package gcfg import ( "fmt" "math/big" "reflect" "strings" "unicode" "unicode/utf8" "gopkg.in/gcfg.v1/types" ) type tag struct { ident string intMode string } var RelaxedParserMode = false func newTag(ts string) tag { t := tag{} s := strings.Split(ts, ",") t.ident = s[0] for _, tse := range s[1:] { if strings.HasPrefix(tse, "int=") { t.intMode = tse[len("int="):] } } return t } func fieldFold(v reflect.Value, name string) (reflect.Value, tag) { var n string r0, _ := utf8.DecodeRuneInString(name) if unicode.IsLetter(r0) && !unicode.IsLower(r0) && !unicode.IsUpper(r0) { n = "X" } n += strings.Replace(name, "-", "_", -1) f, ok := v.Type().FieldByNameFunc(func(fieldName string) bool { if !v.FieldByName(fieldName).CanSet() { return false } f, _ := v.Type().FieldByName(fieldName) t := newTag(f.Tag.Get("gcfg")) if t.ident != "" { return strings.EqualFold(t.ident, name) } return strings.EqualFold(n, fieldName) }) if !ok { return reflect.Value{}, tag{} } return v.FieldByName(f.Name), newTag(f.Tag.Get("gcfg")) } type setter func(destp interface{}, blank bool, val string, t tag) error var errUnsupportedType = fmt.Errorf("unsupported type") var errBlankUnsupported = fmt.Errorf("blank value not supported for type") var setters = []setter{ typeSetter, textUnmarshalerSetter, kindSetter, scanSetter, } func textUnmarshalerSetter(d interface{}, blank bool, val string, t tag) error { dtu, ok := d.(textUnmarshaler) if !ok { return errUnsupportedType } if blank { return errBlankUnsupported } return dtu.UnmarshalText([]byte(val)) } func boolSetter(d interface{}, blank bool, val string, t tag) error { if blank { reflect.ValueOf(d).Elem().Set(reflect.ValueOf(true)) return nil } b, err := types.ParseBool(val) if err == nil { reflect.ValueOf(d).Elem().Set(reflect.ValueOf(b)) } return err } func intMode(mode string) types.IntMode { var m types.IntMode if strings.ContainsAny(mode, "dD") { m |= types.Dec } if strings.ContainsAny(mode, "hH") { m |= types.Hex } if strings.ContainsAny(mode, "oO") { m |= types.Oct } return m } var typeModes = map[reflect.Type]types.IntMode{ reflect.TypeOf(int(0)): types.Dec | types.Hex, reflect.TypeOf(int8(0)): types.Dec | types.Hex, reflect.TypeOf(int16(0)): types.Dec | types.Hex, reflect.TypeOf(int32(0)): types.Dec | types.Hex, reflect.TypeOf(int64(0)): types.Dec | types.Hex, reflect.TypeOf(uint(0)): types.Dec | types.Hex, reflect.TypeOf(uint8(0)): types.Dec | types.Hex, reflect.TypeOf(uint16(0)): types.Dec | types.Hex, reflect.TypeOf(uint32(0)): types.Dec | types.Hex, reflect.TypeOf(uint64(0)): types.Dec | types.Hex, // use default mode (allow dec/hex/oct) for uintptr type reflect.TypeOf(big.Int{}): types.Dec | types.Hex, } func intModeDefault(t reflect.Type) types.IntMode { m, ok := typeModes[t] if !ok { m = types.Dec | types.Hex | types.Oct } return m } func intSetter(d interface{}, blank bool, val string, t tag) error { if blank { return errBlankUnsupported } mode := intMode(t.intMode) if mode == 0 { mode = intModeDefault(reflect.TypeOf(d).Elem()) } return types.ParseInt(d, val, mode) } func stringSetter(d interface{}, blank bool, val string, t tag) error { if blank { return errBlankUnsupported } dsp, ok := d.