1 files changed, 119 insertions, 0 deletions
diff --git a/ethutil/bytes.go b/ethutil/bytes.go
new file mode 100644
index 000000000..5e3ee4a6f
--- /dev/null
+++ b/ethutil/bytes.go
@@ -0,0 +1,119 @@
+package ethutil
+
+import (
+	"bytes"
+	"encoding/binary"
+	"fmt"
+	"math/big"
+	"strings"
+)
+
+// Number to bytes
+//
+// Returns the number in bytes with the specified base
+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):]
+}
+
+// Bytes to number
+//
+// Attempts to cast a byte slice to a unsigned integer
+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 int
+//
+// Read a variable length number in big endian byte order
+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
+}
+
+// Binary length
+//
+// Returns the true binary length of the given number
+func BinaryLength(num int) int {
+	if num == 0 {
+		return 0
+	}
+
+	return 1 + BinaryLength(num>>8)
+}
+
+// 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
+}
+
+func IsHex(str string) bool {
+	l := len(str)
+	return l >= 4 && l%2 == 0 && str[0:2] == "0x"
+}
+
+func StringToByteFunc(str string, cb func(str string) []byte) (ret []byte) {
+	if len(str) > 1 && str[0:2] == "0x" && !strings.Contains(str, "\n") {
+		ret = FromHex(str[2:])
+	} else {
+		ret = cb(str)
+	}
+
+	return
+}
+
+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:] == "\"" {
+		d.SetBytes([]byte(data[1 : len(data)-1]))
+	} else if len(data) > 1 && data[:2] == "0x" {
+		d.SetBytes(FromHex(data[2:]))
+	} else {
+		d.SetString(data, 0)
+	}
+
+	return BigToBytes(d, 256)
+}