Struct Trailer

pub struct Trailer { /* private fields */ }

Holds the current state of a trailer for a response.

This object acts as a shared handle that can be cloned and polled from multiple threads to wait for and act on the response trailer.

There are two typical workflows for accessing trailer headers:

• If you are consuming the response body and then accessing the headers afterward, then all trailers are guaranteed to have arrived (if any). Trailer::try_get will allow you to access them without extra overhead.
• If you are handling trailers in a separate task, callback, or thread, then either Trailer::wait or Trailer::wait_async will allow you to wait for the trailer headers to arrive and then handle them.

Note that in either approach, trailer headers are delivered to your application as a single HeaderMap; it is not possible to handle individual headers as they arrive.

Implementations

impl Trailer

pub fn is_ready(&self) -> bool

Returns true if the trailer has been received (if any).

The trailer will not be received until the body stream associated with this response has been fully consumed.

pub fn try_get(&self) -> Option<&HeaderMap>

Attempt to get the trailer headers without blocking. Returns None if the trailer has not been received yet.

pub fn wait(&self) -> &HeaderMap

Block the current thread until the trailer headers arrive, and then return them.

This is a blocking operation! If you are writing an asynchronous application, then you probably want to use Trailer::wait_async instead.

pub fn wait_timeout(&self, timeout: Duration) -> Option<&HeaderMap>

Block the current thread until the trailer headers arrive or a timeout expires.

If the given timeout expired before the trailer arrived then None is returned.

This is a blocking operation! If you are writing an asynchronous application, then you probably want to use Trailer::wait_async instead.

pub async fn wait_async(&self) -> &HeaderMap

Wait asynchronously until the trailer headers arrive, and then return them.

Trait Implementations

impl Clone for Trailer

fn clone(&self) -> Trailer

Returns a copy of the value.

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

Performs copy-assignment from source.

impl Debug for Trailer

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

Formats the value using the given formatter.