Method stringTuplesToNumericTuples

roomserver/state/state.go:308–345

stringTuplesToNumericTuples converts the string state key tuples into numeric IDs If there isn't a numeric ID for either the event type or the event state key then the tuple is discarded. Returns an error if there was a problem talking to the database.

(
	ctx context.Context,
	stringTuples []gomatrixserverlib.StateKeyTuple,
)

// If there isn't a numeric ID for either the event type or the event state key then the tuple is discarded.
// Returns an error if there was a problem talking to the database.
func (v *StateResolution) stringTuplesToNumericTuples(
	ctx context.Context,
	stringTuples []gomatrixserverlib.StateKeyTuple,
) ([]types.StateKeyTuple, error) {
	span, ctx := opentracing.StartSpanFromContext(ctx, "StateResolution.stringTuplesToNumericTuples")
	defer span.Finish()

	eventTypes := make([]string, len(stringTuples))
	stateKeys := make([]string, len(stringTuples))
	for i := range stringTuples {
		eventTypes[i] = stringTuples[i].EventType
		stateKeys[i] = stringTuples[i].StateKey
	}
	eventTypes = util.UniqueStrings(eventTypes)
	eventTypeMap, err := v.db.EventTypeNIDs(ctx, eventTypes)
	if err != nil {
		return nil, err
	}
	stateKeys = util.UniqueStrings(stateKeys)
	stateKeyMap, err := v.db.EventStateKeyNIDs(ctx, stateKeys)
	if err != nil {
		return nil, err
	}

	var result []types.StateKeyTuple
	for _, stringTuple := range stringTuples {
		var numericTuple types.StateKeyTuple
		var ok1, ok2 bool
		numericTuple.EventTypeNID, ok1 = eventTypeMap[stringTuple.EventType]
		numericTuple.EventStateKeyNID, ok2 = stateKeyMap[stringTuple.StateKey]
		// Discard the tuple if there wasn't a numeric ID for either the event type or the state key.
		if ok1 && ok2 {
			result = append(result, numericTuple)
		}
	}

	return result, nil
}

// loadStateAtSnapshotForNumericTuples loads the state for a list of event type and state key pairs at a snapshot.
// This is used when we only want to load a subset of the room state at a snapshot.