Function extract_number

nodedb/src/control/server/post_aggregate.rs:126–171

Extract a numeric field value from a msgpack map row.

(row: &[u8], field: &str)

/// Extract a numeric field value from a msgpack map row.
fn extract_number(row: &[u8], field: &str) -> Option<f64> {
    use nodedb_query::msgpack_scan::reader;

    let try_field = |name: &str| -> Option<f64> {
        let (start, _end) = nodedb_query::msgpack_scan::extract_field(row, 0, name)?;
        if let Some(i) = reader::read_i64(row, start) {
            return Some(i as f64);
        }
        if let Some(f) = reader::read_f64(row, start) {
            return Some(f);
        }
        // Try parsing string as number.
        reader::read_str(row, start).and_then(|s| s.parse().ok())
    };

    if field == "*" {
        return Some(1.0);
    }

    // Exact match.
    if let Some(v) = try_field(field) {
        return Some(v);
    }

    // Suffix match.
    let suffix = format!(".{field}");
    let (count, mut pos) = nodedb_query::msgpack_scan::reader::map_header(row, 0)?;
    for _ in 0..count {
        let key = nodedb_query::msgpack_scan::reader::read_str(row, pos)?;
        let key_end = nodedb_query::msgpack_scan::reader::skip_value(row, pos)?;
        let val_end = nodedb_query::msgpack_scan::reader::skip_value(row, key_end)?;
        if key.ends_with(&suffix) {
            if let Some(i) = nodedb_query::msgpack_scan::reader::read_i64(row, key_end) {
                return Some(i as f64);
            }
            if let Some(f) = nodedb_query::msgpack_scan::reader::read_f64(row, key_end) {
                return Some(f);
            }
            if let Some(s) = nodedb_query::msgpack_scan::reader::read_str(row, key_end) {
                return s.parse().ok();
            }
        }
        pos = val_end;
    }
    None
}

/// Read a msgpack value at [start..end) as a display string.
fn read_value_as_string(bytes: &[u8], start: usize, end: usize) -> String {