diff --git a/decode_hooks.go b/decode_hooks.go index 24d82f07..2523c6ad 100644 --- a/decode_hooks.go +++ b/decode_hooks.go @@ -36,6 +36,30 @@ func typedDecodeHook(h DecodeHookFunc) DecodeHookFunc { return nil } +// cachedDecodeHook takes a raw DecodeHookFunc (an interface{}) and turns +// it into a closure to be used directly +// if the type fails to convert we return a closure always erroring to keep the previous behaviour +func cachedDecodeHook(raw DecodeHookFunc) func(from reflect.Value, to reflect.Value) (interface{}, error) { + switch f := typedDecodeHook(raw).(type) { + case DecodeHookFuncType: + return func(from reflect.Value, to reflect.Value) (interface{}, error) { + return f(from.Type(), to.Type(), from.Interface()) + } + case DecodeHookFuncKind: + return func(from reflect.Value, to reflect.Value) (interface{}, error) { + return f(from.Kind(), to.Kind(), from.Interface()) + } + case DecodeHookFuncValue: + return func(from reflect.Value, to reflect.Value) (interface{}, error) { + return f(from, to) + } + default: + return func(from reflect.Value, to reflect.Value) (interface{}, error) { + return nil, errors.New("invalid decode hook signature") + } + } +} + // DecodeHookExec executes the given decode hook. This should be used // since it'll naturally degrade to the older backwards compatible DecodeHookFunc // that took reflect.Kind instead of reflect.Type. @@ -61,13 +85,17 @@ func DecodeHookExec( // The composed funcs are called in order, with the result of the // previous transformation. func ComposeDecodeHookFunc(fs ...DecodeHookFunc) DecodeHookFunc { + cached := make([]func(from reflect.Value, to reflect.Value) (interface{}, error), 0, len(fs)) + for _, f := range fs { + cached = append(cached, cachedDecodeHook(f)) + } return func(f reflect.Value, t reflect.Value) (interface{}, error) { var err error data := f.Interface() newFrom := f - for _, f1 := range fs { - data, err = DecodeHookExec(f1, newFrom, t) + for _, c := range cached { + data, err = c(newFrom, t) if err != nil { return nil, err } @@ -81,13 +109,17 @@ func ComposeDecodeHookFunc(fs ...DecodeHookFunc) DecodeHookFunc { // OrComposeDecodeHookFunc executes all input hook functions until one of them returns no error. In that case its value is returned. // If all hooks return an error, OrComposeDecodeHookFunc returns an error concatenating all error messages. func OrComposeDecodeHookFunc(ff ...DecodeHookFunc) DecodeHookFunc { + cached := make([]func(from reflect.Value, to reflect.Value) (interface{}, error), 0, len(ff)) + for _, f := range ff { + cached = append(cached, cachedDecodeHook(f)) + } return func(a, b reflect.Value) (interface{}, error) { var allErrs string var out interface{} var err error - for _, f := range ff { - out, err = DecodeHookExec(f, a, b) + for _, c := range cached { + out, err = c(a, b) if err != nil { allErrs += err.Error() + "\n" continue diff --git a/mapstructure.go b/mapstructure.go index 4b54fae0..39c555d6 100644 --- a/mapstructure.go +++ b/mapstructure.go @@ -283,7 +283,8 @@ type DecoderConfig struct { // structure. The top-level Decode method is just a convenience that sets // up the most basic Decoder. type Decoder struct { - config *DecoderConfig + config *DecoderConfig + cachedDecodeHook func(from reflect.Value, to reflect.Value) (interface{}, error) } // Metadata contains information about decoding a structure that @@ -408,6 +409,9 @@ func NewDecoder(config *DecoderConfig) (*Decoder, error) { result := &Decoder{ config: config, } + if config.DecodeHook != nil { + result.cachedDecodeHook = cachedDecodeHook(config.DecodeHook) + } return result, nil } @@ -462,10 +466,10 @@ func (d *Decoder) decode(name string, input interface{}, outVal reflect.Value) e return nil } - if d.config.DecodeHook != nil { + if d.cachedDecodeHook != nil { // We have a DecodeHook, so let's pre-process the input. var err error - input, err = DecodeHookExec(d.config.DecodeHook, inputVal, outVal) + input, err = d.cachedDecodeHook(inputVal, outVal) if err != nil { return fmt.Errorf("error decoding '%s': %w", name, err) }