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3 Copyright (C) 2012-2017 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
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 * Call the message message handler that was registered
206 * for the type of the given message in the given message queue.
208 * This function is indended to be used for the implementation
211 * @param mq message queue with the handlers
212 * @param mh message to dispatch
215 GNUNET_MQ_inject_message (struct GNUNET_MQ_Handle *mq,
216 const struct GNUNET_MessageHeader *mh)
218 const struct GNUNET_MQ_MessageHandler *handler;
219 int handled = GNUNET_NO;
220 uint16_t msize = ntohs (mh->size);
221 uint16_t mtype = ntohs (mh->type);
223 LOG (GNUNET_ERROR_TYPE_DEBUG,
224 "Received message of type %u and size %u\n",
227 if (NULL == mq->handlers)
229 for (handler = mq->handlers; NULL != handler->cb; handler++)
231 if (handler->type == mtype)
233 handled = GNUNET_YES;
234 if ( (handler->expected_size > msize) ||
235 ( (handler->expected_size != msize) &&
236 (NULL == handler->mv) ) )
238 /* Too small, or not an exact size and
239 no 'mv' handler to check rest */
240 LOG (GNUNET_ERROR_TYPE_ERROR,
241 "Received malformed message of type %u\n",
242 (unsigned int) handler->type);
243 GNUNET_MQ_inject_error (mq,
244 GNUNET_MQ_ERROR_MALFORMED);
247 if ( (NULL == handler->mv) ||
249 handler->mv (handler->cls, mh)) )
251 /* message well-formed, pass to handler */
252 handler->cb (handler->cls, mh);
256 /* Message rejected by check routine */
257 LOG (GNUNET_ERROR_TYPE_ERROR,
258 "Received malformed message of type %u\n",
259 (unsigned int) handler->type);
260 GNUNET_MQ_inject_error (mq,
261 GNUNET_MQ_ERROR_MALFORMED);
267 if (GNUNET_NO == handled)
268 LOG (GNUNET_ERROR_TYPE_INFO,
269 "No handler for message of type %u and size %u\n",
275 * Call the error handler of a message queue with the given
276 * error code. If there is no error handler, log a warning.
278 * This function is intended to be used by the implementation
281 * @param mq message queue
282 * @param error the error type
285 GNUNET_MQ_inject_error (struct GNUNET_MQ_Handle *mq,
286 enum GNUNET_MQ_Error error)
288 if (NULL == mq->error_handler)
290 LOG (GNUNET_ERROR_TYPE_WARNING,
291 "Got error %d, but no handler installed\n",
295 mq->error_handler (mq->error_handler_cls,
301 * Discard the message queue message, free all
302 * allocated resources. Must be called in the event
303 * that a message is created but should not actually be sent.
305 * @param mqm the message to discard
308 GNUNET_MQ_discard (struct GNUNET_MQ_Envelope *ev)
310 GNUNET_assert (NULL == ev->parent_queue);
316 * Obtain the current length of the message queue.
318 * @param mq queue to inspect
319 * @return number of queued, non-transmitted messages
322 GNUNET_MQ_get_length (struct GNUNET_MQ_Handle *mq)
324 if (GNUNET_YES != mq->in_flight)
326 return mq->queue_length;
328 return mq->queue_length - 1;
333 * Send a message with the given message queue.
334 * May only be called once per message.
336 * @param mq message queue
337 * @param ev the envelope with the message to send.
340 GNUNET_MQ_send (struct GNUNET_MQ_Handle *mq,
341 struct GNUNET_MQ_Envelope *ev)
343 GNUNET_assert (NULL != mq);
344 GNUNET_assert (NULL == ev->parent_queue);
347 GNUNET_break (mq->queue_length < 10000); /* This would seem like a bug... */
348 ev->parent_queue = mq;
349 /* is the implementation busy? queue it! */
350 if ( (NULL != mq->current_envelope) ||
351 (NULL != mq->send_task) )
353 GNUNET_CONTAINER_DLL_insert_tail (mq->envelope_head,
358 GNUNET_assert (NULL == mq->envelope_head);
359 mq->current_envelope = ev;
361 LOG (GNUNET_ERROR_TYPE_DEBUG,
362 "sending message of type %u, queue empty (MQ: %p)\n",
373 * Remove the first envelope that has not yet been sent from the message
374 * queue and return it.
