package main
import (
"fmt"
"github.com/ethereum/eth-go"
"github.com/ethereum/eth-go/ethchain"
"github.com/ethereum/eth-go/ethpub"
"github.com/ethereum/eth-go/ethutil"
"github.com/ethereum/go-ethereum/utils"
"github.com/obscuren/otto"
"io/ioutil"
"os"
"path/filepath"
)
type JSRE struct {
ethereum *eth.Ethereum
vm *otto.Otto
lib *ethpub.PEthereum
blockChan chan ethutil.React
changeChan chan ethutil.React
quitChan chan bool
objectCb map[string][]otto.Value
}
func NewJSRE(ethereum *eth.Ethereum) *JSRE {
re := &JSRE{
ethereum,
otto.New(),
ethpub.NewPEthereum(ethereum),
make(chan ethutil.React, 1),
make(chan ethutil.React, 1),
make(chan bool),
make(map[string][]otto.Value),
}
// Init the JS lib
re.vm.Run(jsLib)
// We have to make sure that, whoever calls this, calls "Stop"
go re.mainLoop()
re.Bind("eth", &JSEthereum{re.lib, re.vm})
re.initStdFuncs()
return re
}
func (self *JSRE) Bind(name string, v interface{}) {
self.vm.Set(name, v)
}
func (self *JSRE) Run(code string) (otto.Value, error) {
return self.vm.Run(code)
}
func (self *JSRE) Require(file string) error {
if len(filepath.Ext(file)) == 0 {
file += ".js"
}
fh, err := os.Open(file)
if err != nil {
return err
}
content, _ := ioutil.ReadAll(fh)
self.Run("exports = {};(function() {" + string(content) + "})();")
return nil
}
func (self *JSRE) Stop() {
// Kill the main loop
self.quitChan <- true
close(self.blockChan)
close(self.quitChan)
close(self.changeChan)
}
func (self *JSRE) mainLoop() {
// Subscribe to events
reactor := self.ethereum.Reactor()
reactor.Subscribe("newBlock", self.blockChan)
out:
for {
select {
case <-self.quitChan:
break out
case block := <-self.blockChan:
if _, ok := block.Resource.(*ethchain.Block); ok {
}
case object := <-self.changeChan:
if stateObject, ok := object.Resource.(*ethchain.StateObject); ok {
for _, cb := range self.objectCb[ethutil.Hex(stateObject.Address())] {
val, _ := self.vm.ToValue(ethpub.NewPStateObject(stateObject))
cb.Call(cb, val)
}
} else if storageObject, ok := object.Resource.(*ethchain.StorageState); ok {
for _, cb := range self.objectCb[ethutil.Hex(storageObject.StateAddress)+ethutil.Hex(storageObject.Address)] {
val, _ := self.vm.ToValue(ethpub.NewPStorageState(storageObject))
cb.Call(cb, val)
}
}
}
}
}
func (self *JSRE) initStdFuncs() {
t, _ := self.vm.Get("eth")
eth := t.Object()
eth.Set("watch", self.watch)
eth.Set("addPeer", self.addPeer)
eth.Set("require", self.require)
eth.Set("stopMining", self.stopMining)
eth.Set("startMining", self.startMining)
}
/*
* The following methods are natively implemented javascript functions
*/
func (self *JSRE) stopMining(call otto.FunctionCall) otto.Value {
v, _ := self.vm.ToValue(utils.StopMining(self.ethereum))
return v
}
func (self *JSRE) startMining(call otto.FunctionCall) otto.Value {
v, _ := self.vm.ToValue(utils.StartMining(self.ethereum))
return v
}
// eth.watch
func (self *JSRE) watch(call otto.FunctionCall) otto.Value {
addr, _ := call.Argument(0).ToString()
var storageAddr string
var cb otto.Value
var storageCallback bool
if len(call.ArgumentList) > 2 {
storageCallback = true
storageAddr, _ = call.Argument(1).ToString()
cb = call.Argument(2)
} else {
cb = call.Argument(1)
}
if storageCallback {
self.objectCb[addr+storageAddr] = append(self.objectCb[addr+storageAddr], cb)
event := "storage:" + string(ethutil.FromHex(addr)) + ":" + string(ethutil.FromHex(storageAddr))
self.ethereum.Reactor().Subscribe(event, self.changeChan)
} else {
self.objectCb[addr] = append(self.objectCb[addr], cb)
event := "object:" + string(ethutil.FromHex(addr))
self.ethereum.Reactor().Subscribe(event, self.changeChan)
}
return otto.UndefinedValue()
}
func (self *JSRE) addPeer(call otto.FunctionCall) otto.Value {
host, err := call.Argument(0).ToString()
if err != nil {
return otto.FalseValue()
}
self.ethereum.ConnectToPeer(host)
return otto.TrueValue()
}
func (self *JSRE) require(call otto.FunctionCall) otto.Value {
file, err := call.Argument(0).ToString()
if err != nil {
return otto.UndefinedValue()
}
if err := self.Require(file); err != nil {
fmt.Println("err:", err)
return otto.UndefinedValue()
}
t, _ := self.vm.Get("exports")
return t
}
