Rudimentary pagination of rooms in the rooms filter

syncapi/storage/interface.go

@@ -140,4 +140,6 @@ type Database interface {
 	StoreReceipt(ctx context.Context, roomId, receiptType, userId, eventId string, timestamp gomatrixserverlib.Timestamp) (pos types.StreamPosition, err error)
 	// GetRoomReceipts gets all receipts for a given roomID
 	GetRoomReceipts(ctx context.Context, roomIDs []string, streamPos types.StreamPosition) ([]eduAPI.OutputReceiptEvent, error)
+
+	GetPaginatedRooms(ctx context.Context, userID string, offset, count int) ([]string, error)
 }

syncapi/storage/postgres/memberships_table.go

@@ -19,6 +19,7 @@ import (
 	"database/sql"
 	"fmt"
 
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/storage/tables"
 	"github.com/matrix-org/dendrite/syncapi/types"
@@ -62,9 +63,14 @@ const selectMembershipSQL = "" +
 	" ORDER BY stream_pos DESC" +
 	" LIMIT 1"
 
+const selectMembershipsSQL = "" +
+	"SELECT room_id, membership FROM syncapi_memberships" +
+	" WHERE user_id = $1"
+
 type membershipsStatements struct {
 	upsertMembershipStmt  *sql.Stmt
 	selectMembershipStmt  *sql.Stmt
+	selectMembershipsStmt *sql.Stmt
 }
 
 func NewPostgresMembershipsTable(db *sql.DB) (tables.Memberships, error) {
@@ -79,6 +85,9 @@ func NewPostgresMembershipsTable(db *sql.DB) (tables.Memberships, error) {
 	if s.selectMembershipStmt, err = db.Prepare(selectMembershipSQL); err != nil {
 		return nil, err
 	}
+	if s.selectMembershipsStmt, err = db.Prepare(selectMembershipsSQL); err != nil {
+		return nil, err
+	}
 	return s, nil
 }
 
@@ -109,3 +118,24 @@ func (s *membershipsStatements) SelectMembership(
 	err = stmt.QueryRowContext(ctx, roomID, userID, memberships).Scan(&eventID, &streamPos, &topologyPos)
 	return
 }
+
+func (s *membershipsStatements) SelectMemberships(
+	ctx context.Context, txn *sql.Tx, userID string,
+) (map[string]string, error) {
+	var roomID, membership string
+	result := map[string]string{}
+	stmt := sqlutil.TxStmt(txn, s.selectMembershipsStmt)
+	rows, err := stmt.QueryContext(ctx, userID)
+	if err != nil {
+		return nil, fmt.Errorf("stmt.QueryContext: %w", err)
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "failed to close rows")
+	for rows.Next() {
+		err = rows.Scan(&roomID, &membership)
+		if err != nil {
+			return nil, fmt.Errorf("rows.Scan: %w", err)
+		}
+		result[roomID] = membership
+	}
+	return result, nil
+}

syncapi/storage/postgres/output_room_events_table.go

@@ -19,6 +19,7 @@ import (
 	"context"
 	"database/sql"
 	"encoding/json"
+	"fmt"
 	"sort"
 
 	"github.com/matrix-org/dendrite/internal"
@@ -127,6 +128,13 @@ const selectStateInRangeSQL = "" +
 	" ORDER BY id ASC" +
 	" LIMIT $8"
 
+const bulkSelectMaxStreamPositionsSQL = "" +
+	"SELECT room_id, MAX(id) AS id FROM syncapi_output_room_events" +
+	" WHERE room_id = ANY($1)" +
+	" GROUP BY room_id" +
+	" ORDER BY id DESC" +
+	" OFFSET $2 LIMIT $3"
+
 const deleteEventsForRoomSQL = "" +
 	"DELETE FROM syncapi_output_room_events WHERE room_id = $1"
 
@@ -140,6 +148,7 @@ type outputRoomEventsStatements struct {
 	selectStateInRangeStmt           *sql.Stmt
 	updateEventJSONStmt              *sql.Stmt
 	deleteEventsForRoomStmt          *sql.Stmt
+	bulkSelectMaxStreamPositionsStmt *sql.Stmt
 }
 
 func NewPostgresEventsTable(db *sql.DB) (tables.Events, error) {
@@ -175,6 +184,9 @@ func NewPostgresEventsTable(db *sql.DB) (tables.Events, error) {
 	if s.deleteEventsForRoomStmt, err = db.Prepare(deleteEventsForRoomSQL); err != nil {
 		return nil, err
 	}
+	if s.bulkSelectMaxStreamPositionsStmt, err = db.Prepare(bulkSelectMaxStreamPositionsSQL); err != nil {
+		return nil, err
+	}
 	return s, nil
 }
 
