diff --git a/common/types.go b/common/types.go
index 624f4b8265..e03d99830a 100644
--- a/common/types.go
+++ b/common/types.go
@@ -21,6 +21,7 @@ import (
"math/big"
"math/rand"
"reflect"
+ "encoding/json"
)
const (
@@ -50,6 +51,11 @@ func (h Hash) Bytes() []byte { return h[:] }
func (h Hash) Big() *big.Int { return Bytes2Big(h[:]) }
func (h Hash) Hex() string { return "0x" + Bytes2Hex(h[:]) }
+// Serialize given hash to JSON
+func (h Hash) MarshalJSON() ([]byte, error) {
+ return json.Marshal(h.Hex())
+}
+
// Sets the hash to the value of b. If b is larger than len(h) it will panic
func (h *Hash) SetBytes(b []byte) {
if len(b) > len(h) {
@@ -117,6 +123,11 @@ func (a *Address) Set(other Address) {
}
}
+// Serialize given address to JSON
+func (a Address) MarshalJSON() ([]byte, error) {
+ return json.Marshal(a.Hex())
+}
+
// PP Pretty Prints a byte slice in the following format:
// hex(value[:4])...(hex[len(value)-4:])
func PP(value []byte) string {
diff --git a/ethdb/interface.go b/ethdb/interface.go
index f4b787a52a..a6a3c31ff9 100644
--- a/ethdb/interface.go
+++ b/ethdb/interface.go
@@ -28,3 +28,4 @@ type Batch interface {
Put(key, value []byte) error
Write() error
}
+
diff --git a/rpc/v2/doc.go b/rpc/v2/doc.go
new file mode 100644
index 0000000000..e51494adb0
--- /dev/null
+++ b/rpc/v2/doc.go
@@ -0,0 +1,102 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+/*
+Package rpc provides access to the exported methods of an object across a network
+or other I/O connection. After creating a server instance objects can be registered,
+making it visible from the outside. Exported methods that follow specific
+conventions can be called remotely. It also has support for the publish/subscribe
+pattern.
+
+Methods that satisfy the following criteria are made available for remote access:
+ - object must be exported
+ - method must be exported
+ - method returns 0, 1 (response or error) or 2 (response and error) values
+ - method argument(s) must be exported or builtin types
+ - method returned value(s) must be exported or builtin types
+
+An example method:
+ func (s *CalcService) Div(a, b int) (int, error)
+
+When the returned error isn't nil the returned integer is ignored and the error is
+send back to the client. Otherwise the returned integer is send back to the client.
+
+The server offers the ServeCodec method which accepts a ServerCodec instance. It will
+read requests from the codec, process the request and sends the response back to the
+client using the codec. The server can execute requests concurrently. Responses
+can be send back to the client out of order.
+
+An example server which uses the JSON codec:
+ type CalculatorService struct {}
+
+ func (s *CalculatorService) Add(a, b int) int {
+ return a + b
+ }
+
+ func (s *CalculatorService Div(a, b int) (int, error) {
+ if b == 0 {
+ return 0, errors.New("divide by zero")
+ }
+ return a/b, nil
+ }
+
+ calculator := new(CalculatorService)
+ server := NewServer()
+ server.RegisterName("calculator", calculator")
+
+ l, _ := net.ListenUnix("unix", &net.UnixAddr{Net: "unix", Name: "/tmp/calculator.sock"})
+ for {
+ c, _ := l.AcceptUnix()
+ codec := v2.NewJSONCodec(c)
+ go server.ServeCodec(codec)
+ }
+
+The package also supports the publish subscribe pattern through the use of subscriptions.
+A method that is considered eligible for notifications must satisfy the following criteria:
+ - object must be exported
+ - method must be exported
+ - method argument(s) must be exported or builtin types
+ - method must return the tuple Subscription, error
+
+
+An example method:
+ func (s *BlockChainService) Head() (Subscription, error) {
+ sub := s.bc.eventMux.Subscribe(ChainHeadEvent{})
+ return v2.NewSubscription(sub), nil
+ }
+
+This method will push all raised ChainHeadEvents to subscribed clients. If the client is only
+interested in every N'th block it is possible to add a criteria.
