Trait tk_http::client::Codec [−] [src]

pub trait Codec<S> {
    type Future: Future<Item = EncoderDone<S>, Error = Error>;
    fn start_write(&mut self, e: Encoder<S>) -> Self::Future;
    fn headers_received(&mut self, headers: &Head) -> Result<RecvMode, Error>;
    fn data_received(
        &mut self, 
        data: &[u8], 
        end: bool
    ) -> Result<Async<usize>, Error>;
}

This is a low-level interface to the http client

Your requests starts by sending a codec into a connection Sink or a connection pool. And then it's driven by a callbacks here.

If you don't have any special needs you might want to use client::buffered::Buffered codec implementation instead of implemeting this trait manually.

Associated Types

Future that start_write() returns

Required Methods

Start writing a request

This method is called when there is an open connection and there is some space in the output buffer.

Everything you write into a buffer might be flushed to the network immediately (or as fast as you yield to main loop). On the other hand we might buffer/pipeline multiple requests at once.

Received headers of a response

At this point we already extracted all the headers and other data that we need to ensure correctness of the protocol. If you need to handle some data from the headers you need to store them somewhere (for example on self) for further processing.

Note: headers might be received after request_line is written, but we don't ensure that request is fully written. You should write the state machine as if request and response might be streamed a the same time (including request headers (!) if your start_write future writes them incrementally)

Chunk of the response body received

end equals to true for the last chunk of the data.

Method returns Async::Ready(x) to denote that it has consumed x bytes. If there are some bytes left in the buffer they will be passed again on the call.

If the response is empty, or last chunk arrives later and it's empty we call c.data_received(b"", true) on every wakeup, until Async::Ready(0) is returned (this helps to drive future that might complete on request completion without spawning another ones, but note that next request can't start reading in the meantime).

Protocol panics if returned number of bytes larger than data.len().

Implementors