// 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 console
import (
"encoding/json"
"fmt"
"io"
"time"
"github.com/ethereum/go-ethereum/logger"
"github.com/ethereum/go-ethereum/logger/glog"
"github.com/ethereum/go-ethereum/rpc"
"github.com/robertkrimen/otto"
)
// bridge is a collection of JavaScript utility methods to bride the .js runtime
// environment and the Go RPC connection backing the remote method calls.
type bridge struct {
client rpc.Client // RPC client to execute Ethereum requests through
prompter UserPrompter // Input prompter to allow interactive user feedback
printer io.Writer // Output writer to serialize any display strings to
}
// newBridge creates a new JavaScript wrapper around an RPC client.
func newBridge(client rpc.Client, prompter UserPrompter, printer io.Writer) *bridge {
return &bridge{
client: client,
prompter: prompter,
printer: printer,
}
}
// NewAccount is a wrapper around the personal.newAccount RPC method that uses a
// non-echoing password prompt to aquire the passphrase and executes the original
// RPC method (saved in jeth.newAccount) with it to actually execute the RPC call.
func (b *bridge) NewAccount(call otto.FunctionCall) (response otto.Value) {
var (
password string
confirm string
err error
)
switch {
// No password was specified, prompt the user for it
case len(call.ArgumentList) == 0:
if password, err = b.prompter.PromptPassword("Passphrase: "); err != nil {
throwJSException(err.Error())
}
if confirm, err = b.prompter.PromptPassword("Repeat passphrase: "); err != nil {
throwJSException(err.Error())
}
if password != confirm {
throwJSException("passphrases don't match!")
}
// A single string password was specified, use that
case len(call.ArgumentList) == 1 && call.Argument(0).IsString():
password, _ = call.Argument(0).ToString()
// Otherwise fail with some error
default:
throwJSException("expected 0 or 1 string argument")
}
// Password aquired, execute the call and return
ret, err := call.Otto.Call("jeth.newAccount", nil, password)
if err != nil {
throwJSException(err.Error())
}
return ret
}
// UnlockAccount is a wrapper around the personal.unlockAccount RPC method that
// uses a non-echoing password prompt to aquire the passphrase and executes the
// original RPC method (saved in jeth.unlockAccount) with it to actually execute
// the RPC call.
func (b *bridge) UnlockAccount(call otto.FunctionCall) (response otto.Value) {
// Make sure we have an account specified to unlock
if !call.Argument(0).IsString() {
throwJSException("first argument must be the account to unlock")
}
account := call.Argument(0)
// If password is not given or is the null value, prompt the user for it
var passwd otto.Value
if call.Argument(1).IsUndefined() || call.Argument(1).IsNull() {
fmt.Fprintf(b.printer, "Unlock account %s\n", account)
if input, err := b.prompter.PromptPassword("Passphrase: "); err != nil {
throwJSException(err.Error())
} else {
passwd, _ = otto.ToValue(input)
}
} else {
if !call.Argument(1).IsString() {
throwJSException("password must be a string")
}
passwd = call.Argument(1)
}
// Third argument is the duration how long the account must be unlocked.
duration := otto.NullValue()
if call.Argument(2).IsDefined() && !call.Argument(2).IsNull() {
if !call.Argument(2).IsNumber() {
throwJSException("unlock duration must be a number")
}
duration = call.Argument(2)
}
// Send the request to the backend and return
val, err := call.Otto.Call("jeth.unlockAccount", nil, account, passwd, duration)
if err != nil {
throwJSException(err.Error())
}
return val
}
// Sleep will block the console for the specified number of seconds.
func (b *bridge) Sleep(call otto.FunctionCall) (response otto.Value) {
if call.Argument(0).IsNumber() {
sleep, _ := call.Argument(0).ToInteger()
time.Sleep(time.Duration(sleep) * time.Second)
return otto.TrueValue()
}
return throwJSException("usage: sleep(<number of seconds>)")
}
// SleepBlocks will block the console for a specified number of new blocks optionally
// until the given timeout is reached.
func (b *bridge) SleepBlocks(call otto.FunctionCall) (response otto.Value) {
var (
blocks = int64(0)
sleep = int64(9999999999999999) // indefinitely
)
// Parse the input parameters for the sleep
nArgs := len(call.ArgumentList)
if nArgs == 0 {
throwJSException("usage: sleepBlocks(<n blocks>[, max sleep in seconds])")
}
if nArgs >= 1 {
if call.Argument(0).IsNumber() {
blocks, _ = call.Argument(0).ToInteger()
} else {
throwJSException("expected number as first argument")
}
}
if nArgs >= 2 {
if call.Argument(1).IsNumber() {
sleep, _ = call.Argument(1).ToInteger()
} else {
throwJSException("expected number as second argument")
}
}
// go through the console, this will allow web3 to call the appropriate
// callbacks if a delayed response or notification is received.
