* Don't flake so badly for rejected events
* Moar
* Fix panic
* Don't count rejected events as missing
* Don't treat rejected events without state as missing
* Revert "Don't count rejected events as missing"
This reverts commit 4b6139b62eb91ba059b47415b0275964b37d9b43.
* Missing events should be KindOld
* If we have state, use it, regardless of memberships which could be stale now
* Fetch missing state for KindOld too
* Tweak the condition again
* Clean up a bit
* Use room updater to get latest events in a race-free way
* Return the correct error
* Improve errors
* Remove dependency on saramajetstream & sarama
Signed-off-by: Till Faelligen <tfaelligen@gmail.com>
* Remove internal.ContinualConsumer from federationapi
* Remove internal.ContinualConsumer from syncapi
* Remove internal.ContinualConsumer from keyserver
* Move to new Prepare function
* Remove saramajetstream & sarama dependency
* Delete unneeded file
* Remove duplicate import
* Log error instead of silently irgnoring it
* Move `OffsetNewest` and `OffsetOldest` into keyserver types, change them to be more sane values
* Fix comments
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
It isn't really clear that the deadlines actually help in any way. Currently we can use up our 2 minutes doing something, run out of context time and then return an error which causes the transaction to rollback and forgetting everything we've done. If the message came to us from NATS then we probably will end up retrying just to be in the same situation. We'd be really a lot better if we just spent the time reconciling the problem in the first place, and then we're much less likely to need to fetch those missing auth or prev events in the future.
Also includes matrix-org/gomatrixserverlib#287 so we don't wait so long for servers that are obviously dead.
* Add transaction to all database tables in roomserver, rename latest events updater to room updater, use room updater for all RS input
* Better transaction management
* Tweak order
* Handle cases where the room does not exist
* Other fixes
* More tweaks
* Fill some gaps
* Fill in the gaps
* good lord it gets worse
* Don't roll back transactions when events rejected
* Pass through errors properly
* Fix bugs
* Fix incorrect error check
* Don't panic on nil txns
* Tweaks
* Hopefully fix panics for good in SQLite this time
* Fix rollback
* Minor bug fixes with latest event updater
* Some review comments
* Revert "Some review comments"
This reverts commit 0caf8cf53e62c33f7b83c52e9df1d963871f751e.
* Fix a couple of bugs
* Clearer commit and rollback results
* Remove unnecessary prepares
* PerformInvite: bugfix and rejig control flow
Local clients would not be notified of invites to rooms
Dendrite had already joined in all cases due to not returning
an `api.OutputNewInviteEvent` for local invites. We now do this.
This was an easy mistake to make due to the control flow of the
function which doesn't handle the happy case at the end of the
function and instead forks the function depending on if the
invite was via federation or not. This has now been changed to
handle the federated invite as if it were an error (in that we
check it, do it and bail out) rather than outstay our welcome.
This ends up with the local invite being the happy case, which
now both sends an `InputRoomEvent` to the roomserver _and_ a
`api.OutputNewInviteEvent` is returned.
* Don't send invite pokes in PerformInvite
* Move event ID into logger
* Improve server selection somewhat
* Remove things from the map when we're done
* Be less panicky about auth event signatures in case they are not fatal after all
* Accept HasState in all cases
* Send join asynchronously
* Revert "Send join asynchronously"
This reverts commit 5b685bfcd0b1150a66c7b1e70fb3a3eda509efd1.
* Joins and leaves use background context
* Put federation client functions into their own file
* Look for missing auth events in RS input
* Remove retrieveMissingAuthEvents from federation API
* Logging
* Sorta transplanted the code over
* Use event origin failing all else
* Don't get stuck on mutexes:
* Add verifier
* Don't mark state events with zero snapshot NID as not existing
* Check missing state if not an outlier before storing the event
* Reject instead of soft-fail, don't copy roominfo so much
* Use synchronous contexts, limit time to fetch missing events
* Clean up some commented out bits
* Simplify `/send` endpoint significantly
* Submit async
* Report errors on sending to RS input
* Set max payload in NATS to 16MB
* Tweak metrics
* Add `workerForRoom` for tidiness
* Try skipping unmarshalling errors for RespMissingEvents
* Track missing prev events separately to avoid calculating state when not possible
* Tweak logic around checking missing state
* Care about state when checking missing prev events
* Don't check missing state for create events
* Try that again
* Handle create events better
* Send create room events as new
* Use given event kind when sending auth/state events
* Revert "Use given event kind when sending auth/state events"
This reverts commit 089d64d271b5fca8c104e1554711187420dbebca.