+
+ func (s *BlockChainService) HeadFiltered(nth uint64) (Subscription, error) {
+ sub := s.bc.eventMux.Subscribe(ChainHeadEvent{})
+
+ criteria := func(event interface{}) bool {
+ chainHeadEvent := event.(ChainHeadEvent)
+ if chainHeadEvent.Block.NumberU64() % nth == 0 {
+ return true
+ }
+ return false
+ }
+
+ return v2.NewSubscriptionFiltered(sub, criteria), nil
+ }
+
+Subscriptions are deleted when:
+ - the user sends an unsubscribe request
+ - the connection which was used to create the subscription is closed
+*/
+package v2
diff --git a/rpc/v2/errors.go b/rpc/v2/errors.go
new file mode 100644
index 0000000000..a06d19d84c
--- /dev/null
+++ b/rpc/v2/errors.go
@@ -0,0 +1,85 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package v2
+
+import "fmt"
+
+// request is for an unknown service
+type methodNotFoundError struct {
+ service string
+ method string
+}
+
+func (e *methodNotFoundError) Code() int {
+ return -32601
+}
+
+func (e *methodNotFoundError) Error() string {
+ return fmt.Sprintf("The method %s%s%s does not exist/is not available", e.service, serviceMethodSeparator, e.method)
+}
+
+// received message isn't a valid request
+type invalidRequestError struct {
+ message string
+}
+
+func (e *invalidRequestError) Code() int {
+ return -32600
+}
+
+func (e *invalidRequestError) Error() string {
+ return e.message
+}
+
+// received message is invalid
+type invalidMessageError struct {
+ message string
+}
+
+func (e *invalidMessageError) Code() int {
+ return -32700
+}
+
+func (e *invalidMessageError) Error() string {
+ return e.message
+}
+
+// unable to decode supplied params, or an invalid number of parameters
+type invalidParamsError struct {
+ message string
+}
+
+func (e *invalidParamsError) Code() int {
+ return -32602
+}
+
+func (e *invalidParamsError) Error() string {
+ return e.message
+}
+
+// logic error, callback returned an error
+type callbackError struct {
+ message string
+}
+
+func (e *callbackError) Code() int {
+ return -32000
+}
+
+func (e *callbackError) Error() string {
+ return e.message
+}
diff --git a/rpc/v2/json.go b/rpc/v2/json.go
new file mode 100644
index 0000000000..e8ba340945
--- /dev/null
+++ b/rpc/v2/json.go
@@ -0,0 +1,295 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package v2
+
+import (
+ "encoding/json"
+ "io"
+ "reflect"
+ "strings"
+ "sync/atomic"
+)
+
+const (
+ jsonRPCVersion = "2.0"
+ serviceMethodSeparator = "_"
+ subscribeMethod = "eth_subscribe"
+ unsubscribeMethod = "eth_unsubscribe"
+ notificationMethod = "eth_subscription"
+)
+
+// JSON-RPC request
+type jsonRequest struct {
+ Method string `json:"method"`
+ Version string `json:"jsonrpc"`
+ Id int64 `json:"id"`
+ Payload json.RawMessage `json:"params"`
+}
+
+// JSON-RPC response
+type jsonSuccessResponse struct {
+ Version string `json:"jsonrpc"`
+ Id int64 `json:"id"`
+ Result interface{} `json:"result,omitempty"`
+}
+
+// JSON-RPC error object
+type jsonError struct {
+ Code int `json:"code"`
+ Message string `json:"message"`
+ Data interface{} `json:"data,omitempty"`
+}
+
+// JSON-RPC error response
+type jsonErrResponse struct {
+ Version string `json:"jsonrpc"`
+ Id *int64 `json:"id,omitempty"`
+ Error jsonError `json:"error"`
+}
+
+// JSON-RPC notification payload
+type jsonSubscription struct {
+ Subscription string `json:"subscription"`
+ Result interface{} `json:"result,omitempty"`
+}
+
+// JSON-RPC notification
+type jsonNotification struct {
+ Version string `json:"jsonrpc"`
+ Method string `json:"method"`
+ Params jsonSubscription `json:"params"`
+}
+
+// jsonCodec reads and writes JSON-RPC messages to the underlying connection. It also has support for parsing arguments
+// and serializing (result) objects.
+type jsonCodec struct {
+ closed chan interface{}
+ isClosed int32
+ d *json.Decoder
+ e *json.Encoder
+ req jsonRequest
+ rw io.ReadWriteCloser
+}
+
+// NewJSONCodec creates a new RPC server codec with support for JSON-RPC 2.0
+func NewJSONCodec(rwc io.ReadWriteCloser) ServerCodec {
+ d := json.NewDecoder(rwc)
+ d.UseNumber()
+ return &jsonCodec{closed: make(chan interface{}), d: d, e: json.NewEncoder(rwc), rw: rwc, isClosed: 0}
+}
+
+// isBatch returns true when the first non-whitespace characters is '['
+func isBatch(msg json.RawMessage) bool {
+ for _, c := range msg {
+ // skip insignificant whitespace (http://www.ietf.org/rfc/rfc4627.txt)
+ if c == 0x20 || c == 0x09 || c == 0x0a || c == 0x0d {
+ continue
+ }
+ return c == '['
+ }
+ return false
+}
+
+// ReadRequestHeaders will read new requests without parsing the arguments. It will return a collection of requests, an
+// indication if these requests are in batch form or an error when the incoming message could not be read/parsed.
+func (c *jsonCodec) ReadRequestHeaders() ([]rpcRequest, bool, RPCError) {
+ var incomingMsg json.RawMessage
+ if err := c.d.Decode(&incomingMsg); err != nil {
+ return nil, false, &invalidRequestError{err.Error()}
+ }
+
+ if isBatch(incomingMsg) {
+ return parseBatchRequest(incomingMsg)
+ }
+
+ return parseRequest(incomingMsg)
+}
+
+// parseRequest will parse a single request from the given RawMessage. It will return the parsed request, an indication
+// if the request was a batch or an error when the request could not be parsed.
+func parseRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCError) {
+ var in jsonRequest
+ if err := json.Unmarshal(incomingMsg, &in); err != nil {
+ return nil, false, &invalidMessageError{err.Error()}
+ }
+
+ // subscribe are special, they will always use `subscribeMethod` as service method
+ if in.Method == subscribeMethod {
+ reqs := []rpcRequest{rpcRequest{id: in.Id, isPubSub: true}}
+ if len(in.Payload) > 0 {
+ // first param must be service.method name
+ subscriptionMethod := []reflect.Type{reflect.TypeOf("")}
+ if args, err := parsePositionalArguments(in.Payload, subscriptionMethod); err == nil && len(args) == 1 {
+ elems := strings.Split(args[0].String(), serviceMethodSeparator)
+ if len(elems) == 2 {
+ reqs[0].service, reqs[0].method = elems[0], elems[1]
+ reqs[0].params = in.Payload
+ return reqs, false, nil
+ }
+ }
+ }
+ return nil, false, &invalidRequestError{"Unable to parse subscription request"}
+ }
+
+ if in.Method == unsubscribeMethod {
+ return []rpcRequest{rpcRequest{id: in.Id, isPubSub: true,
+ method: unsubscribeMethod, params: in.Payload}}, false, nil
+ }
+
+ // regular RPC call
+ elems := strings.Split(in.Method, serviceMethodSeparator)
+ if len(elems) != 2 {
+ return nil, false, &methodNotFoundError{in.Method, ""}
+ }
+
+ if len(in.Payload) == 0 {
+ return []rpcRequest{rpcRequest{service: elems[0], method: elems[1], id: in.Id}}, false, nil
+ }
+
+ return []rpcRequest{rpcRequest{service: elems[0], method: elems[1], id: in.Id, params: in.Payload}}, false, nil
+}
+
+// parseBatchRequest will parse a batch request into a collection of requests from the given RawMessage, an indication
+// if the request was a batch or an error when the request could not be read.