blockNumber := func() int64 {
result, err := call.Otto.Run("eth.blockNumber")
if err != nil {
throwJSException(err.Error())
}
block, err := result.ToInteger()
if err != nil {
throwJSException(err.Error())
}
return block
}
// Poll the current block number until either it ot a timeout is reached
targetBlockNr := blockNumber() + blocks
deadline := time.Now().Add(time.Duration(sleep) * time.Second)
for time.Now().Before(deadline) {
if blockNumber() >= targetBlockNr {
return otto.TrueValue()
}
time.Sleep(time.Second)
}
return otto.FalseValue()
}
// Send will serialize the first argument, send it to the node and returns the response.
func (b *bridge) Send(call otto.FunctionCall) (response otto.Value) {
// Ensure that we've got a batch request (array) or a single request (object)
arg := call.Argument(0).Object()
if arg == nil || (arg.Class() != "Array" && arg.Class() != "Object") {
throwJSException("request must be an object or array")
}
// Convert the otto VM arguments to Go values
data, err := call.Otto.Call("JSON.stringify", nil, arg)
if err != nil {
throwJSException(err.Error())
}
reqjson, err := data.ToString()
if err != nil {
throwJSException(err.Error())
}
var (
reqs []rpc.JSONRequest
batch = true
)
if err = json.Unmarshal([]byte(reqjson), &reqs); err != nil {
// single request?
reqs = make([]rpc.JSONRequest, 1)
if err = json.Unmarshal([]byte(reqjson), &reqs[0]); err != nil {
throwJSException("invalid request")
}
batch = false
}
// Iteratively execute the requests
call.Otto.Set("response_len", len(reqs))
call.Otto.Run("var ret_response = new Array(response_len);")
for i, req := range reqs {
// Execute the RPC request and parse the reply
if err = b.client.Send(&req); err != nil {
return newErrorResponse(call, -32603, err.Error(), req.Id)
}
result := make(map[string]interface{})
if err = b.client.Recv(&result); err != nil {
return newErrorResponse(call, -32603, err.Error(), req.Id)
}
// Feed the reply back into the JavaScript runtime environment
id, _ := result["id"]
jsonver, _ := result["jsonrpc"]
call.Otto.Set("ret_id", id)
call.Otto.Set("ret_jsonrpc", jsonver)
call.Otto.Set("response_idx", i)
if res, ok := result["result"]; ok {
payload, _ := json.Marshal(res)
call.Otto.Set("ret_result", string(payload))
response, err = call.Otto.Run(`
ret_response[response_idx] = { jsonrpc: ret_jsonrpc, id: ret_id, result: JSON.parse(ret_result) };
`)
continue
}
if res, ok := result["error"]; ok {
payload, _ := json.Marshal(res)
call.Otto.Set("ret_result", string(payload))
response, err = call.Otto.Run(`
ret_response[response_idx] = { jsonrpc: ret_jsonrpc, id: ret_id, error: JSON.parse(ret_result) };
`)
continue
}
return newErrorResponse(call, -32603, fmt.Sprintf("Invalid response"), new(int64))
}
// Convert single requests back from batch ones
if !batch {
call.Otto.Run("ret_response = ret_response[0];")
}
// Execute any registered callbacks
if call.Argument(1).IsObject() {
call.Otto.Set("callback", call.Argument(1))
call.Otto.Run(`
if (Object.prototype.toString.call(callback) == '[object Function]') {
callback(null, ret_response);
}
`)
}
return
}
// throwJSException panics on an otto.Value. The Otto VM will recover from the
// Go panic and throw msg as a JavaScript error.
func throwJSException(msg interface{}) otto.Value {
val, err := otto.ToValue(msg)
if err != nil {
glog.V(logger.Error).Infof("Failed to serialize JavaScript exception %v: %v", msg, err)
}
panic(val)
}
// newErrorResponse creates a JSON RPC error response for a specific request id,
// containing the specified error code and error message. Beside returning the
// error to the caller, it also sets the ret_error and ret_response JavaScript
// variables.
func newErrorResponse(call otto.FunctionCall, code int, msg string, id interface{}) (response otto.Value) {
// Bundle the error into a JSON RPC call response
res := rpc.JSONErrResponse{
Version: rpc.JSONRPCVersion,
Id: id,
Error: rpc.JSONError{
Code: code,
Message: msg,
},
}
// Serialize the error response into JavaScript variables
errObj, err := json.Marshal(res.Error)
if err != nil {
glog.V(logger.Error).Infof("Failed to serialize JSON RPC error: %v", err)
}
resObj, err := json.Marshal(res)
if err != nil {
glog.V(logger.Error).Infof("Failed to serialize JSON RPC error response: %v", err)
}
if _, err = call.Otto.Run("ret_error = " + string(errObj)); err != nil {
glog.V(logger.Error).Infof("Failed to set `ret_error` to the occurred error: %v", err)
}
resVal, err := call.Otto.Run("ret_response = " + string(resObj))
if err != nil {
glog.V(logger.Error).Infof("Failed to set `ret_response` to the JSON RPC response: %v", err)
}
return resVal
}