* Only search for missing prev events or state for new events
* Tweaks
* We only have missing prev if we don't supply state
* Room version tweaks
* Allow async inputs again
* Apply backpressure to consumers/synchronous requests to hopefully stop things being overwhelmed
* Set timeouts on roomserver input tasks (need to decide what timeout makes sense)
* Use work queue policy, deliver all on restart
* Reduce chance of duplicates being sent by NATS
* Limit the number of servers we attempt to reduce backpressure
* Some review comment fixes
* Tidy up a couple things
* Don't limit servers, randomise order using map
* Some context refactoring
* Update gmsl
* Don't resend create events
* Set stateIDs length correctly or else the roomserver thinks there are missing events when there aren't
* Exclude our own servername
* Try backing off servers
* Make excluding self behaviour optional
* Exclude self from g_m_e
* Update sytest-whitelist
* Update consumers for the roomserver output stream
* Remember to send outliers for state returned from /gme
* Make full HTTP tests less upsetti
* Remove 'If a device list update goes missing, the server resyncs on the next one' from the sytest blacklist
* Remove debugging test
* Fix blacklist again, remove unnecessary duplicate context
* Clearer contexts, don't use background in case there's something happening there
* Don't queue up events more than once in memory
* Correctly identify create events when checking for state
* Fill in gaps again in /gme code
* Remove `AuthEventIDs` from `InputRoomEvent`
* Remove stray field
Co-authored-by: Kegan Dougal <kegan@matrix.org>
The server ACL code on startup will grab all known rooms from
the rooms_table and then call `GetStateEvent` with each found
room ID to find the server ACL event. This can fail for stub
rooms, which will be present in the rooms table. Previously
this would result in an error being returned and the server
failing to start (!). Now we just return no event for stub
rooms.
* Use named NATS durable consumers
* Build fixes
* Remove dupe call to SetFederationAPI
* Use namespaced consumer name
* Fix namespacing
* Fix unit tests hopefully
* Add NATS JetStream support
Update shopify/sarama
* Fix addresses
* Don't change Addresses in Defaults
* Update saramajetstream
* Add missing error check
Keep typing events for at least one minute
* Use all configured NATS addresses
* Update saramajetstream
* Try setting up with NATS
* Make sure NATS uses own persistent directory (TODO: make this configurable)
* Update go.mod/go.sum
* Jetstream package
* Various other refactoring
* Build fixes
* Config tweaks, make random jetstream storage path for CI
* Disable interest policies
* Try to sane default on jetstream base path
* Try to use in-memory for CI
* Restore storage/retention
* Update nats.go dependency
* Adapt changes to config
* Remove unneeded TopicFor
* Dep update
* Revert "Remove unneeded TopicFor"
This reverts commit f5a4e4a339b6f94ec215778dca22204adaa893d1.
* Revert changes made to streams
* Fix build problems
* Update nats-server
* Update go.mod/go.sum
* Roomserver input API queuing using NATS
* Fix topic naming
* Prometheus metrics
* More refactoring to remove saramajetstream
* Add missing topic
* Don't try to populate map that doesn't exist
* Roomserver output topic
* Update go.mod/go.sum
* Message acknowledgements
* Ack tweaks
* Try to resume transaction re-sends
* Try to resume transaction re-sends
* Update to matrix-org/gomatrixserverlib@91dadfb
* Remove internal.PartitionStorer from components that don't consume keychanges
* Try to reduce re-allocations a bit in resolveConflictsV2
* Tweak delivery options on RS input
* Publish send-to-device messages into correct JetStream subject
* Async and sync roomserver input
* Update dendrite-config.yaml
* Remove roomserver tests for now (they need rewriting)
* Remove roomserver test again (was merged back in)
* Update documentation
* Docker updates
* More Docker updates
* Update Docker readme again
* Fix lint issues
* Send final event in `processEvent` synchronously (since this might stop Sytest from being so upset)
* Don't report event rejection errors via `/send`, since apparently this is upsetting tests that don't expect that
* Go 1.16 instead of Go 1.13 for upgrade tests and Complement
* Revert "Don't report event rejection errors via `/send`, since apparently this is upsetting tests that don't expect that"
This reverts commit 368675283fc44501f227639811bdb16dd5deef8c.
