Fix newly joined users presence (#2854)

Fixes #2803 
Also refactors the presence stream to not hit the database for every
user, instead queries all users at once now.

11 files changed, 263 insertions, 75 deletions

diff --git a/syncapi/consumers/presence.go b/syncapi/consumers/presence.go
index 145059c2..6e3150c2 100644
--- a/syncapi/consumers/presence.go
+++ b/syncapi/consumers/presence.go
@@ -78,7 +78,7 @@ func (s *PresenceConsumer) Start() error {
 	// Normal NATS subscription, used by Request/Reply
 	_, err := s.nats.Subscribe(s.requestTopic, func(msg *nats.Msg) {
 		userID := msg.Header.Get(jetstream.UserID)
-		presence, err := s.db.GetPresence(context.Background(), userID)
+		presences, err := s.db.GetPresences(context.Background(), []string{userID})
 		m := &nats.Msg{
 			Header: nats.Header{},
 		}
@@ -89,10 +89,12 @@ func (s *PresenceConsumer) Start() error {
 			}
 			return
 		}
-		if presence == nil {
-			presence = &types.PresenceInternal{
-				UserID: userID,
-			}
+
+		presence := &types.PresenceInternal{
+			UserID: userID,
+		}
+		if len(presences) > 0 {
+			presence = presences[0]
 		}
 
 		deviceRes := api.QueryDevicesResponse{}
diff --git a/syncapi/storage/interface.go b/syncapi/storage/interface.go
index 97c2ced4..75afbce1 100644
--- a/syncapi/storage/interface.go
+++ b/syncapi/storage/interface.go
@@ -106,7 +106,7 @@ type DatabaseTransaction interface {
 	SelectMembershipForUser(ctx context.Context, roomID, userID string, pos int64) (membership string, topologicalPos int, err error)
 	// getUserUnreadNotificationCountsForRooms returns the unread notifications for the given rooms
 	GetUserUnreadNotificationCountsForRooms(ctx context.Context, userID string, roomIDs map[string]string) (map[string]*eventutil.NotificationData, error)
-	GetPresence(ctx context.Context, userID string) (*types.PresenceInternal, error)
+	GetPresences(ctx context.Context, userID []string) ([]*types.PresenceInternal, error)
 	PresenceAfter(ctx context.Context, after types.StreamPosition, filter gomatrixserverlib.EventFilter) (map[string]*types.PresenceInternal, error)
 	RelationsFor(ctx context.Context, roomID, eventID, relType, eventType string, from, to types.StreamPosition, backwards bool, limit int) (events []types.StreamEvent, prevBatch, nextBatch string, err error)
 }
@@ -186,7 +186,7 @@ type Database interface {
 }
 
 type Presence interface {
-	GetPresence(ctx context.Context, userID string) (*types.PresenceInternal, error)
+	GetPresences(ctx context.Context, userIDs []string) ([]*types.PresenceInternal, error)
 	UpdatePresence(ctx context.Context, userID string, presence types.Presence, statusMsg *string, lastActiveTS gomatrixserverlib.Timestamp, fromSync bool) (types.StreamPosition, error)
 }
 
diff --git a/syncapi/storage/postgres/presence_table.go b/syncapi/storage/postgres/presence_table.go
index 7194afea..a3f7c521 100644
--- a/syncapi/storage/postgres/presence_table.go
+++ b/syncapi/storage/postgres/presence_table.go
@@ -19,10 +19,12 @@ import (
 	"database/sql"
 	"time"
 
+	"github.com/lib/pq"
+	"github.com/matrix-org/gomatrixserverlib"
+
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/types"
-	"github.com/matrix-org/gomatrixserverlib"
 )
 
 const presenceSchema = `
@@ -63,9 +65,9 @@ const upsertPresenceFromSyncSQL = "" +
 	" RETURNING id"
 
 const selectPresenceForUserSQL = "" +
-	"SELECT presence, status_msg, last_active_ts" +
+	"SELECT user_id, presence, status_msg, last_active_ts" +
 	" FROM syncapi_presence" +
-	" WHERE user_id = $1 LIMIT 1"
+	" WHERE user_id = ANY($1)"
 
 const selectMaxPresenceSQL = "" +
 	"SELECT COALESCE(MAX(id), 0) FROM syncapi_presence"
@@ -119,20 +121,28 @@ func (p *presenceStatements) UpsertPresence(
 	return
 }
 
