Trait slimproto::Decoder

source ·

pub trait Decoder {
    type Item;
    type Error: From<Error>;

    // Required method
    fn decode(
        &mut self,
        src: &mut BytesMut
    ) -> Result<Option<Self::Item>, Self::Error>;
}

Expand description

The Decoder trait. Objects that implement this trait take a BytesMut and return an item whose type is defined as the associated type Item.

It is important that implementers deplete bytes from src when they are used to form the returned item. This can be done by using the split* methods and the get* and put* methods which become available when you import the Buf and BufMut traits.

There are three possibilities to return from this method:

Ok(Some(Item)) - in which case decoding is complete and the user defined item is returned.
Ok(None)- there is not enough data in src to decode the message. When this is returned read is called again on the underlying Read object.
Err() - An error has occurred. This will close the underlying Read object. If you want to indicate a protocol error it is better to use the user defined Item to do this.