+func parseBatchRequest(incomingMsg json.RawMessage) ([]rpcRequest, bool, RPCError) {
+ var in []jsonRequest
+ if err := json.Unmarshal(incomingMsg, &in); err != nil {
+ return nil, false, &invalidMessageError{err.Error()}
+ }
+
+ requests := make([]rpcRequest, len(in))
+ for i, r := range in {
+ // (un)subscribe are special, they will always use the same service.method
+ if r.Method == subscribeMethod {
+ requests[i] = rpcRequest{id: r.Id, isPubSub: true}
+ if len(r.Payload) > 0 {
+ // first param must be service.method name
+ subscriptionMethod := []reflect.Type{reflect.TypeOf("")}
+ if args, err := parsePositionalArguments(r.Payload, subscriptionMethod); err == nil && len(args) == 1 {
+ elems := strings.Split(args[0].String(), serviceMethodSeparator)
+ if len(elems) == 2 {
+ requests[i].service, requests[i].method = elems[0], elems[1]
+ requests[i].params = r.Payload
+ continue
+ }
+ }
+ }
+
+ return nil, true, &invalidRequestError{"Unable to parse (un)subscribe request arguments"}
+ }
+
+ if r.Method == unsubscribeMethod {
+ requests[i] = rpcRequest{id: r.Id, isPubSub: true, method: unsubscribeMethod, params: r.Payload}
+ continue
+ }
+
+ elems := strings.Split(r.Method, serviceMethodSeparator)
+ if len(elems) != 2 {
+ return nil, true, &methodNotFoundError{r.Method, ""}
+ }
+
+ if len(r.Payload) == 0 {
+ requests[i] = rpcRequest{service: elems[0], method: elems[1], id: r.Id, params: nil}
+ } else {
+ requests[i] = rpcRequest{service: elems[0], method: elems[1], id: r.Id, params: r.Payload}
+ }
+ }
+
+ return requests, true, nil
+}
+
+// ParseRequestArguments tries to parse the given params (json.RawMessage) with the given types. It returns the parsed
+// values or an error when the parsing failed.
+func (c *jsonCodec) ParseRequestArguments(argTypes []reflect.Type, params interface{}) ([]reflect.Value, RPCError) {
+ if args, ok := params.(json.RawMessage); !ok {
+ return nil, &invalidParamsError{"Invalid params supplied"}
+ } else {
+ return parsePositionalArguments(args, argTypes)
+ }
+}
+
+// parsePositionalArguments tries to parse the given args to an array of values with the given types. It returns the
+// parsed values or an error when the args could not be parsed.
+func parsePositionalArguments(args json.RawMessage, argTypes []reflect.Type) ([]reflect.Value, RPCError) {
+ argValues := make([]reflect.Value, len(argTypes))
+ params := make([]interface{}, len(argTypes))
+ for i, t := range argTypes {
+ if t.Kind() == reflect.Ptr {
+ // values must be pointers for the Unmarshal method, reflect.
+ // Dereference otherwise reflect.New would create **SomeType
+ argValues[i] = reflect.New(t.Elem())
+ params[i] = argValues[i].Interface()
+ } else {
+ argValues[i] = reflect.New(t)
+ params[i] = argValues[i].Interface()
+ }
+ }
+
+ if err := json.Unmarshal(args, ¶ms); err != nil {
+ return nil, &invalidParamsError{err.Error()}
+ }
+
+ // Convert pointers back to values where necessary
+ for i, a := range argValues {
+ if a.Kind() != argTypes[i].Kind() {
+ argValues[i] = reflect.Indirect(argValues[i])
+ }
+ }
+
+ return argValues, nil
+}
+
+// CreateResponse will create a JSON-RPC success response with the given id and reply as result.
+func (c *jsonCodec) CreateResponse(id int64, reply interface{}) interface{} {
+ return &jsonSuccessResponse{Version: jsonRPCVersion, Id: id, Result: reply}
+}
+
+// CreateErrorResponse will create a JSON-RPC error response with the given id and error.
+func (c *jsonCodec) CreateErrorResponse(id *int64, err RPCError) interface{} {
+ return &jsonErrResponse{Version: jsonRPCVersion, Id: id, Error: jsonError{Code: err.Code(), Message: err.Error()}}
+}
+
+// CreateErrorResponseWithInfo will create a JSON-RPC error response with the given id and error.
+// info is optional and contains additional information about the error. When an empty string is passed it is ignored.
+func (c *jsonCodec) CreateErrorResponseWithInfo(id *int64, err RPCError, info interface{}) interface{} {
+ return &jsonErrResponse{Version: jsonRPCVersion, Id: id,
+ Error: jsonError{Code: err.Code(), Message: err.Error(), Data: info}}
+}
+
+// CreateNotification will create a JSON-RPC notification with the given subscription id and event as params.
