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22 * @author Florian Dold
24 * @brief general purpose request queue
27 #include "gnunet_util_lib.h"
29 #define LOG(kind,...) GNUNET_log_from (kind, "util-mq",__VA_ARGS__)
32 struct GNUNET_MQ_Envelope
35 * Messages are stored in a linked list.
36 * Each queue has its own list of envelopes.
38 struct GNUNET_MQ_Envelope *next;
41 * Messages are stored in a linked list
42 * Each queue has its own list of envelopes.
44 struct GNUNET_MQ_Envelope *prev;
47 * Actual allocated message header.
48 * The GNUNET_MQ_Envelope header is allocated at
49 * the end of the message.
51 struct GNUNET_MessageHeader *mh;
54 * Queue the message is queued in, NULL if message is not queued.
56 struct GNUNET_MQ_Handle *parent_queue;
59 * Called after the message was sent irrevocably.
61 GNUNET_SCHEDULER_TaskCallback sent_cb;
64 * Closure for @e send_cb
69 * Flags that were set for this envelope by
70 * #GNUNET_MQ_env_set_options(). Only valid if
71 * @e have_custom_options is set.
76 * Additional options buffer set for this envelope by
77 * #GNUNET_MQ_env_set_options(). Only valid if
78 * @e have_custom_options is set.
83 * Did the application call #GNUNET_MQ_env_set_options()?
85 int have_custom_options;
90 * Handle to a message queue.
92 struct GNUNET_MQ_Handle
95 * Handlers array, or NULL if the queue should not receive messages
97 struct GNUNET_MQ_MessageHandler *handlers;
100 * Actual implementation of message sending,
101 * called when a message is added
103 GNUNET_MQ_SendImpl send_impl;
106 * Implementation-dependent queue destruction function
108 GNUNET_MQ_DestroyImpl destroy_impl;
111 * Implementation-dependent send cancel function
113 GNUNET_MQ_CancelImpl cancel_impl;
116 * Implementation-specific state
121 * Callback will be called when an error occurs.
123 GNUNET_MQ_ErrorHandler error_handler;
126 * Closure for the error handler.
128 void *error_handler_cls;
131 * Task to asynchronously run #impl_send_continue().
133 struct GNUNET_SCHEDULER_Task *send_task;
136 * Linked list of messages pending to be sent
138 struct GNUNET_MQ_Envelope *envelope_head;
141 * Linked list of messages pending to be sent
143 struct GNUNET_MQ_Envelope *envelope_tail;
146 * Message that is currently scheduled to be
147 * sent. Not the head of the message queue, as the implementation
148 * needs to know if sending has been already scheduled or not.
150 struct GNUNET_MQ_Envelope *current_envelope;
153 * Map of associations, lazily allocated
155 struct GNUNET_CONTAINER_MultiHashMap32 *assoc_map;
158 * Functions to call on queue destruction; kept in a DLL.
160 struct GNUNET_MQ_DestroyNotificationHandle *dnh_head;
163 * Functions to call on queue destruction; kept in a DLL.
165 struct GNUNET_MQ_DestroyNotificationHandle *dnh_tail;
168 * Additional options buffer set for this queue by
169 * #GNUNET_MQ_set_options(). Default is 0.
171 const void *default_extra;
174 * Flags that were set for this queue by
175 * #GNUNET_MQ_set_options(). Default is 0.
177 uint64_t default_flags;
180 * Next id that should be used for the @e assoc_map,
181 * initialized lazily to a random value together with
187 * Number of entries we have in the envelope-DLL.
189 unsigned int queue_length;
192 * #GNUNET_YES if GNUNET_MQ_impl_evacuate was called.
193 * FIXME: is this dead?
198 * #GNUNET_YES if GNUNET_MQ_impl_send_in_flight() was called.
205 * Implementation-specific state for connection to
206 * client (MQ for server).
208 struct ServerClientSocketState
211 * Handle of the client that connected to the server.
213 struct GNUNET_SERVER_Client *client;
216 * Active transmission request to the client.
218 struct GNUNET_SERVER_TransmitHandle *th;
223 * Call the message message handler that was registered
224 * for the type of the given message in the given message queue.