376 * @param mq queue to remove envelope from
377 * @return NULL if queue is empty (or has no envelope that is not under transmission)
379 struct GNUNET_MQ_Envelope *
380 GNUNET_MQ_unsent_head (struct GNUNET_MQ_Handle *mq)
382 struct GNUNET_MQ_Envelope *env;
384 env = mq->envelope_head;
385 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
389 env->parent_queue = NULL;
395 * Function to copy an envelope. The envelope must not yet
396 * be in any queue or have any options or callbacks set.
398 * @param env envelope to copy
399 * @return copy of @a env
401 struct GNUNET_MQ_Envelope *
402 GNUNET_MQ_env_copy (struct GNUNET_MQ_Envelope *env)
404 GNUNET_assert (NULL == env->next);
405 GNUNET_assert (NULL == env->parent_queue);
406 GNUNET_assert (NULL == env->sent_cb);
407 GNUNET_assert (GNUNET_NO == env->have_custom_options);
408 return GNUNET_MQ_msg_copy (env->mh);
413 * Send a copy of a message with the given message queue.
414 * Can be called repeatedly on the same envelope.
416 * @param mq message queue
417 * @param ev the envelope with the message to send.
420 GNUNET_MQ_send_copy (struct GNUNET_MQ_Handle *mq,
421 const struct GNUNET_MQ_Envelope *ev)
423 struct GNUNET_MQ_Envelope *env;
426 msize = ntohs (ev->mh->size);
427 env = GNUNET_malloc (sizeof (struct GNUNET_MQ_Envelope) +
429 env->mh = (struct GNUNET_MessageHeader *) &env[1];
430 env->sent_cb = ev->sent_cb;
431 env->sent_cls = ev->sent_cls;
432 GNUNET_memcpy (&env[1],
441 * Task run to call the send implementation for the next queued
442 * message, if any. Only useful for implementing message queues,
443 * results in undefined behavior if not used carefully.
445 * @param cls message queue to send the next message with
448 impl_send_continue (void *cls)
450 struct GNUNET_MQ_Handle *mq = cls;
452 mq->send_task = NULL;
453 /* call is only valid if we're actually currently sending
455 if (NULL == mq->envelope_head)
457 mq->current_envelope = mq->envelope_head;
458 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
460 mq->current_envelope);
462 LOG (GNUNET_ERROR_TYPE_DEBUG,
463 "sending message of type %u from queue\n",
464 ntohs(mq->current_envelope->mh->type));
467 mq->current_envelope->mh,
473 * Call the send implementation for the next queued message, if any.
474 * Only useful for implementing message queues, results in undefined
475 * behavior if not used carefully.
477 * @param mq message queue to send the next message with
480 GNUNET_MQ_impl_send_continue (struct GNUNET_MQ_Handle *mq)
482 struct GNUNET_MQ_Envelope *current_envelope;
483 GNUNET_SCHEDULER_TaskCallback cb;
485 GNUNET_assert (0 < mq->queue_length);
487 mq->in_flight = GNUNET_NO;
488 current_envelope = mq->current_envelope;
489 current_envelope->parent_queue = NULL;
490 mq->current_envelope = NULL;
491 GNUNET_assert (NULL == mq->send_task);
492 mq->send_task = GNUNET_SCHEDULER_add_now (&impl_send_continue,
494 if (NULL != (cb = current_envelope->sent_cb))
496 current_envelope->sent_cb = NULL;
497 cb (current_envelope->sent_cls);
499 GNUNET_free (current_envelope);
504 * Call the send notification for the current message, but do not
505 * try to send the next message until #GNUNET_MQ_impl_send_continue
508 * Only useful for implementing message queues, results in undefined
509 * behavior if not used carefully.
