阶段性提交

internal/js/vm.go

@@ -0,0 +1,153 @@
+// Copyright 2021 Liuxiangchao iwind.liu@gmail.com. All rights reserved.
+
+package js
+
+import (
+	"errors"
+	"github.com/dop251/goja"
+	"github.com/iwind/TeaGo/logs"
+	"reflect"
+	"strings"
+)
+
+var sharedPrograms []*goja.Program
+var sharedConsole = &Console{}
+
+func init() {
+	// compile programs
+}
+
+type VM struct {
+	vm *goja.Runtime
+}
+
+func NewVM() *VM {
+	vm := goja.New()
+	vm.SetFieldNameMapper(goja.TagFieldNameMapper("json", true))
+
+	// programs
+	for _, program := range sharedPrograms {
+		_, _ = vm.RunProgram(program)
+	}
+
+	v := &VM{vm: vm}
+	v.initVM()
+	return v
+}
+
+func (this *VM) Set(name string, obj interface{}) error {
+	return this.vm.Set(name, obj)
+}
+
+func (this *VM) AddConstructor(name string, instance interface{}) error {
+	objType := reflect.TypeOf(instance)
+
+	if objType.Kind() != reflect.Ptr {
+		return errors.New("instance should be pointer")
+	}
+
+	// construct
+	newMethod, ok := objType.MethodByName("JSNew")
+	if !ok {
+		return errors.New("can not find 'JSNew()' method in '" + objType.Elem().Name() + "'")
+	}
+
+	var err = this.Set(name, func(call goja.ConstructorCall) *goja.Object {
+		if newMethod.Type.NumIn() != 2 {
+			this.throw(errors.New(objType.Elem().Name() + ".JSNew() should accept a '[]goja.Value' argument"))
+			return nil
+		}
+		if newMethod.Type.In(1).String() != "[]goja.Value" {
+			this.throw(errors.New(objType.Elem().Name() + ".JSNew() should accept a '[]goja.Value' argument"))
+			return nil
+		}
+
+		// new
+		var results = newMethod.Func.Call([]reflect.Value{reflect.ValueOf(instance), reflect.ValueOf(call.Arguments)})
+		if len(results) == 0 {
+			this.throw(errors.New(objType.Elem().Name() + ".JSNew() should return a valid instance"))
+			return nil
+		}
+		var result = results[0]
+		if result.Type() != objType {
+			this.throw(errors.New(objType.Elem().Name() + ".JSNew() should return a same instance"))
+			return nil
+		}
+
+		// methods
+		var resultType = result.Type()
+		var numMethod = result.NumMethod()
+		for i := 0; i < numMethod; i++ {
+			var method = resultType.Method(i)
+			var methodName = strings.ToLower(method.Name[:1]) + method.Name[1:]
+			err := call.This.Set(methodName, result.MethodByName(method.Name).Interface())
+			if err != nil {
+				this.throw(err)
+				continue
+			}
+		}
+
+		//  支持属性
+		var numField = result.Elem().Type().NumField()
+		for i := 0; i < numField; i++ {
+			var field = result.Elem().Field(i)
+			if !field.CanInterface() {
+				continue
+			}
+			var fieldType = objType.Elem().Field(i)
+			tag, ok := fieldType.Tag.Lookup("json")
+			if !ok {
+				tag = fieldType.Name
+				tag = strings.ToLower(tag[:1]) + tag[1:]
+			} else {
+				// TODO 校验tag是否符合变量语法
+			}
+			err := call.This.Set(tag, field.Interface())
+			if err != nil {
+				this.throw(err)
+				continue
+			}
+		}
+
+		return nil
+	})
+	return err
+}
+
+func (this *VM) RunString(str string) (goja.Value, error) {
+	defer func() {
+		e := recover()
+		if e != nil {
+			// TODO 需要打印trace
+			logs.Println("panic:", e)
+		}
+	}()
+	return this.vm.RunString(str)
+}
+
+func (this *VM) SetRequest(req RequestInterface) {
+	{
+		err := this.vm.Set("http", NewHTTP(req))
+		if err != nil {
+			this.throw(err)
+		}
+	}
+}
+
+func (this *VM) initVM() {
+	{
+		err := this.vm.Set("console", sharedConsole)
+		if err != nil {
+			this.throw(err)
+		}
+	}
+}
+
+func (this *VM) throw(err error) {
+	if err == nil {
+		return
+	}
+
+	// TODO
+	logs.Println("js:VM:error: " + err.Error())
+}