From f6d1bfe45bf3709d7bad40bf563b5c09228622e3 Mon Sep 17 00:00:00 2001 From: obscuren Date: Fri, 14 Feb 2014 23:56:09 +0100 Subject: The great merge --- ethutil/bytes.go | 64 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 64 insertions(+) create mode 100644 ethutil/bytes.go (limited to 'ethutil/bytes.go') diff --git a/ethutil/bytes.go b/ethutil/bytes.go new file mode 100644 index 000000000..40903a5f1 --- /dev/null +++ b/ethutil/bytes.go @@ -0,0 +1,64 @@ +package ethutil + +import ( + "bytes" + "encoding/binary" + "fmt" +) + +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):] +} + +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 +} + +// Read variable integer in big endian +func ReadVarint(reader *bytes.Reader) (ret uint64) { + if reader.Len() == 8 { + var num uint64 + binary.Read(reader, binary.BigEndian, &num) + ret = uint64(num) + } else if reader.Len() == 4 { + var num uint32 + binary.Read(reader, binary.BigEndian, &num) + ret = uint64(num) + } else if reader.Len() == 2 { + var num uint16 + binary.Read(reader, binary.BigEndian, &num) + ret = uint64(num) + } else { + var num uint8 + binary.Read(reader, binary.BigEndian, &num) + ret = uint64(num) + } + + return ret +} + +func BinaryLength(num int) int { + if num == 0 { + return 0 + } + + return 1 + BinaryLength(num>>8) +} -- cgit v1.2.3