Package rpc

- the method's type is exported.
- the method is exported.
- the method has two arguments, both exported (or builtin) types.
- the method's second argument is a pointer.
- the method has return type error.

func (t *T) MethodName(argType T1, replyType *T2) error

package server

import "errors"

type Args struct {
	A, B int
}

type Quotient struct {
	Quo, Rem int
}

type Arith int

func (t *Arith) Multiply(args *Args, reply *int) error {
	*reply = args.A * args.B
	return nil
}

func (t *Arith) Divide(args *Args, quo *Quotient) error {
	if args.B == 0 {
		return errors.New("divide by zero")
	}
	quo.Quo = args.A / args.B
	quo.Rem = args.A % args.B
	return nil
}

arith := new(Arith)
rpc.Register(arith)
rpc.HandleHTTP()
l, e := net.Listen("tcp", ":1234")
if e != nil {
	log.Fatal("listen error:", e)
}
go http.Serve(l, nil)

client, err := rpc.DialHTTP("tcp", serverAddress + ":1234")
if err != nil {
	log.Fatal("dialing:", err)
}

// Synchronous call
args := &server.Args{7,8}
var reply int
err = client.Call("Arith.Multiply", args, &reply)
if err != nil {
	log.Fatal("arith error:", err)
}
fmt.Printf("Arith: %d*%d=%d", args.A, args.B, reply)

// Asynchronous call
quotient := new(Quotient)
divCall := client.Go("Arith.Divide", args, quotient, nil)
replyCall := <-divCall.Done	// will be equal to divCall
// check errors, print, etc.

Constants

const (
    // Defaults used by HandleHTTP
    DefaultRPCPath   = "/_goRPC_"
    DefaultDebugPath = "/debug/rpc"
)

Variables

DefaultServer is the default instance of *Server.

var DefaultServer = NewServer()

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

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 HandleHTTP ¶

func HandleHTTP()

HandleHTTP registers an HTTP handler for RPC messages to DefaultServer on DefaultRPCPath and a debugging handler on DefaultDebugPath. It is still necessary to invoke http.Serve(), typically in a go statement.

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 io.ReadWriteCloser)

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.

type Call ¶

Call represents an active RPC.

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.
}

type Client ¶

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.

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

func Dial ¶

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

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

func DialHTTP ¶

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

DialHTTP connects to an HTTP RPC server at the specified network address listening on the default HTTP RPC path.

func DialHTTPPath ¶

func DialHTTPPath(network, address, path string) (*Client, error)

DialHTTPPath connects to an HTTP RPC server at the specified network address and path.

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 ¶

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.

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
}

type Request ¶

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

type Response ¶

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 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
}

type Server ¶

Server represents an RPC Server.

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

func NewServer ¶

func NewServer() *Server

NewServer returns a new Server.

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) HandleHTTP ¶

func (server *Server) HandleHTTP(rpcPath, debugPath string)

HandleHTTP registers an HTTP handler for RPC messages on rpcPath, and a debugging handler on debugPath. It is still necessary to invoke http.Serve(), typically 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 io.ReadWriteCloser)

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 RPC requests.

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.

type ServerCodec ¶

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.

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
}

type ServerError ¶

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

type ServerError string

func (ServerError) Error ¶

func (e ServerError) Error() string

Subdirectories