Update doxygen documentation.

[paraslash.git] / afs.c

diff --git a/afs.c b/afs.c
index 2260344e873ac67ef730d75b21173776b2ec70ee..d7c1ecfded5adf25c0a9c81ed86667c614d4f66e 100644 (file)
--- a/afs.c
+++ b/afs.c
@@ -145,11 +145,20 @@ struct callback_result {
  *
  * \param f The function to be called.
  * \param query Pointer to arbitrary data for the callback.
- * \param result Callback result will be stored here.
+ * \param result_handler Called for each shm area sent by the callback.
+ * \param private_result_data Passed verbatim to \a result_handler.
  *
- * This function creates a shared memory area, copies the buffer pointed to by
- * \a query to that area and notifies the afs process that \a f should be
- * called ASAP.
+ * This function creates a socket for communication with the afs process and a
+ * shared memory area (sma) to which the buffer pointed to by \a query is
+ * copied.  It then notifies the afs process that the callback function \a f
+ * should be executed by sending the shared memory identifier (shmid) to the
+ * socket.
+
+ * If the callback produces a result, it sends any number of shared memory
+ * identifiers back via the socket. For each such identifier received, \a
+ * result_handler is called. The contents of the sma identified by the received
+ * shmid are passed to that function as an osl object. The private_result_data
+ * pointer is passed as the second argument to \a result_handler.
  *
  * \return Negative, on errors, the return value of the callback function
  * otherwise.
@@ -245,7 +254,8 @@ out:
  * \param argc Argument count.
  * \param argv Standard argument vector.
  * \param f The callback function.
- * \param result The result of the query is stored here.
+ * \param result_handler See \ref send_callback_request.
+ * \param private_result_data See \ref send_callback_request.
  *
  * Some commands have a couple of options that are parsed in child context for
  * syntactic correctness and are stored in a special options structure for that
@@ -287,7 +297,8 @@ int send_option_arg_callback_request(struct osl_object *options,
  * \param argc The same meaning as in send_option_arg_callback_request().
  * \param argv The same meaning as in send_option_arg_callback_request().
  * \param f The same meaning as in send_option_arg_callback_request().
- * \param result The same meaning as in send_option_arg_callback_request().
+ * \param result_handler See \ref send_callback_request.
+ * \param private_result_data See \ref send_callback_request.
  *
  * This is similar to send_option_arg_callback_request(), but no options buffer
  * is passed to the parent process.
@@ -407,13 +418,15 @@ static int fd2buf(int fd, unsigned max_size, struct osl_object *obj)
  * \param arg_obj Pointer to the arguments to \a f.
  * \param f The callback function.
  * \param max_len Don't read more than that many bytes from stdin.
- * \param result The result of the query is stored here.
+ * \param result_handler See \ref send_callback_request.
+ * \param private_result_data See \ref send_callback_request.
  *
  * This function is used by commands that wish to let para_server store
  * arbitrary data specified by the user (for instance the add_blob family of
  * commands). First, at most \a max_len bytes are read from \a fd, the result
  * is concatenated with the buffer given by \a arg_obj, and the combined buffer
- * is made available to the parent process via shared memory.
+ * is made available to the afs process via the callback method. See \ref
+ * send_callback_request for details.
  *
  * \return Negative on errors, the return value of the underlying call to
  * send_callback_request() otherwise.
@@ -612,9 +625,19 @@ out:
        free(pb.buf);
 }
 
-int send_result(struct osl_object *result, void *private_result_data)
+/**
+ * Result handler for sending data to the para_client process.
+ *
+ * \param result The data to be sent.
+ * \param fd_ptr Pointer to the file descriptor.
+ *
+ * \return The return value of the underlying call to send_bin_buffer().
+ *
+ * \sa \ref callback_result_handler.
+ */
+int send_result(struct osl_object *result, void *fd_ptr)
 {
-       int fd = *(int *)private_result_data;
+       int fd = *(int *)fd_ptr;
        if (!result->size)
                return 1;
        return send_bin_buffer(fd, result->data, result->size);
@@ -805,9 +828,27 @@ static void command_pre_select(struct sched *s, struct task *t)
        t->ret = 1;
 }
 
-int pass_buffer_as_shm(char *buf, size_t size, void *private_data)
+/**
+ * Send data as shared memory to a file descriptor.
+ *
+ * \param buf The buffer holding the data to be sent.
+ * \param size The size of \a buf.
+ * \param fd_ptr A pointer to the file descriptor.
+ *
+ * This function is used as the \a max_size handler in a \ref para_buffer
+ * structure. If used this way, it is called by \ref para_printf() whenever
+ * the buffer passed to para_printf() is about to exceed its maximal size.
+ *
+ * This function creates a shared memory area large enough to hold
+ * the content given by \a buf and \a size and sends the identifier
+ * of this area to the file descriptor given by \a fd_ptr.
+ *
+ * \return Zero if \a buf is \p NULL or \a size is zero. Negative on errors,
+ * and positive on success.
+ */
+int pass_buffer_as_shm(char *buf, size_t size, void *fd_ptr)
 {
-       int ret, shmid, fd = *(int *)private_data;
+       int ret, shmid, fd = *(int *)fd_ptr;
        void *shm;
        struct callback_result *cr;