Function decode_msgpack_i64

nodedb/src/engine/kv/engine_atomic.rs:405–437

Decode a MessagePack-encoded value as i64. If the value is a map (typed KV entry), extracts the first numeric field.

(bytes: &[u8])

///
/// If the value is a map (typed KV entry), extracts the first numeric field.
fn decode_msgpack_i64(bytes: &[u8]) -> Result<i64, AtomicError> {
    // Try i64 first, then u64 (MessagePack encodes small positive as u64).
    if let Ok(v) = zerompk::from_msgpack::<i64>(bytes) {
        return Ok(v);
    }
    if let Ok(v) = zerompk::from_msgpack::<u64>(bytes) {
        return i64::try_from(v).map_err(|_| AtomicError::Overflow);
    }
    // Try f64 → i64 truncation for values stored as float.
    if let Ok(v) = zerompk::from_msgpack::<f64>(bytes)
        && v.fract() == 0.0
        && v >= i64::MIN as f64
        && v <= i64::MAX as f64
    {
        return Ok(v as i64);
    }
    // If value is a map (typed KV entry), find the first numeric field.
    if let Ok(nodedb_types::Value::Object(map)) = nodedb_types::value_from_msgpack(bytes) {
        for (k, v) in &map {
            if k == "key" {
                continue;
            }
            match v {
                nodedb_types::Value::Integer(i) => return Ok(*i),
                nodedb_types::Value::Float(f) if f.fract() == 0.0 => return Ok(*f as i64),
                _ => {}
            }
        }
    }
    Err(AtomicError::TypeMismatch {
        detail: "value is not an integer".into(),
    })
}

/// Decode a MessagePack-encoded value as f64.
///