path: root/cmd/ethereum/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"
    "io/ioutil"
    "os"
    "path"
    "strings"

    "github.com/ethereum/go-ethereum/core/types"
    "github.com/ethereum/go-ethereum/eth"
    "github.com/ethereum/go-ethereum/ethutil"
    "github.com/ethereum/go-ethereum/javascript"
    "github.com/ethereum/go-ethereum/state"
    "github.com/ethereum/go-ethereum/xeth"
    "github.com/obscuren/otto"
    "github.com/peterh/liner"
)

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

type dumbPrompter struct{ r *bufio.Reader }

func (r dumbPrompter) Prompt(p string) (string, error) {
    fmt.Print(p)
    return r.r.ReadString('\n')
}

func (r dumbPrompter) 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 dumbPrompter) AppendHistory(string) {}

type jsre struct {
    re       *javascript.JSRE
    ethereum *eth.Ethereum
    xeth     *xeth.XEth
    ps1      string
    prompter
}

func newJSRE(ethereum *eth.Ethereum) *jsre {
    js := &jsre{ethereum: ethereum, ps1: "> "}
    js.xeth = xeth.New(ethereum, js)
    js.re = javascript.NewJSRE(js.xeth)
    js.initStdFuncs()

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

func (self *jsre) ConfirmTransaction(tx *types.Transaction) bool {
    p := fmt.Sprintf("Confirm Transaction %v\n[y/n] ", tx)
    answer, _ := self.prompter.Prompt(p)
    return strings.HasPrefix(strings.Trim(answer, " "), "y")
}

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

func (self *jsre) exec(filename string) error {
    file, err := os.Open(filename)
    if err != nil {
        return err
    }
    content, err := ioutil.ReadAll(file)
    if err != nil {
        return err
    }
    if _, err := self.re.Run(string(content)); err != nil {
        return fmt.Errorf("Javascript Error: %v", err)
    }
    return nil
}

func (self *jsre) interactive() {
    for {
        input, err := self.prompter.Prompt(self.ps1)
        if err != nil {
            return
        }
        if input == "" {
            continue
        }
        str += input + "\n"
        self.setIndent()
        if indentCount <= 0 {
            if input == "exit" {
                return
            }
            hist := str[:len(str)-1]
            self.prompter.AppendHistory(hist)
            self.parseInput(str)
            str = ""
        }
    }
}

func (self *jsre) withHistory(op func(*os.File)) {
    hist, err := os.OpenFile(path.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 {
        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{}) {
    method, _ := self.re.Vm.Get("prettyPrint")
    v, err := self.re.Vm.ToValue(v)
    if err == nil {
        val, err := method.Call(method, v)
        if err == nil {
            fmt.Printf("%v", val)
        }
    }
}

func (self *jsre) initStdFuncs() {
    t, _ := self.re.Vm.Get("eth")
    eth := t.Object()
    eth.Set("connect", self.connect)
    eth.Set("stopMining", self.stopMining)
    eth.Set("startMining", self.startMining)
    eth.Set("dump", self.dump)
    eth.Set("export", self.export)
}

/*
 * The following methods are natively implemented javascript functions.
 */

func (self *jsre) dump(call otto.FunctionCall) otto.Value {
    var block *types.Block

    if len(call.ArgumentList) > 0 {
        if call.Argument(0).IsNumber() {
            num, _ := call.Argument(0).ToInteger()
            block = self.ethereum.ChainManager().GetBlockByNumber(uint64(num))
        } else if call.Argument(0).IsString() {
            hash, _ := call.Argument(0).ToString()
            block = self.ethereum.ChainManager().GetBlock(ethutil.Hex2Bytes(hash))
        } else {
            fmt.Println("invalid argument for dump. Either hex string or number")
        }

        if block == nil {
            fmt.Println("block not found")

            return otto.UndefinedValue()
        }

    } else {
        block = self.ethereum.ChainManager().CurrentBlock()
    }

    statedb := state.New(block.Root(), self.ethereum.StateDb())

    v, _ := self.re.Vm.ToValue(statedb.RawDump())

    return v
}

func (self *jsre) stopMining(call otto.FunctionCall) otto.Value {
    self.xeth.Miner().Stop()
    return otto.TrueValue()
}

func (self *jsre) startMining(call otto.FunctionCall) otto.Value {
    self.xeth.Miner().Start()
    return otto.TrueValue()
}

func (self *jsre) connect(call otto.FunctionCall) otto.Value {
    nodeURL, err := call.Argument(0).ToString()
    if err != nil {
        return otto.FalseValue()
    }
    if err := self.ethereum.SuggestPeer(nodeURL); err != nil {
        return otto.FalseValue()
    }
    return otto.TrueValue()
}

func (self *jsre) export(call otto.FunctionCall) otto.Value {
    if len(call.ArgumentList) == 0 {
        fmt.Println("err: require file name")
        return otto.FalseValue()
    }

    fn, err := call.Argument(0).ToString()
    if err != nil {
        fmt.Println(err)
        return otto.FalseValue()
    }

    data := self.ethereum.ChainManager().Export()

    if err := ethutil.WriteFile(fn, data); err != nil {
        fmt.Println(err)
        return otto.FalseValue()
    }

    return otto.TrueValue()
}