Integrate public as bindata optionally (#293)

* Dropped unused codekit config

* Integrated dynamic and static bindata for public

* Ignore public bindata

* Add a general generate make task

* Integrated flexible public assets into web command

* Updated vendoring, added all missiong govendor deps

* Made the linter happy with the bindata and dynamic code

* Moved public bindata definition to modules directory

* Ignoring the new bindata path now

* Updated to the new public modules import path

* Updated public bindata command and drop the new prefix

vendor/github.com/pingcap/tidb/util/codec/bytes.go

@@ -0,0 +1,197 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package codec
+
+import (
+	"bytes"
+	"encoding/binary"
+	"runtime"
+	"unsafe"
+
+	"github.com/juju/errors"
+)
+
+const (
+	encGroupSize = 8
+	encMarker    = byte(0xFF)
+	encPad       = byte(0x0)
+)
+
+var (
+	pads    = make([]byte, encGroupSize)
+	encPads = []byte{encPad}
+)
+
+// EncodeBytes guarantees the encoded value is in ascending order for comparison,
+// encoding with the following rule:
+//  [group1][marker1]...[groupN][markerN]
+//  group is 8 bytes slice which is padding with 0.
+//  marker is `0xFF - padding 0 count`
+// For example:
+//   [] -> [0, 0, 0, 0, 0, 0, 0, 0, 247]
+//   [1, 2, 3] -> [1, 2, 3, 0, 0, 0, 0, 0, 250]
+//   [1, 2, 3, 0] -> [1, 2, 3, 0, 0, 0, 0, 0, 251]
+//   [1, 2, 3, 4, 5, 6, 7, 8] -> [1, 2, 3, 4, 5, 6, 7, 8, 255, 0, 0, 0, 0, 0, 0, 0, 0, 247]
+// Refer: https://github.com/facebook/mysql-5.6/wiki/MyRocks-record-format#memcomparable-format
+func EncodeBytes(b []byte, data []byte) []byte {
+	// Allocate more space to avoid unnecessary slice growing.
+	// Assume that the byte slice size is about `(len(data) / encGroupSize + 1) * (encGroupSize + 1)` bytes,
+	// that is `(len(data) / 8 + 1) * 9` in our implement.
+	dLen := len(data)
+	reallocSize := (dLen/encGroupSize + 1) * (encGroupSize + 1)
+	result := reallocBytes(b, reallocSize)
+	for idx := 0; idx <= dLen; idx += encGroupSize {
+		remain := dLen - idx
+		padCount := 0
+		if remain >= encGroupSize {
+			result = append(result, data[idx:idx+encGroupSize]...)
+		} else {
+			padCount = encGroupSize - remain
+			result = append(result, data[idx:]...)
+			result = append(result, pads[:padCount]...)
+		}
+
+		marker := encMarker - byte(padCount)
+		result = append(result, marker)
+	}
+
+	return result
+}
+
+func decodeBytes(b []byte, reverse bool) ([]byte, []byte, error) {
+	data := make([]byte, 0, len(b))
+	for {
+		if len(b) < encGroupSize+1 {
+			return nil, nil, errors.New("insufficient bytes to decode value")
+		}
+
+		groupBytes := b[:encGroupSize+1]
+		if reverse {
+			reverseBytes(groupBytes)
+		}
+
+		group := groupBytes[:encGroupSize]
+		marker := groupBytes[encGroupSize]
+
+		// Check validity of marker.
+		padCount := encMarker - marker
+		realGroupSize := encGroupSize - padCount