226 * This function is indended to be used for the implementation
229 * @param mq message queue with the handlers
230 * @param mh message to dispatch
233 GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq,
234 const struct GNUNET_MessageHeader *mh)
236 const struct GNUNET_MQ_MessageHandler *handler;
237 int handled = GNUNET_NO;
238 uint16_t msize = ntohs (mh->size);
239 uint16_t mtype = ntohs (mh->type);
241 LOG (GNUNET_ERROR_TYPE_DEBUG,
242 "Received message of type %u and size %u\n",
245 if (NULL == mq->handlers)
247 for (handler = mq->handlers; NULL != handler->cb; handler++)
249 if (handler->type == mtype)
251 handled = GNUNET_YES;
252 if ( (handler->expected_size > msize) ||
253 ( (handler->expected_size != msize) &&
254 (NULL == handler->mv) ) )
256 /* Too small, or not an exact size and
257 no 'mv' handler to check rest */
258 LOG (GNUNET_ERROR_TYPE_ERROR,
259 "Received malformed message of type %u\n",
260 (unsigned int) handler->type);
261 GNUNET_MQ_inject_error (mq,
262 GNUNET_MQ_ERROR_MALFORMED);
265 if ( (NULL == handler->mv) ||
267 handler->mv (handler->cls, mh)) )
269 /* message well-formed, pass to handler */
270 handler->cb (handler->cls, mh);
274 /* Message rejected by check routine */
275 LOG (GNUNET_ERROR_TYPE_ERROR,
276 "Received malformed message of type %u\n",
277 (unsigned int) handler->type);
278 GNUNET_MQ_inject_error (mq,
279 GNUNET_MQ_ERROR_MALFORMED);
285 if (GNUNET_NO == handled)
286 LOG (GNUNET_ERROR_TYPE_INFO,
287 "No handler for message of type %u and size %u\n",
293 * Call the error handler of a message queue with the given
294 * error code. If there is no error handler, log a warning.
296 * This function is intended to be used by the implementation
299 * @param mq message queue
300 * @param error the error type
303 GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
304 enum GNUNET_MQ_Error error)
306 if (NULL == mq->error_handler)
308 LOG (GNUNET_ERROR_TYPE_WARNING,
309 "Got error %d, but no handler installed\n",
313 mq->error_handler (mq->error_handler_cls,
319 * Discard the message queue message, free all
320 * allocated resources. Must be called in the event
321 * that a message is created but should not actually be sent.
323 * @param mqm the message to discard
326 GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *ev)
328 GNUNET_assert (NULL == ev->parent_queue);
334 * Obtain the current length of the message queue.
336 * @param mq queue to inspect
337 * @return number of queued, non-transmitted messages
340 GNUNET_MQ_get_length (struct GNUNET_MQ_Handle *mq)
342 if (GNUNET_YES != mq->in_flight)
344 return mq->queue_length;
346 return mq->queue_length - 1;
351 * Send a message with the given message queue.
352 * May only be called once per message.
354 * @param mq message queue
355 * @param ev the envelope with the message to send.
358 GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq,
359 struct GNUNET_MQ_Envelope *ev)
361 GNUNET_assert (NULL != mq);
362 GNUNET_assert (NULL == ev->parent_queue);
365 GNUNET_break (mq->queue_length < 10000); /* This would seem like a bug... */
366 ev->parent_queue = mq;
367 /* is the implementation busy? queue it! */
368 if ( (NULL != mq->current_envelope) ||
369 (NULL != mq->send_task) )
371 GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head,
376 GNUNET_assert (NULL == mq->envelope_head);
377 mq->current_envelope = ev;
385 * Remove the first envelope that has not yet been sent from the message
386 * queue and return it.
388 * @param mq queue to remove envelope from
389 * @return NULL if queue is empty (or has no envelope that is not under transmission)
391 struct GNUNET_MQ_Envelope *
392 GNUNET_MQ_unsent_head (struct GNUNET_MQ_Handle *mq)
394 struct GNUNET_MQ_Envelope *env;
396 env = mq->envelope_head;
397 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
401 env->parent_queue = NULL;
407 * Function to copy an envelope. The envelope must not yet
408 * be in any queue or have any options or callbacks set.