* Don't report any errors on `/send` to see what fun that creates
* Fix panics on closed channel sends
* Enforce state key matches sender
* Do the same for leave
* Various tweaks to make tests happier
Squashed commit of the following:
commit 13f9028e7a63662759ce7c55504a9d2423058668
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 15:47:14 2022 +0000
Do the same for leave
commit e6be7f05c349fafbdddfe818337a17a60c867be1
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 15:33:42 2022 +0000
Enforce state key matches sender
commit 85ede6d64bf10ce9b91cdd6d80f87350ee55242f
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 14:07:04 2022 +0000
Fix panics on closed channel sends
commit 9755494a98bed62450f8001d8128e40481d27e15
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 13:38:22 2022 +0000
Don't report any errors on `/send` to see what fun that creates
commit 3bb4f87b5dd56882febb4db5621db484c8789b7c
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 13:00:26 2022 +0000
Revert "Don't report event rejection errors via `/send`, since apparently this is upsetting tests that don't expect that"
This reverts commit 368675283fc44501f227639811bdb16dd5deef8c.
commit fe2673ed7be9559eaca134424e403a4faca100b0
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 12:09:34 2022 +0000
Go 1.16 instead of Go 1.13 for upgrade tests and Complement
commit 368675283fc44501f227639811bdb16dd5deef8c
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 11:51:45 2022 +0000
Don't report event rejection errors via `/send`, since apparently this is upsetting tests that don't expect that
commit b028dfc08577bcf52e6cb498026e15fa5d46d07c
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Tue Jan 4 10:29:08 2022 +0000
Send final event in `processEvent` synchronously (since this might stop Sytest from being so upset)
* Merge in NATS Server v2.6.6 and nats.go v1.13 into the in-process connection fork
* Add `jetstream.WithJetStreamMessage` to make ack/nak-ing less messy, use process context in consumers
* Fix consumer component name in federation API
* Add comment explaining where streams are defined
* Tweaks to roomserver input with comments
* Finish that sentence that I apparently forgot to finish in INSTALL.md
* Bump version number of config to 2
* Add comments around asynchronous sends to roomserver in processEventWithMissingState
* More useful error message when the config version does not match
* Set version in generate-config
* Fix version in config.Defaults
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Initial federation sender -> federation API refactoring
* Move base into own package, avoids import cycle
* Fix build errors
* Fix tests
* Add signing key server tables
* Try to fold signing key server into federation API
* Fix dendritejs builds
* Update embedded interfaces
* Fix panic, fix lint error
* Update configs, docker
* Rename some things
* Reuse same keyring on the implementing side
* Fix federation tests, `NewBaseDendrite` can accept freeform options
* Fix build
* Update create_db, configs
* Name tables back
* Don't rename federationsender consumer for now
* Add more logs
To help debug the migration issue in #1924 along with manual data-loss-inducing fixes.
Also log the origin server on processed txns to help debug buggy server origins.
* Fix query
* Do not store 'null' in the database for empty JSON arrays
This can cause issues, though it should be noted that the majority
of the time this will marshal/unmarshal just fine, see
https://play.golang.org/p/Doe2NZUgv7Q
* bugfix: sqlite migration should handle create events as having no 'before' snapshot
The state snapshot for any given event in the roomserver represents the state _before_
the event. For the create event, this is nothing, so the state snapshot nid should be 0.
In some cases this wasn't happening, resulting in a nice mix of possible options including:
- A state snapshot without any state blocks `[]` or `null`.
- A state snapshot with a single state block with a single event, the create event, causing
a circular loop. This is incorrect as it represents the state before the event, not after.
