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use crate::messages::fragment_number_set::FragmentNumberSet_t;
use crate::structure::count::Count_t;
use crate::structure::entity_id::EntityId_t;
use crate::structure::sequence_number::SequenceNumber_t;
use speedy::{Readable, Writable};
/// The NackFrag Submessage is used to communicate the state of a Reader to a
/// Writer. When a data change is sent as a series of fragments, the NackFrag
/// Submessage allows the Reader to inform the Writer about specific fragment
/// numbers it is still missing.
///
/// This Submessage can only contain negative acknowledgements. Note this
/// differs from an AckNack Submessage, which includes both positive and
/// negative acknowledgements.
#[derive(Debug, PartialEq, Readable, Writable)]
pub struct NackFrag {
/// Identifies the Reader entity that requests to receive certain
/// fragments.
pub reader_id: EntityId_t,
/// Identifies the Writer entity that is the target of the NackFrag message.
/// This is the Writer Entity that is being asked to re-send some fragments.
pub writer_id: EntityId_t,
/// The sequence number for which some fragments are missing.
pub writer_sn: SequenceNumber_t,
/// Communicates the state of the reader to the writer.
/// The fragment numbers that appear in the set indicate missing
/// fragments on the reader side. The ones that do not appear in the set
/// are undetermined (could have been received or not).
pub fragment_number_state: FragmentNumberSet_t,
/// A counter that is incremented each time a new NackFrag message is sent.
/// Provides the means for a Writer to detect duplicate NackFrag messages
/// that can result from the presence of redundant communication paths.
pub count: Count_t,
}
#[cfg(test)]
mod tests {
use super::*;
use crate::messages::fragment_number::FragmentNumber_t;
serialization_test!( type = NackFrag,
{
nack_frag,
NackFrag {
reader_id: EntityId_t::ENTITYID_SEDP_BUILTIN_PUBLICATIONS_READER,
writer_id: EntityId_t::ENTITYID_SEDP_BUILTIN_PUBLICATIONS_WRITER,
writer_sn: SequenceNumber_t::from(42),
fragment_number_state: FragmentNumberSet_t::new(FragmentNumber_t::from(1000)),
count: Count_t::from(6),
},
le = [0x00, 0x00, 0x03, 0xC7,
0x00, 0x00, 0x03, 0xC2,
0x00, 0x00, 0x00, 0x00,
0x2A, 0x00, 0x00, 0x00,
0xE8, 0x03, 0x00, 0x00,
0x00, 0x00, 0x00, 0x00,
0x06, 0x00, 0x00, 0x00],
be = [0x00, 0x00, 0x03, 0xC7,
0x00, 0x00, 0x03, 0xC2,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x2A,
0x00, 0x00, 0x03, 0xE8,
0x00, 0x00, 0x00, 0x00,
0x00, 0x00, 0x00, 0x06]
});
}