IQueueGrain

Remarks

The last of the three doc 27 left undeclared at L1, and doc 28 is specific about the shape: a ticket is "a grain-held record". Vixen.Live.Matchmaking's Matchmaker is an in-memory queue, which is the first item on its own owed list.

⚠ The scoring stays a pure function and the grain is a scheduling decision on top. That is exactly the relationship PlacementDirector has to IMapGrain, and it is what lets doc 27 § Testing's property tests run tens of thousands of randomised fleets — a matchmaker that could only be exercised inside a silo is one nobody tests.

⚠ Formed is not started. A roster still needs a shard, and allocating one can fail, so the tickets are held rather than released and the caller either Starts or Abandons. L2's reservation, at a different scale and for the same reason.

⚠ Keyed by the queue definition's address, so "the ranked 3v3 queue" is one grain per region-and-version the caller decides to spell into the key — the same freedom ShardKey gives a map.

Methods (8)

• Task<QueueTicket> Enqueue(QueueEntry entry)

  Joins the queue.

• Task<bool> Cancel(string ticket)

  Gives up.

• Task<QueueTicket?> Ticket(string ticket)

  Where a ticket has got to.

• Task<ImmutableArray<QueueMatch>> Cycle(DateTimeOffset now)

  Forms whatever can be formed.

• Task<bool> Start(Guid match)

  Says a formed match got its shard.

• Task<bool> Abandon(Guid match, DateTimeOffset now)

  Says a formed match did not get one, and puts its tickets back.

• Task<bool> Backfill(Guid match, int seats)

  Says somebody left a running match, so a seat needs filling.

• Task<QueueSnapshot> Read()

  What the queue looks like.

Used by (1)

• QueueGrainVixen.Live.Orchestrator