customu256.go

/*
	Package custom contains custom types for test and example purposes.
	These types are used by the test structures generated by gogoprotobuf.
*/
package custom

import (
	"bytes"
	"encoding/json"
	"errors"
)

type Uint256 [4]uint64

func (u Uint256) Marshal() ([]byte, error) {
	buffer := make([]byte, 32)
	_, err := u.MarshalTo(buffer)
	return buffer, err
}

func (u Uint256) MarshalTo(data []byte) (n int, err error) {
	PutLittleEndianUint256(data, 0, u)
	return 16, nil
}

func GetLittleEndianUint64(b []byte, offset int) uint64 {
	v := uint64(b[offset+7]) << 56
	v += uint64(b[offset+6]) << 48
	v += uint64(b[offset+5]) << 40
	v += uint64(b[offset+4]) << 32
	v += uint64(b[offset+3]) << 24
	v += uint64(b[offset+2]) << 16
	v += uint64(b[offset+1]) << 8
	v += uint64(b[offset])
	return v
}

func PutLittleEndianUint64(b []byte, offset int, v uint64) {
	b[offset] = byte(v)
	b[offset+1] = byte(v >> 8)
	b[offset+2] = byte(v >> 16)
	b[offset+3] = byte(v >> 24)
	b[offset+4] = byte(v >> 32)
	b[offset+5] = byte(v >> 40)
	b[offset+6] = byte(v >> 48)
	b[offset+7] = byte(v >> 56)
}

func PutLittleEndianUint256(buffer []byte, offset int, v [4]uint64) {
	PutLittleEndianUint64(buffer, offset, v[0])
	PutLittleEndianUint64(buffer, offset+8, v[1])
	PutLittleEndianUint64(buffer, offset+16, v[2])
	PutLittleEndianUint64(buffer, offset+24, v[3])
}

func GetLittleEndianUint256(buffer []byte, offset int) (value [4]uint64) {
	value[0] = GetLittleEndianUint64(buffer, offset)
	value[1] = GetLittleEndianUint64(buffer, offset+8)
	value[2] = GetLittleEndianUint64(buffer, offset+16)
	value[3] = GetLittleEndianUint64(buffer, offset+24)
	return
}

func (u *Uint256) Unmarshal(data []byte) error {
	if data == nil {
		u = nil
		return nil
	}
	if len(data) == 0 {
		pu := Uint256{}
		*u = pu
		return nil
	}
	if len(data) != 32 {
		return errors.New("Uint256: invalid length")
	}
	pu := Uint256(GetLittleEndianUint256(data, 0))
	*u = pu
	return nil
}

func (u Uint256) MarshalJSON() ([]byte, error) {
	data, err := u.Marshal()
	if err != nil {
		return nil, err
	}
	return json.Marshal(data)
}

func (u Uint256) Size() int {
	return 32
}

func (u *Uint256) UnmarshalJSON(data []byte) error {
	v := new([]byte)
	err := json.Unmarshal(data, v)
	if err != nil {
		return err
	}
	return u.Unmarshal(*v)
}

func (this Uint256) Equal(that Uint256) bool {
	return this == that
}

func (this Uint256) Compare(that Uint256) int {
	thisdata, err := this.Marshal()
	if err != nil {
		panic(err)
	}
	thatdata, err := that.Marshal()
	if err != nil {
		panic(err)
	}
	return bytes.Compare(thisdata, thatdata)
}

type randy interface {
	Intn(n int) int
}

func NewPopulatedUint256(r randy) *Uint256 {
	data := make([]byte, 256)
	for i := 0; i < 32; i++ {
		data[i] = byte(r.Intn(255))
	}
	u := Uint256(GetLittleEndianUint256(data, 0))
	return &u
}