add dummy response::check_chancel() API to ipc, stream, and loopback …

…responses

include/tateyama/api/server/response.h

@@ -52,11 +52,17 @@ class response {
     virtual void session_id(std::size_t id) = 0;
 
     /**
-     * @brief report error with diagnostics information
+     * @brief report error with diagnostics information.
      * @param record the diagnostic record to report
      * @details report an error with diagnostics information for client. When this function is called, no more
      * body_head() or body() is expected to be called.
      * @attention this function is not thread-safe and should be called from single thread at a time.
+     * @attention After calling this for cancelling the current job, the job must not use the related resources.
+     *    This includes the below:
+     *
+     *    - request object
+     *    - response object
+     *    - resources underlying session context
      */
     virtual void error(proto::diagnostics::Record const& record) = 0;
 
@@ -105,6 +111,17 @@ class response {
      */
     virtual status release_channel(data_channel& ch) = 0;
 
+    /**
+     * @brief returns whether or not cancellation was requested to the corresponding job.
+     * @details To cancel the job, first you must shutdown the operation of this job, and then call error().
+     *    At this time, `OPERATION_CANCELED` is recommended as the diagnostic code for cancelling the job.
+     *    Or, to avoid inappropriate conditions, you can omit the cancel request and complete the job.
+     * @return true if the job is calling for a cancel
+     * @return false otherwise
+     * @see error()
+     */
+    [[nodiscard]] virtual bool check_cancel() const = 0;
+
 };
 
 }

src/tateyama/endpoint/ipc/ipc_response.h

@@ -101,6 +101,10 @@ class ipc_response : public tateyama::api::server::response {
         session_id_ = id;
     }
 
+    [[nodiscard]] bool check_cancel() const override {
+        return false;
+    }
+
 private:
     std::shared_ptr<server_wire_container> server_wire_;
     std::size_t index_;

src/tateyama/endpoint/loopback/loopback_response.h

@@ -84,6 +84,13 @@ class loopback_response: public tateyama::api::server::response {
      */
     tateyama::status release_channel(tateyama::api::server::data_channel &ch) override;
 
+    /**
+     * @see tateyama::server::response::check_cancel()
+     */
+    [[nodiscard]] bool check_cancel() const override {
+        return false;
+    }
+
     // just for unit test
     [[nodiscard]] std::map<std::string, std::vector<std::string>, std::less<>> const& all_committed_data() const noexcept {
         return committed_data_map_;

src/tateyama/endpoint/stream/stream_response.h

@@ -90,6 +90,11 @@ class stream_response : public tateyama::api::server::response {
     void session_id(std::size_t id) override {
         session_id_ = id;
     }
+
+    [[nodiscard]] bool check_cancel() const override {
+        return false;
+    }
+
 private:
     std::shared_ptr<stream_socket> stream_;
     std::uint16_t index_;

test/tateyama/datastore/datastore_test.cpp

@@ -95,6 +95,7 @@ class datastore_test :
         void error(proto::diagnostics::Record const& record) override {}
         status acquire_channel(std::string_view name, std::shared_ptr<api::server::data_channel>& ch) override { return status::ok; }
         status release_channel(api::server::data_channel& ch) override { return status::ok; }
+        bool check_cancel() const override { return false; }
 
         std::size_t session_id_{};
         std::string body_{};

test/tateyama/framework/router_test.cpp

@@ -122,6 +122,7 @@ class router_test :
         }
         status acquire_channel(std::string_view name, std::shared_ptr<api::server::data_channel>& ch) override { return status::ok; }
         status release_channel(api::server::data_channel& ch) override { return status::ok; }
+        bool check_cancel() const override { return false; }
 
         std::size_t session_id_{};
         std::string body_{};

test/tateyama/session/session_test.cpp

@@ -96,6 +96,7 @@ class session_test :
         void error(proto::diagnostics::Record const& record) override {}
         status acquire_channel(std::string_view name, std::shared_ptr<api::server::data_channel>& ch) override { return status::ok; }
         status release_channel(api::server::data_channel& ch) override { return status::ok; }
+        bool check_cancel() const override { return false; }
 
         std::size_t session_id_{};
         std::string body_{};