org.opentripplanner.updater.trip.TripPatternCache Maven / Gradle / Ivy
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package org.opentripplanner.updater.trip;
import java.util.HashMap;
import java.util.Map;
import javax.annotation.Nonnull;
import org.opentripplanner.gtfs.GenerateTripPatternsOperation;
import org.opentripplanner.transit.model.framework.FeedScopedId;
import org.opentripplanner.transit.model.network.Route;
import org.opentripplanner.transit.model.network.StopPattern;
import org.opentripplanner.transit.model.network.TripPattern;
import org.opentripplanner.transit.model.network.TripPatternBuilder;
import org.opentripplanner.transit.model.timetable.Direction;
import org.opentripplanner.transit.model.timetable.Trip;
/**
* Threadsafe mechanism for tracking any TripPatterns added to the graph via GTFS realtime messages.
* This tracks only patterns added by realtime messages, not ones that already existed from the
* scheduled GTFS. This is a "cache" in the sense that it will keep returning the same TripPattern
* when presented with the same StopPattern, so if realtime messages add many trips passing through
* the same sequence of stops, they will all end up on this same TripPattern.
*
* Note that there are two versions of this class, this one for GTFS-RT and another for SIRI.
* TODO RT_AB: consolidate TripPatternCache and SiriTripPatternCache. They seem to only be separate
* because SIRI- or GTFS-specific indexes of the added TripPatterns seem to have been added to
* this primary collection.
* FIXME RT_AB: the name does not make it clear that this has anything to do with elements that are
* only added due to realtime updates, and it is only loosely a cache. RealtimeAddedTripPatterns?
*/
public class TripPatternCache {
/**
* This tracks only patterns added by realtime messages, it is not primed with TripPatterns that
* already existed from the scheduled GTFS.
*/
private final Map cache = new HashMap<>();
/** Used for producing sequential integers to ensure each added pattern has a unique name. */
private int counter = 0;
/**
* Get cached trip pattern or create one if it doesn't exist yet.
*
* @param stopPattern stop pattern to retrieve/create trip pattern
* @param trip the trip the new trip pattern will be created for
* @param originalTripPattern the trip pattern the new pattern is based. If the pattern is
* completely new, this will be null
* @return cached or newly created trip pattern
*/
public synchronized TripPattern getOrCreateTripPattern(
@Nonnull final StopPattern stopPattern,
@Nonnull final Trip trip,
final TripPattern originalTripPattern
) {
Route route = trip.getRoute();
// Check cache for trip pattern
TripPattern tripPattern = cache.get(stopPattern);
// Create TripPattern if it doesn't exist yet
if (tripPattern == null) {
// Generate unique code for trip pattern
var id = generateUniqueTripPatternCode(trip);
tripPattern =
TripPattern
.of(id)
.withRoute(route)
.withMode(trip.getMode())
.withNetexSubmode(trip.getNetexSubMode())
.withStopPattern(stopPattern)
.withCreatedByRealtimeUpdater(true)
.withOriginalTripPattern(originalTripPattern)
.build();
// Add pattern to cache
cache.put(stopPattern, tripPattern);
}
return tripPattern;
}
/**
* Generate unique trip pattern code for real-time added trip pattern. This function roughly
* follows the format of the {@link GenerateTripPatternsOperation}.
* In the SIRI version of this class, this is provided by a SiriTripPatternIdGenerator. If the
* GTFS-RT and SIRI version of these classes are merged, this function could become a second
* implementation of TripPatternIdGenerator.
* This method is not static because it references a monotonically increasing integer counter.
* But like in SiriTripPatternIdGenerator, this could be encapsulated outside the cache object.
* TODO RT_AB: create GtfsRtTripPatternIdGenerator as part of merging the two TripPatternCaches.
*/
private FeedScopedId generateUniqueTripPatternCode(Trip trip) {
FeedScopedId routeId = trip.getRoute().getId();
Direction direction = trip.getDirection();
String directionId = direction == Direction.UNKNOWN ? "" : Integer.toString(direction.gtfsCode);
if (counter == Integer.MAX_VALUE) {
counter = 0;
} else {
counter++;
}
String code = String.format("%s:%s:rt#%d", routeId.getId(), directionId, counter);
return new FeedScopedId(routeId.getFeedId(), code);
}
}