package reflect // import "go.unistack.org/micro/v3/util/reflect" import ( "errors" "fmt" "reflect" "strconv" "strings" "unicode" ) var ( // ErrInvalidStruct happens when passed not struct and not struct pointer ErrInvalidStruct = errors.New("invalid struct specified") // ErrInvalidValue happens when passed invalid value for field ErrInvalidValue = errors.New("invalid value specified") // ErrNotFound happens when struct field not found ErrNotFound = errors.New("struct field not found") ) // Option func signature type Option func(*Options) // Options for merge type Options struct { // Tags specifies tags to lookup Tags []string // SliceAppend controls slice appending SliceAppend bool } // Tags sets the merge tags for lookup func Tags(t []string) Option { return func(o *Options) { o.Tags = t } } // SliceAppend sets the option func SliceAppend(b bool) Option { return func(o *Options) { o.SliceAppend = b } } // Merge merges map[string]interface{} to destination struct func Merge(dst interface{}, mp map[string]interface{}, opts ...Option) error { var err error var sval reflect.Value var fname string options := Options{} for _, o := range opts { o(&options) } dviface := reflect.ValueOf(dst) if dviface.Kind() == reflect.Ptr { dviface = dviface.Elem() } if dviface.Kind() != reflect.Struct { return ErrInvalidStruct } dtype := dviface.Type() for idx := 0; idx < dtype.NumField(); idx++ { dfld := dtype.Field(idx) dval := dviface.Field(idx) if !dval.CanSet() || len(dfld.PkgPath) != 0 || !dval.IsValid() { continue } fname = "" for _, tname := range options.Tags { tvalue, ok := dfld.Tag.Lookup(tname) if !ok { continue } tpart := strings.Split(tvalue, ",") switch tname { case "protobuf": for _, p := range tpart { if idx := strings.Index(p, "name="); idx > 0 { fname = p[idx:] } } default: fname = tpart[0] } if fname != "" { break } } if fname == "" { fname = FieldName(dfld.Name) } val, ok := mp[fname] if !ok { val, ok = mp[dfld.Name] if !ok { continue } } sval = reflect.ValueOf(val) switch getKind(dval) { case reflect.Bool: err = mergeBool(dval, sval) case reflect.String: err = mergeString(dval, sval) case reflect.Int: err = mergeInt(dval, sval) case reflect.Uint: err = mergeUint(dval, sval) case reflect.Float32: err = mergeFloat(dval, sval) case reflect.Struct: mp, ok := sval.Interface().(map[string]interface{}) if !ok { return ErrInvalidValue } err = Merge(dval.Interface(), mp, opts...) case reflect.Ptr: mp, ok := sval.Interface().(map[string]interface{}) if !ok { return ErrInvalidValue } if dval.IsNil() { dval.Set(reflect.New(dval.Type().Elem())) if dval.Elem().Type().Kind() == reflect.Struct { for i := 0; i < dval.Elem().NumField(); i++ { field := dval.Elem().Field(i) if field.Type().Kind() == reflect.Ptr && field.IsNil() && dval.Elem().Type().Field(i).Anonymous { field.Set(reflect.New(field.Type().Elem())) } } } } err = Merge(dval.Interface(), mp, opts...) case reflect.Slice: if !options.SliceAppend && dval.IsNil() { dval.Set(reflect.MakeSlice(dval.Type(), sval.Len(), sval.Len())) } else if options.SliceAppend && dval.IsNil() { dval.Set(reflect.MakeSlice(dval.Type(), 0, 0)) } for idx := 0; idx < sval.Len(); idx++ { var idval reflect.Value if !options.SliceAppend { idval = dval.Index(idx) } else { idval = reflect.Indirect(reflect.New(dval.Type().Elem())) } if getKind(idval) == reflect.Ptr && idval.IsNil() { idval.Set(reflect.New(idval.Type().Elem())) if idval.Elem().Type().Kind() == reflect.Struct { for i := 0; i < idval.Elem().NumField(); i++ { field := idval.Elem().Field(i) if field.Type().Kind() == reflect.Ptr && field.IsNil() && idval.Elem().Type().Field(i).Anonymous { field.Set(reflect.New(field.Type().Elem())) } } } } switch getKind(idval) { case reflect.Bool: err = mergeBool(idval, sval.Index(idx)) case reflect.String: err = mergeString(idval, sval.Index(idx)) case reflect.Int: err = mergeInt(idval, sval.Index(idx)) case reflect.Uint: err = mergeUint(idval, sval.Index(idx)) case reflect.Float32: err = mergeFloat(idval, sval.Index(idx)) case reflect.Struct: imp, ok := sval.Index(idx).Interface().