feat: implement Redis-based message bus and awareness management

- Added RedisMessageBus for message distribution using Redis Pub/Sub.
- Introduced LocalMessageBus as a no-op implementation for single-server mode.
- Created messagebus interface for abstraction of message distribution.
- Implemented awareness management methods: SetAwareness, GetAllAwareness, DeleteAwareness, and ClearAllAwareness.
- Added logger utility for structured logging with zap.
- Refactored SniffYjsClientIDs and MakeYjsDeleteMessage functions for improved readability.

backend/internal/hub/yjs_protocol.go

@@ -8,92 +8,106 @@ import (
 // data: 前端发来的 []byte
 // return: map[clientID]clock
 func SniffYjsClientIDs(data []byte) map[uint64]uint64 {
-    // 简单的防御：如果不是 Type 1 (Awareness) 消息，直接忽略
-    if len(data) < 2 || data[0] != 1 {
-        return nil
-    }
+	// 简单的防御：如果不是 Type 1 (Awareness) 消息，直接忽略
+	if len(data) < 2 || data[0] != 1 {
+		return nil
+	}
 
-    result := make(map[uint64]uint64)
-    offset := 1 // 跳过 [0] MessageType
+	result := make(map[uint64]uint64)
+	offset := 1 // 跳过 [0] MessageType
 
-    // 读取总长度 (跳过)
-    _, n := binary.Uvarint(data[offset:])
-    if n <= 0 { return nil }
-    offset += n
+	// 读取总长度 (跳过)
+	_, n := binary.Uvarint(data[offset:])
+	if n <= 0 {
+		return nil
+	}
+	offset += n
 
-    // 读取 Count (包含几个客户端的信息)
-    count, n := binary.Uvarint(data[offset:])
-    if n <= 0 { return nil }
-    offset += n
+	// 读取 Count (包含几个客户端的信息)
+	count, n := binary.Uvarint(data[offset:])
+	if n <= 0 {
+		return nil
+	}
+	offset += n
 
-    // 循环读取每个客户端的信息
-    for i := 0; i < int(count); i++ {
-        if offset >= len(data) { break }
+	// 循环读取每个客户端的信息
+	for i := 0; i < int(count); i++ {
+		if offset >= len(data) {
+			break
+		}
 
-        // 1. 读取 ClientID
-        id, n := binary.Uvarint(data[offset:])
-        if n <= 0 { break }
-        offset += n
+		// 1. 读取 ClientID
+		id, n := binary.Uvarint(data[offset:])
+		if n <= 0 {
+			break
+		}
+		offset += n
 
-        // 2. 读取 Clock (现在我们需要保存它！)
-        clock, n := binary.Uvarint(data[offset:])
-        if n <= 0 { break }
-        offset += n
+		// 2. 读取 Clock (现在我们需要保存它！)
+		clock, n := binary.Uvarint(data[offset:])
+		if n <= 0 {
+			break
+		}
+		offset += n
 
-        // 保存 clientID -> clock
-        result[id] = clock
+		// 保存 clientID -> clock
+		result[id] = clock
 
-        // 3. 跳过 JSON String
-        if offset >= len(data) { break }
-        strLen, n := binary.Uvarint(data[offset:])
-        if n <= 0 { break }
-        offset += n
+		// 3. 跳过 JSON String
+		if offset >= len(data) {
+			break
+		}
+		strLen, n := binary.Uvarint(data[offset:])
+		if n <= 0 {
+			break
+		}
+		offset += n
 
-        // 跳过具体字符串内容
-        offset += int(strLen)
-    }
+		// 跳过具体字符串内容
+		offset += int(strLen)
+	}
 
-    return result
+	return result
 }
 
 // 这个函数用来伪造一条"删除消息"
 // 输入：clientClocks map[clientID]clock - 要删除的 ClientID 及其最后已知的 clock 值
 // 输出：可以广播给前端的 []byte
 func MakeYjsDeleteMessage(clientClocks map[uint64]uint64) []byte {
-    if len(clientClocks) == 0 {
-        return nil
-    }
+	if len(clientClocks) == 0 {
+		return nil
+	}
 
-    // 构造 Payload (负载)
-    // 格式: [Count] [ID] [Clock] [StringLen] [String] ...
-    payload := make([]byte, 0)
+	// 构造 Payload (负载)
+	// 格式: [Count] [ID] [Clock] [StringLen] [String] ...
+	payload := make([]byte, 0)
 
-    // 写入 Count (变长整数)
-    buf := make([]byte, 10)
-    n := binary.PutUvarint(buf, uint64(len(clientClocks)))
-    payload = append(payload, buf[:n]...)
+	// 写入 Count (变长整数)
+	buf := make([]byte, 10)
+	n := binary.PutUvarint(buf, uint64(len(clientClocks)))
+	payload = append(payload, buf[:n]...)
 
-    for id, clock := range clientClocks {
-        // ClientID
-        n = binary.PutUvarint(buf, id)
-        payload = append(payload, buf[:n]...)
-        // Clock: 必须使用 clock + 1，这样 Yjs 才会接受这个更新！
-        n = binary.PutUvarint(buf, clock+1)
-        payload = append(payload, buf[:n]...)
-        // String Length (填 4，因为 "null" 长度是 4)
-        n = binary.PutUvarint(buf, 4)
-        payload = append(payload, buf[:n]...)
-        // String Content (这里是关键：null 代表删除用户)
-        payload = append(payload, []byte("null")...)
-    }
+	for id, clock := range clientClocks {
+		// ClientID
+		n = binary.PutUvarint(buf, id)
+		payload = append(payload, buf[:n]...)
+		// Clock: 必须使用 clock + 1，这样 Yjs 才会接受这个更新！
+		n = binary.PutUvarint(buf, clock+1)
+		payload = append(payload, buf[:n]...)
+		// String Length (填 4，因为 "null" 长度是 4)
+		n = binary.PutUvarint(buf, 4)
+		payload = append(payload, buf[:n]...)
+		// String Content (这里是关键：null 代表删除用户)
+		payload = append(payload, []byte("null")...)
+	}
 
-    // 构造最终消息: [Type=1] [PayloadLength] [Payload]
-    finalMsg := make([]byte, 0)
-    finalMsg = append(finalMsg, 1) // Type 1
+	// 构造最终消息: [Type=1] [PayloadLength] [Payload]
+	finalMsg := make([]byte, 0)
+	finalMsg = append(finalMsg, 1) // Type 1
 
-    n = binary.PutUvarint(buf, uint64(len(payload)))
-    finalMsg = append(finalMsg, buf[:n]...) // Length
-    finalMsg = append(finalMsg, payload...) // Body
+	n = binary.PutUvarint(buf, uint64(len(payload)))
+	finalMsg = append(finalMsg, buf[:n]...) // Length
+	finalMsg = append(finalMsg, payload...) // Body
 
-    return finalMsg
-}
+	return finalMsg
+}