bytes.go 4.48 KB
Newer Older
obscuren's avatar
obscuren committed
1
package common
obscuren's avatar
obscuren committed
2 3 4 5

import (
	"bytes"
	"encoding/binary"
6
	"encoding/hex"
obscuren's avatar
obscuren committed
7
	"fmt"
obscuren's avatar
obscuren committed
8
	"math/big"
9
	"strings"
obscuren's avatar
obscuren committed
10 11
)

12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33
func ToHex(b []byte) string {
	hex := Bytes2Hex(b)
	// Prefer output of "0x0" instead of "0x"
	if len(hex) == 0 {
		hex = "0"
	}
	return "0x" + hex
}

func FromHex(s string) []byte {
	if len(s) > 1 {
		if s[0:2] == "0x" {
			s = s[2:]
		}
		if len(s)%2 == 1 {
			s = "0" + s
		}
		return Hex2Bytes(s)
	}
	return nil
}

34 35 36 37 38 39 40 41 42
type Bytes []byte

func (self Bytes) String() string {
	return string(self)
}

func DeleteFromByteSlice(s [][]byte, hash []byte) [][]byte {
	for i, h := range s {
		if bytes.Compare(h, hash) == 0 {
obscuren's avatar
obscuren committed
43
			return append(s[:i:i], s[i+1:]...)
44 45 46 47 48 49
		}
	}

	return s
}

50 51 52
// Number to bytes
//
// Returns the number in bytes with the specified base
obscuren's avatar
obscuren committed
53 54 55 56 57 58 59 60 61 62
func NumberToBytes(num interface{}, bits int) []byte {
	buf := new(bytes.Buffer)
	err := binary.Write(buf, binary.BigEndian, num)
	if err != nil {
		fmt.Println("NumberToBytes failed:", err)
	}

	return buf.Bytes()[buf.Len()-(bits/8):]
}

63 64 65
// Bytes to number
//
// Attempts to cast a byte slice to a unsigned integer
obscuren's avatar
obscuren committed
66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81
func BytesToNumber(b []byte) uint64 {
	var number uint64

	// Make sure the buffer is 64bits
	data := make([]byte, 8)
	data = append(data[:len(b)], b...)

	buf := bytes.NewReader(data)
	err := binary.Read(buf, binary.BigEndian, &number)
	if err != nil {
		fmt.Println("BytesToNumber failed:", err)
	}

	return number
}

82 83 84
// Read variable int
//
// Read a variable length number in big endian byte order
85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108
func ReadVarInt(buff []byte) (ret uint64) {
	switch l := len(buff); {
	case l > 4:
		d := LeftPadBytes(buff, 8)
		binary.Read(bytes.NewReader(d), binary.BigEndian, &ret)
	case l > 2:
		var num uint32
		d := LeftPadBytes(buff, 4)
		binary.Read(bytes.NewReader(d), binary.BigEndian, &num)
		ret = uint64(num)
	case l > 1:
		var num uint16
		d := LeftPadBytes(buff, 2)
		binary.Read(bytes.NewReader(d), binary.BigEndian, &num)
		ret = uint64(num)
	default:
		var num uint8
		binary.Read(bytes.NewReader(buff), binary.BigEndian, &num)
		ret = uint64(num)
	}

	return
}

109 110 111
// Binary length
//
// Returns the true binary length of the given number
obscuren's avatar
obscuren committed
112 113 114 115 116 117 118
func BinaryLength(num int) int {
	if num == 0 {
		return 0
	}

	return 1 + BinaryLength(num>>8)
}
obscuren's avatar
obscuren committed
119 120 121 122 123 124 125 126 127 128

// Copy bytes
//
// Returns an exact copy of the provided bytes
func CopyBytes(b []byte) (copiedBytes []byte) {
	copiedBytes = make([]byte, len(b))
	copy(copiedBytes, b)

	return
}
129 130 131 132 133

func IsHex(str string) bool {
	l := len(str)
	return l >= 4 && l%2 == 0 && str[0:2] == "0x"
}
obscuren's avatar
obscuren committed
134

