Struct Envelope 

pub struct Envelope<T> {
    pub seq: u64,
    pub ack: Option<u64>,
    pub timestamp: u64,
    pub payload: T,
}

Message envelope wrapping any payload with delivery metadata.

Used for reliable message delivery with:

• Sequence numbers for ordering
• Acknowledgments for delivery confirmation
• Timestamps for latency measurement and clock sync

Fields

seq: u64

Monotonically increasing sequence number (per connection). Server and client maintain separate sequences.

ack: Option<u64>

Piggyback acknowledgment of the last received sequence number. Allows confirming receipt without a separate ack message.

timestamp: u64

Server timestamp in milliseconds since Unix epoch. Clients can use this for latency calculation and clock sync.

payload: T

The actual message payload.

Implementations

impl<T> Envelope<T>

pub fn new(seq: u64, payload: T) -> Self

Create a new envelope with the given sequence number and payload.

pub fn with_ack(seq: u64, ack: u64, payload: T) -> Self

Create an envelope with a piggyback acknowledgment.

impl<T> Envelope<T>

where T: Clone,

pub fn map<U, F>(self, f: F) -> Envelope<U>

where F: FnOnce(T) -> U,

Transform the payload while preserving envelope metadata.

Trait Implementations

impl<T: Clone> Clone for Envelope<T>

fn clone(&self) -> Envelope<T>

Returns a duplicate of the value.

fn clone_from(&mut self, source: &Self)

Performs copy-assignment from source.

impl<T: Debug> Debug for Envelope<T>

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl<'de, T> Deserialize<'de> for Envelope<T>

where T: Deserialize<'de>,

fn deserialize<__D>(__deserializer: __D) -> Result<Self, __D::Error>

where __D: Deserializer<'de>,

Deserialize this value from the given Serde deserializer.

impl<T> Serialize for Envelope<T>

where T: Serialize,

fn serialize<__S>(&self, __serializer: __S) -> Result<__S::Ok, __S::Error>

where __S: Serializer,

Serialize this value into the given Serde serializer.