翻出历史项目，先上传，未测试（MQTT3.1.1已经支持）

topic.go

@@ -0,0 +1,70 @@
+package beeq
+
+import (
+	"bytes"
+	"errors"
+	"fmt"
+)
+
+func ValidTopic(topic []byte) error {
+	//no + #
+	if bytes.ContainsAny(topic, "+#") {
+		return fmt.Errorf("+ # is not valid (%s)", string(topic))
+	}
+	//no //
+	if bytes.Contains(topic, []byte("//")) {
+		return fmt.Errorf("// is not valid (%s)", string(topic))
+	}
+	return nil
+}
+
+func ValidSubscribe(topic []byte) error {
+	if len(topic) == 0 {
+		return errors.New("Blank topic")
+	}
+	topics := bytes.Split(topic, []byte("/"))
+	if len(topics[0]) == 0 {
+		topics[0] = []byte("/")
+	}
+	for i, tt := range topics {
+		l := len(tt)
+		if l == 0 {
+			return errors.New("inner blank")
+		}
+		if l == 1 && tt[0] == '#' && i < len(topics)-1 {
+			return errors.New("# must be the last one")
+		}
+		if l > 1 && bytes.ContainsAny(tt, "+#") {
+			return errors.New("+ # is alone")
+		}
+	}
+	return nil
+}
+
+func MatchSubscribe(topic []byte, sub []byte) bool {
+	i, j := 0, 0
+	for i < len(topic) && j < len(sub) {
+		t, s := topic[i], sub[j]
+		if s == '#' {
+			return true
+		} else if s == '+' {
+			for t != '/' {
+				i++
+				t = topic[i]
+			}
+			j++ // skip /
+		} else if s != t {
+			break
+		}
+		// else s==t
+		i++
+		j++
+	}
+
+	//Just match
+	if i == len(topic) && j == len(sub) {
+		return true
+	}
+
+	return false
+}