+		if padCount > encGroupSize {
+			return nil, nil, errors.Errorf("invalid marker byte, group bytes %q", groupBytes)
+		}
+
+		data = append(data, group[:realGroupSize]...)
+		b = b[encGroupSize+1:]
+
+		if marker != encMarker {
+			// Check validity of padding bytes.
+			if bytes.Count(group[realGroupSize:], encPads) != int(padCount) {
+				return nil, nil, errors.Errorf("invalid padding byte, group bytes %q", groupBytes)
+			}
+
+			break
+		}
+	}
+
+	return b, data, nil
+}
+
+// DecodeBytes decodes bytes which is encoded by EncodeBytes before,
+// returns the leftover bytes and decoded value if no error.
+func DecodeBytes(b []byte) ([]byte, []byte, error) {
+	return decodeBytes(b, false)
+}
+
+// EncodeBytesDesc first encodes bytes using EncodeBytes, then bitwise reverses
+// encoded value to guarantee the encoded value is in descending order for comparison.
+func EncodeBytesDesc(b []byte, data []byte) []byte {
+	n := len(b)
+	b = EncodeBytes(b, data)
+	reverseBytes(b[n:])
+	return b
+}
+
+// DecodeBytesDesc decodes bytes which is encoded by EncodeBytesDesc before,
+// returns the leftover bytes and decoded value if no error.
+func DecodeBytesDesc(b []byte) ([]byte, []byte, error) {
+	return decodeBytes(b, true)
+}
+
+// EncodeCompactBytes joins bytes with its length into a byte slice. It is more
+// efficient in both space and time compare to EncodeBytes. Note that the encoded
+// result is not memcomparable.
+func EncodeCompactBytes(b []byte, data []byte) []byte {
+	b = reallocBytes(b, binary.MaxVarintLen64+len(data))
+	b = EncodeVarint(b, int64(len(data)))
+	return append(b, data...)
+}
+
+// DecodeCompactBytes decodes bytes which is encoded by EncodeCompactBytes before.
+func DecodeCompactBytes(b []byte) ([]byte, []byte, error) {
+	b, n, err := DecodeVarint(b)
+	if err != nil {
+		return nil, nil, errors.Trace(err)
+	}
+	if int64(len(b)) < n {
+		return nil, nil, errors.Errorf("insufficient bytes to decode value, expected length: %v", n)
+	}
+	return b[n:], b[:n], nil
+}
+
+// See https://golang.org/src/crypto/cipher/xor.go
+const wordSize = int(unsafe.Sizeof(uintptr(0)))
+const supportsUnaligned = runtime.GOARCH == "386" || runtime.GOARCH == "amd64"
+
+func fastReverseBytes(b []byte) {
+	n := len(b)
+	w := n / wordSize
+	if w > 0 {
+		bw := *(*[]uintptr)(unsafe.Pointer(&b))
+		for i := 0; i < w; i++ {
+			bw[i] = ^bw[i]
+		}
+	}
+
+	for i := w * wordSize; i < n; i++ {
+		b[i] = ^b[i]
+	}
+}
+
+func safeReverseBytes(b []byte) {
+	for i := range b {
+		b[i] = ^b[i]
+	}
+}
+
+func reverseBytes(b []byte) {
+	if supportsUnaligned {
+		fastReverseBytes(b)
+		return
+	}
+
+	safeReverseBytes(b)
+}
+
+// like realloc.
+func reallocBytes(b []byte, n int) []byte {
+	newSize := len(b) + n
+	if cap(b) < newSize {
+		bs := make([]byte, len(b), newSize)
+		copy(bs, b)
+		return bs
+	}
+
+	// slice b has capability to store n bytes
+	return b
+}

