93 lines
2.1 KiB
Go
93 lines
2.1 KiB
Go
// Copyright 2014 The go-ethereum Authors
|
|
// This file is part of the go-ethereum library.
|
|
//
|
|
// The go-ethereum library is free software: you can redistribute it and/or modify
|
|
// it under the terms of the GNU Lesser General Public License as published by
|
|
// the Free Software Foundation, either version 3 of the License, or
|
|
// (at your option) any later version.
|
|
//
|
|
// The go-ethereum library is distributed in the hope that it will be useful,
|
|
// but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
// GNU Lesser General Public License for more details.
|
|
//
|
|
// You should have received a copy of the GNU Lesser General Public License
|
|
// along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
|
|
|
|
package trie
|
|
|
|
import (
|
|
"bytes"
|
|
"encoding/hex"
|
|
"strings"
|
|
)
|
|
|
|
func CompactEncode(hexSlice []byte) string {
|
|
terminator := 0
|
|
if hexSlice[len(hexSlice)-1] == 16 {
|
|
terminator = 1
|
|
}
|
|
|
|
if terminator == 1 {
|
|
hexSlice = hexSlice[:len(hexSlice)-1]
|
|
}
|
|
|
|
oddlen := len(hexSlice) % 2
|
|
flags := byte(2*terminator + oddlen)
|
|
if oddlen != 0 {
|
|
hexSlice = append([]byte{flags}, hexSlice...)
|
|
} else {
|
|
hexSlice = append([]byte{flags, 0}, hexSlice...)
|
|
}
|
|
|
|
var buff bytes.Buffer
|
|
for i := 0; i < len(hexSlice); i += 2 {
|
|
buff.WriteByte(byte(16*hexSlice[i] + hexSlice[i+1]))
|
|
}
|
|
|
|
return buff.String()
|
|
}
|
|
|
|
func CompactDecode(str string) []byte {
|
|
base := CompactHexDecode(str)
|
|
base = base[:len(base)-1]
|
|
if base[0] >= 2 {
|
|
base = append(base, 16)
|
|
}
|
|
if base[0]%2 == 1 {
|
|
base = base[1:]
|
|
} else {
|
|
base = base[2:]
|
|
}
|
|
|
|
return base
|
|
}
|
|
|
|
func CompactHexDecode(str string) []byte {
|
|
base := "0123456789abcdef"
|
|
var hexSlice []byte
|
|
|
|
enc := hex.EncodeToString([]byte(str))
|
|
for _, v := range enc {
|
|
hexSlice = append(hexSlice, byte(strings.IndexByte(base, byte(v))))
|
|
}
|
|
hexSlice = append(hexSlice, 16)
|
|
|
|
return hexSlice
|
|
}
|
|
|
|
func DecodeCompact(key []byte) string {
|
|
const base = "0123456789abcdef"
|
|
var str string
|
|
|
|
for _, v := range key {
|
|
if v < 16 {
|
|
str += string(base[v])
|
|
}
|
|
}
|
|
|
|
res, _ := hex.DecodeString(str)
|
|
|
|
return string(res)
|
|
}
|