Function paimon_read_builder_with_projection

bindings/c/src/table.rs:122–154

(
    rb: *mut paimon_read_builder,
    columns: *const *const std::ffi::c_char,
)

/// `columns` must be a null-terminated array of null-terminated C strings, or null for no projection.
#[no_mangle]
pub unsafe extern "C" fn paimon_read_builder_with_projection(
    rb: *mut paimon_read_builder,
    columns: *const *const std::ffi::c_char,
) -> *mut paimon_error {
    if let Err(e) = check_non_null(rb, "rb") {
        return e;
    }

    let state = &mut *((*rb).inner as *mut ReadBuilderState);

    if columns.is_null() {
        state.projected_columns = None;
        return std::ptr::null_mut();
    }

    let mut col_names = Vec::new();
    let mut ptr = columns;
    while !(*ptr).is_null() {
        let c_str = std::ffi::CStr::from_ptr(*ptr);
        match c_str.to_str() {
            Ok(s) => col_names.push(s.to_string()),
            Err(e) => {
                return paimon_error::from_paimon(paimon::Error::ConfigInvalid {
                    message: format!("Invalid UTF-8 in column name: {e}"),
                });
            }
        }
        ptr = ptr.add(1);
    }

    state.projected_columns = Some(col_names);
    std::ptr::null_mut()
}

/// Set a filter predicate for scan planning.
///