410 * @param env envelope to copy
411 * @return copy of @a env
413 struct GNUNET_MQ_Envelope *
414 GNUNET_MQ_env_copy (struct GNUNET_MQ_Envelope *env)
416 GNUNET_assert (NULL == env->next);
417 GNUNET_assert (NULL == env->parent_queue);
418 GNUNET_assert (NULL == env->sent_cb);
419 GNUNET_assert (GNUNET_NO == env->have_custom_options);
420 return GNUNET_MQ_msg_copy (env->mh);
425 * Send a copy of a message with the given message queue.
426 * Can be called repeatedly on the same envelope.
428 * @param mq message queue
429 * @param ev the envelope with the message to send.
432 GNUNET_MQ_send_copy (struct GNUNET_MQ_Handle *mq,
433 const struct GNUNET_MQ_Envelope *ev)
435 struct GNUNET_MQ_Envelope *env;
438 msize = ntohs (ev->mh->size);
439 env = GNUNET_malloc (sizeof (struct GNUNET_MQ_Envelope) +
441 env->mh = (struct GNUNET_MessageHeader *) &env[1];
442 env->sent_cb = ev->sent_cb;
443 env->sent_cls = ev->sent_cls;
444 GNUNET_memcpy (&env[1],
453 * Task run to call the send implementation for the next queued
454 * message, if any. Only useful for implementing message queues,
455 * results in undefined behavior if not used carefully.
457 * @param cls message queue to send the next message with
460 impl_send_continue (void *cls)
462 struct GNUNET_MQ_Handle *mq = cls;
464 mq->send_task = NULL;
465 /* call is only valid if we're actually currently sending
467 if (NULL == mq->envelope_head)
469 mq->current_envelope = mq->envelope_head;
470 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
472 mq->current_envelope);
474 mq->current_envelope->mh,
480 * Call the send implementation for the next queued message, if any.
481 * Only useful for implementing message queues, results in undefined
482 * behavior if not used carefully.
484 * @param mq message queue to send the next message with
487 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
489 struct GNUNET_MQ_Envelope *current_envelope;
490 GNUNET_SCHEDULER_TaskCallback cb;
492 GNUNET_assert (0 < mq->queue_length);
494 mq->in_flight = GNUNET_NO;
495 current_envelope = mq->current_envelope;
496 current_envelope->parent_queue = NULL;
497 mq->current_envelope = NULL;
498 GNUNET_assert (NULL == mq->send_task);
499 mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
501 if (NULL != (cb = current_envelope->sent_cb))
503 current_envelope->sent_cb = NULL;
504 cb (current_envelope->sent_cls);
506 GNUNET_free (current_envelope);
511 * Call the send notification for the current message, but do not
512 * try to send the next message until #GNUNET_MQ_impl_send_continue
515 * Only useful for implementing message queues, results in undefined
516 * behavior if not used carefully.
518 * @param mq message queue to send the next message with
521 GNUNET_MQ_impl_send_in_flight (struct GNUNET_MQ_Handle *mq)
523 struct GNUNET_MQ_Envelope *current_envelope;
524 GNUNET_SCHEDULER_TaskCallback cb;
526 mq->in_flight = GNUNET_YES;
527 /* call is only valid if we're actually currently sending
529 current_envelope = mq->current_envelope;
530 GNUNET_assert (NULL != current_envelope);
531 /* can't call cancel from now on anymore */
532 current_envelope->parent_queue = NULL;
533 if (NULL != (cb = current_envelope->sent_cb))
535 current_envelope->sent_cb = NULL;
536 cb (current_envelope->sent_cls);
542 * Create a message queue for the specified handlers.
