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