Hprose 中间件 - 执行顺序

Hprose 中间件的顺序执行是按照添加的前后顺序执行的，假设添加的中间件处理器分别为：handler1, handler2 … handlerN，那幺执行顺序就是 handler1, handler2 … handlerN。

不同类型的 Hprose 中间件和 Hprose 其它过程的执行流程如下图所示：

+------------------------------------------------------------------+
|                 +-----------------batch invoke----------------+  |
|       +------+  | +-----+   +------+       +------+   +-----+ |  |
|       |invoke|  | |begin|   |invoke|  ...  |invoke|   | end | |  |
|       +------+  | +-----+   +------+       +------+   +-----+ |  |
|           ^     +---------------------------------------------+  |
|           |                            ^                         |
|           |                            |                         |
|           v                            v                         |
| +-------------------+        +------------------+                |
| | invoke middleware |        | batch middleware |                |
| +-------------------+        +------------------+                |
|           ^                            ^                         |
|           |     +---------------+      |                         |
|           +---->| encode/decode |<-----+                         |
|                 +---------------+                                |
|                         ^                                        |
|                         |                                        |
|                         v                                        |
|           +--------------------------+                           |
|           | before filter middleware |                           |
|           +--------------------------+                           |
|                         ^                                        |
|                         |       _  _ ___  ____ ____ ____ ____    |
|                         v       |__| |__] |__/ |  | [__  |___    |
|                    +--------+   |  | |    |  \ |__| ___] |___    |
|                    | filter |                                    |
|                    +--------+     ____ _    _ ____ _  _ ___      |
|                         ^         |    |    | |___ |\ |  |       |
|                         |         |___ |___ | |___ | \|  |       |
|                         v                                        |
|            +-------------------------+                           |
|            | after filter middleware |                           |
|            +-------------------------+                           |
+------------------------------------------------------------------+
                                  ^                                 
                                  |                                 
                                  |                                 
                                  v                                 
+------------------------------------------------------------------+
|           +--------------------------+                           |
|           | before filter middleware |                           |
|           +--------------------------+                           |
|                         ^                                        |
|                         |        _  _ ___  ____ ____ ____ ____   |
|                         v        |__| |__] |__/ |  | [__  |___   |
|                    +--------+    |  | |    |  \ |__| ___] |___   |
|                    | filter |                                    |
|                    +--------+    ____ ____ ____ _  _ ____ ____   |
|                         ^        [__  |___ |__/ |  | |___ |__/   |
|                         |        ___] |___ |  \  \/  |___ |  \   |
|                         v                                        |
|            +-------------------------+                           |
|            | after filter middleware |                           |
|            +-------------------------+                           |
|                         ^                                        |
|                         |                                        |
|                         v                                        |
|                 +---------------+                                |
|    +----------->| encode/decode |<---------------------+         |
|    |            +---------------+                      |         |
|    |                    |                              |         |
|    |                    |                              |         |
|    |                    v                              |         |
|    |            +---------------+                      |         |
|    |            | before invoke |-------------+        |         |
|    |            +---------------+             |        |         |
|    |                    |                     |        |         |
|    |                    |                     |        |         |
|    |                    v                     v        |         |
|    |          +-------------------+    +------------+  |         |
|    |          | invoke middleware |--->| send error |--+         |
|    |          +-------------------+    +------------+            |
|    |                    |                     ^                  |
|    |                    |                     |                  |
|    |                    v                     |                  |
|    |            +--------------+              |                  |
|    |            | after invoke |--------------+                  |
|    |            +--------------+                                 |
|    |                    |                                        |
|    |                    |                                        |
|    +--------------------+                                        |
+------------------------------------------------------------------+