544 * @param send function the implements sending messages
545 * @param destroy function that implements destroying the queue
546 * @param cancel function that implements canceling a message
547 * @param impl_state for the queue, passed to 'send' and 'destroy'
548 * @param handlers array of message handlers
549 * @param error_handler handler for read and write errors
550 * @param error_handler_cls closure for @a error_handler
551 * @return a new message queue
553 struct GNUNET_MQ_Handle *
554 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
555 GNUNET_MQ_DestroyImpl destroy,
556 GNUNET_MQ_CancelImpl cancel,
558 const struct GNUNET_MQ_MessageHandler *handlers,
559 GNUNET_MQ_ErrorHandler error_handler,
560 void *error_handler_cls)
562 struct GNUNET_MQ_Handle *mq;
564 mq = GNUNET_new (struct GNUNET_MQ_Handle);
565 mq->send_impl = send;
566 mq->destroy_impl = destroy;
567 mq->cancel_impl = cancel;
568 mq->handlers = GNUNET_MQ_copy_handlers (handlers);
569 mq->error_handler = error_handler;
570 mq->error_handler_cls = error_handler_cls;
571 mq->impl_state = impl_state;
578 * Change the closure argument in all of the `handlers` of the
581 * @param mq to modify
582 * @param handlers_cls new closure to use
585 GNUNET_MQ_set_handlers_closure (struct GNUNET_MQ_Handle *mq,
590 if (NULL == mq->handlers)
592 for (i=0;NULL != mq->handlers[i].cb; i++)
593 mq->handlers[i].cls = handlers_cls;
598 * Get the message that should currently be sent.
599 * Fails if there is no current message.
600 * Only useful for implementing message queues,
601 * results in undefined behavior if not used carefully.
603 * @param mq message queue with the current message
604 * @return message to send, never NULL
606 const struct GNUNET_MessageHeader *
607 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
609 GNUNET_assert (NULL != mq->current_envelope);
610 GNUNET_assert (NULL != mq->current_envelope->mh);
611 return mq->current_envelope->mh;
616 * Get the implementation state associated with the
619 * While the GNUNET_MQ_Impl* callbacks receive the
620 * implementation state, continuations that are scheduled
621 * by the implementation function often only have one closure
622 * argument, with this function it is possible to get at the
623 * implementation state when only passing the GNUNET_MQ_Handle
626 * @param mq message queue with the current message
627 * @return message to send, never NULL
630 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
632 return mq->impl_state;
636 struct GNUNET_MQ_Envelope *
637 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp,
641 struct GNUNET_MQ_Envelope *ev;
643 ev = GNUNET_malloc (size + sizeof (struct GNUNET_MQ_Envelope));
644 ev->mh = (struct GNUNET_MessageHeader *) &ev[1];
645 ev->mh->size = htons (size);
646 ev->mh->type = htons (type);
654 * Create a new envelope by copying an existing message.
656 * @param hdr header of the message to copy
657 * @return envelope containing @a hdr
659 struct GNUNET_MQ_Envelope *
660 GNUNET_MQ_msg_copy (const struct GNUNET_MessageHeader *hdr)
662 struct GNUNET_MQ_Envelope *mqm;
663 uint16_t size = ntohs (hdr->size);
665 mqm = GNUNET_malloc (sizeof (*mqm) + size);
666 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
667 GNUNET_memcpy (mqm->mh,
675 * Implementation of the #GNUNET_MQ_msg_nested_mh macro.
677 * @param mhp pointer to the message header pointer that will be changed to allocate at
678 * the newly allocated space for the message.
679 * @param base_size size of the data before the nested message
680 * @param type type of the message in the envelope
681 * @param nested_mh the message to append to the message after base_size
683 struct GNUNET_MQ_Envelope *
684 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp,
687 const struct GNUNET_MessageHeader *nested_mh)
689 struct GNUNET_MQ_Envelope *mqm;
692 if (NULL == nested_mh)
693 return GNUNET_MQ_msg_ (mhp, base_size, type);
695 size = base_size + ntohs (nested_mh->size);
697 /* check for uint16_t overflow */
698 if (size < base_size)
701 mqm = GNUNET_MQ_msg_ (mhp, size, type);
702 GNUNET_memcpy ((char *) mqm->mh + base_size,
704 ntohs (nested_mh->size));
711 * Transmit a queued message to the session's client.
