path: root/cmd/geth/js.go

// Copyright (c) 2013-2014, Jeffrey Wilcke. All rights reserved.
//
// This library is free software; you can redistribute it and/or
// modify it under the terms of the GNU General Public
// License as published by the Free Software Foundation; either
// version 2.1 of the License, or (at your option) any later version.
//
// This 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
// General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with this library; if not, write to the Free Software
// Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
// MA 02110-1301  USA

package main

import (
    "bufio"
    "fmt"
    "math/big"
    "os"
    "os/signal"
    "path/filepath"
    "strings"

    "github.com/ethereum/go-ethereum/cmd/utils"
    "github.com/ethereum/go-ethereum/common"
    "github.com/ethereum/go-ethereum/common/docserver"
    "github.com/ethereum/go-ethereum/common/natspec"
    "github.com/ethereum/go-ethereum/eth"
    re "github.com/ethereum/go-ethereum/jsre"
    "github.com/ethereum/go-ethereum/rpc"
    "github.com/ethereum/go-ethereum/xeth"
    "github.com/peterh/liner"
    "github.com/robertkrimen/otto"
)

type prompter interface {
    AppendHistory(string)
    Prompt(p string) (string, error)
    PasswordPrompt(p string) (string, error)
}

type dumbterm struct{ r *bufio.Reader }

func (r dumbterm) Prompt(p string) (string, error) {
    fmt.Print(p)
    line, err := r.r.ReadString('\n')
    return strings.TrimSuffix(line, "\n"), err
}

func (r dumbterm) PasswordPrompt(p string) (string, error) {
    fmt.Println("!! Unsupported terminal, password will echo.")
    fmt.Print(p)
    input, err := bufio.NewReader(os.Stdin).ReadString('\n')
    fmt.Println()
    return input, err
}

func (r dumbterm) AppendHistory(string) {}

type jsre struct {
    re         *re.JSRE
    ethereum   *eth.Ethereum
    xeth       *xeth.XEth
    wait       chan *big.Int
    ps1        string
    atexit     func()
    corsDomain string
    prompter
}

func newJSRE(ethereum *eth.Ethereum, libPath, corsDomain, ipcpath string, interactive bool, f xeth.Frontend) *jsre {
    js := &jsre{ethereum: ethereum, ps1: "> "}
    // set default cors domain used by startRpc from CLI flag
    js.corsDomain = corsDomain
    if f == nil {
        f = js
    }
    js.xeth = xeth.New(ethereum, f)
    js.wait = js.xeth.UpdateState()
    // update state in separare forever blocks
    js.re = re.New(libPath)
    js.apiBindings(ipcpath, f)
    js.adminBindings()

    if !liner.TerminalSupported() || !interactive {
        js.prompter = dumbterm{bufio.NewReader(os.Stdin)}
    } else {
        lr := liner.NewLiner()
        js.withHistory(func(hist *os.File) { lr.ReadHistory(hist) })
        lr.SetCtrlCAborts(true)
        js.prompter = lr
        js.atexit = func() {
            js.withHistory(func(hist *os.File) { hist.Truncate(0); lr.WriteHistory(hist) })
            lr.Close()
            close(js.wait)
        }
    }
    return js
}

func (js *jsre) apiBindings(ipcpath string, f xeth.Frontend) {
    xe := xeth.New(js.ethereum, f)
    ethApi := rpc.NewEthereumApi(xe)
    jeth := rpc.NewJeth(ethApi, js.re, ipcpath)

    js.re.Set("jeth", struct{}{})
    t, _ := js.re.Get("jeth")
    jethObj := t.Object()
    jethObj.Set("send", jeth.Send)
    jethObj.Set("sendAsync", jeth.Send)

    err := js.re.Compile("bignumber.js", re.BigNumber_JS)
    if err != nil {
        utils.Fatalf("Error loading bignumber.js: %v", err)
    }

    err = js.re.Compile("ethereum.js", re.Web3_JS)
    if err != nil {
        utils.Fatalf("Error loading ethereum.js: %v", err)
    }

    _, err = js.re.Eval("var web3 = require('web3');")
    if err != nil {
        utils.Fatalf("Error requiring web3: %v", err)
    }

