CalendarServiceDataFactoryImpl is a memory hog

[marcioaguiar]

I went through some performance problems and high memory usage when using OpenTripPlanner before. But recently I was using only onebusaway-gtfs to read a GTFS into memory and found it to be inviable because of the implementation of CalendarServiceDataFactoryImpl.

A simple GTFS was consuming more than 1Gb of memory to boot (not sure how much more it would go because the system throws OutOfMemory before it ends). Investigating the cause of the problem I found out that CalendarServiceDataFactoryImpl has a pretty naive implementation, storing all operation dates of all trips in memory.

In my application the operator can create trips with no end date planned. I store this trips with an end date in the year 3000. That generates almost 360.000 instances of Calendar for each Trip.

I am sure there is a more efficient way to implement the calendar service. Are there plans to improve this service?