Method getSheet

backend/store/sheet.go:60–106

getSheet is the internal helper for fetching a single sheet by SHA256.

(ctx context.Context, sha256Hex string, loadFull bool)

// getSheet is the internal helper for fetching a single sheet by SHA256.
func (s *Store) getSheet(ctx context.Context, sha256Hex string, loadFull bool) (*SheetMessage, error) {
	statementField := fmt.Sprintf("LEFT(content, %d)", common.MaxSheetSize)
	if loadFull {
		statementField = "content"
	}

	q := qb.Q().Space(fmt.Sprintf(`
		SELECT
			%s,
			OCTET_LENGTH(content)
		FROM sheet_blob
		WHERE sha256 = decode(?, 'hex')`, statementField), sha256Hex)

	query, args, err := q.ToSQL()
	if err != nil {
		return nil, errors.Wrapf(err, "failed to build sql")
	}

	rows, err := s.GetDB().QueryContext(ctx, query, args...)
	if err != nil {
		return nil, err
	}
	defer rows.Close()

	var sheet *SheetMessage
	if rows.Next() {
		sheet = &SheetMessage{
			Sha256: sha256Hex,
		}
		if err := rows.Scan(
			&sheet.Statement,
			&sheet.Size,
		); err != nil {
			return nil, err
		}
	}

	if err := rows.Err(); err != nil {
		return nil, err
	}

	if sheet == nil {
		return nil, nil
	}

	return sheet, nil
}

// CreateSheets creates sheet blobs using content-addressed storage.
// Each sheet is identified by the SHA256 hash of its statement.