@@ -435,6 +447,28 @@ func (s *outputRoomEventsStatements) DeleteEventsForRoom(
 	return err
 }
 
+func (s *outputRoomEventsStatements) BulkSelectMaxStreamPositions(
+	ctx context.Context, txn *sql.Tx, roomIDs []string, offset, count int,
+) (map[string]types.StreamPosition, error) {
+	result := map[string]types.StreamPosition{}
+	stmt := sqlutil.TxStmt(txn, s.bulkSelectMaxStreamPositionsStmt)
+	rows, err := stmt.QueryContext(ctx, roomIDs, offset, count)
+	if err != nil {
+		return nil, fmt.Errorf("stmt.QueryContext: %w", err)
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "failed to close rows")
+	for rows.Next() {
+		var roomID string
+		var pos types.StreamPosition
+		err = rows.Scan(&roomID, &pos)
+		if err != nil {
+			return nil, fmt.Errorf("rows.Scan: %w", err)
+		}
+		result[roomID] = pos
+	}
+	return result, nil
+}
+
 func rowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, error) {
 	var result []types.StreamEvent
 	for rows.Next() {

syncapi/storage/shared/syncserver.go

@@ -956,3 +956,23 @@ func (d *Database) GetRoomReceipts(ctx context.Context, roomIDs []string, stream
 	_, receipts, err := d.Receipts.SelectRoomReceiptsAfter(ctx, roomIDs, streamPos)
 	return receipts, err
 }
+
+func (d *Database) GetPaginatedRooms(ctx context.Context, userID string, offset, count int) ([]string, error) {
+	memberships, err := d.Memberships.SelectMemberships(ctx, nil, userID)
+	if err != nil {
+		return nil, fmt.Errorf("d.Memberships.SelectMemberships: %w", err)
+	}
+	rooms := []string{}
+	for roomID := range memberships {
+		rooms = append(rooms, roomID)
+	}
+	positions, err := d.OutputEvents.BulkSelectMaxStreamPositions(ctx, nil, rooms, offset, count)
+	if err != nil {
+		return nil, fmt.Errorf("d.Events.BulkSelectMaxStreamPositions: %w", err)
+	}
+	rooms = rooms[:0]
+	for roomID := range positions {
+		rooms = append(rooms, roomID)
+	}
+	return rooms, nil
+}

syncapi/storage/sqlite3/memberships_table.go

@@ -20,6 +20,7 @@ import (
 	"fmt"
 	"strings"
 
+	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/syncapi/storage/tables"
 	"github.com/matrix-org/dendrite/syncapi/types"
@@ -63,9 +64,14 @@ const selectMembershipSQL = "" +
 	" ORDER BY stream_pos DESC" +
 	" LIMIT 1"
 
+const selectMembershipsSQL = "" +
+	"SELECT room_id, membership FROM syncapi_memberships" +
+	" WHERE user_id = $1"
+
 type membershipsStatements struct {
 	db                    *sql.DB
 	upsertMembershipStmt  *sql.Stmt
+	selectMembershipsStmt *sql.Stmt
 }
 
 func NewSqliteMembershipsTable(db *sql.DB) (tables.Memberships, error) {
@@ -79,6 +85,9 @@ func NewSqliteMembershipsTable(db *sql.DB) (tables.Memberships, error) {
 	if s.upsertMembershipStmt, err = db.Prepare(upsertMembershipSQL); err != nil {
 		return nil, err
 	}
+	if s.selectMembershipsStmt, err = db.Prepare(selectMembershipsSQL); err != nil {
+		return nil, err
+	}
 	return s, nil
 }
 
@@ -117,3 +126,24 @@ func (s *membershipsStatements) SelectMembership(
 	err = sqlutil.TxStmt(txn, stmt).QueryRowContext(ctx, params...).Scan(&eventID, &streamPos, &topologyPos)
 	return
 }
+
+func (s *membershipsStatements) SelectMemberships(
+	ctx context.Context, txn *sql.Tx, userID string,
+) (map[string]string, error) {
+	var roomID, membership string
+	result := map[string]string{}
+	stmt := sqlutil.TxStmt(txn, s.selectMembershipsStmt)
+	rows, err := stmt.QueryContext(ctx, userID)
+	if err != nil {
+		return nil, fmt.Errorf("stmt.QueryContext: %w", err)
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "failed to close rows")
+	for rows.Next() {
+		err = rows.Scan(&roomID, &membership)
+		if err != nil {
+			return nil, fmt.Errorf("rows.Scan: %w", err)
+		}
+		result[roomID] = membership
+	}
+	return result, nil
+}

syncapi/storage/sqlite3/output_room_events_table.go

@@ -21,6 +21,7 @@ import (
 	"encoding/json"
 	"fmt"
 	"sort"
+	"strings"
 