vendor/github.com/pingcap/tidb/util/codec/codec.go

@@ -0,0 +1,165 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package codec
+
+import (
+	"time"
+
+	"github.com/juju/errors"
+	"github.com/pingcap/tidb/mysql"
+	"github.com/pingcap/tidb/util/types"
+)
+
+const (
+	nilFlag byte = iota
+	bytesFlag
+	compactBytesFlag
+	intFlag
+	uintFlag
+	floatFlag
+	decimalFlag
+	durationFlag
+)
+
+func encode(b []byte, vals []types.Datum, comparable bool) ([]byte, error) {
+	for _, val := range vals {
+		switch val.Kind() {
+		case types.KindInt64:
+			b = append(b, intFlag)
+			b = EncodeInt(b, val.GetInt64())
+		case types.KindUint64:
+			b = append(b, uintFlag)
+			b = EncodeUint(b, val.GetUint64())
+		case types.KindFloat32, types.KindFloat64:
+			b = append(b, floatFlag)
+			b = EncodeFloat(b, val.GetFloat64())
+		case types.KindString, types.KindBytes:
+			b = encodeBytes(b, val.GetBytes(), comparable)
+		case types.KindMysqlTime:
+			b = encodeBytes(b, []byte(val.GetMysqlTime().String()), comparable)
+		case types.KindMysqlDuration:
+			// duration may have negative value, so we cannot use String to encode directly.
+			b = append(b, durationFlag)
+			b = EncodeInt(b, int64(val.GetMysqlDuration().Duration))
+		case types.KindMysqlDecimal:
+			b = append(b, decimalFlag)
+			b = EncodeDecimal(b, val.GetMysqlDecimal())
+		case types.KindMysqlHex:
+			b = append(b, intFlag)
+			b = EncodeInt(b, int64(val.GetMysqlHex().ToNumber()))
+		case types.KindMysqlBit:
+			b = append(b, uintFlag)
+			b = EncodeUint(b, uint64(val.GetMysqlBit().ToNumber()))
+		case types.KindMysqlEnum:
+			b = append(b, uintFlag)
+			b = EncodeUint(b, uint64(val.GetMysqlEnum().ToNumber()))
+		case types.KindMysqlSet:
+			b = append(b, uintFlag)
+			b = EncodeUint(b, uint64(val.GetMysqlSet().ToNumber()))
+		case types.KindNull:
+			b = append(b, nilFlag)
+		default:
+			return nil, errors.Errorf("unsupport encode type %d", val.Kind())
+		}
+	}
+
+	return b, nil
+}
+
+func encodeBytes(b []byte, v []byte, comparable bool) []byte {
+	if comparable {
+		b = append(b, bytesFlag)
+		b = EncodeBytes(b, v)
+	} else {
+		b = append(b, compactBytesFlag)
+		b = EncodeCompactBytes(b, v)
+	}
+	return b
+}
+
+// EncodeKey appends the encoded values to byte slice b, returns the appended
+// slice. It guarantees the encoded value is in ascending order for comparison.
+func EncodeKey(b []byte, v ...types.Datum) ([]byte, error) {
+	return encode(b, v, true)
+}
+
+// EncodeValue appends the encoded values to byte slice b, returning the appended
+// slice. It does not guarantee the order for comparison.
+func EncodeValue(b []byte, v ...types.Datum) ([]byte, error) {
+	return encode(b, v, false)
+}
+
+// Decode decodes values from a byte slice generated with EncodeKey or EncodeValue
+// before.
+func Decode(b []byte) ([]types.Datum, error) {
+	if len(b) < 1 {
+		return nil, errors.New("invalid encoded key")
+	}
+
+	var (
+		flag   byte
+		err    error
+		values = make([]types.Datum, 0, 1)
+	)
+
+	for len(b) > 0 {
+		flag = b[0]
+		b = b[1:]
+		var d types.Datum
+		switch flag {
+		case intFlag:
+			var v int64
+			b, v, err = DecodeInt(b)
+			d.SetInt64(v)
+		case uintFlag:
+			var v uint64
+			b, v, err = DecodeUint(b)
+			d.SetUint64(v)
+		case floatFlag:
+			var v float64
+			b, v, err = DecodeFloat(b)
+			d.SetFloat64(v)
+		case bytesFlag:
+			var v []byte
+			b, v, err = DecodeBytes(b)
+			d.SetBytes(v)
+		case compactBytesFlag:
+			var v []byte
+			b, v, err = DecodeCompactBytes(b)
+			d.SetBytes(v)
+		case decimalFlag:
+			var v mysql.Decimal
+			b, v, err = DecodeDecimal(b)
+			d.SetValue(v)
+		case durationFlag:
+			var r int64
+			b, r, err = DecodeInt(b)
+			if err == nil {
+				// use max fsp, let outer to do round manually.
+				v := mysql.Duration{Duration: time.Duration(r), Fsp: mysql.MaxFsp}
+				d.SetValue(v)
+			}
+		case nilFlag:
+		default:
+			return nil, errors.Errorf("invalid encoded key flag %v", flag)
+		}
+		if err != nil {
+			return nil, errors.Trace(err)
+		}
+
+		values = append(values, d)
+	}
+
+	return values, nil
+}