(*string) if !ok { return errUnsupportedType } *dsp = val return nil } var kindSetters = map[reflect.Kind]setter{ reflect.String: stringSetter, reflect.Bool: boolSetter, reflect.Int: intSetter, reflect.Int8: intSetter, reflect.Int16: intSetter, reflect.Int32: intSetter, reflect.Int64: intSetter, reflect.Uint: intSetter, reflect.Uint8: intSetter, reflect.Uint16: intSetter, reflect.Uint32: intSetter, reflect.Uint64: intSetter, reflect.Uintptr: intSetter, } var typeSetters = map[reflect.Type]setter{ reflect.TypeOf(big.Int{}): intSetter, } func typeSetter(d interface{}, blank bool, val string, tt tag) error { t := reflect.ValueOf(d).Type().Elem() setter, ok := typeSetters[t] if !ok { return errUnsupportedType } return setter(d, blank, val, tt) } func kindSetter(d interface{}, blank bool, val string, tt tag) error { k := reflect.ValueOf(d).Type().Elem().Kind() setter, ok := kindSetters[k] if !ok { return errUnsupportedType } return setter(d, blank, val, tt) } func scanSetter(d interface{}, blank bool, val string, tt tag) error { if blank { return errBlankUnsupported } return types.ScanFully(d, val, 'v') } func set(cfg interface{}, sect, sub, name string, blank bool, value string) error { vPCfg := reflect.ValueOf(cfg) if vPCfg.Kind() != reflect.Ptr || vPCfg.Elem().Kind() != reflect.Struct { panic(fmt.Errorf("config must be a pointer to a struct")) } vCfg := vPCfg.Elem() vSect, _ := fieldFold(vCfg, sect) if !vSect.IsValid() { if RelaxedParserMode { return nil } return fmt.Errorf("invalid section: section %q", sect) } if vSect.Kind() == reflect.Map { vst := vSect.Type() if vst.Key().Kind() != reflect.String || vst.Elem().Kind() != reflect.Ptr || vst.Elem().Elem().Kind() != reflect.Struct { panic(fmt.Errorf("map field for section must have string keys and "+ " pointer-to-struct values: section %q", sect)) } if vSect.IsNil() { vSect.Set(reflect.MakeMap(vst)) } k := reflect.ValueOf(sub) pv := vSect.MapIndex(k) if !pv.IsValid() { vType := vSect.Type().Elem().Elem() pv = reflect.New(vType) vSect.SetMapIndex(k, pv) } vSect = pv.Elem() } else if vSect.Kind() != reflect.Struct { panic(fmt.Errorf("field for section must be a map or a struct: "+ "section %q", sect)) } else if sub != "" { return fmt.Errorf("invalid subsection: "+ "section %q subsection %q", sect, sub) } // Empty name is a special value, meaning that only the // section/subsection object is to be created, with no values set. if name == "" { return nil } vVar, t := fieldFold(vSect, name) if !vVar.IsValid() { if RelaxedParserMode { return nil } return fmt.Errorf("invalid variable: "+ "section %q subsection %q variable %q", sect, sub, name) } // vVal is either single-valued var, or newly allocated value within multi-valued var var vVal reflect.Value // multi-value if unnamed slice type isMulti := vVar.Type().Name() == "" && vVar.Kind() == reflect.Slice || vVar.Type().Name() == "" && vVar.Kind() == reflect.Ptr && vVar.Type().Elem().Name() == "" && vVar.Type().Elem().Kind() == reflect.Slice if isMulti && vVar.Kind() == reflect.Ptr { if vVar.IsNil() { vVar.Set(reflect.New(vVar.Type().Elem())) } vVar = vVar.Elem() } if isMulti && blank { vVar.Set(reflect.Zero(vVar.Type())) return nil } if isMulti { vVal = reflect.New(vVar.Type().Elem()).Elem() } else { vVal = vVar } isDeref := vVal.Type().Name() == "" && vVal.Type().Kind() == reflect.Ptr isNew := isDeref && vVal.IsNil() // vAddr is address of value to set (dereferenced & allocated as needed) var vAddr reflect.Value switch { case isNew: vAddr = reflect.New(vVal.Type().Elem()) case isDeref && !isNew: vAddr = vVal default: vAddr = vVal.Addr() } vAddrI := vAddr.Interface() err, ok := error(nil), false for _, s := range setters { err = s(vAddrI, blank, value, t) if err == nil { ok = true break } if err != errUnsupportedType { return err } } if !ok { // in case all setters returned errUnsupportedType return err } if isNew { // set reference if it was dereferenced and newly allocated vVal.Set(vAddr) } if isMulti { // append if multi-valued vVar.Set(reflect.Append(vVar, vVal)) } return nil }