Function mergeBook

pkg/cli/cmd/sync/sync.go:271–303

mergeBook inserts or updates the given book in the local database. If a book with a duplicate label exists locally, it renames the duplicate by appending a number.

(tx *database.DB, b client.SyncFragBook, mode int)

// mergeBook inserts or updates the given book in the local database.
// If a book with a duplicate label exists locally, it renames the duplicate by appending a number.
func mergeBook(tx *database.DB, b client.SyncFragBook, mode int) error {
	var count int
	if err := tx.QueryRow("SELECT count(*) FROM books WHERE label = ?", b.Label).Scan(&count); err != nil {
		return errors.Wrapf(err, "checking for books with a duplicate label %s", b.Label)
	}

	// if duplicate exists locally, rename it and mark it dirty
	if count > 0 {
		newLabel, err := resolveLabel(tx, b.Label)
		if err != nil {
			return errors.Wrap(err, "getting a new book label for conflict resolution")
		}

		if _, err := tx.Exec("UPDATE books SET label = ?, dirty = ? WHERE label = ? AND uuid != ?", newLabel, true, b.Label, b.UUID); err != nil {
			return errors.Wrap(err, "resolving duplicate book label")
		}
	}

	if mode == modeInsert {
		book := database.NewBook(b.UUID, b.Label, b.USN, false, false)
		if err := book.Insert(tx); err != nil {
			return errors.Wrapf(err, "inserting note with uuid %s", b.UUID)
		}
	} else if mode == modeUpdate {
		// The state from the server overwrites the local state. In other words, the server change always wins.
		if _, err := tx.Exec("UPDATE books SET usn = ?, uuid = ?, label = ?, deleted = ? WHERE uuid = ?",
			b.USN, b.UUID, b.Label, b.Deleted, b.UUID); err != nil {
			return errors.Wrapf(err, "updating local book %s", b.UUID)
		}
	}

	return nil
}

func stepSyncBook(tx *database.DB, b client.SyncFragBook) error {
	var localUSN int