713 * @param cls consensus session
714 * @param size number of bytes available in @a buf
715 * @param buf where the callee should write the message
716 * @return number of bytes written to @a buf
719 transmit_queued (void *cls,
723 struct GNUNET_MQ_Handle *mq = cls;
724 struct ServerClientSocketState *state = GNUNET_MQ_impl_state (mq);
725 const struct GNUNET_MessageHeader *msg = GNUNET_MQ_impl_current (mq);
728 GNUNET_assert (NULL != buf);
729 msg_size = ntohs (msg->size);
730 GNUNET_assert (size >= msg_size);
731 GNUNET_memcpy (buf, msg, msg_size);
734 GNUNET_MQ_impl_send_continue (mq);
741 server_client_destroy_impl (struct GNUNET_MQ_Handle *mq,
744 struct ServerClientSocketState *state = impl_state;
746 if (NULL != state->th)
748 GNUNET_SERVER_notify_transmit_ready_cancel (state->th);
752 GNUNET_assert (NULL != mq);
753 GNUNET_assert (NULL != state);
754 GNUNET_SERVER_client_drop (state->client);
760 server_client_send_impl (struct GNUNET_MQ_Handle *mq,
761 const struct GNUNET_MessageHeader *msg,
764 GNUNET_assert (NULL != mq);
766 LOG (GNUNET_ERROR_TYPE_DEBUG,
767 "Sending message of type %u and size %u\n",
768 ntohs (msg->type), ntohs (msg->size));
770 struct ServerClientSocketState *state = impl_state;
771 state->th = GNUNET_SERVER_notify_transmit_ready (state->client,
773 GNUNET_TIME_UNIT_FOREVER_REL,
779 struct GNUNET_MQ_Handle *
780 GNUNET_MQ_queue_for_server_client (struct GNUNET_SERVER_Client *client)
782 struct GNUNET_MQ_Handle *mq;
783 struct ServerClientSocketState *scss;
785 mq = GNUNET_new (struct GNUNET_MQ_Handle);
786 scss = GNUNET_new (struct ServerClientSocketState);
787 mq->impl_state = scss;
788 scss->client = client;
789 GNUNET_SERVER_client_keep (client);
790 mq->send_impl = &server_client_send_impl;
791 mq->destroy_impl = &server_client_destroy_impl;
797 * Associate the assoc_data in mq with a unique request id.
799 * @param mq message queue, id will be unique for the queue
800 * @param assoc_data to associate
803 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
808 if (NULL == mq->assoc_map)
810 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
814 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map, id, assoc_data,
815 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
821 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq,
824 if (NULL == mq->assoc_map)
826 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map, request_id);
831 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq,
836 if (NULL == mq->assoc_map)
838 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
840 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map,
847 * Call a callback once the envelope has been sent, that is,
848 * sending it can not be canceled anymore.
849 * There can be only one notify sent callback per envelope.
851 * @param ev message to call the notify callback for
852 * @param cb the notify callback
853 * @param cb_cls closure for the callback
856 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
857 GNUNET_SCHEDULER_TaskCallback cb,
860 GNUNET_assert (NULL == ev->sent_cb);
862 ev->sent_cls = cb_cls;
867 * Handle we return for callbacks registered to be
868 * notified when #GNUNET_MQ_destroy() is called on a queue.
870 struct GNUNET_MQ_DestroyNotificationHandle
875 struct GNUNET_MQ_DestroyNotificationHandle *prev;
880 struct GNUNET_MQ_DestroyNotificationHandle *next;
883 * Queue to notify about.
885 struct GNUNET_MQ_Handle *mq;
890 GNUNET_SCHEDULER_TaskCallback cb;
900 * Destroy the message queue.