vendor/github.com/pingcap/tidb/util/codec/decimal.go

@@ -0,0 +1,183 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package codec
+
+import (
+	"bytes"
+	"math/big"
+
+	"github.com/juju/errors"
+	"github.com/pingcap/tidb/mysql"
+)
+
+const (
+	negativeSign int64 = 8
+	zeroSign     int64 = 16
+	positiveSign int64 = 24
+)
+
+func codecSign(value int64) int64 {
+	if value < 0 {
+		return negativeSign
+	}
+
+	return positiveSign
+}
+
+func encodeExp(expValue int64, expSign int64, valSign int64) int64 {
+	if expSign == negativeSign {
+		expValue = -expValue
+	}
+
+	if expSign != valSign {
+		expValue = ^expValue
+	}
+
+	return expValue
+}
+
+func decodeExp(expValue int64, expSign int64, valSign int64) int64 {
+	if expSign != valSign {
+		expValue = ^expValue
+	}
+
+	if expSign == negativeSign {
+		expValue = -expValue
+	}
+
+	return expValue
+}
+
+func codecValue(value []byte, valSign int64) {
+	if valSign == negativeSign {
+		reverseBytes(value)
+	}
+}
+
+// EncodeDecimal encodes a decimal d into a byte slice which can be sorted lexicographically later.
+// EncodeDecimal guarantees that the encoded value is in ascending order for comparison.
+// Decimal encoding:
+// Byte -> value sign
+// Byte -> exp sign
+// EncodeInt -> exp value
+// EncodeBytes -> abs value bytes
+func EncodeDecimal(b []byte, d mysql.Decimal) []byte {
+	if d.Equals(mysql.ZeroDecimal) {
+		return append(b, byte(zeroSign))
+	}
+
+	v := d.BigIntValue()
+	valSign := codecSign(int64(v.Sign()))
+
+	absVal := new(big.Int)
+	absVal.Abs(v)
+
+	value := []byte(absVal.String())
+
+	// Trim right side "0", like "12.34000" -> "12.34" or "0.1234000" -> "0.1234".
+	if d.Exponent() != 0 {
+		value = bytes.TrimRight(value, "0")
+	}
+
+	// Get exp and value, format is "value":"exp".
+	// like "12.34" -> "0.1234":"2".
+	// like "-0.01234" -> "-0.1234":"-1".
+	exp := int64(0)
+	div := big.NewInt(10)
+	for ; ; exp++ {
+		if absVal.Sign() == 0 {
+			break
+		}
+		absVal = absVal.Div(absVal, div)
+	}
+
+	expVal := exp + int64(d.Exponent())
+	expSign := codecSign(expVal)
+
+	// For negtive exp, do bit reverse for exp.
+	// For negtive decimal, do bit reverse for exp and value.
+	expVal = encodeExp(expVal, expSign, valSign)
+	codecValue(value, valSign)
+
+	b = append(b, byte(valSign))
+	b = append(b, byte(expSign))
+	b = EncodeInt(b, expVal)
+	b = EncodeBytes(b, value)
+	return b
+}
+
+// DecodeDecimal decodes bytes to decimal.
+// DecodeFloat decodes a float from a byte slice
+// Decimal decoding:
+// Byte -> value sign
+// Byte -> exp sign
+// DecodeInt -> exp value
+// DecodeBytes -> abs value bytes
+func DecodeDecimal(b []byte) ([]byte, mysql.Decimal, error) {
+	var (
+		r   = b
+		d   mysql.Decimal
+		err error
+	)
+
+	// Decode value sign.
+	valSign := int64(r[0])
+	r = r[1:]
+	if valSign == zeroSign {
+		d, err = mysql.ParseDecimal("0")
+		return r, d, errors.Trace(err)
+	}
+
+	// Decode exp sign.
+	expSign := int64(r[0])
+	r = r[1:]
+
+	// Decode exp value.
+	expVal := int64(0)
+	r, expVal, err = DecodeInt(r)
+	if err != nil {
+		return r, d, errors.Trace(err)
+	}
+	expVal = decodeExp(expVal, expSign, valSign)
+
+	// Decode abs value bytes.
+	value := []byte{}
+	r, value, err = DecodeBytes(r)
+	if err != nil {
+		return r, d, errors.Trace(err)
+	}
+	codecValue(value, valSign)
+
+	// Generate decimal string value.
+	var decimalStr []byte
+	if valSign == negativeSign {
+		decimalStr = append(decimalStr, '-')
+	}
+
+	if expVal <= 0 {
+		// Like decimal "0.1234" or "0.01234".
+		decimalStr = append(decimalStr, '0')
+		decimalStr = append(decimalStr, '.')
+		decimalStr = append(decimalStr, bytes.Repeat([]byte{'0'}, -int(expVal))...)
+		decimalStr = append(decimalStr, value...)
+	} else {
+		// Like decimal "12.34".
+		decimalStr = append(decimalStr, value[:expVal]...)
+		decimalStr = append(decimalStr, '.')
+		decimalStr = append(decimalStr, value[expVal:]...)
+	}
+
+	d, err = mysql.ParseDecimal(string(decimalStr))
+	return r, d, errors.Trace(err)
+}