-// GetPresenceForUser returns the current presence of a user.
-func (p *presenceStatements) GetPresenceForUser(
+// GetPresenceForUsers returns the current presence for a list of users.
+// If the user doesn't have a presence status yet, it is omitted from the response.
+func (p *presenceStatements) GetPresenceForUsers(
 	ctx context.Context, txn *sql.Tx,
-	userID string,
-) (*types.PresenceInternal, error) {
-	result := &types.PresenceInternal{
-		UserID: userID,
-	}
+	userIDs []string,
+) ([]*types.PresenceInternal, error) {
+	result := make([]*types.PresenceInternal, 0, len(userIDs))
 	stmt := sqlutil.TxStmt(txn, p.selectPresenceForUsersStmt)
-	err := stmt.QueryRowContext(ctx, userID).Scan(&result.Presence, &result.ClientFields.StatusMsg, &result.LastActiveTS)
-	if err == sql.ErrNoRows {
-		return nil, nil
+	rows, err := stmt.QueryContext(ctx, pq.Array(userIDs))
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "GetPresenceForUsers: rows.close() failed")
+
+	for rows.Next() {
+		presence := &types.PresenceInternal{}
+		if err = rows.Scan(&presence.UserID, &presence.Presence, &presence.ClientFields.StatusMsg, &presence.LastActiveTS); err != nil {
+			return nil, err
+		}
+		presence.ClientFields.Presence = presence.Presence.String()
+		result = append(result, presence)
 	}
-	result.ClientFields.Presence = result.Presence.String()
 	return result, err
 }
 
diff --git a/syncapi/storage/shared/storage_consumer.go b/syncapi/storage/shared/storage_consumer.go
index f2064fb8..df2338cf 100644
--- a/syncapi/storage/shared/storage_consumer.go
+++ b/syncapi/storage/shared/storage_consumer.go
@@ -564,8 +564,8 @@ func (d *Database) UpdatePresence(ctx context.Context, userID string, presence t
 	return pos, err
 }
 
-func (d *Database) GetPresence(ctx context.Context, userID string) (*types.PresenceInternal, error) {
-	return d.Presence.GetPresenceForUser(ctx, nil, userID)
+func (d *Database) GetPresences(ctx context.Context, userIDs []string) ([]*types.PresenceInternal, error) {
+	return d.Presence.GetPresenceForUsers(ctx, nil, userIDs)
 }
 
 func (d *Database) SelectMembershipForUser(ctx context.Context, roomID, userID string, pos int64) (membership string, topologicalPos int, err error) {
diff --git a/syncapi/storage/shared/storage_sync.go b/syncapi/storage/shared/storage_sync.go
index c3763521..77afa029 100644
--- a/syncapi/storage/shared/storage_sync.go
+++ b/syncapi/storage/shared/storage_sync.go
@@ -596,8 +596,8 @@ func (d *DatabaseTransaction) GetUserUnreadNotificationCountsForRooms(ctx contex
 	return d.NotificationData.SelectUserUnreadCountsForRooms(ctx, d.txn, userID, roomIDs)
 }
 
-func (d *DatabaseTransaction) GetPresence(ctx context.Context, userID string) (*types.PresenceInternal, error) {
-	return d.Presence.GetPresenceForUser(ctx, d.txn, userID)
+func (d *DatabaseTransaction) GetPresences(ctx context.Context, userIDs []string) ([]*types.PresenceInternal, error) {
+	return d.Presence.GetPresenceForUsers(ctx, d.txn, userIDs)
 }
 
 func (d *DatabaseTransaction) PresenceAfter(ctx context.Context, after types.StreamPosition, filter gomatrixserverlib.EventFilter) (map[string]*types.PresenceInternal, error) {
diff --git a/syncapi/storage/sqlite3/presence_table.go b/syncapi/storage/sqlite3/presence_table.go
index b61a825d..7641de92 100644
--- a/syncapi/storage/sqlite3/presence_table.go
+++ b/syncapi/storage/sqlite3/presence_table.go
@@ -17,12 +17,14 @@ package sqlite3
 import (
 	"context"
 	"database/sql"
+	"strings"
 	"time"
 