    _, err = js.re.Eval("web3.setProvider(jeth)")
    if err != nil {
        utils.Fatalf("Error setting web3 provider: %v", err)
    }
    _, err = js.re.Eval(`
var eth = web3.eth;
var shh = web3.shh;
var db  = web3.db;
var net = web3.net;
  `)
    if err != nil {
        utils.Fatalf("Error setting namespaces: %v", err)
    }

    js.re.Eval(globalRegistrar + "registrar = GlobalRegistrar.at(\"" + globalRegistrarAddr + "\");")
}

var ds, _ = docserver.New("/")

func (self *jsre) ConfirmTransaction(tx string) bool {
    if self.ethereum.NatSpec {
        notice := natspec.GetNotice(self.xeth, tx, ds)
        fmt.Println(notice)
        answer, _ := self.Prompt("Confirm Transaction [y/n]")
        return strings.HasPrefix(strings.Trim(answer, " "), "y")
    } else {
        return true
    }
}

func (self *jsre) UnlockAccount(addr []byte) bool {
    fmt.Printf("Please unlock account %x.\n", addr)
    pass, err := self.PasswordPrompt("Passphrase: ")
    if err != nil {
        return false
    }
    // TODO: allow retry
    if err := self.ethereum.AccountManager().Unlock(common.BytesToAddress(addr), pass); err != nil {
        return false
    } else {
        fmt.Println("Account is now unlocked for this session.")
        return true
    }
}

func (self *jsre) exec(filename string) error {
    if err := self.re.Exec(filename); err != nil {
        self.re.Stop(false)
        return fmt.Errorf("Javascript Error: %v", err)
    }
    self.re.Stop(true)
    return nil
}

func (self *jsre) interactive() {
    // Read input lines.
    prompt := make(chan string)
    inputln := make(chan string)
    go func() {
        defer close(inputln)
        for {
            line, err := self.Prompt(<-prompt)
            if err != nil {
                return
            }
            inputln <- line
        }
    }()
    // Wait for Ctrl-C, too.
    sig := make(chan os.Signal, 1)
    signal.Notify(sig, os.Interrupt)

    defer func() {
        if self.atexit != nil {
            self.atexit()
        }
        self.re.Stop(false)
    }()
    for {
        prompt <- self.ps1
        select {
        case <-sig:
            fmt.Println("caught interrupt, exiting")
            return
        case input, ok := <-inputln:
            if !ok || indentCount <= 0 && input == "exit" {
                return
            }
            if input == "" {
                continue
            }
            str += input + "\n"
            self.setIndent()
            if indentCount <= 0 {
                hist := str[:len(str)-1]
                self.AppendHistory(hist)
                self.parseInput(str)
                str = ""
            }
        }
    }
}

func (self *jsre) withHistory(op func(*os.File)) {
    hist, err := os.OpenFile(filepath.Join(self.ethereum.DataDir, "history"), os.O_RDWR|os.O_CREATE, os.ModePerm)
    if err != nil {
        fmt.Printf("unable to open history file: %v\n", err)
        return
    }
    op(hist)
    hist.Close()
}

func (self *jsre) parseInput(code string) {
    defer func() {
        if r := recover(); r != nil {
            fmt.Println("[native] error", r)
        }
    }()
    value, err := self.re.Run(code)
    if err != nil {
        if ottoErr, ok := err.(*otto.Error); ok {
            fmt.Println(ottoErr.String())
        } else {
            fmt.Println(err)
        }
        return
    }
    self.printValue(value)
}

var indentCount = 0
var str = ""

func (self *jsre) setIndent() {
    open := strings.Count(str, "{")
    open += strings.Count(str, "(")
    closed := strings.Count(str, "}")
    closed += strings.Count(str, ")")
    indentCount = open - closed
    if indentCount <= 0 {
        self.ps1 = "> "
    } else {
        self.ps1 = strings.Join(make([]string, indentCount*2), "..")
        self.ps1 += " "
    }
}

func (self *jsre) printValue(v interface{}) {
    val, err := self.re.PrettyPrint(v)
    if err == nil {
        fmt.Printf("%v", val)
    }
}