 	"github.com/matrix-org/dendrite/internal"
 	"github.com/matrix-org/dendrite/roomserver/api"
@@ -90,6 +91,13 @@ const selectStateInRangeSQL = "" +
 const deleteEventsForRoomSQL = "" +
 	"DELETE FROM syncapi_output_room_events WHERE room_id = $1"
 
+const bulkSelectMaxStreamPositionsSQL = "" +
+	"SELECT room_id, MAX(id) AS id FROM syncapi_output_room_events" +
+	" WHERE room_id IN ($1)" +
+	" GROUP BY room_id" +
+	" ORDER BY id DESC" +
+	" LIMIT $2 OFFSET $3"
+
 type outputRoomEventsStatements struct {
 	db                      *sql.DB
 	streamIDStatements      *streamIDStatements
@@ -424,6 +432,40 @@ func (s *outputRoomEventsStatements) DeleteEventsForRoom(
 	return err
 }
 
+func (s *outputRoomEventsStatements) BulkSelectMaxStreamPositions(
+	ctx context.Context, txn *sql.Tx, roomIDs []string, offset, count int,
+) (map[string]types.StreamPosition, error) {
+	origSQL := strings.Replace(bulkSelectMaxStreamPositionsSQL, "$2", fmt.Sprintf("$%d", len(roomIDs)+1), 1)
+	origSQL = strings.Replace(origSQL, "$3", fmt.Sprintf("$%d", len(roomIDs)+2), 1)
+	origSQL = strings.Replace(origSQL, "($1)", sqlutil.QueryVariadic(len(roomIDs)), 1)
+	origStmt, err := s.db.Prepare(origSQL)
+	if err != nil {
+		return nil, fmt.Errorf("s.db.Prepare: %w", err)
+	}
+	params := []interface{}{}
+	for _, roomID := range roomIDs {
+		params = append(params, roomID)
+	}
+	params = append(params, count, offset)
+	result := map[string]types.StreamPosition{}
+	stmt := sqlutil.TxStmt(txn, origStmt)
+	rows, err := stmt.QueryContext(ctx, params...)
+	if err != nil {
+		return nil, fmt.Errorf("stmt.QueryContext: %w", err)
+	}
+	defer internal.CloseAndLogIfError(ctx, rows, "failed to close rows")
+	for rows.Next() {
+		var roomID string
+		var pos types.StreamPosition
+		err = rows.Scan(&roomID, &pos)
+		if err != nil {
+			return nil, fmt.Errorf("rows.Scan: %w", err)
+		}
+		result[roomID] = pos
+	}
+	return result, nil
+}
+
 func rowsToStreamEvents(rows *sql.Rows) ([]types.StreamEvent, error) {
 	var result []types.StreamEvent
 	for rows.Next() {

syncapi/storage/tables/interface.go

@@ -63,6 +63,7 @@ type Events interface {
 	UpdateEventJSON(ctx context.Context, event *gomatrixserverlib.HeaderedEvent) error
 	// DeleteEventsForRoom removes all event information for a room. This should only be done when removing the room entirely.
 	DeleteEventsForRoom(ctx context.Context, txn *sql.Tx, roomID string) (err error)
+	BulkSelectMaxStreamPositions(ctx context.Context, txn *sql.Tx, roomIDs []string, offset, count int) (map[string]types.StreamPosition, error)
 }
 
 // Topology keeps track of the depths and stream positions for all events.
@@ -166,4 +167,5 @@ type Receipts interface {
 type Memberships interface {
 	UpsertMembership(ctx context.Context, txn *sql.Tx, event *gomatrixserverlib.HeaderedEvent, streamPos, topologicalPos types.StreamPosition) error
 	SelectMembership(ctx context.Context, txn *sql.Tx, roomID, userID, memberships []string) (eventID string, streamPos, topologyPos types.StreamPosition, err error)
+	SelectMemberships(ctx context.Context, txn *sql.Tx, userID string) (map[string]string, error)
 }

syncapi/sync/request.go

@@ -69,6 +69,18 @@ func newSyncRequest(req *http.Request, device userapi.Device, syncDB storage.Dat
 		}
 	}
 
+	switch req.URL.Query().Get("paginate_by") {
+	case "latest":
+		offset, _ := strconv.Atoi(req.URL.Query().Get("offset"))
+		count, _ := strconv.Atoi(req.URL.Query().Get("count"))
+		rooms, err := syncDB.GetPaginatedRooms(req.Context(), device.UserID, offset, count)
+		if err != nil {
+			return nil, fmt.Errorf("syncDB.GetPaginatedRooms: %w", err)
+		}
+		filter.Room.Rooms = rooms
+		logrus.Warnf("Filtering by rooms: %v", rooms)
+	}
+
 	logger := util.GetLogger(req.Context()).WithFields(logrus.Fields{
 		"user_id":   device.UserID,
 		"device_id": device.ID,