+	"github.com/matrix-org/gomatrixserverlib"
+
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/types"
-	"github.com/matrix-org/gomatrixserverlib"
 )
 
 const presenceSchema = `
@@ -62,9 +64,9 @@ const upsertPresenceFromSyncSQL = "" +
 	" RETURNING id"
 
 const selectPresenceForUserSQL = "" +
-	"SELECT presence, status_msg, last_active_ts" +
+	"SELECT user_id, presence, status_msg, last_active_ts" +
 	" FROM syncapi_presence" +
-	" WHERE user_id = $1 LIMIT 1"
+	" WHERE user_id IN ($1)"
 
 const selectMaxPresenceSQL = "" +
 	"SELECT COALESCE(MAX(id), 0) FROM syncapi_presence"
@@ -134,20 +136,38 @@ func (p *presenceStatements) UpsertPresence(
 	return
 }
 
-// GetPresenceForUser returns the current presence of a user.
-func (p *presenceStatements) GetPresenceForUser(
+// GetPresenceForUsers returns the current presence for a list of users.
+// If the user doesn't have a presence status yet, it is omitted from the response.
+func (p *presenceStatements) GetPresenceForUsers(
 	ctx context.Context, txn *sql.Tx,
-	userID string,
-) (*types.PresenceInternal, error) {
-	result := &types.PresenceInternal{
-		UserID: userID,
+	userIDs []string,
+) ([]*types.PresenceInternal, error) {
+	qry := strings.Replace(selectPresenceForUserSQL, "($1)", sqlutil.QueryVariadic(len(userIDs)), 1)
+	prepStmt, err := p.db.Prepare(qry)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, prepStmt, "GetPresenceForUsers: stmt.close() failed")
+
+	params := make([]interface{}, len(userIDs))
+	for i := range userIDs {
+		params[i] = userIDs[i]
 	}
-	stmt := sqlutil.TxStmt(txn, p.selectPresenceForUsersStmt)
-	err := stmt.QueryRowContext(ctx, userID).Scan(&result.Presence, &result.ClientFields.StatusMsg, &result.LastActiveTS)
-	if err == sql.ErrNoRows {
-		return nil, nil
+
+	rows, err := sqlutil.TxStmt(txn, prepStmt).QueryContext(ctx, params...)
+	if err != nil {
+		return nil, err
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "GetPresenceForUsers: rows.close() failed")
+	result := make([]*types.PresenceInternal, 0, len(userIDs))
+	for rows.Next() {
+		presence := &types.PresenceInternal{}
+		if err = rows.Scan(&presence.UserID, &presence.Presence, &presence.ClientFields.StatusMsg, &presence.LastActiveTS); err != nil {
+			return nil, err
+		}
+		presence.ClientFields.Presence = presence.Presence.String()
+		result = append(result, presence)
 	}
-	result.ClientFields.Presence = result.Presence.String()
 	return result, err
 }
 
diff --git a/syncapi/storage/tables/interface.go b/syncapi/storage/tables/interface.go
index 2c4f04ec..a0574b25 100644
--- a/syncapi/storage/tables/interface.go
+++ b/syncapi/storage/tables/interface.go
@@ -207,7 +207,7 @@ type Ignores interface {
 