vendor/github.com/pingcap/tidb/util/codec/float.go

@@ -0,0 +1,65 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package codec
+
+import (
+	"math"
+
+	"github.com/juju/errors"
+)
+
+func encodeFloatToCmpUint64(f float64) uint64 {
+	u := math.Float64bits(f)
+	if f >= 0 {
+		u |= signMask
+	} else {
+		u = ^u
+	}
+	return u
+}
+
+func decodeCmpUintToFloat(u uint64) float64 {
+	if u&signMask > 0 {
+		u &= ^signMask
+	} else {
+		u = ^u
+	}
+	return math.Float64frombits(u)
+}
+
+// EncodeFloat encodes a float v into a byte slice which can be sorted lexicographically later.
+// EncodeFloat guarantees that the encoded value is in ascending order for comparison.
+func EncodeFloat(b []byte, v float64) []byte {
+	u := encodeFloatToCmpUint64(v)
+	return EncodeUint(b, u)
+}
+
+// DecodeFloat decodes a float from a byte slice generated with EncodeFloat before.
+func DecodeFloat(b []byte) ([]byte, float64, error) {
+	b, u, err := DecodeUint(b)
+	return b, decodeCmpUintToFloat(u), errors.Trace(err)
+}
+
+// EncodeFloatDesc encodes a float v into a byte slice which can be sorted lexicographically later.
+// EncodeFloatDesc guarantees that the encoded value is in descending order for comparison.
+func EncodeFloatDesc(b []byte, v float64) []byte {
+	u := encodeFloatToCmpUint64(v)
+	return EncodeUintDesc(b, u)
+}
+
+// DecodeFloatDesc decodes a float from a byte slice generated with EncodeFloatDesc before.
+func DecodeFloatDesc(b []byte) ([]byte, float64, error) {
+	b, u, err := DecodeUintDesc(b)
+	return b, decodeCmpUintToFloat(u), errors.Trace(err)
+}