(map[string]interface{}) if !ok { return ErrInvalidValue } err = Merge(idval.Interface(), imp, opts...) case reflect.Ptr: nsval := sval.Index(idx) if getKind(sval.Index(idx)) == reflect.Interface { nsval = reflect.ValueOf(nsval.Interface()) } switch reflect.Indirect(idval).Type().String() { case "wrapperspb.BoolValue": if eva := reflect.Indirect(idval).FieldByName("Value"); eva.IsValid() { err = mergeBool(eva, nsval) } case "wrapperspb.BytesValue": if eva := reflect.Indirect(idval).FieldByName("Value"); eva.IsValid() { err = mergeUint(eva, nsval) } case "wrapperspb.DoubleValue", "wrapperspb.FloatValue": if eva := reflect.Indirect(idval).FieldByName("Value"); eva.IsValid() { err = mergeFloat(eva, nsval) } case "wrapperspb.Int32Value", "wrapperspb.Int64Value": if eva := reflect.Indirect(idval).FieldByName("Value"); eva.IsValid() { err = mergeInt(eva, nsval) } case "wrapperspb.StringValue": if eva := reflect.Indirect(idval).FieldByName("Value"); eva.IsValid() { err = mergeString(eva, nsval) } case "wrapperspb.UInt32Value", "wrapperspb.UInt64Value": if eva := reflect.Indirect(idval).FieldByName("Value"); eva.IsValid() { err = mergeUint(eva, nsval) } default: imp, ok := nsval.Interface().(map[string]interface{}) if !ok { return ErrInvalidValue } if idval.IsNil() { idval.Set(reflect.New(idval.Type().Elem())) if idval.Elem().Type().Kind() == reflect.Struct { for i := 0; i < idval.Elem().NumField(); i++ { field := idval.Elem().Field(i) if field.Type().Kind() == reflect.Ptr && field.IsNil() && idval.Elem().Type().Field(i).Anonymous { field.Set(reflect.New(field.Type().Elem())) } } } } err = Merge(idval.Interface(), imp, opts...) } } if options.SliceAppend { dval.Set(reflect.Append(dval, idval)) } } /* case reflect.Interface: err = d.decodeBasic(name, input, outVal) case reflect.Map: err = merge(dval, sval) case reflect.Array: err = mergeArray(dval, sval) */ default: err = ErrInvalidValue } if err != nil { err = fmt.Errorf("%v key %v invalid val %v", err, fname, sval.Interface()) } } return nil } func mergeBool(dval reflect.Value, sval reflect.Value) error { switch getKind(sval) { case reflect.Int: switch sval.Int() { case 1: dval.SetBool(true) case 0: dval.SetBool(false) default: return ErrInvalidValue } case reflect.Uint: switch sval.Uint() { case 1: dval.SetBool(true) case 0: dval.SetBool(false) default: return ErrInvalidValue } case reflect.Float32: switch sval.Float() { case 1: dval.SetBool(true) case 0: dval.SetBool(false) default: return ErrInvalidValue } case reflect.Bool: dval.SetBool(sval.Bool()) case reflect.String: switch sval.String() { case "t", "T", "true", "TRUE", "True", "1", "yes": dval.SetBool(true) case "f", "F", "false", "FALSE", "False", "0", "no": dval.SetBool(false) default: return ErrInvalidValue } case reflect.Interface: return mergeBool(dval, reflect.ValueOf(fmt.Sprintf("%v", sval.Interface()))) default: return ErrInvalidValue } return nil } func mergeString(dval reflect.Value, sval reflect.Value) error { switch getKind(sval) { case reflect.Int: dval.SetString(strconv.FormatInt(sval.Int(), sval.Type().Bits())) case reflect.Uint: dval.SetString(strconv.FormatUint(sval.Uint(), sval.Type().Bits())) case reflect.Float32: dval.SetString(strconv.FormatFloat(sval.Float(), 'f', -1, sval.Type().Bits())) case reflect.Bool: switch sval.Bool() { case true: dval.SetString(strconv.FormatBool(true)) case false: dval.SetString(strconv.FormatBool(false)) } case reflect.String: dval.SetString(sval.String()) case reflect.Interface: return