Struct ProtocolCodec 

pub struct ProtocolCodec { /* private fields */ }

Codec that translates between wire-format messages and the unified internal ClientMessage / ServerMessage types.

Implementations

impl ProtocolCodec

pub const fn new(protocol: WsProtocol) -> Self

Create a new codec for the given protocol.

pub const fn protocol(&self) -> WsProtocol

The negotiated protocol.

pub fn decode(&self, raw: &str) -> Result<ClientMessage, ProtocolError>

Decode a raw JSON string from the WebSocket into a ClientMessage.

For graphql-transport-ws this is a passthrough deserialisation. For the legacy graphql-ws protocol, message types are translated:

• start → subscribe
• stop → complete

Errors

Returns a ProtocolError if the JSON is malformed.

pub fn encode( &self, msg: &ServerMessage, ) -> Result<Option<String>, ProtocolError>

Encode a ServerMessage to a JSON string for sending over the WebSocket.

For graphql-transport-ws this serialises directly. For the legacy graphql-ws protocol, message types are translated:

• next → data
• ping → ka (keepalive, no payload)
• pong → dropped (legacy protocol has no pong)

Returns None for messages that should be suppressed (e.g. pong in legacy mode).

Errors

Returns a ProtocolError if serialisation fails.

Panics

Cannot panic in practice — the expect on wire_type is guarded by an is_none() early-return immediately above.

pub fn uses_keepalive(&self) -> bool

Whether the protocol uses periodic keepalive (ka) messages instead of ping/pong.