rpc

Documentation

Index

• Variables
• func Accept(lis net.Listener)
• func NewHTTPServer(srv *Server, cors []string) *http.Server
• func NewWSServer(srv *Server, allowedOrigins []string) *http.Server
• func Register(rcvr interface{}) error
• func RegisterName(name string, rcvr interface{}) error
• func ServeCodec(codec ServerCodec)
• func ServeConn(conn Conn)
• func ServeRequest(codec ServerCodec) error
• type API
• type Call
• type Client
  • func Dial(network, address string) (*Client, error)
  • func DialHTTP(url string) (*Client, error)
  • func DialWebsocket(ctx context.Context, endpoint, origin string) (*Client, error)
  • func NewClient(conn io.ReadWriteCloser) *Client
  • func NewClientWithCodec(codec ClientCodec) *Client
  • func (client *Client) Call(serviceMethod string, args interface{}, reply interface{}) error
  • func (client *Client) Close() error
  • func (client *Client) Go(serviceMethod string, args interface{}, reply interface{}, done chan *Call) *Call
• type ClientCodec
  • func NewJSONClientCodec(conn io.ReadWriteCloser, encode, decode func(v interface{}) error) ClientCodec
• type Conn
• type Request
• type Response
• type Server
  • func NewServer() *Server
  • func StartRPCAndHTTP(endpoint string, apis []API, cors []string) (net.Listener, *Server, error)
  • func StartWSEndpoint(endpoint string, wsOrigins []string, apis []API) (net.Listener, *Server, error)
  • func (server *Server) Accept(lis net.Listener)
  • func (server *Server) Register(rcvr interface{}) error
  • func (server *Server) RegisterName(name string, rcvr interface{}) error
  • func (server *Server) ServeCodec(codec ServerCodec)
  • func (server *Server) ServeConn(conn Conn)
  • func (server *Server) ServeHTTP(w http.ResponseWriter, req *http.Request)
  • func (server *Server) ServeRequest(codec ServerCodec) error
  • func (s *Server) WebsocketHandler(allowedOrigins []string) http.Handler
• type ServerCodec
  • func NewJSONServerCodec(conn Conn, encode, decode func(v interface{}) error) ServerCodec
• type ServerError
  • func (e ServerError) Error() string

Variables

var DefaultServer = NewServer()

DefaultServer is the default instance of *Server.

var ErrShutdown = errors.New("connection is shut down")

Functions

func Accept

func Accept(lis net.Listener)

Accept accepts connections on the listener and serves requests to DefaultServer for each incoming connection. Accept blocks; the caller typically invokes it in a go statement.

func NewHTTPServer

func NewHTTPServer(srv *Server, cors []string) *http.Server

NewHTTPServer creates a new HTTP RPC server around an API provider.

func NewWSServer

func NewWSServer(srv *Server, allowedOrigins []string) *http.Server

NewWSServer creates a new websocket RPC server around an API provider.

Deprecated: use Server.WebsocketHandler

func Register

func Register(rcvr interface{}) error

Register publishes the receiver's methods in the DefaultServer.

func RegisterName

func RegisterName(name string, rcvr interface{}) error

RegisterName is like Register but uses the provided name for the type instead of the receiver's concrete type.

func ServeCodec

func ServeCodec(codec ServerCodec)

ServeCodec is like ServeConn but uses the specified codec to decode requests and encode responses.

func ServeConn

func ServeConn(conn Conn)

ServeConn runs the DefaultServer on a single connection. ServeConn blocks, serving the connection until the client hangs up. The caller typically invokes ServeConn in a go statement. ServeConn uses the gob wire format (see package gob) on the connection. To use an alternate codec, use ServeCodec.

func ServeRequest

func ServeRequest(codec ServerCodec) error

ServeRequest is like ServeCodec but synchronously serves a single request. It does not close the codec upon completion.

Types

type API

type API struct {
	Namespace string
	Version   string
	Service   interface{}
}

type Call

type Call struct {
	ServiceMethod string      // The name of the service and method to call.
	Args          interface{} // The argument to the function (*struct).
	Reply         interface{} // The reply from the function (*struct).
	Error         error       // After completion, the error status.
	Done          chan *Call  // Strobes when call is complete.
}

Call represents an active RPC.

type Client

type Client struct {
	// contains filtered or unexported fields
}

Client represents an RPC Client. There may be multiple outstanding Calls associated with a single Client, and a Client may be used by multiple goroutines simultaneously.

func Dial

func Dial(network, address string) (*Client, error)

Dial connects to an RPC server at the specified network address.

func DialHTTP

func DialHTTP(url string) (*Client, error)

DialHTTP creates a new RPC clients that connection to an RPC server over HTTP.

func DialWebsocket

func DialWebsocket(ctx context.Context, endpoint, origin string) (*Client, error)

DialWebsocket creates a new RPC client that communicates with a JSON-RPC server that is listening on the given endpoint.

