pub struct Channel { /* private fields */ }
Expand description

A default batteries included transport channel.

This provides a fully featured http2 gRPC client based on hyper::Client and tower services.

Multiplexing requests

Sending a request on a channel requires a &mut self and thus can only send one request in flight. This is intentional and is required to follow the Service contract from the tower library which this channel implementation is built on top of.

tower itself has a concept of poll_ready which is the main mechanism to apply back pressure. poll_ready takes a &mut self and when it returns Poll::Ready we know the Service is able to accept only one request before we must poll_ready again. Due to this fact any async fn that wants to poll for readiness and submit the request must have a &mut self reference.

To work around this and to ease the use of the channel, Channel provides a Clone implementation that is cheap. This is because at the very top level the channel is backed by a tower_buffer::Buffer which runs the connection in a background task and provides a mpsc channel interface. Due to this cloning the Channel type is cheap and encouraged.

Implementations

Create an Endpoint builder that can create Channels.

Create an Endpoint from a static string.

Channel::from_static("https://example.com");

Create an Endpoint from shared bytes.

Channel::from_shared("https://example.com");

Balance a list of Endpoint’s.

This creates a Channel that will load balance accross all the provided endpoints.

Balance a list of Endpoint’s.

This creates a Channel that will listen to a stream of change events and will add or remove provided endpoints.

Trait Implementations

Returns a copy of the value. Read more
Performs copy-assignment from source. Read more
Formats the value using the given formatter. Read more
Responses given by the service.
Errors produced by the service.
The future response value.
Returns Poll::Ready(Ok(())) when the service is able to process requests. Read more
Process the request and return the response asynchronously. Read more

Auto Trait Implementations

Blanket Implementations

Gets the TypeId of self. Read more
Immutably borrows from an owned value. Read more
Mutably borrows from an owned value. Read more

Returns the argument unchanged.

Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more
Instruments this type with the provided Span, returning an Instrumented wrapper. Read more
Instruments this type with the current Span, returning an Instrumented wrapper. Read more

Calls U::from(self).

That is, this conversion is whatever the implementation of [From]<T> for U chooses to do.

Yields a mutable reference to the service when it is ready to accept a request.
👎Deprecated since 0.4.6: please use the ServiceExt::ready method instead
Yields a mutable reference to the service when it is ready to accept a request.
Yields the service when it is ready to accept a request.
Consume this Service, calling with the providing request once it is ready.
Process all requests from the given Stream, and produce a Stream of their responses. Read more
Executes a new future after this service’s future resolves. This does not alter the behaviour of the poll_ready method. Read more
Maps this service’s response value to a different value. This does not alter the behaviour of the poll_ready method. Read more
Maps this service’s error value to a different value. This does not alter the behaviour of the poll_ready method. Read more
Maps this service’s result type (Result<Self::Response, Self::Error>) to a different value, regardless of whether the future succeeds or fails. Read more
Composes a function in front of the service. Read more
Composes an asynchronous function after this service. Read more
Composes a function that transforms futures produced by the service. Read more
Convert the service into a Service + [Send] trait object. Read more
Convert the service into a Service + [Clone] + [Send] trait object. Read more
The resulting type after obtaining ownership.
Creates owned data from borrowed data, usually by cloning. Read more
Uses borrowed data to replace owned data, usually by cloning. Read more
The type returned in the event of a conversion error.
Performs the conversion.
The type returned in the event of a conversion error.
Performs the conversion.
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the provided Subscriber to this type, returning a WithDispatch wrapper. Read more
Attaches the current default Subscriber to this type, returning a WithDispatch wrapper. Read more