* Add state key check
* Topologically sort outliers in SendEventWithState
* Knock in membership updater
* Update gomatrixserverlib
* Update gomatrixserverlib
* Get the NID of the knock event properly for the membership updater
* Generate m.room.canonical_alias instead of legacy m.room.aliases
* Add omitempty tags
* Add aliases endpoint to client API
* Check power levels when setting aliases
* Don't return null on /aliases
* Don't return error if the state event fails
* Update sytest-whitelist
* Don't send updated m.room.canonical_alias events
* Don't check PLs after all because for local aliases they are apparently irrelevant
* Fix some bugs
* Allow deleting a local alias with enough PL
* Fix some more bugs
* Update sytest-whitelist
* Fix copyright notices
* Review comments
* Add room membership and powerlevel checks for func SendBan
* Added non-error return to func GetStateEvent when no state events with the specified state key are found
* Add passing tests to whitelist
* Fixed formatting
* Update roomserver/storage/shared/storage.go
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
Co-authored-by: kegsay <kegan@matrix.org>
Co-authored-by: kegsay <kegsay@gmail.com>
* bugfix: retire invites even when we cannot talk to the remote server to make/send_leave
Also modify the leave response in /sync to include a fake event as this is ultimately
what clients (and sytest) will use to determine leave-ness.
* hash the event ID
* Base64 not hex
* Add more optimised code path for checking if we're in a room
* Fix database queries
* Fix federation API test
* Fix logging
* Review comments
* Make separate API call for room membership
* Logging
* Revert "Logging"
This reverts commit 23ce334182d8a70f8e0381786f9dea77a9b91ed8.
* bugfix: order the state blocks so recreating state snapshots works correctly
* db migration: fix#1844 and add additional assertions
- Migration scripts will now check to see if there are any unconverted
snapshot IDs and fail the migration if there are any. This should
prevent people from getting a corrupt database in the event the root
cause is still unknown.
- Add an ORDER BY clause when doing batch queries in the postgres
migration. LIMIT and OFFSET without ORDER BY are undefined and must
not be relied upon to produce a deterministic ordering (e.g row order).
See https://www.postgresql.org/docs/current/queries-limit.html
* Linting
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Hash-deduplicated state storage (and migrations) for PostgreSQL and SQLite
* Refactor droomserver database setup for migrations
* Fix conflict statements
* Update migration names
* Set a boundary for old to new block/snapshot IDs so we don't rewrite them more than once accidentally
* Create sequence if not exists
* Fix boundary queries
* Fix boundary queries
* Use Query
* Break out queries a bit
* More sequence tweaks
* Query parameters are not playing the game
* Injection escaping may not work for CREATE SEQUENCE after all
* Fix snapshot sequence name
* Use boundaried IDs in SQLite too
* Use IFNULL for SQLite
* Use COALESCE in PostgreSQL
* Review comments @Kegsay
* Check membership of room
* Use QueryStateAfterEventsResponse
* Fix complexity
* Add field ShouldHitAppservice to GetRoomIDForAlias
* Hit appservice when trying to join a non-existent alias
* remove unused
* Changes that I made a long time ago
* Rename to appserviceJoinedAtEvent
* Check membership in GetMemberships
* Update QueryMembershipsForRoom
* Tweaks in client API
* Update appserviceJoinedAtEvent
* Comments
* Try QueryMembershipForUser instead
* Undo some changes to client API that shouldn't be needed
* More /event tweaks
* Refactor /event bit
* Go back to QueryMembershipsForRoom because appservices are hard
* Fix bugs in onMessage
* Add comments
* More logical naming, clean up a bit
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Check membership of room
* Use QueryStateAfterEventsResponse
* Fix complexity
* Changes that I made a long time ago
* Rename to appserviceJoinedAtEvent
* Check membership in GetMemberships
* Update QueryMembershipsForRoom
* Tweaks in client API
* Update appserviceJoinedAtEvent
* Comments
* Try QueryMembershipForUser instead
* Undo some changes to client API that shouldn't be needed
* More /event tweaks
* Refactor /event bit
* Go back to QueryMembershipsForRoom because appservices are hard
* Fix bugs in onMessage
* Add comments
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Look up servers less often, don't hit API for missing auth events unless there are actually missing auth events
* Remove ResolveConflictsAdhoc (since it is already in GMSL), other tweaks
* Update gomatrixserverlib to matrix-org/gomatrixserverlib#254
* Fix resolve-state
* Initialise t.servers on first use
MSC1772 needs this because the create event contains info on if
the room is a space or not. The create event itself isn't sensitive
so other people may find this useful too.