+func (c *jsonCodec) CreateNotification(subid string, event interface{}) interface{} {
+ return &jsonNotification{Version: jsonRPCVersion, Method: notificationMethod,
+ Params: jsonSubscription{Subscription: subid, Result: event}}
+}
+
+// Write message to client
+func (c *jsonCodec) Write(res interface{}) error {
+ return c.e.Encode(res)
+}
+
+// Close the underlying connection
+func (c *jsonCodec) Close() {
+ if atomic.CompareAndSwapInt32(&c.isClosed, 0, 1) {
+ close(c.closed)
+ c.rw.Close()
+ }
+}
+
+// Closed returns a channel which will be closed when Close is called
+func (c *jsonCodec) Closed() <-chan interface{} {
+ return c.closed
+}
diff --git a/rpc/v2/json_test.go b/rpc/v2/json_test.go
new file mode 100644
index 0000000000..dc80a863ff
--- /dev/null
+++ b/rpc/v2/json_test.go
@@ -0,0 +1,73 @@
+package v2
+
+import (
+ "bufio"
+ "bytes"
+ "reflect"
+ "testing"
+)
+
+type RWC struct {
+ *bufio.ReadWriter
+}
+
+func (rwc *RWC) Close() error {
+ return nil
+}
+
+func TestJSONRequestParsing(t *testing.T) {
+ server := NewServer()
+ service := new(Service)
+
+ if err := server.RegisterName("calc", service); err != nil {
+ t.Fatalf("%v", err)
+ }
+
+ req := bytes.NewBufferString(`{"id": 1234, "jsonrpc": "2.0", "method": "calc_Add", "params": [11, 22]}`)
+ var str string
+ reply := bytes.NewBufferString(str)
+ rw := &RWC{bufio.NewReadWriter(bufio.NewReader(req), bufio.NewWriter(reply))}
+
+ codec := NewJSONCodec(rw)
+
+ requests, batch, err := codec.ReadRequestHeaders()
+ if err != nil {
+ t.Fatalf("%v", err)
+ }
+
+ if batch {
+ t.Fatalf("Request isn't a batch")
+ }
+
+ if len(requests) != 1 {
+ t.Fatalf("Expected 1 request but got %d requests - %v", len(requests), requests)
+ }
+
+ if requests[0].service != "calc" {
+ t.Fatalf("Expected service 'calc' but got '%s'", requests[0].service)
+ }
+
+ if requests[0].method != "Add" {
+ t.Fatalf("Expected method 'Add' but got '%s'", requests[0].method)
+ }
+
+ if requests[0].id != 1234 {
+ t.Fatalf("Expected id 1234 but got %d", requests[0].id)
+ }
+
+ var arg int
+ args := []reflect.Type{reflect.TypeOf(arg), reflect.TypeOf(arg)}
+
+ v, err := codec.ParseRequestArguments(args, requests[0].params)
+ if err != nil {
+ t.Fatalf("%v", err)
+ }
+
+ if len(v) != 2 {
+ t.Fatalf("Expected 2 argument values, got %d", len(v))
+ }
+
+ if v[0].Int() != 11 || v[1].Int() != 22 {
+ t.Fatalf("expected %d == 11 && %d == 22", v[0].Int(), v[1].Int())
+ }
+}
diff --git a/rpc/v2/server.go b/rpc/v2/server.go
new file mode 100644
index 0000000000..6f6f6af19c
--- /dev/null
+++ b/rpc/v2/server.go
@@ -0,0 +1,449 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package v2
+
+import (
+ "fmt"
+ "reflect"
+
+ "github.com/ethereum/go-ethereum/event"
+ "github.com/ethereum/go-ethereum/logger"
+ "github.com/ethereum/go-ethereum/logger/glog"
+)
+
+// NewServer will create a new server instance with no registered handlers.
+func NewServer() *Server {
+ return &Server{services: make(serviceRegistry), subscriptions: make(subscriptionRegistry)}
+}
+
+// Register publishes suitable methods of rcvr. Methods will be published
+// with a dot between the rcrv and method, e.g. Calculator.Add. The supplied
+// rcvr must be a pointer.
+func (s *Server) Register(rcvr interface{}) error {
+ return s.register(rcvr, "", false)
+}
+
+// RegisterName publishes suitable methods of rcvr. Methods will be published
+// with a dot between the given name and method, e.g. Calculator.Add. The
+// supplied rcvr must be a pointer.
+func (s *Server) RegisterName(name string, rcvr interface{}) error {
+ return s.register(rcvr, name, true)
+}
+
+// register will create an service for the given rcvr type under the given name if specified in useName.
+// When no methods on the given rcvr match the criteria to be either a RPC method or a subscription an error is
+// returned. Otherwise a new service is created and added to the service collection this server instance serves.
+func (s *Server) register(rcvr interface{}, name string, useName bool) error {
+ if s.services == nil {
+ s.services = make(serviceRegistry)
+ }
+
+ svc := new(service)
+ svc.typ = reflect.TypeOf(rcvr)
+ svc.rcvr = reflect.ValueOf(rcvr)
+
+ sname := reflect.Indirect(svc.rcvr).Type().Name()
+ if useName {
+ sname = name
+ }
+ if sname == "" {
+ return fmt.Errorf("no service name for type %s", svc.typ.String())
+ }
+ if !isExported(sname) && !useName {
+ return fmt.Errorf("%s is not exported", sname)
+ }
+
+ if _, present := s.services[sname]; present {
+ return fmt.Errorf("%s already registered", sname)
+ }
+
+ svc.name = sname
+ svc.callbacks, svc.subscriptions = suitableCallbacks(svc.typ)
+
+ if len(svc.callbacks) == 0 && len(svc.subscriptions) == 0 {
+ return fmt.Errorf("Service doesn't have any suitable methods/subscriptions to expose")
+ }
+
+ s.services[svc.name] = svc
+
+ return nil
+}
+
+// ServeCodec reads incoming requests from codec, calls the appropriate callback and writes the
+// response back using the given codec. It will block until the codec is closed.
