neo-go/pkg/network/rpc.go
2018-02-01 08:18:38 +01:00

129 lines
3.1 KiB
Go

package network
import (
"encoding/json"
"fmt"
"net/http"
)
const (
rpcPortMainNet = 20332
rpcPortTestNet = 10332
rpcVersion = "2.0"
// error response messages
methodNotFound = "Method not found"
parseError = "Parse error"
)
// Each NEO node has a set of optional APIs for accessing blockchain
// data and making things easier for development of blockchain apps.
// APIs are provided via JSON-RPC , comm at bottom layer is with http/https protocol.
// listenHTTP creates an ingress bridge from the outside world to the passed
// server, by installing handlers for all the necessary RPCs to the passed mux.
func listenHTTP(s *Server, port int) {
api := &API{s}
p := fmt.Sprintf(":%d", port)
s.logger.Printf("serving RPC on %d", port)
s.logger.Printf("%s", http.ListenAndServe(p, api))
}
// API serves JSON-RPC.
type API struct {
s *Server
}
func (s *API) ServeHTTP(w http.ResponseWriter, r *http.Request) {
// Official nodes respond a parse error if the method is not POST.
// Instead of returning a decent response for this, let's do the same.
if r.Method != "POST" {
writeError(w, 0, 0, parseError)
}
var req Request
if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
writeError(w, 0, 0, parseError)
return
}
defer r.Body.Close()
if req.Version != rpcVersion {
writeJSON(w, http.StatusBadRequest, nil)
return
}
switch req.Method {
case "getconnectioncount":
if err := s.getConnectionCount(w, &req); err != nil {
writeError(w, 0, 0, parseError)
return
}
case "getblockcount":
case "getbestblockhash":
default:
writeError(w, 0, 0, methodNotFound)
}
}
// This is an Example on how we could handle incomming RPC requests.
func (s *API) getConnectionCount(w http.ResponseWriter, req *Request) error {
count := s.s.peerCount()
resp := ConnectionCountResponse{
Version: rpcVersion,
Result: count,
ID: 1,
}
return writeJSON(w, http.StatusOK, resp)
}
// writeError returns a JSON error with given parameters. All error HTTP
// status codes are 200. According to the official API.
func writeError(w http.ResponseWriter, id, code int, msg string) error {
resp := RequestError{
Version: rpcVersion,
ID: id,
Error: Error{
Code: code,
Message: msg,
},
}
return writeJSON(w, http.StatusOK, resp)
}
func writeJSON(w http.ResponseWriter, status int, v interface{}) error {
w.Header().Set("Content-Type", "application/json")
w.WriteHeader(status)
return json.NewEncoder(w).Encode(v)
}
// Request is an object received through JSON-RPC from the client.
type Request struct {
Version string `json:"jsonrpc"`
Method string `json:"method"`
Params []string `json:"params"`
ID int `json:"id"`
}
// ConnectionCountResponse ..
type ConnectionCountResponse struct {
Version string `json:"jsonrpc"`
Result int `json:"result"`
ID int `json:"id"`
}
// RequestError ..
type RequestError struct {
Version string `json:"jsonrpc"`
ID int `json:"id"`
Error Error `json:"error"`
}
// Error holds information about an RCP error.
type Error struct {
Code int `json:"code"`
Message string `json:"message"`
}