d5d570f793
This one makes a little more obvious that we're operating with LE representations mostly. Refs. #307. See #314 also.
94 lines
2.5 KiB
Go
94 lines
2.5 KiB
Go
package util
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import (
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"bytes"
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"encoding/hex"
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"encoding/json"
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"fmt"
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"strings"
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)
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const uint256Size = 32
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// Uint256 is a 32 byte long unsigned integer.
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type Uint256 [uint256Size]uint8
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// Uint256DecodeReverseString attempts to decode the given string (in LE representation) into an Uint256.
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func Uint256DecodeReverseString(s string) (u Uint256, err error) {
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if len(s) != uint256Size*2 {
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return u, fmt.Errorf("expected string size of %d got %d", uint256Size*2, len(s))
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}
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b, err := hex.DecodeString(s)
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if err != nil {
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return u, err
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}
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return Uint256DecodeReverseBytes(b)
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}
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// Uint256DecodeReverseBytes attempts to decode the given string (in LE representation) into an Uint256.
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func Uint256DecodeReverseBytes(b []byte) (u Uint256, err error) {
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b = ArrayReverse(b)
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if len(b) != uint256Size {
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return u, fmt.Errorf("expected []byte of size %d got %d", uint256Size, len(b))
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}
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copy(u[:], b)
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return u, nil
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}
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// Bytes returns a byte slice representation of u.
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func (u Uint256) Bytes() []byte {
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return u[:]
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}
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// Reverse reverses the Uint256 object
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func (u Uint256) Reverse() Uint256 {
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res, _ := Uint256DecodeReverseBytes(u.Bytes())
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return res
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}
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// BytesReverse return a reversed byte representation of u.
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func (u Uint256) BytesReverse() []byte {
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return ArrayReverse(u.Bytes())
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}
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// Equals returns true if both Uint256 values are the same.
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func (u Uint256) Equals(other Uint256) bool {
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return u == other
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}
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// String implements the stringer interface.
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func (u Uint256) String() string {
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return hex.EncodeToString(u.Bytes())
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}
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// ReverseString produces string representation of Uint256 with LE byte order.
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func (u Uint256) ReverseString() string {
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return hex.EncodeToString(u.BytesReverse())
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}
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// UnmarshalJSON implements the json unmarshaller interface.
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func (u *Uint256) UnmarshalJSON(data []byte) (err error) {
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var js string
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if err = json.Unmarshal(data, &js); err != nil {
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return err
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}
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js = strings.TrimPrefix(js, "0x")
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*u, err = Uint256DecodeReverseString(js)
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return err
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}
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// Size returns the lenght of the bytes representation of Uint256
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func (u Uint256) Size() int {
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return uint256Size
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}
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// MarshalJSON implements the json marshaller interface.
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func (u Uint256) MarshalJSON() ([]byte, error) {
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return []byte(`"0x` + u.ReverseString() + `"`), nil
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}
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// CompareTo compares two Uint256 with each other. Possible output: 1, -1, 0
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// 1 implies u > other.
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// -1 implies u < other.
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// 0 implies u = other.
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func (u Uint256) CompareTo(other Uint256) int { return bytes.Compare(u[:], other[:]) }
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