diff --git a/utils/bytes.go b/utils/bytes.go new file mode 100644 index 000000000..3ae0c652f --- /dev/null +++ b/utils/bytes.go @@ -0,0 +1,112 @@ +package utils + +import "encoding/hex" + +// ToHex returns the hex representation of b, prefixed with '0x'. +// For empty slices, the return value is "0x0". +// +// Deprecated: use hexutil.Encode instead. +func ToHex(b []byte) string { + hex := Bytes2Hex(b) + if len(hex) == 0 { + hex = "0" + } + return "0x" + hex +} + +// FromHex returns the bytes represented by the hexadecimal string s. +// s may be prefixed with "0x". +func FromHex(s string) []byte { + if len(s) > 1 { + if s[0:2] == "0x" || s[0:2] == "0X" { + s = s[2:] + } + } + if len(s)%2 == 1 { + s = "0" + s + } + return Hex2Bytes(s) +} + +// CopyBytes returns an exact copy of the provided bytes. +func CopyBytes(b []byte) (copiedBytes []byte) { + if b == nil { + return nil + } + copiedBytes = make([]byte, len(b)) + copy(copiedBytes, b) + + return +} + +// hasHexPrefix validates str begins with '0x' or '0X'. +func hasHexPrefix(str string) bool { + return len(str) >= 2 && str[0] == '0' && (str[1] == 'x' || str[1] == 'X') +} + +// isHexCharacter returns bool of c being a valid hexadecimal. +func isHexCharacter(c byte) bool { + return ('0' <= c && c <= '9') || ('a' <= c && c <= 'f') || ('A' <= c && c <= 'F') +} + +// isHex validates whether each byte is valid hexadecimal string. +func isHex(str string) bool { + if len(str)%2 != 0 { + return false + } + for _, c := range []byte(str) { + if !isHexCharacter(c) { + return false + } + } + return true +} + +// Bytes2Hex returns the hexadecimal encoding of d. +func Bytes2Hex(d []byte) string { + return hex.EncodeToString(d) +} + +// Hex2Bytes returns the bytes represented by the hexadecimal string str. +func Hex2Bytes(str string) []byte { + h, _ := hex.DecodeString(str) + return h +} + +// Hex2BytesFixed returns bytes of a specified fixed length flen. +func Hex2BytesFixed(str string, flen int) []byte { + h, _ := hex.DecodeString(str) + if len(h) == flen { + return h + } + if len(h) > flen { + return h[len(h)-flen:] + } + hh := make([]byte, flen) + copy(hh[flen-len(h):flen], h[:]) + return hh +} + +// RightPadBytes zero-pads slice to the right up to length l. +func RightPadBytes(slice []byte, l int) []byte { + if l <= len(slice) { + return slice + } + + padded := make([]byte, l) + copy(padded, slice) + + return padded +} + +// LeftPadBytes zero-pads slice to the left up to length l. +func LeftPadBytes(slice []byte, l int) []byte { + if l <= len(slice) { + return slice + } + + padded := make([]byte, l) + copy(padded[l-len(slice):], slice) + + return padded +}