bbgo_origin/pkg/bbgo/reflect.go

104 lines
2.0 KiB
Go

package bbgo
import (
"errors"
"fmt"
"reflect"
)
type InstanceIDProvider interface {
InstanceID() string
}
func callID(obj interface{}) string {
sv := reflect.ValueOf(obj)
st := reflect.TypeOf(obj)
if st.Implements(reflect.TypeOf((*InstanceIDProvider)(nil)).Elem()) {
m := sv.MethodByName("InstanceID")
ret := m.Call(nil)
return ret[0].String()
}
return ""
}
func isSymbolBasedStrategy(rs reflect.Value) (string, bool) {
if rs.Kind() == reflect.Ptr {
rs = rs.Elem()
}
field := rs.FieldByName("Symbol")
if !field.IsValid() {
return "", false
}
if field.Kind() != reflect.String {
return "", false
}
return field.String(), true
}
func hasField(rs reflect.Value, fieldName string) (field reflect.Value, ok bool) {
field = rs.FieldByName(fieldName)
return field, field.IsValid()
}
type StructFieldIterator func(tag string, ft reflect.StructField, fv reflect.Value) error
var errCanNotIterateNilPointer = errors.New("can not iterate struct on a nil pointer")
func iterateFieldsByTag(obj interface{}, tagName string, cb StructFieldIterator) error {
sv := reflect.ValueOf(obj)
st := reflect.TypeOf(obj)
if st.Kind() != reflect.Ptr {
return fmt.Errorf("f should be a pointer of a struct, %s given", st)
}
// for pointer, check if it's nil
if sv.IsNil() {
return errCanNotIterateNilPointer
}
// solve the reference
st = st.Elem()
sv = sv.Elem()
if st.Kind() != reflect.Struct {
return fmt.Errorf("f should be a struct, %s given", st)
}
for i := 0; i < sv.NumField(); i++ {
fv := sv.Field(i)
ft := st.Field(i)
// skip unexported fields
if !st.Field(i).IsExported() {
continue
}
tag, ok := ft.Tag.Lookup(tagName)
if !ok {
continue
}
if err := cb(tag, ft, fv); err != nil {
return err
}
}
return nil
}
// https://github.com/xiaojun207/go-base-utils/blob/master/utils/Clone.go
func newTypeValueInterface(typ reflect.Type) interface{} {
if typ.Kind() == reflect.Ptr {
typ = typ.Elem()
dst := reflect.New(typ).Elem()
return dst.Addr().Interface()
}
dst := reflect.New(typ)
return dst.Interface()
}