* a very very WIP first cut of peeking via MSC2753.
doesn't yet compile or work.
needs to actually add the peeking block into the sync response.
checking in now before it gets any bigger, and to gather any initial feedback on the vague shape of it.
* make PeekingDeviceSet private
* add server_name param
* blind stab at adding a `peek` section to /sync
* make it build
* make it launch
* add peeking to getResponseWithPDUsForCompleteSync
* cancel any peeks when we join a room
* spell out how to runoutside of docker if you want speed
* fix SQL
* remove unnecessary txn for SelectPeeks
* fix s/join/peek/ cargocult fail
* HACK: Track goroutine IDs to determine when we write by the wrong thread
To use: set `DENDRITE_TRACE_SQL=1` then grep for `unsafe`
* Track partition offsets and only log unsafe for non-selects
* Put redactions in the writer goroutine
* Update filters on writer goroutine
* wrap peek storage in goid hack
* use exclusive writer, and MarkPeeksAsOld more efficiently
* don't log ascii in binary at sql trace...
* strip out empty roomd deltas
* re-add txn to SelectPeeks
* re-add accidentally deleted field
* reject peeks for non-worldreadable rooms
* move perform_peek
* fix package
* correctly refactor perform_peek
* WIP of implementing MSC2444
* typo
* Revert "Merge branch 'kegan/HACK-goid-sqlite-db-is-locked' into matthew/peeking"
This reverts commit 3cebd8dbfbccdf82b7930b7b6eda92095ca6ef41, reversing
changes made to ed4b3a58a7855acc43530693cc855b439edf9c7c.
* (almost) make it build
* clean up bad merge
* support SendEventWithState with optional event
* fix build & lint
* fix build & lint
* reinstate federated peeks in the roomserver (doh)
* fix sql thinko
* todo for authenticating state returned by /peek
* support returning current state from QueryStateAndAuthChain
* handle SS /peek
* reimplement SS /peek to prod the RS to tell the FS about the peek
* rename RemotePeeks as OutboundPeeks
* rename remote_peeks_table as outbound_peeks_table
* add perform_handle_remote_peek.go
* flesh out federation doc
* add inbound peeks table and hook it up
* rename ambiguous RemotePeek as InboundPeek
* rename FSAPI's PerformPeek as PerformOutboundPeek
* setup inbound peeks db correctly
* fix api.SendEventWithState with no event
* track latestevent on /peek
* go fmt
* document the peek send stream race better
* fix SendEventWithRewrite not to bail if handed a non-state event
* add fixme
* switch SS /peek to use SendEventWithRewrite
* fix comment
* use reverse topo ordering to find latest extrem
* support postgres for federated peeking
* go fmt
* back out bogus go.mod change
* Fix performOutboundPeekUsingServer
* Fix getAuthChain -> GetAuthChain
* Fix build issues
* Fix build again
* Fix getAuthChain -> GetAuthChain
* Don't repeat outbound peeks for the same room ID to the same servers
* Fix lint
* Don't omitempty to appease sytest
Co-authored-by: Kegan Dougal <kegan@matrix.org>
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Light-weight checking of state changes when updating forward extremities
* Only do this for non-state events, since state events will always result in state change at extremities
Squashed commit of the following:
commit e5e2d793119733ecbcf9b85f966e018ab0318741
Author: Neil Alexander <neilalexander@users.noreply.github.com>
Date: Wed Jan 13 17:28:12 2021 +0000
Add dendrite_roomserver_processroomevent_duration_millis to prometheus
* Add RoomInfo cache, remove RoomServerRoomNID cache, ensure caches are thread-safe
* Don't panic if the roomInfo isn't known yet
* LRU package is already threadsafe
* Use RoomInfo cache to find room version if possible in Events()
* Adding comments about RoomInfoCache safety
* Hit the database far less to find room NIDs for event NIDs
* Close the rows
* Fix SQLite selectRoomNIDsForEventNIDsSQL
* Give same treatment to room version lookups
* Update GMSL
* Add MSC2836EventRelationships to fedsender
* Call MSC2836EventRelationships in reqCtx
* auth remote servers
* Extract room ID and servers from previous events; refactor a bit
* initial cut of federated threading
* Use the right client/fed struct in the response
* Add QueryAuthChain for use with MSC2836
* Add auth chain to federated response
* Fix pointers
* under CI: more logging and enable mscs, nil fix
* Handle direction: up
* Actually send message events to the roomserver..