511 * @param mq message queue to send the next message with
514 GNUNET_MQ_impl_send_in_flight (struct GNUNET_MQ_Handle *mq)
516 struct GNUNET_MQ_Envelope *current_envelope;
517 GNUNET_SCHEDULER_TaskCallback cb;
519 mq->in_flight = GNUNET_YES;
520 /* call is only valid if we're actually currently sending
522 current_envelope = mq->current_envelope;
523 GNUNET_assert (NULL != current_envelope);
524 /* can't call cancel from now on anymore */
525 current_envelope->parent_queue = NULL;
526 if (NULL != (cb = current_envelope->sent_cb))
528 current_envelope->sent_cb = NULL;
529 cb (current_envelope->sent_cls);
535 * Create a message queue for the specified handlers.
537 * @param send function the implements sending messages
538 * @param destroy function that implements destroying the queue
539 * @param cancel function that implements canceling a message
540 * @param impl_state for the queue, passed to 'send' and 'destroy'
541 * @param handlers array of message handlers
542 * @param error_handler handler for read and write errors
543 * @param error_handler_cls closure for @a error_handler
544 * @return a new message queue
546 struct GNUNET_MQ_Handle *
547 GNUNET_MQ_queue_for_callbacks (GNUNET_MQ_SendImpl send,
548 GNUNET_MQ_DestroyImpl destroy,
549 GNUNET_MQ_CancelImpl cancel,
551 const struct GNUNET_MQ_MessageHandler *handlers,
552 GNUNET_MQ_ErrorHandler error_handler,
553 void *error_handler_cls)
555 struct GNUNET_MQ_Handle *mq;
557 mq = GNUNET_new (struct GNUNET_MQ_Handle);
558 mq->send_impl = send;
559 mq->destroy_impl = destroy;
560 mq->cancel_impl = cancel;
561 mq->handlers = GNUNET_MQ_copy_handlers (handlers);
562 mq->error_handler = error_handler;
563 mq->error_handler_cls = error_handler_cls;
564 mq->impl_state = impl_state;
571 * Change the closure argument in all of the `handlers` of the
574 * @param mq to modify
575 * @param handlers_cls new closure to use
578 GNUNET_MQ_set_handlers_closure (struct GNUNET_MQ_Handle *mq,
581 if (NULL == mq->handlers)
583 for (unsigned int i=0;NULL != mq->handlers[i].cb; i++)
584 mq->handlers[i].cls = handlers_cls;
589 * Get the message that should currently be sent.
590 * Fails if there is no current message.
591 * Only useful for implementing message queues,
592 * results in undefined behavior if not used carefully.
594 * @param mq message queue with the current message
595 * @return message to send, never NULL
597 const struct GNUNET_MessageHeader *
598 GNUNET_MQ_impl_current (struct GNUNET_MQ_Handle *mq)
600 GNUNET_assert (NULL != mq->current_envelope);
601 GNUNET_assert (NULL != mq->current_envelope->mh);
602 return mq->current_envelope->mh;
607 * Get the implementation state associated with the
610 * While the GNUNET_MQ_Impl* callbacks receive the
611 * implementation state, continuations that are scheduled
612 * by the implementation function often only have one closure
613 * argument, with this function it is possible to get at the
614 * implementation state when only passing the GNUNET_MQ_Handle
617 * @param mq message queue with the current message
618 * @return message to send, never NULL
621 GNUNET_MQ_impl_state (struct GNUNET_MQ_Handle *mq)
623 return mq->impl_state;
627 struct GNUNET_MQ_Envelope *
628 GNUNET_MQ_msg_ (struct GNUNET_MessageHeader **mhp,
632 struct GNUNET_MQ_Envelope *ev;
634 ev = GNUNET_malloc (size + sizeof (struct GNUNET_MQ_Envelope));
635 ev->mh = (struct GNUNET_MessageHeader *) &ev[1];
636 ev->mh->size = htons (size);
637 ev->mh->type = htons (type);
645 * Create a new envelope by copying an existing message.