+//
+// This server will:
+// 1. allow for asynchronous and parallel request execution
+// 2. supports notifications (pub/sub)
+// 3. supports request batches
+func (s *Server) ServeCodec(codec ServerCodec) {
+ defer codec.Close()
+
+ for {
+ reqs, batch, err := s.readRequest(codec)
+ if err != nil {
+ glog.V(logger.Debug).Infof("%v\n", err)
+ codec.Write(codec.CreateErrorResponse(nil, err))
+ break
+ }
+
+ if batch {
+ go s.execBatch(codec, reqs)
+ } else {
+ go s.exec(codec, reqs[0])
+ }
+ }
+}
+
+// sendNotification will create a notification from the given event by serializing member fields of the event.
+// It will then send the notification to the client, when it fails the codec is closed. When the event has multiple
+// fields an array of values is returned.
+func sendNotification(codec ServerCodec, subid string, event interface{}) {
+ typ := reflect.TypeOf(event)
+ val := reflect.ValueOf(event)
+ for typ.Kind() == reflect.Ptr {
+ typ = typ.Elem()
+ val = val.Elem()
+ }
+
+ fields := make(map[string]interface{})
+ var notification interface{}
+
+ if typ.Kind() == reflect.Struct {
+ if typ.NumField() == 1 {
+ notification = codec.CreateNotification(subid, val.Field(0).Interface())
+ } else {
+ for i := 0; i < typ.NumField(); i++ {
+ fields[typ.Field(i).Name] = val.Field(i).Interface()
+ }
+ notification = codec.CreateNotification(subid, fields)
+ }
+ } else {
+ notification = codec.CreateNotification(subid, val.Interface())
+ }
+
+ if err := codec.Write(notification); err != nil {
+ codec.Close()
+ }
+}
+
+// createSubscription will register a new subscription and waits for raised events. When an event is raised it will:
+// 1. test if the event is raised matches the criteria the user has (optionally) specified
+// 2. create a notification of the event and send it the client when it matches the criteria
+// It will unsubscribe the subscription when the socket is closed or the subscription is unsubscribed by the user.
+func (s *Server) createSubscription(c ServerCodec, req *serverRequest) (string, error) {
+ args := []reflect.Value{req.rcvr}
+ if len(req.args) > 0 {
+ args = append(args, req.args...)
+ }
+
+ subid, err := newSubscriptionId()
+ if err != nil {
+ return "", err
+ }
+
+ reply := req.callb.method.Func.Call(args)
+
+ if reply[1].IsNil() { // no error
+ if subscription, ok := reply[0].Interface().(Subscription); ok {
+ s.muSubcriptions.Lock()
+ s.subscriptions[subid] = subscription
+ s.muSubcriptions.Unlock()
+ go func() {
+ cases := []reflect.SelectCase{
+ reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(subscription.Chan())}, // new event
+ reflect.SelectCase{Dir: reflect.SelectRecv, Chan: reflect.ValueOf(c.Closed())}, // connection closed
+ }
+
+ for {
+ idx, notification, recvOk := reflect.Select(cases)
+ switch idx {
+ case 0: // new event, or channel closed
+ if recvOk { // send notification
+ if event, ok := notification.Interface().(*event.Event); ok {
+ if subscription.match == nil || subscription.match(event.Data) {
+ sendNotification(c, subid, event.Data)
+ }
+ }
+ } else { // user send an eth_unsubscribe request
+ return
+ }
+ case 1: // connection closed
+ s.unsubscribe(subid)
+ return
+ }
+ }
+ }()
+ } else { // unable to create subscription
+ s.muSubcriptions.Lock()
+ delete(s.subscriptions, subid)
+ s.muSubcriptions.Unlock()
+ }
+ } else {
+ return "", fmt.Errorf("Unable to create subscription")
+ }
+
+ return subid, nil
+}
+
+// unsubscribe calls the Unsubscribe method on the subscription and removes a subscription from the subscription
+// registry.
+func (s *Server) unsubscribe(subid string) bool {
+ s.muSubcriptions.Lock()
+ defer s.muSubcriptions.Unlock()
+ if sub, ok := s.subscriptions[subid]; ok {
+ sub.Unsubscribe()
+ delete(s.subscriptions, subid)
+ return true
+ }
+ return false
+}
+
+// exec executes the given request and writes the result back using the codec.
+func (s *Server) exec(codec ServerCodec, req *serverRequest) {
+ if req.err != nil { // error during request parsing
+ rpcErr := codec.CreateErrorResponse(&req.id, req.err)
+ if err := codec.Write(rpcErr); err != nil {
+ codec.Close()
+ }
+ return
+ }
+
+ if req.isUnsubscribe { // first param must be the subscription id
+ if len(req.args) >= 1 && req.args[0].Kind() == reflect.String {
+ subid := req.args[0].String()
+ if s.unsubscribe(subid) {
+ if err := codec.Write(codec.CreateResponse(req.id, true)); err != nil {
+ codec.Close()
+ }
+ } else {
+ rpcErr := codec.CreateErrorResponse(&req.id,
+ &callbackError{fmt.Sprintf("subscription '%s' not found", subid)})
+ if err := codec.Write(rpcErr); err != nil {
+ codec.Close()
+ }
+ }
+ } else {
+ rpcErr := codec.CreateErrorResponse(&req.id, &invalidParamsError{"Expected subscription id as argument"})
+ if err := codec.Write(rpcErr); err != nil {
+ codec.Close()
+ }
+ }
+ return
+ }
+
+ if req.callb.isSubscribe {
+ subid, err := s.createSubscription(codec, req)
+ var response interface{}
+ if err == nil {
+ response = codec.CreateResponse(req.id, subid)
+ } else {
+ response = codec.CreateErrorResponse(&req.id, &callbackError{err.Error()})
+ }
+
+ if err = codec.Write(response); err != nil {
+ codec.Close()
+ }
+ return
+ }
+
+ // regular RPC call
+ if len(req.args) != len(req.callb.argTypes) {
+ rpcErr := &invalidParamsError{fmt.Sprintf("%s%s%s expects %d parameters, got %d",
+ req.svcname, serviceMethodSeparator, req.callb.method.Name,
+ len(req.callb.argTypes), len(req.args))}
+
+ res := codec.CreateErrorResponse(&req.id, rpcErr)
+ if err := codec.Write(res); err != nil {
+ codec.Close()
+ }
+ return
+ }
+
+ arguments := []reflect.Value{req.rcvr}
+ if len(req.args) > 0 {
+ arguments = append(arguments, req.args...)
