Struct MethodInfo 

pub struct MethodInfo {

    pub name: String,
    pub method_type: MethodType,
    pub params_schema: SchemaRef,
    pub result_schema: SchemaRef,
    pub header_schema: Option<SchemaRef>,
    pub doc: Option<String>,
    pub param_types: Vec<(String, String)>,
    pub param_defaults: Vec<(String, Value)>,
    pub param_docs: Vec<(String, String)>,
    pub has_return: bool,
    pub unary: Option<UnaryHandler>,
    pub stream: Option<StreamHandler>,
    pub state_decoder: Option<StateDecoder>,
}

Describes one RPC method — the metadata required both for dispatch and introspection via __describe__.

Build via MethodInfo::unary / MethodInfo::stream and attach additional describe-time metadata through the builder helpers (.doc, .param_type, .param_default, .param_doc, .header_schema).

Fields

name: String

method_type: MethodType

params_schema: SchemaRef

Schema of the request parameters (one row).

result_schema: SchemaRef

Schema of the unary result; empty for streams.

header_schema: Option<SchemaRef>

For streams that emit a typed header, the header batch schema.

doc: Option<String>

Method-level docstring (the first line of Python’s docstring).

param_types: Vec<(String, String)>

Parameter type names in source order, matching the Python describe wire format (“str”, “int”, “liststr”, “Point”, “str | None”).

param_defaults: Vec<(String, Value)>

Parameter defaults; values are anything JSON-serializable.

param_docs: Vec<(String, String)>

Per-parameter documentation (matches the Python param_docs_json).

has_return: bool

Whether the method has a non-void return. false for streams/void.

unary: Option<UnaryHandler>

stream: Option<StreamHandler>

state_decoder: Option<StateDecoder>

Decoder that reconstructs the method’s StreamStateKind from a byte slice produced by ProducerState::encode_state / ExchangeState::encode_state. Required for HTTP streaming (the stateless-worker model); None for unary methods and for streams that will only ever run over pipe/unix.

Implementations

impl MethodInfo

pub fn unary( name: impl Into<String>, params_schema: SchemaRef, result_schema: SchemaRef, handler: impl Fn(&Request, &CallContext) -> Result<Option<RecordBatch>> + Send + Sync + 'static, ) -> Self

Start building a unary method registration.

pub fn stream( name: impl Into<String>, method_type: MethodType, params_schema: SchemaRef, handler: impl Fn(&Request, &CallContext) -> Result<StreamResult> + Send + Sync + 'static, ) -> Self

Start building a streaming method registration.

Note: this form registers the method without a state decoder, so it will work for pipe/unix transports but HTTP continuation requests will fail. Use [MethodInfo::producer_with_codec] / [MethodInfo::exchange_with_codec] when HTTP is enabled.

pub fn with_state_decoder(self, decoder: StateDecoder) -> Self

Attach a state decoder function. See StateDecoder.

pub fn doc(self, s: impl Into<String>) -> Self

pub fn param_type(self, param: impl Into<String>, ty: impl Into<String>) -> Self

pub fn param_default(self, param: impl Into<String>, value: Value) -> Self

pub fn param_doc(self, param: impl Into<String>, doc: impl Into<String>) -> Self

pub fn header_schema(self, schema: SchemaRef) -> Self