647 * @param hdr header of the message to copy
648 * @return envelope containing @a hdr
650 struct GNUNET_MQ_Envelope *
651 GNUNET_MQ_msg_copy (const struct GNUNET_MessageHeader *hdr)
653 struct GNUNET_MQ_Envelope *mqm;
654 uint16_t size = ntohs (hdr->size);
656 mqm = GNUNET_malloc (sizeof (*mqm) + size);
657 mqm->mh = (struct GNUNET_MessageHeader *) &mqm[1];
658 GNUNET_memcpy (mqm->mh,
666 * Implementation of the #GNUNET_MQ_msg_nested_mh macro.
668 * @param mhp pointer to the message header pointer that will be changed to allocate at
669 * the newly allocated space for the message.
670 * @param base_size size of the data before the nested message
671 * @param type type of the message in the envelope
672 * @param nested_mh the message to append to the message after base_size
674 struct GNUNET_MQ_Envelope *
675 GNUNET_MQ_msg_nested_mh_ (struct GNUNET_MessageHeader **mhp,
678 const struct GNUNET_MessageHeader *nested_mh)
680 struct GNUNET_MQ_Envelope *mqm;
683 if (NULL == nested_mh)
684 return GNUNET_MQ_msg_ (mhp, base_size, type);
686 size = base_size + ntohs (nested_mh->size);
688 /* check for uint16_t overflow */
689 if (size < base_size)
692 mqm = GNUNET_MQ_msg_ (mhp, size, type);
693 GNUNET_memcpy ((char *) mqm->mh + base_size,
695 ntohs (nested_mh->size));
702 * Associate the assoc_data in mq with a unique request id.
704 * @param mq message queue, id will be unique for the queue
705 * @param assoc_data to associate
708 GNUNET_MQ_assoc_add (struct GNUNET_MQ_Handle *mq,
713 if (NULL == mq->assoc_map)
715 mq->assoc_map = GNUNET_CONTAINER_multihashmap32_create (8);
719 GNUNET_assert (GNUNET_OK ==
720 GNUNET_CONTAINER_multihashmap32_put (mq->assoc_map,
723 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
729 * Get the data associated with a @a request_id in a queue
731 * @param mq the message queue with the association
732 * @param request_id the request id we are interested in
733 * @return the associated data
736 GNUNET_MQ_assoc_get (struct GNUNET_MQ_Handle *mq,
739 if (NULL == mq->assoc_map)
741 return GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
747 * Remove the association for a @a request_id
749 * @param mq the message queue with the association
750 * @param request_id the request id we want to remove
751 * @return the associated data
754 GNUNET_MQ_assoc_remove (struct GNUNET_MQ_Handle *mq,
759 if (NULL == mq->assoc_map)
761 val = GNUNET_CONTAINER_multihashmap32_get (mq->assoc_map,
763 GNUNET_CONTAINER_multihashmap32_remove_all (mq->assoc_map,
770 * Call a callback once the envelope has been sent, that is,
771 * sending it can not be canceled anymore.
772 * There can be only one notify sent callback per envelope.
774 * @param ev message to call the notify callback for
775 * @param cb the notify callback
776 * @param cb_cls closure for the callback
779 GNUNET_MQ_notify_sent (struct GNUNET_MQ_Envelope *ev,
780 GNUNET_SCHEDULER_TaskCallback cb,
783 /* allow setting *OR* clearing callback */
784 GNUNET_assert ( (NULL == ev->sent_cb) ||
787 ev->sent_cls = cb_cls;
792 * Handle we return for callbacks registered to be
793 * notified when #GNUNET_MQ_destroy() is called on a queue.
