先看内存中的数据是否为空，不为空直接返回，为空查询redis，看redis中的数据是否为空，不为空直接返回，为空利用分布式锁查询mysql，查不到重新执行该流程，查到到内存和redis，然后返回数据。 帮我给以上逻辑生成个流程图

好的，以下是你所描述的逻辑的流程图：

+---------------------+                +----------------+
| Check if data exists|                |   Return data  |
+---------------------+                +----------------+
          |                                     |
          | Data exists in memory                |
          V                                     V
+---------------------+                +----------------+
|   Return data       |                |   Return data  |
+---------------------+                +----------------+
          |                                     |
          | Data not in memory, check redis      |
          V                                     V
+---------------------+                +----------------+
| Data exists in redis|                | Query MySQL   |
+---------------------+                +----------------+
          |                                     |
          | Data not in redis, lock and query     |
          V                                     V
+---------------------+                +----------------+
| Query MySQL success |                | Query failed,  |
|                     |----------------| retry the whole|
| Store in memory     |                |   process      |
| Store in redis      |                +----------------+
+---------------------+