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
+}