+ }
+
+ reply := req.callb.method.Func.Call(arguments)
+
+ if len(reply) == 0 {
+ if err := codec.Write(codec.CreateResponse(req.id, nil)); err != nil {
+ codec.Close()
+ }
+ return
+ }
+
+ if req.callb.errPos >= 0 { // test if method returned an error
+ if !reply[req.callb.errPos].IsNil() {
+ e := reply[req.callb.errPos].Interface().(error)
+ res := codec.CreateErrorResponse(&req.id, &callbackError{e.Error()})
+ if err := codec.Write(res); err != nil {
+ codec.Close()
+ }
+ return
+ }
+ }
+
+ if err := codec.Write(codec.CreateResponse(req.id, reply[0].Interface())); err != nil {
+ codec.Close()
+ }
+}
+
+// execBatch executes the given requests and writes the result back using the codec. It will only write the response
+// back when the last request is processed.
+func (s *Server) execBatch(codec ServerCodec, requests []*serverRequest) {
+ responses := make([]interface{}, len(requests))
+
+ for i, req := range requests {
+ if req.err != nil { // error during parsing of request
+ responses[i] = codec.CreateErrorResponse(&req.id, req.err)
+ continue
+ }
+
+ if req.isUnsubscribe {
+ if len(req.args) == 1 && req.args[0].Kind() == reflect.String {
+ subid := req.args[0].String()
+ if s.unsubscribe(subid) {
+ responses[i] = codec.CreateResponse(req.id, true)
+ } else {
+ e := &callbackError{fmt.Sprintf("subscription '%s' not found", subid)}
+ responses[i] = codec.CreateErrorResponse(&req.id, e)
+ }
+ } else {
+ e := &invalidParamsError{"Expected subscription id as argument"}
+ responses[i] = codec.CreateErrorResponse(&req.id, e)
+ }
+ continue
+ }
+
+ if req.callb.isSubscribe {
+ subid, err := s.createSubscription(codec, req)
+ var response interface{}
+ if err == nil {
+ response = codec.CreateResponse(req.id, subid)
+ } else {
+ response = codec.CreateErrorResponse(&req.id, &callbackError{err.Error()})
+ }
+
+ responses[i] = response
+ continue
+ }
+
+ var reply []reflect.Value
+
+ if len(req.args) != len(req.callb.argTypes) {
+ rpcErr := &invalidParamsError{fmt.Sprintf("%s%s%s expects %d parameters, got %d",
+ req.svcname, serviceMethodSeparator, req.callb.method.Name, len(req.callb.argTypes), len(req.args))}
+ responses[i] = codec.CreateErrorResponse(&req.id, rpcErr)
+ continue
+ }
+
+ arguments := []reflect.Value{req.rcvr}
+ if len(req.args) > 0 {
+ arguments = append(arguments, req.args...)
+ }
+
+ reply = req.callb.method.Func.Call(arguments)
+
+ if len(reply) == 0 {
+ responses[i] = codec.CreateResponse(req.id, nil)
+ continue
+ }
+
+ if req.callb.errPos >= 0 {
+ if !reply[req.callb.errPos].IsNil() {
+ if e, ok := reply[req.callb.errPos].Interface().(error); ok {
+ rpcErr := &callbackError{e.Error()}
+ responses[i] = codec.CreateErrorResponse(&req.id, rpcErr)
+ continue
+ }
+ }
+ }
+
+ responses[i] = codec.CreateResponse(req.id, reply[0].Interface())
+ }
+
+ if err := codec.Write(responses); err != nil {
+ glog.V(logger.Error).Infof("%v\n", err)
+ codec.Close()
+ }
+}
+
+// readRequest requests the next (batch) request from the codec. It will return the collection of requests, an
+// indication if the request was a batch, the invalid request identifier and an error when the request could not be
+// read/parsed.
+func (s *Server) readRequest(codec ServerCodec) ([]*serverRequest, bool, RPCError) {
+ reqs, batch, err := codec.ReadRequestHeaders()
+ if err != nil {
+ return nil, batch, err
+ }
+
+ requests := make([]*serverRequest, len(reqs))
+
+ // verify requests
+ for i, r := range reqs {
+ var ok bool
+ var svc *service
+
+ if r.isPubSub && r.method == unsubscribeMethod {
+ requests[i] = &serverRequest{id: r.id, isUnsubscribe: true}
+ argTypes := []reflect.Type{reflect.TypeOf("")}
+ if args, err := codec.ParseRequestArguments(argTypes, r.params); err == nil {
+ requests[i].args = args
+ } else {
+ requests[i].err = &invalidParamsError{err.Error()}
+ }
+ continue
+ }
+
+ if svc, ok = s.services[r.service]; !ok {
+ requests[i] = &serverRequest{id: r.id, err: &methodNotFoundError{r.service, r.method}}
+ continue
+ }
+
+ if callb, ok := svc.subscriptions[r.method]; ok {
+ requests[i] = &serverRequest{id: r.id, svcname: svc.name, rcvr: svc.rcvr, callb: callb}
+ if r.params != nil && len(callb.argTypes) > 0 {
+ argTypes := []reflect.Type{reflect.TypeOf("")}
+ argTypes = append(argTypes, callb.argTypes...)
