orderid.go

package match

import (
	"encoding/hex"
	"fmt"
)

// OrderID represents an order's unique ID.
// This is a byte array alias because sometimes the ID will be represented as text, and sometimes it will be represented as bytes.
// We conform it to the BinaryMarshaler interface and TextMarshaler interface.
type OrderID [32]byte

// MarshalBinary encodes the receiver into a binary form and returns the result. This conforms to the BinaryMarshaler interface
func (o *OrderID) MarshalBinary() (data []byte, err error) {
	// size array, then copy
	oSlice := o[:]
	data = make([]byte, len(oSlice))
	copy(data, oSlice)
	return
}

// UnmarshalBinary decodes the form generated by MarshalBinary. This conforms to the BinaryMarshaler interface
func (o *OrderID) UnmarshalBinary(data []byte) (err error) {
	// no need to size because orderid is [32]byte
	copy(o[:], data)
	return
}

// MarshalText encodes the receiver into UTF-8-encoded text and returns the result. This conforms to the TextMarshaler interface
func (o *OrderID) MarshalText() (text []byte, err error) {
	// size array, then copy
	oSlice := []byte(hex.EncodeToString(o[:]))
	text = make([]byte, len(oSlice))
	copy(text, oSlice)
	return
}

// UnmarshalText deocdes the form generated by MarshalText. This conforms to the TextMarshaler interface
func (o *OrderID) UnmarshalText(text []byte) (err error) {
	if _, err = hex.Decode(o[:], text); err != nil {
		err = fmt.Errorf("Error unmarshalling text OrderID: %s", err)
		return
	}
	return
}

// GobEncode returns a byte slice representing the encoding of the
// receiver for transmission to a GobDecoder, usually of the same
// concrete type.
func (o *OrderID) GobEncode() (ret []byte, err error) {
	if ret, err = o.MarshalBinary(); err != nil {
		err = fmt.Errorf("Error gob encoding by marshalling binary: %s", err)
		return
	}
	return
}

// GobDecode overwrites the receiver, which must be a pointer,
// with the value represented by the byte slice, which was written
// by GobEncode, usually for the same concrete type.
func (o *OrderID) GobDecode(in []byte) (err error) {
	if err = o.UnmarshalBinary(in); err != nil {
		err = fmt.Errorf("Error gob encoding by unmarshalling binary: %s", err)
		return
	}
	return
}