Roomserver/federation input refactor (#2104)

* 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>

federationapi/routing/send_test.go

@@ -4,7 +4,6 @@ import (
 	"context"
 	"encoding/json"
 	"fmt"
-	"reflect"
 	"testing"
 	"time"
 
@@ -244,8 +243,6 @@ func mustCreateTransaction(rsAPI api.RoomserverInternalAPI, fedClient txnFederat
 		eduAPI:     &testEDUProducer{},
 		keys:       &test.NopJSONVerifier{},
 		federation: fedClient,
-		haveEvents: make(map[string]*gomatrixserverlib.HeaderedEvent),
-		hadEvents:  make(map[string]bool),
 		roomsMu:    internal.NewMutexByRoom(),
 	}
 	t.PDUs = pdus
@@ -279,6 +276,7 @@ NextPDU:
 	}
 }
 
+/*
 func fromStateTuples(tuples []gomatrixserverlib.StateKeyTuple, omitTuples []gomatrixserverlib.StateKeyTuple) (result []*gomatrixserverlib.HeaderedEvent) {
 NextTuple:
 	for _, t := range tuples {
@@ -294,6 +292,7 @@ NextTuple:
 	}
 	return
 }
+*/
 
 func assertInputRoomEvents(t *testing.T, got []api.InputRoomEvent, want []*gomatrixserverlib.HeaderedEvent) {
 	for _, g := range got {
@@ -355,6 +354,7 @@ func TestTransactionFailAuthChecks(t *testing.T) {
 // we request them from /get_missing_events. It works by setting PrevEventsExist=false in the roomserver query response,
 // resulting in a call to /get_missing_events which returns the missing prev event. Both events should be processed in
 // topological order and sent to the roomserver.
+/*
 func TestTransactionFetchMissingPrevEvents(t *testing.T) {
 	haveEvent := testEvents[len(testEvents)-3]
 	prevEvent := testEvents[len(testEvents)-2]
@@ -619,3 +619,4 @@ func TestTransactionFetchMissingStateByStateIDs(t *testing.T) {
 	mustProcessTransaction(t, txn, nil)
 	assertInputRoomEvents(t, rsAPI.inputRoomEvents, []*gomatrixserverlib.HeaderedEvent{eventB, eventC, eventD})
 }
+*/