Trait tokio_core::io::FramedIo

pub trait FramedIo {
    type In;
    type Out;
    fn poll_read(&mut self) -> Async<()>;
    fn read(&mut self) -> Poll<Self::Out, Error>;
    fn poll_write(&mut self) -> Async<()>;
    fn write(&mut self, req: Self::In) -> Poll<(), Error>;
    fn flush(&mut self) -> Poll<(), Error>;
}

A trait for framed reading and writing.

Most implementations of FramedIo are for doing protocol level serialization and deserialization.

Imporantly, the methods of this trait are intended to be used in conjuction with the current task of a future. Namely whenever any of them return a value that indicates "would block" the current future's task is arranged to receive a notification when the method would otherwise not indicate that it would block.

Associated Types

type In

Messages written

type Out

Messages read

Required Methods

fn poll_read(&mut self) -> Async<()>

Tests to see if this FramedIo may be readable.

fn read(&mut self) -> Poll<Self::Out, Error>

Read a message frame from the FramedIo

fn poll_write(&mut self) -> Async<()>

Tests to see if this FramedIo may be writable.

Unlike most other calls to poll readiness, it is important that when FramedIo::poll_write returns Async::Ready that a write will succeed.

fn write(&mut self, req: Self::In) -> Poll<(), Error>

Write a message frame to the FramedIo

fn flush(&mut self) -> Poll<(), Error>

Flush pending writes or do any other work not driven by reading / writing.

Since the backing source is non-blocking, there is no guarantee that a call to FramedIo::write is able to write the full message to the backing source immediately. In this case, the FramedIo will need to buffer the remaining data to write. Calls to FramedIo:flush attempt to write any remaining data in the write buffer to the underlying source.

Implementors