faster hex-prefix codec and string -> []byte

This commit is contained in:
Ethan Buchman 2015-08-06 03:11:10 -04:00
parent 98100f472c
commit c1d516546d
5 changed files with 30 additions and 39 deletions

View File

@ -18,11 +18,9 @@ package trie
import (
"bytes"
"encoding/hex"
"strings"
)
func CompactEncode(hexSlice []byte) string {
func CompactEncode(hexSlice []byte) []byte {
terminator := 0
if hexSlice[len(hexSlice)-1] == 16 {
terminator = 1
@ -45,10 +43,10 @@ func CompactEncode(hexSlice []byte) string {
buff.WriteByte(byte(16*hexSlice[i] + hexSlice[i+1]))
}
return buff.String()
return buff.Bytes()
}
func CompactDecode(str string) []byte {
func CompactDecode(str []byte) []byte {
base := CompactHexDecode(str)
base = base[:len(base)-1]
if base[0] >= 2 {
@ -63,30 +61,23 @@ func CompactDecode(str string) []byte {
return base
}
func CompactHexDecode(str string) []byte {
base := "0123456789abcdef"
var hexSlice []byte
func CompactHexDecode(str []byte) []byte {
var nibbles []byte
enc := hex.EncodeToString([]byte(str))
for _, v := range enc {
hexSlice = append(hexSlice, byte(strings.IndexByte(base, byte(v))))
for _, b := range str {
nibbles = append(nibbles, b/16)
nibbles = append(nibbles, b%16)
}
hexSlice = append(hexSlice, 16)
return hexSlice
nibbles = append(nibbles, 16)
return nibbles
}
func DecodeCompact(key []byte) string {
const base = "0123456789abcdef"
var str string
for _, v := range key {
if v < 16 {
str += string(base[v])
// assumes key is odd length
func DecodeCompact(key []byte) []byte {
var res []byte
for i := 0; i < len(key)-1; i += 2 {
v1, v0 := key[i], key[i+1]
res = append(res, v1*16+v0)
}
}
res, _ := hex.DecodeString(str)
return string(res)
return res
}

View File

@ -48,28 +48,28 @@ func (s *TrieEncodingSuite) TestCompactEncode(c *checker.C) {
func (s *TrieEncodingSuite) TestCompactHexDecode(c *checker.C) {
exp := []byte{7, 6, 6, 5, 7, 2, 6, 2, 16}
res := CompactHexDecode("verb")
res := CompactHexDecode([]byte("verb"))
c.Assert(res, checker.DeepEquals, exp)
}
func (s *TrieEncodingSuite) TestCompactDecode(c *checker.C) {
// odd compact decode
exp := []byte{1, 2, 3, 4, 5}
res := CompactDecode("\x11\x23\x45")
res := CompactDecode([]byte("\x11\x23\x45"))
c.Assert(res, checker.DeepEquals, exp)
// even compact decode
exp = []byte{0, 1, 2, 3, 4, 5}
res = CompactDecode("\x00\x01\x23\x45")
res = CompactDecode([]byte("\x00\x01\x23\x45"))
c.Assert(res, checker.DeepEquals, exp)
// even terminated compact decode
exp = []byte{0, 15, 1, 12, 11, 8 /*term*/, 16}
res = CompactDecode("\x20\x0f\x1c\xb8")
res = CompactDecode([]byte("\x20\x0f\x1c\xb8"))
c.Assert(res, checker.DeepEquals, exp)
// even terminated compact decode
exp = []byte{15, 1, 12, 11, 8 /*term*/, 16}
res = CompactDecode("\x3f\x1c\xb8")
res = CompactDecode([]byte("\x3f\x1c\xb8"))
c.Assert(res, checker.DeepEquals, exp)
}

View File

@ -41,7 +41,7 @@ func (self *Iterator) Next() bool {
self.Key = make([]byte, 32)
}
key := RemTerm(CompactHexDecode(string(self.Key)))
key := RemTerm(CompactHexDecode(self.Key))
k := self.next(self.trie.root, key, isIterStart)
self.Key = []byte(DecodeCompact(k))

View File

@ -26,7 +26,7 @@ type ShortNode struct {
}
func NewShortNode(t *Trie, key []byte, value Node) *ShortNode {
return &ShortNode{t, []byte(CompactEncode(key)), value, false}
return &ShortNode{t, CompactEncode(key), value, false}
}
func (self *ShortNode) Value() Node {
self.value = self.trie.trans(self.value)
@ -49,7 +49,7 @@ func (self *ShortNode) Hash() interface{} {
}
func (self *ShortNode) Key() []byte {
return CompactDecode(string(self.key))
return CompactDecode(self.key)
}
func (self *ShortNode) setDirty(dirty bool) {

View File

@ -69,7 +69,7 @@ func (self *Trie) Iterator() *Iterator {
func (self *Trie) Copy() *Trie {
cpy := make([]byte, 32)
copy(cpy, self.roothash)
copy(cpy, self.roothash) // NOTE: cpy isn't being used anywhere?
trie := New(nil, nil)
trie.cache = self.cache.Copy()
if self.root != nil {
@ -131,7 +131,7 @@ func (self *Trie) Update(key, value []byte) Node {
self.mu.Lock()
defer self.mu.Unlock()
k := CompactHexDecode(string(key))
k := CompactHexDecode(key)
if len(value) != 0 {
node := NewValueNode(self, value)
@ -149,7 +149,7 @@ func (self *Trie) Get(key []byte) []byte {
self.mu.Lock()
defer self.mu.Unlock()
k := CompactHexDecode(string(key))
k := CompactHexDecode(key)
n := self.get(self.root, k)
if n != nil {
@ -164,7 +164,7 @@ func (self *Trie) Delete(key []byte) Node {
self.mu.Lock()
defer self.mu.Unlock()
k := CompactHexDecode(string(key))
k := CompactHexDecode(key)
self.root = self.delete(self.root, k)
return self.root
@ -336,7 +336,7 @@ func (self *Trie) mknode(value *common.Value) Node {
case 2:
// A value node may consists of 2 bytes.
if value.Get(0).Len() != 0 {
key := CompactDecode(string(value.Get(0).Bytes()))
key := CompactDecode(value.Get(0).Bytes())
if key[len(key)-1] == 16 {
return NewShortNode(self, key, NewValueNode(self, value.Get(1).Bytes()))
} else {