init: v1.0.0

sm/endian.go

@@ -0,0 +1,69 @@
+package sm
+
+import (
+	"encoding/binary"
+)
+
+// GM/T 0018中，bits等uint转为字节串时，没有规定大小端序列。这里可以设置按哪种端序进行处理。
+// 更新：从字符串转为struct时可以忽略端序，不管大小端，代码中分别进行如下判断。
+// 比如[]byte{00,01,00,00}. 小端序为0x00000100 = 256，大端序为0x00010000.
+// 可以根据上下文判断是否超过最大值而采用某种端序。
+
+type endian struct {
+	isBigEndian bool
+}
+
+func (e *endian) PutUint32(b []byte, v uint32) {
+	if e.isBigEndian {
+		binary.BigEndian.PutUint32(b, v)
+	} else {
+		binary.LittleEndian.PutUint32(b, v)
+	}
+}
+
+func (e *endian) Uint32(b []byte) uint32 {
+	if e.isBigEndian {
+		return binary.BigEndian.Uint32(b)
+	}
+	return binary.LittleEndian.Uint32(b)
+
+}
+
+var (
+	// Endian marshal时int类型的存储端序 - 默认为大端序
+	Endian = endian{true}
+)
+
+var callBackSetToBigEndian []func()
+var callBackSetToLittleEndian []func()
+var callBackSetToDefaultEndian []func()
+
+func RegisterCallBack(setToBigEndian, setToLittleEndian, setToDefaultEndian func()) {
+	callBackSetToBigEndian = append(callBackSetToBigEndian, setToBigEndian)
+	callBackSetToLittleEndian = append(callBackSetToLittleEndian, setToLittleEndian)
+	callBackSetToDefaultEndian = append(callBackSetToDefaultEndian, setToDefaultEndian)
+}
+
+// SetToBigEndian 将端序设置为大端序
+func SetToBigEndian() {
+	Endian.isBigEndian = true
+	for _, f := range callBackSetToBigEndian {
+		f()
+	}
+}
+
+// SetToLittleEndian 设置为小端序
+func SetToLittleEndian() {
+	Endian.isBigEndian = false
+	for _, f := range callBackSetToLittleEndian {
+		f()
+	}
+}
+
+// SetToDefaultEndian 恢复默认端序-大端
+func SetToDefaultEndian() {
+	Endian.isBigEndian = true
+	for _, f := range callBackSetToDefaultEndian {
+		f()
+	}
+}