Give receipts their own stream ID in the database (#1631)

* Give read recipts their own database sequence

* Give receipts their own stream ID

* Change migration names

* Reset sequences

* Add max receipt queries, missing stream_id table entry for SQLite

4 files changed, 99 insertions, 3 deletions

diff --git a/syncapi/storage/sqlite3/deltas/20201211125500_sequences.go b/syncapi/storage/sqlite3/deltas/20201211125500_sequences.go
new file mode 100644
index 00000000..64905013
--- /dev/null
+++ b/syncapi/storage/sqlite3/deltas/20201211125500_sequences.go
@@ -0,0 +1,58 @@
+// Copyright 2020 The Matrix.org Foundation C.I.C.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package deltas
+
+import (
+	"database/sql"
+	"fmt"
+
+	"github.com/matrix-org/dendrite/internal/sqlutil"
+	"github.com/pressly/goose"
+)
+
+func LoadFromGoose() {
+	goose.AddMigration(UpFixSequences, DownFixSequences)
+}
+
+func LoadFixSequences(m *sqlutil.Migrations) {
+	m.AddMigration(UpFixSequences, DownFixSequences)
+}
+
+func UpFixSequences(tx *sql.Tx) error {
+	_, err := tx.Exec(`
+		-- We need to delete all of the existing receipts because the indexes
+		-- will be wrong, and we'll get primary key violations if we try to
+		-- reuse existing stream IDs from a different sequence.
+		DELETE FROM syncapi_receipts;
+		UPDATE syncapi_stream_id SET stream_id=1 WHERE stream_name="receipt";
+	`)
+	if err != nil {
+		return fmt.Errorf("failed to execute upgrade: %w", err)
+	}
+	return nil
+}
+
+func DownFixSequences(tx *sql.Tx) error {
+	_, err := tx.Exec(`
+		-- We need to delete all of the existing receipts because the indexes
+		-- will be wrong, and we'll get primary key violations if we try to
+		-- reuse existing stream IDs from a different sequence.
+		DELETE FROM syncapi_receipts;
+	`)
+	if err != nil {
+		return fmt.Errorf("failed to execute downgrade: %w", err)
+	}
+	return nil
+}
diff --git a/syncapi/storage/sqlite3/receipt_table.go b/syncapi/storage/sqlite3/receipt_table.go
index b1770e80..dfde1fd2 100644
--- a/syncapi/storage/sqlite3/receipt_table.go
+++ b/syncapi/storage/sqlite3/receipt_table.go
@@ -55,11 +55,15 @@ const selectRoomReceipts = "" +
 	" FROM syncapi_receipts" +
 	" WHERE id > $1 and room_id in ($2)"
 
+const selectMaxReceiptIDSQL = "" +
+	"SELECT MAX(id) FROM syncapi_receipts"
+
 type receiptStatements struct {
 	db                 *sql.DB
 	streamIDStatements *streamIDStatements
 	upsertReceipt      *sql.Stmt
 	selectRoomReceipts *sql.Stmt
+	selectMaxReceiptID *sql.Stmt
 }
 
 func NewSqliteReceiptsTable(db *sql.DB, streamID *streamIDStatements) (tables.Receipts, error) {
@@ -77,12 +81,15 @@ func NewSqliteReceiptsTable(db *sql.DB, streamID *streamIDStatements) (tables.Re
 	if r.selectRoomReceipts, err = db.Prepare(selectRoomReceipts); err != nil {
 		return nil, fmt.Errorf("unable to prepare selectRoomReceipts statement: %w", err)
 	}
+	if r.selectMaxReceiptID, err = db.Prepare(selectMaxReceiptIDSQL); err != nil {
+		return nil, fmt.Errorf("unable to prepare selectRoomReceipts statement: %w", err)
+	}
 	return r, nil
 }
 
