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conveyal / gtfs-editor

A web-based GTFS editing framework. THIS PROJECT IS DEPRECATED. See https://github.com/ibi-group/datatools-ui for current version.
https://github.com/ibi-group/datatools-ui
MIT License
134 stars 63 forks source link

MapDB: use atomic longs rather than UUIDs when generating IDs #185

Closed mattwigway closed 9 years ago

mattwigway commented 9 years ago

UUIDs are ugly and we do present them to the user (for instance in the route view, although maybe that needs rethinking as well. Nonetheless, we probably don't want UUIDs used as entity IDs in the GTFS export either . . . )

In order to reduce transaction overhead, we can put the atomic long in a separate database with a single global transaction. We wrap that in call that makes a commit in versioned data store, so that an ID is not returned until it has been written to disk. That way, in a crash, the worst thing that can happen is that we skip a few ids - not the end of the world.

mattwigway commented 9 years ago

Oops, that wasn't supposed to close this.