902 * @param mq message queue to destroy
905 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
907 struct GNUNET_MQ_DestroyNotificationHandle *dnh;
909 if (NULL != mq->destroy_impl)
911 mq->destroy_impl (mq, mq->impl_state);
913 if (NULL != mq->send_task)
915 GNUNET_SCHEDULER_cancel (mq->send_task);
916 mq->send_task = NULL;
918 while (NULL != mq->envelope_head)
920 struct GNUNET_MQ_Envelope *ev;
922 ev = mq->envelope_head;
923 ev->parent_queue = NULL;
924 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
927 GNUNET_assert (0 < mq->queue_length);
929 GNUNET_MQ_discard (ev);
931 if (NULL != mq->current_envelope)
933 /* we can only discard envelopes that
935 mq->current_envelope->parent_queue = NULL;
936 GNUNET_MQ_discard (mq->current_envelope);
937 mq->current_envelope = NULL;
938 GNUNET_assert (0 < mq->queue_length);
941 GNUNET_assert (0 == mq->queue_length);
942 while (NULL != (dnh = mq->dnh_head))
944 dnh->cb (dnh->cb_cls);
945 GNUNET_MQ_destroy_notify_cancel (dnh);
947 if (NULL != mq->assoc_map)
949 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
950 mq->assoc_map = NULL;
952 GNUNET_free_non_null (mq->handlers);
957 const struct GNUNET_MessageHeader *
958 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh,
962 uint16_t nested_size;
963 const struct GNUNET_MessageHeader *nested_msg;
965 whole_size = ntohs (mh->size);
966 GNUNET_assert (whole_size >= base_size);
967 nested_size = whole_size - base_size;
968 if (0 == nested_size)
970 if (nested_size < sizeof (struct GNUNET_MessageHeader))
975 nested_msg = (const struct GNUNET_MessageHeader *) ((char *) mh + base_size);
976 if (ntohs (nested_msg->size) != nested_size)
986 * Cancel sending the message. Message must have been sent with
987 * #GNUNET_MQ_send before. May not be called after the notify sent
988 * callback has been called
990 * @param ev queued envelope to cancel
993 GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
995 struct GNUNET_MQ_Handle *mq = ev->parent_queue;
997 GNUNET_assert (NULL != mq);
998 GNUNET_assert (NULL != mq->cancel_impl);
1000 mq->evacuate_called = GNUNET_NO;
1002 if (mq->current_envelope == ev)
1004 /* complex case, we already started with transmitting
1005 the message using the callbacks. */
1006 GNUNET_assert (0 < mq->queue_length);
1008 mq->cancel_impl (mq,
1010 /* continue sending the next message, if any */
1011 mq->current_envelope = mq->envelope_head;
1012 if (NULL != mq->current_envelope)
1014 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
1016 mq->current_envelope);
1018 mq->current_envelope->mh,
1024 /* simple case, message is still waiting in the queue */
1025 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
1028 GNUNET_assert (0 < mq->queue_length);
1032 if (GNUNET_YES != mq->evacuate_called)
1034 ev->parent_queue = NULL;
1043 * Function to obtain the current envelope
1044 * from within #GNUNET_MQ_SendImpl implementations.
1046 * @param mq message queue to interrogate
1047 * @return the current envelope
1049 struct GNUNET_MQ_Envelope *
1050 GNUNET_MQ_get_current_envelope (struct GNUNET_MQ_Handle *mq)
1052 return mq->current_envelope;
1057 * Function to obtain the last envelope in the queue.
1059 * @param mq message queue to interrogate
1060 * @return the last envelope in the queue
1062 struct GNUNET_MQ_Envelope *
1063 GNUNET_MQ_get_last_envelope (struct GNUNET_MQ_Handle *mq)
1065 if (NULL != mq->envelope_tail)
1066 return mq->envelope_tail;
1068 return mq->current_envelope;
1073 * Set application-specific options for this envelope.
1074 * Overrides the options set for the queue with
1075 * #GNUNET_MQ_set_options() for this message only.
1077 * @param env message to set options for
1078 * @param flags flags to use (meaning is queue-specific)
1079 * @param extra additional buffer for further data (also queue-specific)
1082 GNUNET_MQ_env_set_options (struct GNUNET_MQ_Envelope *env,
1088 env->have_custom_options = GNUNET_YES;
1093 * Get application-specific options for this envelope.
1095 * @param env message to set options for
1096 * @param[out] flags set to flags to use (meaning is queue-specific)
1097 * @return extra additional buffer for further data (also queue-specific)
1100 GNUNET_MQ_env_get_options (struct GNUNET_MQ_Envelope *env,
1103 struct GNUNET_MQ_Handle *mq = env->parent_queue;
1105 if (GNUNET_YES == env->have_custom_options)
1107 *flags = env->flags;
1115 *flags = mq->default_flags;
1116 return mq->default_extra;
1121 * Set application-specific options for this queue.
