feat(store): seen-set read state with floor baseline and compaction

2026-06-21 23:43:35 +01:00
parent a1e9f601ce
commit a4e72b2178
2 changed files with 261 additions and 0 deletions
@@ -0,0 +1,154 @@
+package store
+
+import "database/sql"
+
+// EnsureFolderBaseline initialises folder_state on first contact, or resets it
+// when the server's UIDVALIDITY differs from what we stored.
+func (s *Store) EnsureFolderBaseline(account, folder string, uidvalidity, maxUID uint32) error {
+	a, err := s.GetAccount(account)
+	if err != nil {
+		return err
+	}
+	var (
+		curUIDValidity uint32
+		haveRow        bool
+	)
+	row := s.db.QueryRow(
+		"SELECT uidvalidity FROM folder_state WHERE account_id=? AND folder=?", a.ID, folder)
+	switch err := row.Scan(&curUIDValidity); err {
+	case nil:
+		haveRow = true
+	case sql.ErrNoRows:
+		haveRow = false
+	default:
+		return err
+	}
+	if haveRow && curUIDValidity == uidvalidity {
+		return nil // already baselined, same validity
+	}
+
+	floor := maxUID
+	if a.ProcessBacklog {
+		floor = 0
+	}
+	tx, err := s.db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+	if _, err := tx.Exec("DELETE FROM acked WHERE account_id=? AND folder=?", a.ID, folder); err != nil {
+		return err
+	}
+	if _, err := tx.Exec(`
+		INSERT INTO folder_state(account_id,folder,uidvalidity,floor_uid)
+		VALUES(?,?,?,?)
+		ON CONFLICT(account_id,folder) DO UPDATE SET uidvalidity=excluded.uidvalidity, floor_uid=excluded.floor_uid`,
+		a.ID, folder, uidvalidity, floor); err != nil {
+		return err
+	}
+	return tx.Commit()
+}
+
+func (s *Store) floor(account, folder string) (uint32, error) {
+	id, err := s.accountID(account)
+	if err != nil {
+		return 0, err
+	}
+	var f uint32
+	err = s.db.QueryRow(
+		"SELECT floor_uid FROM folder_state WHERE account_id=? AND folder=?", id, folder).Scan(&f)
+	return f, err
+}
+
+// IsNew reports whether uid is unread: above the floor and not acked.
+func (s *Store) IsNew(account, folder string, uid uint32) (bool, error) {
+	id, err := s.accountID(account)
+	if err != nil {
+		return false, err
+	}
+	var floor uint32
+	if err := s.db.QueryRow(
+		"SELECT floor_uid FROM folder_state WHERE account_id=? AND folder=?", id, folder).Scan(&floor); err != nil {
+		return false, err
+	}
+	if uid <= floor {
+		return false, nil
+	}
+	var one int
+	err = s.db.QueryRow(
+		"SELECT 1 FROM acked WHERE account_id=? AND folder=? AND uid=?", id, folder, uid).Scan(&one)
+	if err == sql.ErrNoRows {
+		return true, nil
+	}
+	if err != nil {
+		return false, err
+	}
+	return false, nil // present in acked
+}
+
+// FilterNew returns the subset of uids that are new, preserving order.
+func (s *Store) FilterNew(account, folder string, uids []uint32) ([]uint32, error) {
+	out := make([]uint32, 0, len(uids))
+	for _, u := range uids {
+		n, err := s.IsNew(account, folder, u)
+		if err != nil {
+			return nil, err
+		}
+		if n {
+			out = append(out, u)
+		}
+	}
+	return out, nil
+}
+
+// Ack records uids as processed (ignoring any at or below the floor) then compacts.
+func (s *Store) Ack(account, folder string, uidvalidity uint32, uids ...uint32) error {
+	id, err := s.accountID(account)
+	if err != nil {
+		return err
+	}
+	tx, err := s.db.Begin()
+	if err != nil {
+		return err
+	}
+	defer tx.Rollback()
+
+	var floor uint32
+	if err := tx.QueryRow(
+		"SELECT floor_uid FROM folder_state WHERE account_id=? AND folder=?", id, folder).Scan(&floor); err != nil {
+		return err
+	}
+	for _, u := range uids {
+		if u <= floor {
+			continue
+		}
+		if _, err := tx.Exec(
+			"INSERT OR IGNORE INTO acked(account_id,folder,uidvalidity,uid) VALUES(?,?,?,?)",
+			id, folder, uidvalidity, u); err != nil {
+			return err
+		}
+	}
+	// Compact: while floor+1 is acked, advance floor and drop that row.
+	for {
+		next := floor + 1
+		var present int
+		err := tx.QueryRow(
+			"SELECT 1 FROM acked WHERE account_id=? AND folder=? AND uid=?", id, folder, next).Scan(&present)
+		if err == sql.ErrNoRows {
+			break
+		}
+		if err != nil {
+			return err
+		}
+		if _, err := tx.Exec(
+			"DELETE FROM acked WHERE account_id=? AND folder=? AND uid=?", id, folder, next); err != nil {
+			return err
+		}
+		floor = next
+	}
+	if _, err := tx.Exec(
+		"UPDATE folder_state SET floor_uid=? WHERE account_id=? AND folder=?", floor, id, folder); err != nil {
+		return err
+	}
+	return tx.Commit()
+}