+ if args, err := codec.ParseRequestArguments(argTypes, r.params); err == nil {
+ requests[i].args = args[1:] // first one is service.method name which isn't an actual argument
+ } else {
+ requests[i].err = &invalidParamsError{err.Error()}
+ }
+ }
+ continue
+ }
+
+ if callb, ok := svc.callbacks[r.method]; ok {
+ requests[i] = &serverRequest{id: r.id, svcname: svc.name, rcvr: svc.rcvr, callb: callb}
+ if r.params != nil && len(callb.argTypes) > 0 {
+ if args, err := codec.ParseRequestArguments(callb.argTypes, r.params); err == nil {
+ requests[i].args = args
+ } else {
+ requests[i].err = &invalidParamsError{err.Error()}
+ }
+ }
+ continue
+ }
+
+ requests[i] = &serverRequest{id: r.id, err: &methodNotFoundError{r.service, r.method}}
+ }
+
+ return requests, batch, nil
+}
diff --git a/rpc/v2/server_test.go b/rpc/v2/server_test.go
new file mode 100644
index 0000000000..3ff22fdd71
--- /dev/null
+++ b/rpc/v2/server_test.go
@@ -0,0 +1,57 @@
+package v2
+
+import "testing"
+
+type Service struct{}
+
+type Args struct {
+ S string
+}
+
+func (s *Service) NoArgsRets() {
+}
+
+func (s *Service) Args(str string, i int, args *Args) {
+}
+
+func (s *Service) Rets() (string, error) {
+ return "", nil
+}
+
+func (s *Service) InvalidRets1() (error, string) {
+ return nil, ""
+}
+
+func (s *Service) InvalidRets2() (string, string) {
+ return "", ""
+}
+
+func (s *Service) InvalidRets3() (string, string, error) {
+ return "", "", nil
+}
+
+func TestServerRegister(t *testing.T) {
+ server := NewServer()
+ service := new(Service)
+
+ if err := server.RegisterName("calc", service); err != nil {
+ t.Fatalf("%v", err)
+ }
+
+ if err := server.RegisterName("calc", service); err == nil {
+ t.Fatal("Second time registering the same service should raise an error")
+ }
+
+ if len(server.services) != 1 {
+ t.Fatalf("Expected 1 service entry but got %d", len(server.services))
+ }
+
+ svc, ok := server.services["calc"]
+ if !ok {
+ t.Fatalf("Expected service calc to be registered")
+ }
+
+ if len(svc.callbacks) != 3 {
+ t.Fatalf("Expected 3 callbacks for service 'calc', got %d", len(svc.callbacks))
+ }
+}
diff --git a/rpc/v2/types.go b/rpc/v2/types.go
new file mode 100644
index 0000000000..a9286e2c6b
--- /dev/null
+++ b/rpc/v2/types.go
@@ -0,0 +1,137 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package v2
+
+import (
+ "reflect"
+
+ "sync"
+
+ "github.com/ethereum/go-ethereum/event"
+)
+
+// callback is a method callback which was registered in the server
+type callback struct {
+ method reflect.Method // callback
+ argTypes []reflect.Type // input argument types
+ errPos int // err return idx, of -1 when method cannot return error
+ isSubscribe bool // indication if the callback is a subscription
+}
+
+// service represents a registered object
+type service struct {
+ name string // name for service
+ rcvr reflect.Value // receiver of methods for the service
+ typ reflect.Type // receiver type
+ callbacks callbacks // registered handlers
+ subscriptions subscriptions // available subscriptions/notifications
+}
+
+// serverRequest is an incoming request
+type serverRequest struct {
+ id int64
+ svcname string
+ rcvr reflect.Value
+ callb *callback
+ args []reflect.Value
+ isUnsubscribe bool
+ err RPCError
+}
+
+type serviceRegistry map[string]*service // collection of services
+type callbacks map[string]*callback // collection of RPC callbacks
+type subscriptions map[string]*callback // collection of subscription callbacks
+type subscriptionRegistry map[string]Subscription // collection of subscriptions
+
+// Server represents a RPC server
+type Server struct {
+ services serviceRegistry
+ muSubcriptions sync.Mutex // protects subscriptions
+ subscriptions subscriptionRegistry
+}
+
+// rpcRequest represents a raw incoming RPC request
+type rpcRequest struct {
+ service string
+ method string
+ id int64
+ isPubSub bool
+ params interface{}
+}
+
+// RPCError implements RPC error, is add support for error codec over regular go errors
+type RPCError interface {
+ // RPC error code
+ Code() int
+ // Error message
+ Error() string
+}
+
+// ServerCodec implements reading, parsing and writing RPC messages for the server side of
+// a RPC session. Implementations must be go-routine safe since the codec can be called in
+// multiple go-routines concurrently.
+type ServerCodec interface {
+ // Read next request
+ ReadRequestHeaders() ([]rpcRequest, bool, RPCError)
+ // Parse request argument to the given types
+ ParseRequestArguments([]reflect.Type, interface{}) ([]reflect.Value, RPCError)
+ // Assemble success response
+ CreateResponse(int64, interface{}) interface{}
+ // Assemble error response
+ CreateErrorResponse(*int64, RPCError) interface{}
+ // Assemble error response with extra information about the error through info
+ CreateErrorResponseWithInfo(id *int64, err RPCError, info interface{}) interface{}
+ // Create notification response
+ CreateNotification(string, interface{}) interface{}
+ // Write msg to client.
