diff --git a/bytesconv/byteconv_test.go b/bytesconv/byteconv_test.go new file mode 100644 index 0000000..bced062 --- /dev/null +++ b/bytesconv/byteconv_test.go @@ -0,0 +1,8 @@ +package bytesconv + +import "testing" + +func TestBytesToUint64(t *testing.T) { + t.Log(BigEndian.BytesToUInt64([]byte{0x88, 0x45})) + t.Log(LittleEndian.BytesToUInt64([]byte{0x88, 0x45})) +} diff --git a/bytesconv/bytesconv.go b/bytesconv/bytesconv.go new file mode 100644 index 0000000..12c813c --- /dev/null +++ b/bytesconv/bytesconv.go @@ -0,0 +1,54 @@ +package bytesconv + +import ( + "fmt" + "unsafe" +) + +// StringToBytes converts string to byte slice without a memory allocation. +func StringToBytes(s string) (b []byte) { + return *(*[]byte)(unsafe.Pointer( + &struct { + string + Cap int + }{s, len(s)}, + )) +} + +// BytesToString converts byte slice to string without a memory allocation. +func BytesToString(b []byte) string { + return *(*string)(unsafe.Pointer(&b)) +} + +type endian int + +const ( + BigEndian endian = iota + 1 + LittleEndian +) + +func (e endian) BytesToUInt64(data []byte) (uint64, error) { + if len(data) > 8 { + return 0, fmt.Errorf("bytes to uint64, bytes length is invaild") + } + + var ret uint64 + var len int = len(data) + + if e == BigEndian { + for i := 0; i < len; i++ { + ret = ret | (uint64(data[len-1-i]) << (i * 8)) + } + } else { + for i := 0; i < len; i++ { + ret = ret | (uint64(data[i]) << (i * 8)) + } + } + + return ret, nil +} + +func BytesToUInt64Big() { + // binary.BigEndian + // binary.LittleEndian +}