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package binstruct
import (
"fmt"
"reflect"
)
var handlerCache = make(map[reflect.Type]handler)
func getHandler(typ reflect.Type) (handler, error) {
h, ok := handlerCache[typ]
if ok {
return h, nil
}
h, err := genHandler(typ)
if err != nil {
return nil, err
}
handlerCache[typ] = h
return h, nil
}
func Unmarshal(dat []byte, dst interface{}) error {
_dst := reflect.ValueOf(dst)
if _dst.Kind() != reflect.Ptr {
return fmt.Errorf("not a pointer: %v", _dst.Type())
}
handler, err := getHandler(_dst.Type().Elem())
if err != nil {
return err
}
if int64(len(dat)) < handler.Size() {
return fmt.Errorf("need at least %d bytes of data, only have %d",
handler.Size(), len(dat))
}
val := handler.Unmarshal(dat[:handler.Size()])
_dst.Elem().Set(reflect.ValueOf(val))
return nil
}
func Marshal(val interface{}) ([]byte, error) {
handler, err := getHandler(reflect.TypeOf(val))
if err != nil {
return nil, err
}
bs := handler.Marshal(val)
if int64(len(bs)) != handler.Size() {
return nil, fmt.Errorf("got %d bytes but expected %d bytes",
len(bs), handler.Size())
}
return bs, nil
}
func Size(val interface{}) (int64, error) {
handler, err := getHandler(reflect.TypeOf(val))
if err != nil {
return 0, err
}
return handler.Size(), nil
}
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