// 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 <http://www.gnu.org/licenses/>.
package rpc
import (
"fmt"
"math"
"math/big"
"reflect"
"strings"
"sync"
"gopkg.in/fatih/set.v0"
)
// API describes the set of methods offered over the RPC interface
type API struct {
Namespace string // namespace under which the rpc methods of Service are exposed
Version string // api version for DApp's
Service interface{} // receiver instance which holds the methods
Public bool // indication if the methods must be considered safe for public use
}
// callback is a method callback which was registered in the server
type callback struct {
rcvr reflect.Value // receiver of method
method reflect.Method // callback
argTypes []reflect.Type // input argument types
hasCtx bool // method's first argument is a context (not included in argTypes)
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]*callback // collection of subscription callbacks
// Server represents a RPC server
type Server struct {
services serviceRegistry
muSubcriptions sync.Mutex // protects subscriptions
subscriptions subscriptionRegistry
run int32
codecsMu sync.Mutex
codecs *set.Set
}
// 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{}
}
// HexNumber serializes a number to hex format using the "%#x" format
type HexNumber big.Int
// NewHexNumber creates a new hex number instance which will serialize the given val with `%#x` on marshal.
func NewHexNumber(val interface{}) *HexNumber {
if val == nil {
return nil // note, this doesn't catch nil pointers, only passing nil directly!
}
if v, ok := val.(*big.Int); ok {
if v != nil {
return (*HexNumber)(new(big.Int).Set(v))
}
return nil
}
rval := reflect.ValueOf(val)
var unsigned uint64
utype := reflect.TypeOf(unsigned)
if t := rval.Type(); t.ConvertibleTo(utype) {
hn := new(big.Int).SetUint64(rval.Convert(utype).Uint())
return (*HexNumber)(hn)
}
var signed int64
stype := reflect.TypeOf(signed)
if t := rval.Type(); t.ConvertibleTo(stype) {
hn := new(big.Int).SetInt64(rval.Convert(stype).Int())
return (*HexNumber)(hn)
}
return nil
}
func (h *HexNumber) UnmarshalJSON(input []byte) error {
length := len(input)
if length >= 2 && input[0] == '"' && input[length-1] == '"' {
input = input[1 : length-1]
}
hn := (*big.Int)(h)
if _, ok := hn.SetString(string(input), 0); ok {
return nil
}
return fmt.Errorf("Unable to parse number")
}
// MarshalJSON serialize the hex number instance to a hex representation.
func (h *HexNumber) MarshalJSON() ([]byte, error) {
if h != nil {
hn := (*big.Int)(h)
if hn.BitLen() == 0 {
return []byte(`"0x0"`), nil
}
return []byte(fmt.Sprintf(`"0x%x"`, hn)), nil
}
return nil, nil
}
func (h *HexNumber) Int() int {
hn := (*big.Int)(h)
return int(hn.Int64())
}
func (h *HexNumber) Int64() int64 {
hn := (*big.Int)(h)
return hn.Int64()
}
func (h *HexNumber) Uint() uint {
hn := (*big.Int)(h)
return uint(hn.Uint64())
}
func (h *HexNumber) Uint64() uint64 {
hn := (*big.Int)(h)
return hn.Uint64()
}
func (h *HexNumber) BigInt() *big.Int {
return (*big.Int)(h)
}
type Number int64
func (n *Number) UnmarshalJSON(data []byte) error {
input := strings.TrimSpace(string(data))
if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
input = input[1 : len(input)-1]
}
if len(input) == 0 {
*n = Number(latestBlockNumber.Int64())
return nil
}
in := new(big.Int)
_, ok := in.SetString(input, 0)
if !ok { // test if user supplied string tag
return fmt.Errorf(`invalid number %s`, data)
}
if in.Cmp(earliestBlockNumber) >= 0 && in.Cmp(maxBlockNumber) <= 0 {
*n = Number(in.Int64())
return nil
}
return fmt.Errorf("blocknumber not in range [%d, %d]", earliestBlockNumber, maxBlockNumber)
}
func (n *Number) Int64() int64 {
return *(*int64)(n)
}
func (n *Number) BigInt() *big.Int {
return big.NewInt(n.Int64())
}
var (
pendingBlockNumber = big.NewInt(-2)
latestBlockNumber = big.NewInt(-1)
earliestBlockNumber = big.NewInt(0)
maxBlockNumber = big.NewInt(math.MaxInt64)
)
type BlockNumber int64
const (
PendingBlockNumber = BlockNumber(-2)
LatestBlockNumber = BlockNumber(-1)
)
// UnmarshalJSON parses the given JSON fragement into a BlockNumber. It supports:
// - "latest", "earliest" or "pending" as string arguments
// - the block number
// Returned errors:
// - an invalid block number error when the given argument isn't a known strings
// - an out of range error when the given block number is either too little or too large
func (bn *BlockNumber) UnmarshalJSON(data []byte) error {
input := strings.TrimSpace(string(data))
if len(input) >= 2 && input[0] == '"' && input[len(input)-1] == '"' {
input = input[1 : len(input)-1]
}
if len(input) == 0 {
*bn = BlockNumber(latestBlockNumber.Int64())
return nil
}
in := new(big.Int)
_, ok := in.SetString(input, 0)
if !ok { // test if user supplied string tag
strBlockNumber := input
if strBlockNumber == "latest" {
*bn = BlockNumber(latestBlockNumber.Int64())
return nil
}
if strBlockNumber == "earliest" {
*bn = BlockNumber(earliestBlockNumber.Int64())
return nil
}
if strBlockNumber == "pending" {
*bn = BlockNumber(pendingBlockNumber.Int64())
return nil
}
return fmt.Errorf(`invalid blocknumber %s`, data)
}
if in.Cmp(earliestBlockNumber) >= 0 && in.Cmp(maxBlockNumber) <= 0 {
*bn = BlockNumber(in.Int64())
return nil
}
return fmt.Errorf("blocknumber not in range [%d, %d]", earliestBlockNumber, maxBlockNumber)
}
func (bn *BlockNumber) Int64() int64 {
return (int64)(*bn)
}
// Client defines the interface for go client that wants to connect to a geth RPC endpoint
type Client interface {
// SupportedModules returns the collection of API's the server offers
SupportedModules() (map[string]string, error)
Send(req interface{}) error
Recv(msg interface{}) error
Close()
}