1123 * @param mq message queue to set options for
1124 * @param flags flags to use (meaning is queue-specific)
1125 * @param extra additional buffer for further data (also queue-specific)
1128 GNUNET_MQ_set_options (struct GNUNET_MQ_Handle *mq,
1132 mq->default_flags = flags;
1133 mq->default_extra = extra;
1138 * Register function to be called whenever @a mq is being
1141 * @param mq message queue to watch
1142 * @param cb function to call on @a mq destruction
1143 * @param cb_cls closure for @a cb
1144 * @return handle for #GNUNET_MQ_destroy_notify_cancel().
1146 struct GNUNET_MQ_DestroyNotificationHandle *
1147 GNUNET_MQ_destroy_notify (struct GNUNET_MQ_Handle *mq,
1148 GNUNET_SCHEDULER_TaskCallback cb,
1151 struct GNUNET_MQ_DestroyNotificationHandle *dnh;
1153 dnh = GNUNET_new (struct GNUNET_MQ_DestroyNotificationHandle);
1156 dnh->cb_cls = cb_cls;
1157 GNUNET_CONTAINER_DLL_insert (mq->dnh_head,
1165 * Cancel registration from #GNUNET_MQ_destroy_notify().
1167 * @param dnh handle for registration to cancel
1170 GNUNET_MQ_destroy_notify_cancel (struct GNUNET_MQ_DestroyNotificationHandle *dnh)
1172 struct GNUNET_MQ_Handle *mq = dnh->mq;
1174 GNUNET_CONTAINER_DLL_remove (mq->dnh_head,
1182 * Insert @a env into the envelope DLL starting at @a env_head
1183 * Note that @a env must not be in any MQ while this function
1184 * is used with DLLs defined outside of the MQ module. This
1185 * is just in case some application needs to also manage a
1186 * FIFO of envelopes independent of MQ itself and wants to
1187 * re-use the pointers internal to @a env. Use with caution.
1189 * @param[in|out] env_head of envelope DLL
1190 * @param[in|out] env_tail tail of envelope DLL
1191 * @param[in|out] env element to insert at the tail
1194 GNUNET_MQ_dll_insert_tail (struct GNUNET_MQ_Envelope **env_head,
1195 struct GNUNET_MQ_Envelope **env_tail,
1196 struct GNUNET_MQ_Envelope *env)
1198 GNUNET_CONTAINER_DLL_insert_tail (*env_head,
1205 * Remove @a env from the envelope DLL starting at @a env_head.
1206 * Note that @a env must not be in any MQ while this function
1207 * is used with DLLs defined outside of the MQ module. This
1208 * is just in case some application needs to also manage a
1209 * FIFO of envelopes independent of MQ itself and wants to
1210 * re-use the pointers internal to @a env. Use with caution.
1212 * @param[in|out] env_head of envelope DLL
1213 * @param[in|out] env_tail tail of envelope DLL
1214 * @param[in|out] env element to remove from the DLL
1217 GNUNET_MQ_dll_remove (struct GNUNET_MQ_Envelope **env_head,
1218 struct GNUNET_MQ_Envelope **env_tail,
1219 struct GNUNET_MQ_Envelope *env)
1221 GNUNET_CONTAINER_DLL_remove (*env_head,
1228 * Copy an array of handlers.
1230 * Useful if the array has been delared in local memory and needs to be
1231 * persisted for future use.
1233 * @param handlers Array of handlers to be copied. Can be NULL (nothing done).
1234 * @return A newly allocated array of handlers.
1235 * Needs to be freed with #GNUNET_free.
1237 struct GNUNET_MQ_MessageHandler *
1238 GNUNET_MQ_copy_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
1240 struct GNUNET_MQ_MessageHandler *copy;
1243 if (NULL == handlers)
1246 count = GNUNET_MQ_count_handlers (handlers);
1247 copy = GNUNET_new_array (count + 1,
1248 struct GNUNET_MQ_MessageHandler);
1249 GNUNET_memcpy (copy,
1251 count * sizeof (struct GNUNET_MQ_MessageHandler));
1257 * Count the handlers in a handler array.
1259 * @param handlers Array of handlers to be counted.
1260 * @return The number of handlers in the array.
1263 GNUNET_MQ_count_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
1267 if (NULL == handlers)
1270 for (i=0; NULL != handlers[i].cb; i++) ;