Struct ChannelCodec

pub struct ChannelCodec {
    link_version: u16,
}

This object can be used to encode and decode channel cells.

NOTE: only link protocol versions 3 and higher are supported. VERSIONS cells are not supported via the encoder/decoder, since VERSIONS cells always use a two-byte circuit-ID for backwards compatibility with protocol versions < 4.

The implemented format is one of the following:

Variable-length cells (since protocol versions 2 and 3 respectively):

    u32 circid;
    u8 command;
    u16 len;
    u8 body[len];

Fixed-width cells (since protocol version 1 and 4 respectively):

    u32 circid;
    u8 command;
    u8 body[509];

Fields

link_version: u16

The link protocol version being used for this channel.

(We don’t currently support any versions of the link protocol where this version matters, but for protocol versions below 4, it would affect the length of the circuit ID.)

Implementations

impl ChannelCodec

pub fn new(link_version: u16) -> Self

Create a new ChannelCodec with a given link protocol version

pub fn write_cell<M: ChanMsg>( &mut self, item: ChanCell<M>, dst: &mut BytesMut, ) -> Result<()>

Write the given cell into the provided BytesMut object.

pub fn decode_cell<M: ChanMsg>( &mut self, src: &mut BytesMut, ) -> Result<Option<ChanCell<M>>>

Try to decode a cell from the provided BytesMut object.

On a definite decoding error, return Err(_). On a cell that might just be truncated, return Ok(None).