First of all, fix the logic which looks for identical input state groups so
that we actually use them. This turned out to be most easily done by factoring
the relevant code out to a separate function so that we could do an early
return.
Secondly, avoid building the whole `conflicted_state` dict (which was only ever
used as a boolean flag).
Thirdly, replace the construction of the `state` dict (which mapped from keys
to events that set them), with an optimistic construction of the resolution
result assuming there will be no conflicts. This should be no slower than
building the old `state` dict, and:
- in the conflicted case, we'll short-cut it, saving part of the work
- in the unconflicted case, it saves rebuilding the resolution from the
`state` dict.
Finally, do a couple of s/values/itervalues/.
* Split state group persist into seperate storage func
* Add per database engine code for state group id gen
* Move store_state_group to StateReadStore
This allows other workers to use it, and so resolve state.
* Hook up store_state_group
* Fix tests
* Rename _store_mult_state_groups_txn
* Rename StateGroupReadStore
* Remove redundant _have_persisted_state_group_txn
* Update comments
* Comment compute_event_context
* Set start val for state_group_id_seq
... otherwise we try to recreate old state groups
* Update comments
* Don't store state for outliers
* Update comment
* Update docstring as state groups are ints
We extract the storage-independent bits of the state group resolution out to a
separate functiom, and stick it in a new handler, in preparation for its use
from the storage layer.
this param doesn't seem to be used, and is a bit pointless anyway because it
can easily be replicated by the caller. It is also horrible, because it changes
the return type of the method.
This bypasses a bug where using the state groups to figure out if a host
is in a room sometimes errors if the servers isn't in the room. (For
example when the server rejected an invite to a remote room)
A few non-functional changes:
* A bunch of docstrings to document types
* Split `EventsStore._persist_events_txn` up a bit. Hopefully it's a bit more
readable.
* Rephrase `EventFederationStore._update_min_depth_for_room_txn` to avoid
mind-bending conditional.
* Rephrase rejected/outlier conditional in `_update_outliers_txn` to avoid
mind-bending conditional.
