字节数组与整数转换

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}))
+}

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
+}