Function build_group_key_indexed

nodedb-query/src/msgpack_scan/group_key.rs:35–51

Build a GROUP BY key using a pre-built `FieldIndex` for O(1) lookups.

(doc: &[u8], group_fields: &[String], idx: &FieldIndex)

/// Build a GROUP BY key using a pre-built `FieldIndex` for O(1) lookups.
pub fn build_group_key_indexed(doc: &[u8], group_fields: &[String], idx: &FieldIndex) -> String {
    if group_fields.is_empty() {
        return "__all__".to_string();
    }

    let mut key_buf = String::new();
    key_buf.push('[');
    for (i, field) in group_fields.iter().enumerate() {
        if i > 0 {
            key_buf.push(',');
        }
        let range = idx.get(field);
        append_field_value_range(&mut key_buf, doc, range);
    }
    key_buf.push(']');
    key_buf
}

/// Append a single field's value to the key buffer as a JSON literal.
fn append_field_value(buf: &mut String, doc: &[u8], field: &str) {