795 struct GNUNET_MQ_DestroyNotificationHandle
800 struct GNUNET_MQ_DestroyNotificationHandle *prev;
805 struct GNUNET_MQ_DestroyNotificationHandle *next;
808 * Queue to notify about.
810 struct GNUNET_MQ_Handle *mq;
815 GNUNET_SCHEDULER_TaskCallback cb;
825 * Destroy the message queue.
827 * @param mq message queue to destroy
830 GNUNET_MQ_destroy (struct GNUNET_MQ_Handle *mq)
832 struct GNUNET_MQ_DestroyNotificationHandle *dnh;
834 if (NULL != mq->destroy_impl)
836 mq->destroy_impl (mq, mq->impl_state);
838 if (NULL != mq->send_task)
840 GNUNET_SCHEDULER_cancel (mq->send_task);
841 mq->send_task = NULL;
843 while (NULL != mq->envelope_head)
845 struct GNUNET_MQ_Envelope *ev;
847 ev = mq->envelope_head;
848 ev->parent_queue = NULL;
849 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
852 GNUNET_assert (0 < mq->queue_length);
854 LOG (GNUNET_ERROR_TYPE_DEBUG,
855 "MQ destroy drops message of type %u\n",
856 ntohs (ev->mh->type));
857 GNUNET_MQ_discard (ev);
859 if (NULL != mq->current_envelope)
861 /* we can only discard envelopes that
863 mq->current_envelope->parent_queue = NULL;
864 LOG (GNUNET_ERROR_TYPE_DEBUG,
865 "MQ destroy drops current message of type %u\n",
866 ntohs (mq->current_envelope->mh->type));
867 GNUNET_MQ_discard (mq->current_envelope);
868 mq->current_envelope = NULL;
869 GNUNET_assert (0 < mq->queue_length);
872 GNUNET_assert (0 == mq->queue_length);
873 while (NULL != (dnh = mq->dnh_head))
875 dnh->cb (dnh->cb_cls);
876 GNUNET_MQ_destroy_notify_cancel (dnh);
878 if (NULL != mq->assoc_map)
880 GNUNET_CONTAINER_multihashmap32_destroy (mq->assoc_map);
881 mq->assoc_map = NULL;
883 GNUNET_free_non_null (mq->handlers);
888 const struct GNUNET_MessageHeader *
889 GNUNET_MQ_extract_nested_mh_ (const struct GNUNET_MessageHeader *mh,
893 uint16_t nested_size;
894 const struct GNUNET_MessageHeader *nested_msg;
896 whole_size = ntohs (mh->size);
897 GNUNET_assert (whole_size >= base_size);
898 nested_size = whole_size - base_size;
899 if (0 == nested_size)
901 if (nested_size < sizeof (struct GNUNET_MessageHeader))
906 nested_msg = (const struct GNUNET_MessageHeader *) ((char *) mh + base_size);
907 if (ntohs (nested_msg->size) != nested_size)
917 * Cancel sending the message. Message must have been sent with
918 * #GNUNET_MQ_send before. May not be called after the notify sent
919 * callback has been called
921 * @param ev queued envelope to cancel
924 GNUNET_MQ_send_cancel (struct GNUNET_MQ_Envelope *ev)
926 struct GNUNET_MQ_Handle *mq = ev->parent_queue;
928 GNUNET_assert (NULL != mq);
929 GNUNET_assert (NULL != mq->cancel_impl);
931 mq->evacuate_called = GNUNET_NO;
933 if (mq->current_envelope == ev)
935 /* complex case, we already started with transmitting
936 the message using the callbacks. */
937 GNUNET_assert (0 < mq->queue_length);
941 /* continue sending the next message, if any */
942 mq->current_envelope = mq->envelope_head;
943 if (NULL != mq->current_envelope)
945 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
947 mq->current_envelope);
949 LOG (GNUNET_ERROR_TYPE_DEBUG,
950 "sending canceled message of type %u queue\n",
951 ntohs(ev->mh->type));
954 mq->current_envelope->mh,
960 /* simple case, message is still waiting in the queue */
961 GNUNET_CONTAINER_DLL_remove (mq->envelope_head,
964 GNUNET_assert (0 < mq->queue_length);
968 if (GNUNET_YES != mq->evacuate_called)
970 ev->parent_queue = NULL;
979 * Function to obtain the current envelope
980 * from within #GNUNET_MQ_SendImpl implementations.