 type Presence interface {
 	UpsertPresence(ctx context.Context, txn *sql.Tx, userID string, statusMsg *string, presence types.Presence, lastActiveTS gomatrixserverlib.Timestamp, fromSync bool) (pos types.StreamPosition, err error)
-	GetPresenceForUser(ctx context.Context, txn *sql.Tx, userID string) (presence *types.PresenceInternal, err error)
+	GetPresenceForUsers(ctx context.Context, txn *sql.Tx, userIDs []string) (presence []*types.PresenceInternal, err error)
 	GetMaxPresenceID(ctx context.Context, txn *sql.Tx) (pos types.StreamPosition, err error)
 	GetPresenceAfter(ctx context.Context, txn *sql.Tx, after types.StreamPosition, filter gomatrixserverlib.EventFilter) (presences map[string]*types.PresenceInternal, err error)
 }
diff --git a/syncapi/storage/tables/presence_table_test.go b/syncapi/storage/tables/presence_table_test.go
new file mode 100644
index 00000000..dce0c695
--- /dev/null
+++ b/syncapi/storage/tables/presence_table_test.go
@@ -0,0 +1,136 @@
+package tables_test
+
+import (
+	"context"
+	"database/sql"
+	"reflect"
+	"testing"
+	"time"
+
+	"github.com/matrix-org/gomatrixserverlib"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/matrix-org/dendrite/setup/config"
+	"github.com/matrix-org/dendrite/syncapi/storage/postgres"
+	"github.com/matrix-org/dendrite/syncapi/storage/sqlite3"
+	"github.com/matrix-org/dendrite/syncapi/storage/tables"
+	"github.com/matrix-org/dendrite/syncapi/types"
+	"github.com/matrix-org/dendrite/test"
+)
+
+func mustPresenceTable(t *testing.T, dbType test.DBType) (tables.Presence, func()) {
+	t.Helper()
+	connStr, close := test.PrepareDBConnectionString(t, dbType)
+	db, err := sqlutil.Open(&config.DatabaseOptions{
+		ConnectionString: config.DataSource(connStr),
+	}, sqlutil.NewExclusiveWriter())
+	if err != nil {
+		t.Fatalf("failed to open db: %s", err)
+	}
+
+	var tab tables.Presence
+	switch dbType {
+	case test.DBTypePostgres:
+		tab, err = postgres.NewPostgresPresenceTable(db)
+	case test.DBTypeSQLite:
+		var stream sqlite3.StreamIDStatements
+		if err = stream.Prepare(db); err != nil {
+			t.Fatalf("failed to prepare stream stmts: %s", err)
+		}
+		tab, err = sqlite3.NewSqlitePresenceTable(db, &stream)
+	}
+	if err != nil {
+		t.Fatalf("failed to make new table: %s", err)
+	}
+	return tab, close
+}
+
+func TestPresence(t *testing.T) {
+	alice := test.NewUser(t)
+	bob := test.NewUser(t)
+	ctx := context.Background()
+
+	statusMsg := "Hello World!"
+	timestamp := gomatrixserverlib.AsTimestamp(time.Now())
+
+	var txn *sql.Tx
+	test.WithAllDatabases(t, func(t *testing.T, dbType test.DBType) {
+		tab, closeDB := mustPresenceTable(t, dbType)
+		defer closeDB()
+
+		// Insert some presences
+		pos, err := tab.UpsertPresence(ctx, txn, alice.ID, &statusMsg, types.PresenceOnline, timestamp, false)
+		if err != nil {
+			t.Error(err)
+		}
+		wantPos := types.StreamPosition(1)
+		if pos != wantPos {
+			t.Errorf("expected pos to be %d, got %d", wantPos, pos)
+		}
+		pos, err = tab.UpsertPresence(ctx, txn, bob.ID, &statusMsg, types.PresenceOnline, timestamp, false)
+		if err != nil {
+			t.Error(err)
+		}
+		wantPos = 2
+		if pos != wantPos {
+			t.Errorf("expected pos to be %d, got %d", wantPos, pos)
+		}
+
+		// verify the expected max presence ID
+		maxPos, err := tab.GetMaxPresenceID(ctx, txn)
+		if err != nil {
+			t.Error(err)
+		}
+		if maxPos != wantPos {
+			t.Errorf("expected max pos to be %d, got %d", wantPos, maxPos)
+		}
+
+		// This should increment the position
+		pos, err = tab.UpsertPresence(ctx, txn, bob.ID, &statusMsg, types.PresenceOnline, timestamp, true)
+		if err != nil {
+			t.Error(err)
+		}
+		wantPos = pos
+		if wantPos <= maxPos {
+			t.Errorf("expected pos to be %d incremented, got %d", wantPos, pos)
+		}
+
+		// This should return only Bobs status
+		presences, err := tab.GetPresenceAfter(ctx, txn, maxPos, gomatrixserverlib.EventFilter{Limit: 10})
+		if err != nil {
+			t.Error(err)
+		}
+
+		if c := len(presences); c > 1 {
+			t.Errorf("expected only one presence, got %d", c)
+		}
+
+		// Validate the response
+		wantPresence := &types.PresenceInternal{
+			UserID:       bob.ID,
+			Presence:     types.PresenceOnline,
+			StreamPos:    wantPos,
+			LastActiveTS: timestamp,
+			ClientFields: types.PresenceClientResponse{
+				LastActiveAgo: 0,
+				Presence:      types.PresenceOnline.String(),
+				StatusMsg:     &statusMsg,
+			},
+		}
+		if !reflect.DeepEqual(wantPresence, presences[bob.ID]) {
+			t.Errorf("unexpected presence result:\n%+v, want\n%+v", presences[bob.ID], wantPresence)
+		}
+
+		// Try getting presences for existing and non-existing users
+		getUsers := []string{alice.ID, bob.ID, "@doesntexist:test"}
+		presencesForUsers, err := tab.GetPresenceForUsers(ctx, nil, getUsers)
+		if err != nil {
+			t.Error(err)
+		}
+
+		if len(presencesForUsers) >= len(getUsers) {
+			t.Errorf("expected less presences, but they are the same/more as requested: %d >= %d", len(presencesForUsers), len(getUsers))
+		}
+	})
+
+}
diff --git a/syncapi/streams/stream_presence.go b/syncapi/streams/stream_presence.go
index 030b7c5d..445e46b3 100644
--- a/syncapi/streams/stream_presence.go
+++ b/syncapi/streams/stream_presence.go
@@ -17,6 +17,7 @@ package streams
 import (
 	"context"
 	"encoding/json"
+	"fmt"
 	"sync"
 