+ Write(interface{}) error
+ // Close underlying data stream
+ Close()
+ // Closed when underlying connection is closed
+ Closed() <-chan interface{}
+}
+
+// SubscriptionMatcher returns true if the given value matches the criteria specified by the user
+type SubscriptionMatcher func(interface{}) bool
+
+// Subscription is used by the server to send notifications to the client
+type Subscription struct {
+ sub event.Subscription
+ match SubscriptionMatcher
+}
+
+// NewSubscription create a new RPC subscription
+func NewSubscription(sub event.Subscription) Subscription {
+ return Subscription{sub, nil}
+}
+
+// NewSubscriptionFiltered will create a new subscription. For each raised event the given matcher is
+// called. If it returns true the event is send as notification to the client, otherwise it is ignored.
+func NewSubscriptionFiltered(sub event.Subscription, match SubscriptionMatcher) Subscription {
+ return Subscription{sub, match}
+}
+
+// Chan returns the channel where new events will be published. It's up the user to call the matcher to
+// determine if the events are interesting for the client.
+func (s *Subscription) Chan() <-chan *event.Event {
+ return s.sub.Chan()
+}
+
+// Unsubscribe will end the subscription and closes the event channel
+func (s *Subscription) Unsubscribe() {
+ s.sub.Unsubscribe()
+}
diff --git a/rpc/v2/utils.go b/rpc/v2/utils.go
new file mode 100644
index 0000000000..ee6ee777d0
--- /dev/null
+++ b/rpc/v2/utils.go
@@ -0,0 +1,169 @@
+// Copyright 2015 The go-ethereum Authors
+// This file is part of the go-ethereum library.
+//
+// The go-ethereum library is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Lesser General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// The go-ethereum library is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+// GNU Lesser General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see .
+
+package v2
+
+import (
+ "crypto/rand"
+ "encoding/hex"
+ "errors"
+ "reflect"
+ "unicode"
+ "unicode/utf8"
+)
+
+// Is this an exported - upper case - name?
+func isExported(name string) bool {
+ rune, _ := utf8.DecodeRuneInString(name)
+ return unicode.IsUpper(rune)
+}
+
+// Is this type exported or a builtin?
+func isExportedOrBuiltinType(t reflect.Type) bool {
+ for t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+ // PkgPath will be non-empty even for an exported type,
+ // so we need to check the type name as well.
+ return isExported(t.Name()) || t.PkgPath() == ""
+}
+
+var errorType = reflect.TypeOf((*error)(nil)).Elem()
+
+// Implements this type the error interface
+func isErrorType(t reflect.Type) bool {
+ for t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+ return t.Implements(errorType)
+}
+
+var subscriptionType = reflect.TypeOf((*Subscription)(nil)).Elem()
+
+func isSubscriptionType(t reflect.Type) bool {
+ for t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+ return t == subscriptionType
+}
+
+// isPubSub tests whether the given method return the pair
+// (v2.Subscription, error)
+func isPubSub(methodType reflect.Type) bool {
+ if methodType.NumOut() != 2 {
+ return false
+ }
+
+ return isSubscriptionType(methodType.Out(0)) && isErrorType(methodType.Out(1))
+}
+
+// suitableCallbacks iterates over the methods of the given type. It will determine if a method satisfies the criteria
+// for a RPC callback or a subscription callback and adds it to the collection of callbacks or subscriptions. See server
+// documentation for a summary of these criteria.
+func suitableCallbacks(typ reflect.Type) (callbacks, subscriptions) {
+ callbacks := make(callbacks)
+ subscriptions := make(subscriptions)
+
+METHODS:
+ for m := 0; m < typ.NumMethod(); m++ {
+ method := typ.Method(m)
+ mtype := method.Type
+ mname := method.Name
+ if method.PkgPath != "" { // method must be exported
+ continue
+ }
+
+ if isPubSub(mtype) {
+ var h callback
+ h.method = method
+ h.errPos = -1
+ h.isSubscribe = true
+
+ h.argTypes = make([]reflect.Type, mtype.NumIn()-1) // skip rcvr type
+ for i := 1; i < mtype.NumIn(); i++ {
+ argType := mtype.In(i)
+ if isExportedOrBuiltinType(argType) {
+ h.argTypes[i-1] = argType
+ } else {
+ continue METHODS
+ }
+ }
+
+ subscriptions[mname] = &h
+ continue METHODS
+ }
+
+ var h callback
+ h.method = method
+ numIn := mtype.NumIn()
+
+ // determine method arguments, ignore first arg since it's the receiver type
+ // Arguments must be exported or builtin
+ h.argTypes = make([]reflect.Type, numIn-1)
+ for i := 1; i < numIn; i++ {
+ argType := mtype.In(i)
+ if !isExportedOrBuiltinType(argType) {
+ continue METHODS
+ }
+ h.argTypes[i-1] = argType
+ }
+
+ // check that all returned values are exported or builtin values
+ for i := 0; i < mtype.NumOut(); i++ {
+ if !isExportedOrBuiltinType(mtype.Out(i)) {
+ continue METHODS
+ }
+ }
+
+ // when a method returns an error it must be the last returned value
+ h.errPos = -1
+ for i := 0; i < mtype.NumOut(); i++ {
+ if isErrorType(mtype.Out(i)) {
+ h.errPos = i
+ break
+ }
+ }
+
+ if h.errPos >= 0 && h.errPos != mtype.NumOut()-1 {
+ continue METHODS
+ }
+
+ switch mtype.NumOut() {
+ case 0, 1:
+ break
+ case 2:
+ if h.errPos == -1 { // method must one return value and 1 error
+ continue METHODS
+ }
+ break
+ default:
+ continue METHODS
+ }
+
+ callbacks[mname] = &h
+ }
+
+ return callbacks, subscriptions
+}
+
+func newSubscriptionId() (string, error) {
+ var subid [16]byte
+ n, _ := rand.Read(subid[:])
+ if n != 16 {
+ return "", errors.New("Unable to generate subscription id")
+ }
+ return "0x" + hex.EncodeToString(subid[:]), nil
+}