Rankings broken when games aren't ordered by date

[j3k0]

When games aren't ordered by date, the users ranking/points computation is wrong: new points count takes into account games played in the future.

This wasn't an issue until I migrated the database and lost the correspondence between the game's timestamp and database's sequence number...

Find below the proposed fix.

Definitions:

• let archive(X)
  • be the list of games already processed and archived for player X.
• let future(D, X)
  • be the subset of games in archive(X) having their date >= D.
• let database
  • be the list of games in the database sorted by sequence number seq
  • seq is unrelated to date.
• let lastSeq
  • be the last sequence number read from database.
• let waitingList
  • be an ordered list of games sorted by date.
• let ranking(PlayerArchive, OpponentArchive, Game, X)
  • be the updated ranking for player X after playing Game based on PlayerArchive and OpponentArchive of games.

Current code:

• [x] read N entries from database
• [x] increase lastSeq by N
• [x] for each entry just read from database Game with Game.players = [ A, B ]
  • [x] add [Game, ranking(archive(A), archive(B), Game, A)] to archive(A)
  • [x] add [Game, ranking(archive(B), archive(A), Game, B)] to archive(B)

New code:

• [x] read N entries from database
• [x] increase lastSeq by N
• [x] for each entry Game just read from database with Game.players = [ A, B ]
  • [ ] remove future(Game.date, A) from archive(A), add to waitingList.
  • [ ] remove future(Game.date, B) from archive(B), add to waitingList.
  • [x] add [Game, ranking(archive(A), archive(B), Game, A)] to archive(A)
  • [x] add [Game, ranking(archive(B), archive(A), Game, B)] to archive(B)
• [ ] for each entry Game in waitingList with Game.players = [ A, B ]
  • [ ] remove Game from waitingList.
  • [ ] add [Game, ranking(archive(A), archive(B), Game, A)] to archive(A)
  • [ ] add [Game, ranking(archive(B), archive(A), Game, B)] to archive(B)

note: waitingList is ordered by date, so, even though processing of waitingList could share the same code as processing of readingList, there shouldn't be any future game to remove from archive...

[j3k0]

no... would be better to add entries read from database right into waiting list... then process waiting list until it's empty