Struct MessageBuilder 

pub struct MessageBuilder { /* private fields */ }

Aggregate JSON-RPC message builder/parser.

Holds the three sub-components needed to drive a JSON-RPC session:

• RequestBuilder — produces outbound requests and assigns monotonically-increasing ids; held mutably because it mutates that id counter on every call.
• ResponseHandler — parses inbound replies keyed by id; fully stateless, so a shared reference is enough.
• NotificationHandler — parses server-initiated pushes (subscription events, heartbeats); also stateless.

One instance per WebSocket connection is the intended lifetime: the id counter must not be shared across connections, and the handlers hold no connection-specific state.

Implementations

impl MessageBuilder

pub fn new() -> Self

Create a new aggregate message builder with a fresh id counter and stateless response/notification parsers.

pub fn request_builder(&mut self) -> &mut RequestBuilder

Borrow the request builder mutably.

Mutability is required because every outbound request advances the builder’s id counter. Prefer calling this from a single task: the MessageBuilder itself is not Sync-protected.

pub fn response_handler(&self) -> &ResponseHandler

Borrow the response handler.

Returned as an immutable reference because the handler is a pure JSON-to-DTO parser with no internal state.

pub fn notification_handler(&self) -> &NotificationHandler

Borrow the notification handler.

Returned as an immutable reference because the handler is a pure JSON-to-DTO parser with no internal state.

pub fn parse_message(&self, data: &str) -> Result<MessageType, Error>

Classify and parse a raw JSON-RPC frame.

Attempts the response path first (JSON-RPC 2.0 responses always carry an id), then the notification path (notifications never have id). Outbound-only JsonRpcRequests — the third MessageType variant — are produced by RequestBuilder, not by this parser, so receiving a “request-shaped” frame from the server is treated as invalid data.

Errors

Returns a serde_json::Error of kind std::io::ErrorKind::InvalidData when data parses as neither a response nor a notification — typically because it is malformed JSON, lacks both an id and a method, or looks like an outbound request rather than an inbound frame.

Trait Implementations

impl Debug for MessageBuilder

fn fmt(&self, f: &mut Formatter<'_>) -> Result

Formats the value using the given formatter.

impl Default for MessageBuilder

fn default() -> Self

Returns the “default value” for a type.