mergeString(dval, reflect.ValueOf(fmt.Sprintf("%v", sval.Interface()))) default: return ErrInvalidValue } return nil } func mergeInt(dval reflect.Value, sval reflect.Value) error { switch getKind(sval) { case reflect.Int: dval.SetInt(sval.Int()) case reflect.Uint: dval.SetInt(int64(sval.Uint())) case reflect.Float32: dval.SetInt(int64(sval.Float())) case reflect.Bool: switch sval.Bool() { case true: dval.SetInt(1) case false: dval.SetInt(0) } case reflect.String: l, err := strconv.ParseInt(sval.String(), 0, dval.Type().Bits()) if err != nil { return err } dval.SetInt(l) case reflect.Interface: return mergeInt(dval, reflect.ValueOf(fmt.Sprintf("%v", sval.Interface()))) default: return ErrInvalidValue } return nil } func mergeUint(dval reflect.Value, sval reflect.Value) error { switch getKind(sval) { case reflect.Int: dval.SetUint(uint64(sval.Int())) case reflect.Uint: dval.SetUint(sval.Uint()) case reflect.Float32: dval.SetUint(uint64(sval.Float())) case reflect.Bool: switch sval.Bool() { case true: dval.SetUint(1) case false: dval.SetUint(0) } case reflect.String: l, err := strconv.ParseUint(sval.String(), 0, dval.Type().Bits()) if err != nil { return err } dval.SetUint(l) case reflect.Interface: return mergeUint(dval, reflect.ValueOf(fmt.Sprintf("%v", sval.Interface()))) default: return ErrInvalidValue } return nil } func mergeFloat(dval reflect.Value, sval reflect.Value) error { switch getKind(sval) { case reflect.Int: dval.SetFloat(float64(sval.Int())) case reflect.Uint: dval.SetFloat(float64(sval.Uint())) case reflect.Float32: dval.SetFloat(sval.Float()) case reflect.Bool: switch sval.Bool() { case true: dval.SetFloat(1) case false: dval.SetFloat(0) } case reflect.String: l, err := strconv.ParseFloat(sval.String(), dval.Type().Bits()) if err != nil { return err } dval.SetFloat(l) case reflect.Interface: return mergeFloat(dval, reflect.ValueOf(fmt.Sprintf("%v", sval.Interface()))) default: return ErrInvalidValue } return nil } func getKind(val reflect.Value) reflect.Kind { kind := val.Kind() switch { case kind >= reflect.Int && kind <= reflect.Int64: return reflect.Int case kind >= reflect.Uint && kind <= reflect.Uint64: return reflect.Uint case kind >= reflect.Float32 && kind <= reflect.Float64: return reflect.Float32 } return kind } // IsZero returns true if struct is zero (not have any defined values) func IsZero(src interface{}) bool { v := reflect.ValueOf(src) return IsEmpty(v) } // Zero creates new zero interface func Zero(src interface{}) (interface{}, error) { sv := reflect.ValueOf(src) if sv.Kind() == reflect.Ptr { sv = sv.Elem() } if sv.Kind() == reflect.Invalid { return nil, ErrInvalidStruct } dst := reflect.New(sv.Type()) return dst.Interface(), nil } // IsEmpty returns true if value empty func IsEmpty(v reflect.Value) bool { switch getKind(v) { case reflect.Array, reflect.Map, reflect.Slice, reflect.String: return v.Len() == 0 case reflect.Bool: return !v.Bool() case reflect.Int: return v.Int() == 0 case reflect.Uint: return v.Uint() == 0 case reflect.Float32: return v.Float() == 0 case reflect.Interface, reflect.Ptr: if v.IsNil() { return true } return IsEmpty(v.Elem()) case reflect.Func: return v.IsNil() case reflect.Invalid: return true case reflect.Struct: var ok bool for i := 0; i < v.NumField(); i++ { ok = IsEmpty(v.FieldByIndex([]int{i})) if !ok { return false } } default: return false } return true } // FieldName returns map field name that can be looked up in struct field func FieldName(name string) string { newstr := make([]rune, 0, len(name)) for idx, chr := range name { if idx == 0 { newstr = append(newstr, unicode.ToLower(chr)) continue } else if unicode.IsUpper(chr) { newstr = append(newstr, '_') newstr = append(newstr, unicode.ToLower(chr)) continue } newstr = append(newstr, chr) } return string(newstr) }