 	"github.com/matrix-org/gomatrixserverlib"
@@ -70,39 +71,25 @@ func (p *PresenceStreamProvider) IncrementalSync(
 		return from
 	}
 
-	if len(presences) == 0 {
+	getPresenceForUsers, err := p.getNeededUsersFromRequest(ctx, req, presences)
+	if err != nil {
+		req.Log.WithError(err).Error("getNeededUsersFromRequest failed")
+		return from
+	}
+
+	// Got no presence between range and no presence to get from the database
+	if len(getPresenceForUsers) == 0 && len(presences) == 0 {
 		return to
 	}
 
-	// add newly joined rooms user presences
-	newlyJoined := joinedRooms(req.Response, req.Device.UserID)
-	if len(newlyJoined) > 0 {
-		// TODO: Check if this is working better than before.
-		if err = p.notifier.LoadRooms(ctx, p.DB, newlyJoined); err != nil {
-			req.Log.WithError(err).Error("unable to refresh notifier lists")
-			return from
-		}
-	NewlyJoinedLoop:
-		for _, roomID := range newlyJoined {
-			roomUsers := p.notifier.JoinedUsers(roomID)
-			for i := range roomUsers {
-				// we already got a presence from this user
-				if _, ok := presences[roomUsers[i]]; ok {
-					continue
-				}
-				// Bear in mind that this might return nil, but at least populating
-				// a nil means that there's a map entry so we won't repeat this call.
-				presences[roomUsers[i]], err = snapshot.GetPresence(ctx, roomUsers[i])
-				if err != nil {
-					req.Log.WithError(err).Error("unable to query presence for user")
-					_ = snapshot.Rollback()
-					return from
-				}
-				if len(presences) > req.Filter.Presence.Limit {
-					break NewlyJoinedLoop
-				}
-			}
-		}
+	dbPresences, err := snapshot.GetPresences(ctx, getPresenceForUsers)
+	if err != nil {
+		req.Log.WithError(err).Error("unable to query presence for user")
+		_ = snapshot.Rollback()
+		return from
+	}
+	for _, presence := range dbPresences {
+		presences[presence.UserID] = presence
 	}
 
