Struct Connection

pub struct Connection<T, B: Buf> { /* private fields */ }

Accepts inbound HTTP/2 streams on a connection.

A Connection is backed by an I/O resource (usually a TCP socket) and implements the HTTP/2 server logic for that connection. It is responsible for receiving inbound streams initiated by the client as well as driving the internal state forward.

Connection values are created by calling handshake. Once a Connection value is obtained, the caller must call poll or poll_close in order to drive the internal connection state forward.

See module level documentation for more details

Examples

let mut server = server::handshake(my_io).await.unwrap();
while let Some(request) = server.accept().await {
    tokio::spawn(async move {
        let (request, respond) = request.unwrap();
        // Process the request and send the response back to the client
        // using `respond`.
    });
}

Implementations

impl<T, B> Connection<T, B>

where T: AsyncRead + AsyncWrite + Unpin, B: Buf,

pub async fn accept( &mut self, ) -> Option<Result<(Request<RecvStream>, SendResponse<B>), Error>>

Accept the next incoming request on this connection.

pub fn set_target_window_size(&mut self, size: u32)

Sets the target window size for the whole connection.

If size is greater than the current value, then a WINDOW_UPDATE frame will be immediately sent to the remote, increasing the connection level window by size - current_value.

If size is less than the current value, nothing will happen immediately. However, as window capacity is released by FlowControl instances, no WINDOW_UPDATE frames will be sent out until the number of “in flight” bytes drops below size.

The default value is 65,535.

See FlowControl documentation for more details.

pub fn set_initial_window_size(&mut self, size: u32) -> Result<(), Error>

Set a new INITIAL_WINDOW_SIZE setting (in octets) for stream-level flow control for received data.

The SETTINGS will be sent to the remote, and only applied once the remote acknowledges the change.

This can be used to increase or decrease the window size for existing streams.

Errors

Returns an error if a previous call is still pending acknowledgement from the remote endpoint.

pub fn enable_connect_protocol(&mut self) -> Result<(), Error>

Enables the extended CONNECT protocol.

Errors

Returns an error if a previous call is still pending acknowledgement from the remote endpoint.

pub fn poll_closed(&mut self, cx: &mut Context<'_>) -> Poll<Result<(), Error>>

Returns Ready when the underlying connection has closed.

If any new inbound streams are received during a call to poll_closed, they will be queued and returned on the next call to poll_accept.

This function will advance the internal connection state, driving progress on all the other handles (e.g. RecvStream and SendStream).

See here for more details.

pub fn abrupt_shutdown(&mut self, reason: Reason)

Sets the connection to a GOAWAY state.

Does not terminate the connection. Must continue being polled to close connection.

After flushing the GOAWAY frame, the connection is closed. Any outstanding streams do not prevent the connection from closing. This should usually be reserved for shutting down when something bad external to h2 has happened, and open streams cannot be properly handled.

For graceful shutdowns, see graceful_shutdown.

pub fn graceful_shutdown(&mut self)

Starts a graceful shutdown process.

Must continue being polled to close connection.

It’s possible to receive more requests after calling this method, since they might have been in-flight from the client already. After about 1 RTT, no new requests should be accepted. Once all active streams have completed, the connection is closed.

pub fn ping_pong(&mut self) -> Option<PingPong>

Takes a PingPong instance from the connection.

Note

This may only be called once. Calling multiple times will return None.

pub fn has_streams(&self) -> bool

Checks if there are any streams

pub fn max_concurrent_send_streams(&self) -> usize

Returns the maximum number of concurrent streams that may be initiated by the server on this connection.

This limit is configured by the client peer by sending the SETTINGS_MAX_CONCURRENT_STREAMS parameter in a SETTINGS frame. This method returns the currently acknowledged value received from the remote.

pub fn max_concurrent_recv_streams(&self) -> usize

Returns the maximum number of concurrent streams that may be initiated by the client on this connection.

This returns the value of the SETTINGS_MAX_CONCURRENT_STREAMS parameter sent in a SETTINGS frame that has been acknowledged by the remote peer. The value to be sent is configured by the Builder::max_concurrent_streams method before handshaking with the remote peer.

Trait Implementations

impl<T, B> Debug for Connection<T, B>

where T: Debug, B: Debug + Buf,

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

Formats the value using the given formatter.

impl<T, B> Stream for Connection<T, B>

where T: AsyncRead + AsyncWrite + Unpin, B: Buf,

type Item = Result<(Request<RecvStream>, SendResponse<B>), Error>

Values yielded by the stream.

fn poll_next( self: Pin<&mut Self>, cx: &mut Context<'_>, ) -> Poll<Option<Self::Item>>

Attempt to pull out the next value of this stream, registering the current task for wakeup if the value is not yet available, and returning None if the stream is exhausted.

fn size_hint(&self) -> (usize, Option<usize>)

Returns the bounds on the remaining length of the stream.