116 lines
2.2 KiB
Go
116 lines
2.2 KiB
Go
package jsre
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import (
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"fmt"
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"github.com/obscuren/otto"
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"io/ioutil"
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"github.com/ethereum/go-ethereum/common"
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)
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/*
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JSRE is a generic JS runtime environment embedding the otto JS interpreter.
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It provides some helper functions to
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- load code from files
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- run code snippets
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- require libraries
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- bind native go objects
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*/
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type JSRE struct {
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assetPath string
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vm *otto.Otto
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}
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func New(assetPath string) *JSRE {
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re := &JSRE{
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assetPath,
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otto.New(),
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}
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// load prettyprint func definition
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re.vm.Run(pp_js)
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re.vm.Set("loadScript", re.loadScript)
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return re
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}
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// Exec(file) loads and runs the contents of a file
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// if a relative path is given, the jsre's assetPath is used
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func (self *JSRE) Exec(file string) error {
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return self.exec(common.AbsolutePath(self.assetPath, file))
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}
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func (self *JSRE) exec(path string) error {
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code, err := ioutil.ReadFile(path)
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if err != nil {
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return err
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}
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_, err = self.vm.Run(code)
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return err
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}
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func (self *JSRE) Bind(name string, v interface{}) (err error) {
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self.vm.Set(name, v)
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return
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}
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func (self *JSRE) Run(code string) (otto.Value, error) {
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return self.vm.Run(code)
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}
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func (self *JSRE) Get(ns string) (otto.Value, error) {
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return self.vm.Get(ns)
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}
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func (self *JSRE) Set(ns string, v interface{}) error {
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return self.vm.Set(ns, v)
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}
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func (self *JSRE) loadScript(call otto.FunctionCall) otto.Value {
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file, err := call.Argument(0).ToString()
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if err != nil {
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return otto.FalseValue()
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}
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if err := self.Exec(file); err != nil {
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fmt.Println("err:", err)
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return otto.FalseValue()
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}
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return otto.TrueValue()
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}
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func (self *JSRE) PrettyPrint(v interface{}) (val otto.Value, err error) {
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var method otto.Value
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v, err = self.vm.ToValue(v)
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if err != nil {
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return
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}
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method, err = self.vm.Get("prettyPrint")
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if err != nil {
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return
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}
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return method.Call(method, v)
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}
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func (self *JSRE) ToVal(v interface{}) otto.Value {
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result, err := self.vm.ToValue(v)
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if err != nil {
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fmt.Println("Value unknown:", err)
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return otto.UndefinedValue()
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}
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return result
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}
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func (self *JSRE) Eval(code string) (s string, err error) {
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var val otto.Value
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val, err = self.Run(code)
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if err != nil {
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return
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}
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val, err = self.PrettyPrint(val)
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if err != nil {
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return
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}
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return fmt.Sprintf("%v", val), nil
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}
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