 	lastPos := from
@@ -164,6 +151,39 @@ func (p *PresenceStreamProvider) IncrementalSync(
 	return lastPos
 }
 
+func (p *PresenceStreamProvider) getNeededUsersFromRequest(ctx context.Context, req *types.SyncRequest, presences map[string]*types.PresenceInternal) ([]string, error) {
+	getPresenceForUsers := []string{}
+	// Add presence for users which newly joined a room
+	for userID := range req.MembershipChanges {
+		if _, ok := presences[userID]; ok {
+			continue
+		}
+		getPresenceForUsers = append(getPresenceForUsers, userID)
+	}
+
+	// add newly joined rooms user presences
+	newlyJoined := joinedRooms(req.Response, req.Device.UserID)
+	if len(newlyJoined) == 0 {
+		return getPresenceForUsers, nil
+	}
+
+	// TODO: Check if this is working better than before.
+	if err := p.notifier.LoadRooms(ctx, p.DB, newlyJoined); err != nil {
+		return getPresenceForUsers, fmt.Errorf("unable to refresh notifier lists: %w", err)
+	}
+	for _, roomID := range newlyJoined {
+		roomUsers := p.notifier.JoinedUsers(roomID)
+		for i := range roomUsers {
+			// we already got a presence from this user
+			if _, ok := presences[roomUsers[i]]; ok {
+				continue
+			}
+			getPresenceForUsers = append(getPresenceForUsers, roomUsers[i])
+		}
+	}
+	return getPresenceForUsers, nil
+}
+
 func joinedRooms(res *types.Response, userID string) []string {
 	var roomIDs []string
 	for roomID, join := range res.Rooms.Join {
diff --git a/syncapi/sync/requestpool.go b/syncapi/sync/requestpool.go
index 29d92b29..b086567b 100644
--- a/syncapi/sync/requestpool.go
+++ b/syncapi/sync/requestpool.go
@@ -145,12 +145,12 @@ func (rp *RequestPool) updatePresence(db storage.Presence, presence string, user
 	}
 
 	// ensure we also send the current status_msg to federated servers and not nil
-	dbPresence, err := db.GetPresence(context.Background(), userID)
+	dbPresence, err := db.GetPresences(context.Background(), []string{userID})
 	if err != nil && err != sql.ErrNoRows {
 		return
 	}
-	if dbPresence != nil {
-		newPresence.ClientFields = dbPresence.ClientFields
+	if len(dbPresence) > 0 && dbPresence[0] != nil {
+		newPresence.ClientFields = dbPresence[0].ClientFields
 	}
 	newPresence.ClientFields.Presence = presenceID.String()
 
diff --git a/syncapi/sync/requestpool_test.go b/syncapi/sync/requestpool_test.go
index 3e5769d8..faa0b49c 100644
--- a/syncapi/sync/requestpool_test.go
+++ b/syncapi/sync/requestpool_test.go
@@ -29,8 +29,8 @@ func (d dummyDB) UpdatePresence(ctx context.Context, userID string, presence typ
 	return 0, nil
 }
 
-func (d dummyDB) GetPresence(ctx context.Context, userID string) (*types.PresenceInternal, error) {
-	return &types.PresenceInternal{}, nil
+func (d dummyDB) GetPresences(ctx context.Context, userID []string) ([]*types.PresenceInternal, error) {
+	return []*types.PresenceInternal{}, nil
 }
 
 func (d dummyDB) PresenceAfter(ctx context.Context, after types.StreamPosition, filter gomatrixserverlib.EventFilter) (map[string]*types.PresenceInternal, error) {