91 lines
1.8 KiB
Go
91 lines
1.8 KiB
Go
package ethutil
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import (
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"bytes"
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"encoding/binary"
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"fmt"
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)
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// Number to bytes
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//
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// Returns the number in bytes with the specified base
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func NumberToBytes(num interface{}, bits int) []byte {
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buf := new(bytes.Buffer)
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err := binary.Write(buf, binary.BigEndian, num)
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if err != nil {
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fmt.Println("NumberToBytes failed:", err)
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}
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return buf.Bytes()[buf.Len()-(bits/8):]
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}
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// Bytes to number
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//
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// Attempts to cast a byte slice to a unsigned integer
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func BytesToNumber(b []byte) uint64 {
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var number uint64
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// Make sure the buffer is 64bits
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data := make([]byte, 8)
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data = append(data[:len(b)], b...)
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buf := bytes.NewReader(data)
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err := binary.Read(buf, binary.BigEndian, &number)
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if err != nil {
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fmt.Println("BytesToNumber failed:", err)
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}
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return number
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}
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// Read variable int
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//
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// Read a variable length number in big endian byte order
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func ReadVarint(reader *bytes.Reader) (ret uint64) {
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if reader.Len() == 8 {
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var num uint64
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binary.Read(reader, binary.BigEndian, &num)
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ret = uint64(num)
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} else if reader.Len() == 4 {
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var num uint32
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binary.Read(reader, binary.BigEndian, &num)
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ret = uint64(num)
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} else if reader.Len() == 2 {
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var num uint16
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binary.Read(reader, binary.BigEndian, &num)
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ret = uint64(num)
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} else {
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var num uint8
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binary.Read(reader, binary.BigEndian, &num)
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ret = uint64(num)
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}
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return ret
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}
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// Binary length
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//
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// Returns the true binary length of the given number
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func BinaryLength(num int) int {
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if num == 0 {
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return 0
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}
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return 1 + BinaryLength(num>>8)
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}
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// Copy bytes
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//
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// Returns an exact copy of the provided bytes
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func CopyBytes(b []byte) (copiedBytes []byte) {
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copiedBytes = make([]byte, len(b))
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copy(copiedBytes, b)
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return
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}
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func IsHex(str string) bool {
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l := len(str)
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return l >= 4 && l%2 == 0 && str[0:2] == "0x"
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}
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