Trait Op 

pub trait Op: Sized {
    // Required methods
    fn decode<R: BufRead>(
        tag: u8,
        r: &mut EntryBufferReader<'_, R>,
    ) -> Result<Self, CodecError>;
    fn encode(&self, w: &mut EntryBufferWriter<'_>) -> Result<(), CodecError>;
}

An op vocabulary that can be encoded to / decoded from the log wire format.

Each data domain implements this for its own op type (e.g. the table op enum in ubiquisync-tables, which is also named Op). The generic Encoder and Decoder drive it: the framing reads the entry tag and hands it to decode, which decodes the body; encode is responsible for the whole op — it writes the tag and the body. The framing supplies everything else (timestamp, attribution, integrity hash).

Reserved tag

Tag 255 (0xFF, TAG_EXPUNGED) is reserved by the framing for expunged-entry markers and is not a valid op tag. An implementation must never write 0xFF as its tag, and decode is never called with tag == 0xFF — the framing intercepts that value before dispatching. Emitting 0xFF from encode would make the entry decode as an expunged marker, silently corrupting the log.

Required Methods

fn decode<R: BufRead>( tag: u8, r: &mut EntryBufferReader<'_, R>, ) -> Result<Self, CodecError>

Decode an op body for the given entry tag, which the framing has already read. tag is never 0xFF (TAG_EXPUNGED) — the framing handles that reserved value itself.

fn encode(&self, w: &mut EntryBufferWriter<'_>) -> Result<(), CodecError>

Encode the op as a tag byte followed by its body. The tag must never be 0xFF (TAG_EXPUNGED), which is reserved.

Dyn Compatibility

This trait is not dyn compatible.

In older versions of Rust, dyn compatibility was called "object safety".

Implementors