vendor/github.com/pingcap/tidb/util/codec/number.go

@@ -0,0 +1,170 @@
+// Copyright 2015 PingCAP, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package codec
+
+import (
+	"encoding/binary"
+
+	"github.com/juju/errors"
+)
+
+const signMask uint64 = 0x8000000000000000
+
+func encodeIntToCmpUint(v int64) uint64 {
+	u := uint64(v)
+	if u&signMask > 0 {
+		u &= ^signMask
+	} else {
+		u |= signMask
+	}
+
+	return u
+}
+
+func decodeCmpUintToInt(u uint64) int64 {
+	if u&signMask > 0 {
+		u &= ^signMask
+	} else {
+		u |= signMask
+	}
+
+	return int64(u)
+}
+
+// EncodeInt appends the encoded value to slice b and returns the appended slice.
+// EncodeInt guarantees that the encoded value is in ascending order for comparison.
+func EncodeInt(b []byte, v int64) []byte {
+	var data [8]byte
+	u := encodeIntToCmpUint(v)
+	binary.BigEndian.PutUint64(data[:], u)
+	return append(b, data[:]...)
+}
+
+// EncodeIntDesc appends the encoded value to slice b and returns the appended slice.
+// EncodeIntDesc guarantees that the encoded value is in descending order for comparison.
+func EncodeIntDesc(b []byte, v int64) []byte {
+	var data [8]byte
+	u := encodeIntToCmpUint(v)
+	binary.BigEndian.PutUint64(data[:], ^u)
+	return append(b, data[:]...)
+}
+
+// DecodeInt decodes value encoded by EncodeInt before.
+// It returns the leftover un-decoded slice, decoded value if no error.
+func DecodeInt(b []byte) ([]byte, int64, error) {
+	if len(b) < 8 {
+		return nil, 0, errors.New("insufficient bytes to decode value")
+	}
+
+	u := binary.BigEndian.Uint64(b[:8])
+	v := decodeCmpUintToInt(u)
+	b = b[8:]
+	return b, v, nil
+}
+
+// DecodeIntDesc decodes value encoded by EncodeInt before.
+// It returns the leftover un-decoded slice, decoded value if no error.
+func DecodeIntDesc(b []byte) ([]byte, int64, error) {
+	if len(b) < 8 {
+		return nil, 0, errors.New("insufficient bytes to decode value")
+	}
+
+	u := binary.BigEndian.Uint64(b[:8])
+	v := decodeCmpUintToInt(^u)
+	b = b[8:]
+	return b, v, nil
+}
+
+// EncodeUint appends the encoded value to slice b and returns the appended slice.
+// EncodeUint guarantees that the encoded value is in ascending order for comparison.
+func EncodeUint(b []byte, v uint64) []byte {
+	var data [8]byte
+	binary.BigEndian.PutUint64(data[:], v)
+	return append(b, data[:]...)
+}
+
+// EncodeUintDesc appends the encoded value to slice b and returns the appended slice.
+// EncodeUintDesc guarantees that the encoded value is in descending order for comparison.
+func EncodeUintDesc(b []byte, v uint64) []byte {
+	var data [8]byte
+	binary.BigEndian.PutUint64(data[:], ^v)
+	return append(b, data[:]...)
+}
+
+// DecodeUint decodes value encoded by EncodeUint before.
+// It returns the leftover un-decoded slice, decoded value if no error.
+func DecodeUint(b []byte) ([]byte, uint64, error) {
+	if len(b) < 8 {
+		return nil, 0, errors.New("insufficient bytes to decode value")
+	}
+
+	v := binary.BigEndian.Uint64(b[:8])
+	b = b[8:]
+	return b, v, nil
+}
+
+// DecodeUintDesc decodes value encoded by EncodeInt before.
+// It returns the leftover un-decoded slice, decoded value if no error.
+func DecodeUintDesc(b []byte) ([]byte, uint64, error) {
+	if len(b) < 8 {
+		return nil, 0, errors.New("insufficient bytes to decode value")
+	}
+
+	data := b[:8]
+	v := binary.BigEndian.Uint64(data)
+	b = b[8:]
+	return b, ^v, nil
+}
+
+// EncodeVarint appends the encoded value to slice b and returns the appended slice.
+// Note that the encoded result is not memcomparable.
+func EncodeVarint(b []byte, v int64) []byte {
+	var data [binary.MaxVarintLen64]byte
+	n := binary.PutVarint(data[:], v)
+	return append(b, data[:n]...)
+}
+
+// DecodeVarint decodes value encoded by EncodeVarint before.
+// It returns the leftover un-decoded slice, decoded value if no error.
+func DecodeVarint(b []byte) ([]byte, int64, error) {
+	v, n := binary.Varint(b)
+	if n > 0 {
+		return b[n:], v, nil
+	}
+	if n < 0 {
+		return nil, 0, errors.New("value larger than 64 bits")
+	}
+	return nil, 0, errors.New("insufficient bytes to decode value")
+}
+
+// EncodeUvarint appends the encoded value to slice b and returns the appended slice.
+// Note that the encoded result is not memcomparable.
+func EncodeUvarint(b []byte, v uint64) []byte {
+	var data [binary.MaxVarintLen64]byte
+	n := binary.PutUvarint(data[:], v)
+	return append(b, data[:n]...)
+}
+
+// DecodeUvarint decodes value encoded by EncodeUvarint before.
+// It returns the leftover un-decoded slice, decoded value if no error.
+func DecodeUvarint(b []byte) ([]byte, uint64, error) {
+	v, n := binary.Uvarint(b)
+	if n > 0 {
+		return b[n:], v, nil
+	}
+	if n < 0 {
+		return nil, 0, errors.New("value larger than 64 bits")
+	}
+	return nil, 0, errors.New("insufficient bytes to decode value")
+}