opentripplanner.routing.edgetype.TimetableSnapshot

public class TimetableSnapshot
extends Object

Part of concurrency control for stoptime updates. All updates should be performed on a snapshot before it is handed off to any searches. A single snapshot should be used for an entire search, and should remain unchanged for that duration to provide a consistent view not only of trips that have been boarded, but of relative arrival and departure times of other trips that have not necessarily been boarded. At this point, only one writing thread at a time is supported.

Nested Class Summary

Nested Classes

Modifier and Type	Class and Description
protected static class	TimetableSnapshot.SortedTimetableComparator
protected class	TimetableSnapshot.TripIdAndServiceDate Class to use as key in HashMap containing trip id and service date

Constructor Summary

Constructors

Constructor and Description
TimetableSnapshot()

Method Summary

Modifier and Type	Method and Description
void	clear() Clear all data of snapshot
TimetableSnapshot	commit() This produces a small delay of typically around 50ms, which is almost entirely due to the indexing step.
TimetableSnapshot	commit(boolean force)
TripPattern	getLastAddedTripPattern(String tripId, org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate) Get the last added trip pattern given a trip id (without agency) and a service date as a result of a call to update(TripPattern, TripTimes, ServiceDate) with trip times of a trip that didn't exist yet in the trip pattern.
boolean	isDirty()
boolean	purgeExpiredData(org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate) Removes all Timetables which are valid for a ServiceDate on-or-before the one supplied.
Timetable	resolve(TripPattern pattern, org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate) Returns an updated timetable for the specified pattern if one is available in this snapshot, or the originally scheduled timetable if there are no updates in this snapshot.
String	toString()
boolean	update(TripPattern pattern, TripTimes updatedTripTimes, org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate) Update the trip times of one trip in a timetable of a trip pattern.

Methods inherited from class java.lang.Object

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

Constructor Detail

TimetableSnapshot

public TimetableSnapshot()

Method Detail

resolve

public Timetable resolve(TripPattern pattern,
                         org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate)

Returns an updated timetable for the specified pattern if one is available in this snapshot, or the originally scheduled timetable if there are no updates in this snapshot.

getLastAddedTripPattern

public TripPattern getLastAddedTripPattern(String tripId,
                                           org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate)

Get the last added trip pattern given a trip id (without agency) and a service date as a result of a call to update(TripPattern, TripTimes, ServiceDate) with trip times of a trip that didn't exist yet in the trip pattern.

Parameters:

tripId - trip id (without agency)

serviceDate - service date

Returns:

last added trip pattern; null if trip never was added to a trip pattern

update

public boolean update(TripPattern pattern,
                      TripTimes updatedTripTimes,
                      org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate)

Update the trip times of one trip in a timetable of a trip pattern. If the trip of the trip times does not exist yet in the timetable, add it.

Parameters:

pattern - trip pattern

updatedTripTimes - updated trip times

serviceDate - service day for which this update is valid

Returns:

whether or not the update was actually applied

commit

public TimetableSnapshot commit()

This produces a small delay of typically around 50ms, which is almost entirely due to the indexing step. Cloning the map is much faster (2ms). It is perhaps better to index timetables as they are changed to avoid experiencing all this lag at once, but we want to avoid re-indexing when receiving multiple updates for the same timetable in rapid succession. This compromise is expressed by the maxSnapshotFrequency property of StoptimeUpdater. The indexing could be made much more efficient as well.

Returns:

an immutable copy of this TimetableSnapshot with all updates applied

commit

public TimetableSnapshot commit(boolean force)

clear

public void clear()

Clear all data of snapshot

purgeExpiredData

public boolean purgeExpiredData(org.onebusaway.gtfs.model.calendar.ServiceDate serviceDate)

Removes all Timetables which are valid for a ServiceDate on-or-before the one supplied.

isDirty

public boolean isDirty()

toString

public String toString()

Overrides:

toString in class Object