* Add children and children_hash to unsigned, with tests
* Add logic for exploring threads and tracking children; missing storage functions
* Implement storage functions for children
* Add fetchUnknownEvent
* Do federated hits for include_children if we have unexplored children
* Use /ev_rel rather than /event as the former includes child metadata
* Remove cross-room threading impl
* Enable MSC2836 in the p2p demo
* Namespace mscs db
* Enable msc2836 for ygg
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Don't recalculate event IDs so often
* Revert invite change
* Make sure we're using the right NIDs
* Update gomatrixserverlib
* Update to NewEventFromTrustedJSONWithEventID
* Fix go.mod
* Update gomatrixserverlib to matrix-org/gomatrixserverlib#243
* Use BulkSelectEventID
* Add mscs/hooks package, begin work for msc2836
* Flesh out hooks and add SQL schema
* Begin implementing core msc2836 logic
* Add test harness
* Linting
* Implement visibility checks; stub out APIs for tests
* Flesh out testing
* Flesh out walkThread a bit
* Persist the origin_server_ts as well
* Edges table instead of relationships
* Add nodes table for event metadata
* LEFT JOIN to extract origin_server_ts for children
* Add graph walking structs
* Implement walking algorithm
* Add more graph walking tests
* Add auto_join for local rooms
* Fix create table syntax on postgres
* Add relationship_room_id|servers to the unsigned section of events
* Persist the parent room_id/servers in edge metadata
Other events cannot assert the true room_id/servers for the
parent event, only make claims to them, hence why this is
edge metadata.
* guts to pass through room_id/servers
* Refactor msc2836 to allow handling from federation
* Add JoinedVia to PerformJoin responses
* Fix tests; review comments
The previous implementation was only checking if room history was
"shared", which it wasn't for rooms where a user was invited, or world
readable rooms.
This implementation leverages the IsServerAllowed method, which already
implements the complete verification algorithm.
Signed-off-by: `Mayeul Cantan <oss+matrix@mayeul.net>`
Co-authored-by: Kegsay <kegan@matrix.org>
* Add basic storage methods
* Add internal api handler
* Add check for forgotten room
* Add /rooms/{roomID}/forget endpoint
* Add missing rsAPI method
* Remove unused parameters
* Add passing tests
Signed-off-by: Till Faelligen <tfaelligen@gmail.com>
* Add missing file
* Add postgres migration
* Add sqlite migration
* Use Forgetter to forget room
* Remove empty line
* Update HTTP status codes
It looks like the spec calls for these to be 400, rather than 403: https://matrix.org/docs/spec/client_server/r0.6.1#post-matrix-client-r0-rooms-roomid-forget
Co-authored-by: Neil Alexander <neilalexander@users.noreply.github.com>
* Add configuration for max_message_bytes for sarama
* Log all errors when sending multiple messages
Signed-off-by: Till Faelligen <tfaelligen@gmail.com>
* Add missing config
* - Better comments on what MaxMessageBytes is used for
- Also sets the size the consumer may use
* Set RewritesState once
* Check if any new state provided
* Obey rewritesState
* Don't nuke everything the sync API knows when purging state
* Fix panic from duplicate insert
* Consistency
* Use HasState
* Remove nolint
* Clean up joined rooms on state rewrite
* Add resolve-state helper
* Tweaks
* Refactor forward extremities, again
* Tweaks
* Minor optimisation
* Make path a bit clearer
* Only process state/membership if forward extremities have changed
* Usage comments in resolve-state