135 136 137 138 139 140
func Bytes2Hex(d []byte) string {
	return hex.EncodeToString(d)
}

func Hex2Bytes(str string) []byte {
	h, _ := hex.DecodeString(str)
obscuren's avatar
obscuren committed
141

142 143 144
	return h
}

obscuren's avatar
obscuren committed
145
func StringToByteFunc(str string, cb func(str string) []byte) (ret []byte) {
146
	if len(str) > 1 && str[0:2] == "0x" && !strings.Contains(str, "\n") {
147
		ret = Hex2Bytes(str[2:])
obscuren's avatar
obscuren committed
148 149 150 151 152 153
	} else {
		ret = cb(str)
	}

	return
}
obscuren's avatar
obscuren committed
154 155 156 157 158 159 160 161

func FormatData(data string) []byte {
	if len(data) == 0 {
		return nil
	}
	// Simple stupid
	d := new(big.Int)
	if data[0:1] == "\"" && data[len(data)-1:] == "\"" {
obscuren's avatar
obscuren committed
162
		return RightPadBytes([]byte(data[1:len(data)-1]), 32)
obscuren's avatar
obscuren committed
163
	} else if len(data) > 1 && data[:2] == "0x" {
164
		d.SetBytes(Hex2Bytes(data[2:]))
obscuren's avatar
obscuren committed
165 166 167 168 169 170
	} else {
		d.SetString(data, 0)
	}

	return BigToBytes(d, 256)
}
171

obscuren's avatar
obscuren committed
172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191
func ParseData(data ...interface{}) (ret []byte) {
	for _, item := range data {
		switch t := item.(type) {
		case string:
			var str []byte
			if IsHex(t) {
				str = Hex2Bytes(t[2:])
			} else {
				str = []byte(t)
			}

			ret = append(ret, RightPadBytes(str, 32)...)
		case []byte:
			ret = append(ret, LeftPadBytes(t, 32)...)
		}
	}

	return
}

obscuren's avatar
obscuren committed
192
func RightPadBytes(slice []byte, l int) []byte {
obscuren's avatar
obscuren committed
193
	if l < len(slice) {
194 195 196 197 198 199 200 201 202
		return slice
	}

	padded := make([]byte, l)
	copy(padded[0:len(slice)], slice)

	return padded
}

obscuren's avatar
obscuren committed
203
func LeftPadBytes(slice []byte, l int) []byte {
obscuren's avatar
obscuren committed
204
	if l < len(slice) {
205 206 207 208 209 210 211 212
		return slice
	}

	padded := make([]byte, l)
	copy(padded[l-len(slice):], slice)

	return padded
}
213

obscuren's avatar
obscuren committed
214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235
func LeftPadString(str string, l int) string {
	if l < len(str) {
		return str
	}

	zeros := Bytes2Hex(make([]byte, (l-len(str))/2))

	return zeros + str

}

func RightPadString(str string, l int) string {
	if l < len(str) {
		return str
	}

	zeros := Bytes2Hex(make([]byte, (l-len(str))/2))

	return str + zeros

}

obscuren's avatar
obscuren committed
236
func ToAddress(slice []byte) (addr []byte) {
237
	if len(slice) < 20 {
obscuren's avatar
obscuren committed
238
		addr = LeftPadBytes(slice, 20)
239
	} else if len(slice) > 20 {
obscuren's avatar
obscuren committed
240 241 242
		addr = slice[len(slice)-20:]
	} else {
		addr = slice
243 244
	}

obscuren's avatar
obscuren committed
245 246 247
	addr = CopyBytes(addr)

	return
248
}
obscuren's avatar
obscuren committed
249 250 251 252 253 254 255 256

func ByteSliceToInterface(slice [][]byte) (ret []interface{}) {
	for _, i := range slice {
		ret = append(ret, i)
	}

	return
}