Make struct tevent_req opaque

Move struct tevent_req in tevent_internal, and ad getters and setters
for private data and the callback function.
This patch also renames 'private_state' into 'data'. What is held in this
pointer is in fact data and not a state like enum tevent_req_state.
Calling it 'state' is confusing.

The functions addedd are:
tevent_req_set_callback() - sets req->async.fn and req->async.private_data
tevent_req_set_print_fn() - sets req->private_print
tevent_req_callback_data() - gets req->async.private_data
tevent_req_data() - gets rea->data

This way it is much simpler to keep API/ABI compatibility in the future.

1 files changed, 13 insertions, 89 deletions

diff --git a/lib/tevent/tevent.h b/lib/tevent/tevent.h
index 8c119ffb8ed..5089d18ec21 100644
--- a/lib/tevent/tevent.h
+++ b/lib/tevent/tevent.h
@@ -183,98 +183,22 @@ enum tevent_req_state {
  * finished. This can happen while the completion function is called.
  */
 
-struct tevent_req {
-	/**
-	 * @brief What to do on completion
-	 *
-	 * This is used for the user of an async request, fn is called when
-	 * the request completes, either successfully or with an error.
-	 */
-	struct {
-		/**
-		 * @brief Completion function
-		 * Completion function, to be filled by the API user
-		 */
-		void (*fn)(struct tevent_req *);
-		/**
-		 * @brief Private data for the completion function
-		 */
-		void *private_data;
-	} async;
+struct tevent_req;
 
-	/**
-	 * @brief Private state pointer for the actual implementation
-	 *
-	 * The implementation doing the work for the async request needs a
-	 * current state like for example a fd event. The user of an async
-	 * request should not touch this.
-	 */
-	void *private_state;
+typedef void (*tevent_req_fn)(struct tevent_req *);
 
-	/**
-	 * @brief A function to overwrite the default print function
-	 *
-	 * The implementation doing the work may want to imeplement a
-	 * custom function to print the text representation of the async
-	 * request.
-	 */
-	char *(*private_print)(struct tevent_req *req, TALLOC_CTX *mem_ctx);
+void tevent_req_set_callback(struct tevent_req *req, tevent_req_fn fn, void *pvt);
+void *_tevent_req_callback_data(struct tevent_req *req);
+void *_tevent_req_data(struct tevent_req *req);
 
-	/**
-	 * @brief Internal state of the request
-	 *
-	 * Callers should only access this via functions and never directly.
-	 */
-	struct {
-		/**
-		 * @brief The talloc type of the private_state pointer
-		 *
-		 * This is filled by the tevent_req_create() macro.
-		 *
-		 * This for debugging only.
-		 */
-		const char *private_type;
-
-		/**
-		 * @brief The location where the request was created
-		 *
-		 * This uses the __location__ macro via the tevent_req_create()
-		 * macro.
-		 *
-		 * This for debugging only.
-		 */
-		const char *location;
-
-		/**
-		 * @brief The external state - will be queried by the caller
-		 *
-		 * While the async request is being processed, state will remain in
-		 * TEVENT_REQ_IN_PROGRESS. A request is finished if
-		 * req->state>=TEVENT_REQ_DONE.
-		 */
-		enum tevent_req_state state;
-
-		/**
-		 * @brief status code when finished
-		 *
-		 * This status can be queried in the async completion function. It
-		 * will be set to 0 when everything went fine.
-		 */
-		uint64_t error;
-
-		/**
-		 * @brief the timer event if tevent_req_post was used
-		 *
-		 */
-		struct tevent_timer *trigger;
-
-		/**
-		 * @brief the timer event if tevent_req_set_timeout was used
-		 *
-		 */
-		struct tevent_timer *timer;
-	} internal;
-};
+#define tevent_req_callback_data(_req, _type) \
+	talloc_get_type_abort(_tevent_req_callback_data(_req), _type)
+#define tevent_req_data(_req, _type) \
+	talloc_get_type_abort(_tevent_req_data(_req), _type)
+
+typedef char *(*tevent_req_print_fn)(struct tevent_req *, TALLOC_CTX *);
+
+void tevent_req_set_print_fn(struct tevent_req *req, tevent_req_print_fn fn);
 
 char *tevent_req_default_print(struct tevent_req *req, TALLOC_CTX *mem_ctx);