Function parse_lsn

src/sql-server-util/src/inspect.rs:210–231

Parse an [`Lsn`] from the first column of the provided [`tiberius::Row`]. Returns an error if the provided slice doesn't have exactly one row.

(result: &[tiberius::Row])

///
/// Returns an error if the provided slice doesn't have exactly one row.
fn parse_lsn(result: &[tiberius::Row]) -> Result<Lsn, SqlServerError> {
    match result {
        [row] => {
            let val = row
                .try_get::<&[u8], _>(0)?
                .ok_or_else(|| SqlServerError::NullLsn)?;
            if val.is_empty() {
                Err(SqlServerError::NullLsn)
            } else {
                let lsn = Lsn::try_from(val).map_err(|msg| SqlServerError::InvalidData {
                    column_name: "lsn".to_string(),
                    error: msg,
                })?;
                Ok(lsn)
            }
        }
        other => Err(SqlServerError::InvalidData {
            column_name: "lsn".to_string(),
            error: format!("expected 1 column, got {other:?}"),
        }),
    }
}

/// Queries the specified capture instance and returns all changes from
/// `[start_lsn, end_lsn)`, ordered by `start_lsn` in an ascending fashion.