Struct aws_smithy_eventstream::frame::DeferredSigner

pub struct DeferredSigner { /* private fields */ }

Deferred event stream signer to allow a signer to be wired up later.

HTTP request signing takes place after serialization, and the event stream message stream body is established during serialization. Since event stream signing may need context from the initial HTTP signing operation, this DeferredSigner is needed to wire up the signer later in the request lifecycle.

This signer basically just establishes a MPSC channel so that the sender can be placed in the request’s config. Then the HTTP signer implementation can retrieve the sender from that config and send an actual signing implementation with all the context needed.

When an event stream implementation needs to sign a message, the first call to sign will acquire a signing implementation off of the channel and cache it for the remainder of the operation.

Implementations

impl DeferredSigner

pub fn new() -> (Self, DeferredSignerSender)

Trait Implementations

impl Debug for DeferredSigner

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

Formats the value using the given formatter.

impl SignMessage for DeferredSigner

fn sign(&mut self, message: Message) -> Result<Message, SignMessageError>

fn sign_empty(&mut self) -> Option<Result<Message, SignMessageError>>

SigV4 requires an empty last signed message to be sent. Other protocols do not require one. Return Some(_) to send a signed last empty message, before completing the stream. Return None to not send one and terminate the stream immediately.