The context is used for the initial connection establishment. It does not affect subsequent interactions with the client.

func NewClient

func NewClient(conn io.ReadWriteCloser) *Client

NewClient returns a new Client to handle requests to the set of services at the other end of the connection. It adds a buffer to the write side of the connection so the header and payload are sent as a unit.

func NewClientWithCodec

func NewClientWithCodec(codec ClientCodec) *Client

NewClientWithCodec is like NewClient but uses the specified codec to encode requests and decode responses.

func (*Client) Call

func (client *Client) Call(serviceMethod string, args interface{}, reply interface{}) error

Call invokes the named function, waits for it to complete, and returns its error status.

func (*Client) Close

func (client *Client) Close() error

Close calls the underlying codec's Close method. If the connection is already shutting down, ErrShutdown is returned.

func (*Client) Go

func (client *Client) Go(serviceMethod string, args interface{}, reply interface{}, done chan *Call) *Call

Go invokes the function asynchronously. It returns the Call structure representing the invocation. The done channel will signal when the call is complete by returning the same Call object. If done is nil, Go will allocate a new channel. If non-nil, done must be buffered or Go will deliberately crash.

type ClientCodec

type ClientCodec interface {
	// WriteRequest must be safe for concurrent use by multiple goroutines.
	WriteRequest(*Request, interface{}) error
	ReadResponseHeader(*Response) error
	ReadResponseBody(interface{}) error

	Close() error
}

A ClientCodec implements writing of RPC requests and reading of RPC responses for the client side of an RPC session. The client calls WriteRequest to write a request to the connection and calls ReadResponseHeader and ReadResponseBody in pairs to read responses. The client calls Close when finished with the connection. ReadResponseBody may be called with a nil argument to force the body of the response to be read and then discarded.

func NewJSONClientCodec

func NewJSONClientCodec(conn io.ReadWriteCloser, encode, decode func(v interface{}) error) ClientCodec

NewJSONClientCodec returns a new ClientCodec using JSON-RPC on conn.

type Conn

type Conn interface {
	io.ReadWriteCloser
	SetWriteDeadline(time.Time) error
}

Conn is a subset of the methods of net.Conn which are sufficient for ServerCodec.

type Request

type Request struct {
	ServiceMethod string // format: "Service.Method"
	Seq           uint64 // sequence number chosen by client
	// contains filtered or unexported fields
}

Request is a header written before every RPC call. It is used internally but documented here as an aid to debugging, such as when analyzing network traffic.

type Response

type Response struct {
	ServiceMethod string // echoes that of the Request
	Seq           uint64 // echoes that of the request
	Error         string // error, if any.
	// contains filtered or unexported fields
}

Response is a header written before every RPC return. It is used internally but documented here as an aid to debugging, such as when analyzing network traffic.

type Server

type Server struct {
	// contains filtered or unexported fields
}

Server represents an RPC Server.

func NewServer

func NewServer() *Server

NewServer returns a new Server.

func StartRPCAndHTTP

func StartRPCAndHTTP(endpoint string, apis []API, cors []string) (net.Listener, *Server, error)

StartRPCAndHTTP start RPC and HTTP service

func StartWSEndpoint

func StartWSEndpoint(endpoint string, wsOrigins []string, apis []API) (net.Listener, *Server, error)

StartWSEndpoint starts a websocket endpoint

func (*Server) Accept

func (server *Server) Accept(lis net.Listener)

Accept accepts connections on the listener and serves requests for each incoming connection. Accept blocks until the listener returns a non-nil error. The caller typically invokes Accept in a go statement.

func (*Server) Register

func (server *Server) Register(rcvr interface{}) error

Register publishes in the server the set of methods of the receiver value that satisfy the following conditions:

• exported method of exported type
• two arguments, both of exported type
• the second argument is a pointer
• one return value, of type error

It returns an error if the receiver is not an exported type or has no suitable methods. It also logs the error using package log. The client accesses each method using a string of the form "Type.Method", where Type is the receiver's concrete type.

func (*Server) RegisterName

func (server *Server) RegisterName(name string, rcvr interface{}) error

RegisterName is like Register but uses the provided name for the type instead of the receiver's concrete type.

func (*Server) ServeCodec

func (server *Server) ServeCodec(codec ServerCodec)

ServeCodec is like ServeConn but uses the specified codec to decode requests and encode responses.

func (*Server) ServeConn

func (server *Server) ServeConn(conn Conn)

ServeConn runs the server on a single connection. ServeConn blocks, serving the connection until the client hangs up. The caller typically invokes ServeConn in a go statement. ServeConn uses the gob wire format (see package gob) on the connection. To use an alternate codec, use ServeCodec.

func (*Server) ServeHTTP

func (server *Server) ServeHTTP(w http.ResponseWriter, req *http.Request)

ServeHTTP implements an http.Handler that answers every RPC requests. Overwrite this method, we can wrapper a simple JSON-RPC framework.

func (*Server) ServeRequest

func (server *Server) ServeRequest(codec ServerCodec) error

ServeRequest is like ServeCodec but synchronously serves a single request. It does not close the codec upon completion.

func (*Server) WebsocketHandler

func (s *Server) WebsocketHandler(allowedOrigins []string) http.Handler

WebsocketHandler returns a handler that serves JSON-RPC to WebSocket connections.

allowedOrigins should be a comma-separated list of allowed origin URLs. To allow connections with any origin, pass "*".

type ServerCodec

type ServerCodec interface {
	ReadRequestHeader(*Request) error
	ReadRequestBody(interface{}) error
	// WriteResponse must be safe for concurrent use by multiple goroutines.
	WriteResponse(*Response, interface{}) error

	Close() error
}

A ServerCodec implements reading of RPC requests and writing of RPC responses for the server side of an RPC session. The server calls ReadRequestHeader and ReadRequestBody in pairs to read requests from the connection, and it calls WriteResponse to write a response back. The server calls Close when finished with the connection. ReadRequestBody may be called with a nil argument to force the body of the request to be read and discarded.

func NewJSONServerCodec

func NewJSONServerCodec(conn Conn, encode, decode func(v interface{}) error) ServerCodec

NewJSONServerCodec returns a new ServerCodec using JSON-RPC on conn.

type ServerError

type ServerError string

ServerError represents an error that has been returned from the remote side of the RPC connection.

func (ServerError) Error

func (e ServerError) Error() string