Struct h2::client::Connection

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

Manages all state associated with an HTTP/2 client connection.

A Connection is backed by an I/O resource (usually a TCP socket) and implements the HTTP/2 client logic for that connection. It is responsible for driving the internal state forward, performing the work requested of the associated handles (SendRequest, ResponseFuture, SendStream, RecvStream).

Connection values are created by calling handshake. Once a Connection value is obtained, the caller must repeatedly call poll until Ready is returned. The easiest way to do this is to submit the Connection instance to an executor.

Examples

    let (send_request, connection) = client::handshake(my_io).await?;
    // Submit the connection handle to an executor.
    tokio::spawn(async { connection.await.expect("connection failed"); });

    // Now, use `send_request` to initialize HTTP/2 streams.
    // ...

Implementations

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

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

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 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 max_concurrent_send_streams(&self) -> usize

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

This limit is configured by the server 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 server 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: AsyncRead + AsyncWrite + Debug, B: Debug + Buf,

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

Formats the value using the given formatter.

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

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

type Output = Result<(), Error>

The type of value produced on completion.

fn poll(self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output>

Attempts to resolve the future to a final value, registering the current task for wakeup if the value is not yet available.