use super::*;
pub(super) fn can_segment(segmentation: Segmentation) -> bool {
matches!(segmentation, Segmentation::BOTH | Segmentation::TRANSMIT)
}
pub(super) fn limit(peer: u16, local: u32) -> u16 {
peer.min(u16::try_from(local).unwrap_or(u16::MAX))
}
pub(super) async fn response(
db: &RwLock<ObjectDatabase>,
request: &ConfirmedRequestPdu,
effective_max_apdu: u16,
segmented_response_available: bool,
) -> Apdu {
let service_ack_budget = (!segmented_response_available).then(|| {
unsegmented_complex_ack_service_budget(
request.invoke_id,
request.service_choice,
effective_max_apdu,
)
});
let mut service_ack = BytesMut::new();
let db = db.read().await;
match handlers::handle_get_event_information_with_budget(
&db,
&request.service_request,
&mut service_ack,
service_ack_budget,
) {
Ok(()) => Apdu::ComplexAck(ComplexAck {
segmented: false,
more_follows: false,
invoke_id: request.invoke_id,
sequence_number: None,
proposed_window_size: None,
service_choice: request.service_choice,
service_ack: service_ack.freeze(),
}),
Err(error) => confirmed_response::error_apdu_from_error(
request.invoke_id,
request.service_choice,
&error,
),
}
}
fn unsegmented_complex_ack_service_budget(
invoke_id: u8,
service_choice: ConfirmedServiceChoice,
max_apdu: u16,
) -> usize {
let envelope = Apdu::ComplexAck(ComplexAck {
segmented: false,
more_follows: false,
invoke_id,
sequence_number: None,
proposed_window_size: None,
service_choice,
service_ack: Bytes::new(),
});
let mut encoded = BytesMut::new();
encode_apdu(&mut encoded, &envelope).expect("valid empty ComplexACK encoding");
usize::from(max_apdu).saturating_sub(encoded.len())
}