github.com/philpearl/plenc@v0.0.15/marshal.go (about)

     1  package plenc
     2  
     3  import (
     4  	"fmt"
     5  	"reflect"
     6  	"unsafe"
     7  )
     8  
     9  func Marshal(data []byte, value interface{}) ([]byte, error) {
    10  	return defaultPlenc.Marshal(data, value)
    11  }
    12  
    13  func Unmarshal(data []byte, value interface{}) error {
    14  	return defaultPlenc.Unmarshal(data, value)
    15  }
    16  
    17  func (p *Plenc) Marshal(data []byte, value interface{}) ([]byte, error) {
    18  	typ := reflect.TypeOf(value)
    19  	ptr := unpackEFace(value).data
    20  	if typ.Kind() == reflect.Ptr {
    21  		typ = typ.Elem()
    22  
    23  		// When marshalling we don't want a pointer to a map as a map is a
    24  		// pointer-ish type itself.
    25  		if typ.Kind() == reflect.Map {
    26  			ptr = *(*unsafe.Pointer)(ptr)
    27  		}
    28  	}
    29  
    30  	c, err := p.CodecForType(typ)
    31  	if err != nil {
    32  		return nil, err
    33  	}
    34  
    35  	if c.Omit(ptr) {
    36  		return nil, nil
    37  	}
    38  	if data == nil {
    39  		data = make([]byte, 0, c.Size(ptr, nil))
    40  	}
    41  
    42  	return c.Append(data, ptr, nil), nil
    43  }
    44  
    45  func (p *Plenc) Unmarshal(data []byte, value interface{}) error {
    46  	rv := reflect.ValueOf(value)
    47  	if rv.Kind() != reflect.Ptr || rv.IsNil() {
    48  		return fmt.Errorf("you must pass in a non-nil pointer")
    49  	}
    50  
    51  	c, err := p.CodecForType(rv.Type().Elem())
    52  	if err != nil {
    53  		return err
    54  	}
    55  
    56  	_, err = c.Read(data, unsafe.Pointer(rv.Pointer()), c.WireType())
    57  	return err
    58  }