move fundamental interfaces from vmess to common

common/protocol/id.go

@@ -0,0 +1,51 @@
+package protocol
+
+import (
+	"crypto/md5"
+	"errors"
+
+	"github.com/v2ray/v2ray-core/common/uuid"
+)
+
+const (
+	IDBytesLen = 16
+)
+
+var (
+	InvalidID = errors.New("Invalid ID.")
+)
+
+// The ID of en entity, in the form of an UUID.
+type ID struct {
+	uuid   *uuid.UUID
+	cmdKey [IDBytesLen]byte
+}
+
+func (this *ID) Equals(another *ID) bool {
+	return this.uuid.Equals(another.uuid)
+}
+
+func (this *ID) Bytes() []byte {
+	return this.uuid.Bytes()
+}
+
+func (this *ID) String() string {
+	return this.uuid.String()
+}
+
+func (this *ID) UUID() *uuid.UUID {
+	return this.uuid
+}
+
+func (v ID) CmdKey() []byte {
+	return v.cmdKey[:]
+}
+
+func NewID(uuid *uuid.UUID) *ID {
+	id := &ID{uuid: uuid}
+	md5hash := md5.New()
+	md5hash.Write(uuid.Bytes())
+	md5hash.Write([]byte("c48619fe-8f02-49e0-b9e9-edf763e17e21"))
+	md5hash.Sum(id.cmdKey[:0])
+	return id
+}