forked from cerc-io/plugeth
80 lines
1.9 KiB
Go
80 lines
1.9 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
|
|
|
|
func CompactEncode(hexSlice []byte) []byte {
|
|
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...)
|
|
}
|
|
|
|
l := len(hexSlice) / 2
|
|
var buf = make([]byte, l)
|
|
for i := 0; i < l; i++ {
|
|
buf[i] = 16*hexSlice[2*i] + hexSlice[2*i+1]
|
|
}
|
|
return buf
|
|
}
|
|
|
|
func CompactDecode(str []byte) []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 []byte) []byte {
|
|
l := len(str)*2 + 1
|
|
var nibbles = make([]byte, l)
|
|
for i, b := range str {
|
|
nibbles[i*2] = b / 16
|
|
nibbles[i*2+1] = b % 16
|
|
}
|
|
nibbles[l-1] = 16
|
|
return nibbles
|
|
}
|
|
|
|
func DecodeCompact(key []byte) []byte {
|
|
l := len(key) / 2
|
|
var res = make([]byte, l)
|
|
for i := 0; i < l; i++ {
|
|
v1, v0 := key[2*i], key[2*i+1]
|
|
res[i] = v1*16 + v0
|
|
}
|
|
return res
|
|
}
|