 // UpsertReceipt creates new user receipts
 func (r *receiptStatements) UpsertReceipt(ctx context.Context, txn *sql.Tx, roomId, receiptType, userId, eventId string, timestamp gomatrixserverlib.Timestamp) (pos types.StreamPosition, err error) {
-	pos, err = r.streamIDStatements.nextStreamID(ctx, txn)
+	pos, err = r.streamIDStatements.nextReceiptID(ctx, txn)
 	if err != nil {
 		return
 	}
@@ -116,3 +123,15 @@ func (r *receiptStatements) SelectRoomReceiptsAfter(ctx context.Context, roomIDs
 	}
 	return res, rows.Err()
 }
+
+func (s *receiptStatements) SelectMaxReceiptID(
+	ctx context.Context, txn *sql.Tx,
+) (id int64, err error) {
+	var nullableID sql.NullInt64
+	stmt := sqlutil.TxStmt(txn, s.selectMaxReceiptID)
+	err = stmt.QueryRowContext(ctx).Scan(&nullableID)
+	if nullableID.Valid {
+		id = nullableID.Int64
+	}
+	return
+}
diff --git a/syncapi/storage/sqlite3/stream_id_table.go b/syncapi/storage/sqlite3/stream_id_table.go
index e6bdc4fc..f73be422 100644
--- a/syncapi/storage/sqlite3/stream_id_table.go
+++ b/syncapi/storage/sqlite3/stream_id_table.go
@@ -18,6 +18,8 @@ CREATE TABLE IF NOT EXISTS syncapi_stream_id (
 );
 INSERT INTO syncapi_stream_id (stream_name, stream_id) VALUES ("global", 0)
   ON CONFLICT DO NOTHING;
+INSERT INTO syncapi_stream_id (stream_name, stream_id) VALUES ("receipt", 0)
+  ON CONFLICT DO NOTHING;
 `
 
 const increaseStreamIDStmt = "" +
@@ -56,3 +58,13 @@ func (s *streamIDStatements) nextStreamID(ctx context.Context, txn *sql.Tx) (pos
 	err = selectStmt.QueryRowContext(ctx, "global").Scan(&pos)
 	return
 }
+
+func (s *streamIDStatements) nextReceiptID(ctx context.Context, txn *sql.Tx) (pos types.StreamPosition, err error) {
+	increaseStmt := sqlutil.TxStmt(txn, s.increaseStreamIDStmt)
+	selectStmt := sqlutil.TxStmt(txn, s.selectStreamIDStmt)
+	if _, err = increaseStmt.ExecContext(ctx, "receipt"); err != nil {
+		return
+	}
+	err = selectStmt.QueryRowContext(ctx, "receipt").Scan(&pos)
+	return
+}
diff --git a/syncapi/storage/sqlite3/syncserver.go b/syncapi/storage/sqlite3/syncserver.go
index 7df71b38..1ad0e947 100644
--- a/syncapi/storage/sqlite3/syncserver.go
+++ b/syncapi/storage/sqlite3/syncserver.go
@@ -25,6 +25,7 @@ import (
 	"github.com/matrix-org/dendrite/internal/sqlutil"
 	"github.com/matrix-org/dendrite/setup/config"
 	"github.com/matrix-org/dendrite/syncapi/storage/shared"
+	"github.com/matrix-org/dendrite/syncapi/storage/sqlite3/deltas"
 )
 
 // SyncServerDatasource represents a sync server datasource which manages
@@ -46,13 +47,14 @@ func NewDatabase(dbProperties *config.DatabaseOptions) (*SyncServerDatasource, e
 		return nil, err
 	}
 	d.writer = sqlutil.NewExclusiveWriter()
-	if err = d.prepare(); err != nil {
+	if err = d.prepare(dbProperties); err != nil {
 		return nil, err
 	}
 	return &d, nil
 }
 
-func (d *SyncServerDatasource) prepare() (err error) {
+// nolint:gocyclo
+func (d *SyncServerDatasource) prepare(dbProperties *config.DatabaseOptions) (err error) {
 	if err = d.PartitionOffsetStatements.Prepare(d.db, d.writer, "syncapi"); err != nil {
 		return err
 	}
@@ -99,6 +101,11 @@ func (d *SyncServerDatasource) prepare() (err error) {
 	if err != nil {
 		return err
 	}
+	m := sqlutil.NewMigrations()
+	deltas.LoadFixSequences(m)
+	if err = m.RunDeltas(d.db, dbProperties); err != nil {
+		return err
+	}
 	d.Database = shared.Database{
 		DB:                  d.db,
 		Writer:              d.writer,