982 * @param mq message queue to interrogate
983 * @return the current envelope
985 struct GNUNET_MQ_Envelope *
986 GNUNET_MQ_get_current_envelope (struct GNUNET_MQ_Handle *mq)
988 return mq->current_envelope;
993 * Function to obtain the last envelope in the queue.
995 * @param mq message queue to interrogate
996 * @return the last envelope in the queue
998 struct GNUNET_MQ_Envelope *
999 GNUNET_MQ_get_last_envelope (struct GNUNET_MQ_Handle *mq)
1001 if (NULL != mq->envelope_tail)
1002 return mq->envelope_tail;
1004 return mq->current_envelope;
1009 * Set application-specific options for this envelope.
1010 * Overrides the options set for the queue with
1011 * #GNUNET_MQ_set_options() for this message only.
1013 * @param env message to set options for
1014 * @param flags flags to use (meaning is queue-specific)
1015 * @param extra additional buffer for further data (also queue-specific)
1018 GNUNET_MQ_env_set_options (struct GNUNET_MQ_Envelope *env,
1024 env->have_custom_options = GNUNET_YES;
1029 * Get application-specific options for this envelope.
1031 * @param env message to set options for
1032 * @param[out] flags set to flags to use (meaning is queue-specific)
1033 * @return extra additional buffer for further data (also queue-specific)
1036 GNUNET_MQ_env_get_options (struct GNUNET_MQ_Envelope *env,
1039 struct GNUNET_MQ_Handle *mq = env->parent_queue;
1041 if (GNUNET_YES == env->have_custom_options)
1043 *flags = env->flags;
1051 *flags = mq->default_flags;
1052 return mq->default_extra;
1057 * Set application-specific options for this queue.
1059 * @param mq message queue to set options for
1060 * @param flags flags to use (meaning is queue-specific)
1061 * @param extra additional buffer for further data (also queue-specific)
1064 GNUNET_MQ_set_options (struct GNUNET_MQ_Handle *mq,
1068 mq->default_flags = flags;
1069 mq->default_extra = extra;
1074 * Obtain message contained in envelope.
1076 * @param env the envelope
1077 * @return message contained in the envelope
1079 const struct GNUNET_MessageHeader *
1080 GNUNET_MQ_env_get_msg (const struct GNUNET_MQ_Envelope *env)
1087 * Return next envelope in queue.
1089 * @param env a queued envelope
1090 * @return next one, or NULL
1092 const struct GNUNET_MQ_Envelope *
1093 GNUNET_MQ_env_next (const struct GNUNET_MQ_Envelope *env)
1100 * Register function to be called whenever @a mq is being
1103 * @param mq message queue to watch
1104 * @param cb function to call on @a mq destruction
1105 * @param cb_cls closure for @a cb
1106 * @return handle for #GNUNET_MQ_destroy_notify_cancel().
1108 struct GNUNET_MQ_DestroyNotificationHandle *
1109 GNUNET_MQ_destroy_notify (struct GNUNET_MQ_Handle *mq,
1110 GNUNET_SCHEDULER_TaskCallback cb,
1113 struct GNUNET_MQ_DestroyNotificationHandle *dnh;
1115 dnh = GNUNET_new (struct GNUNET_MQ_DestroyNotificationHandle);
1118 dnh->cb_cls = cb_cls;
1119 GNUNET_CONTAINER_DLL_insert (mq->dnh_head,
1127 * Cancel registration from #GNUNET_MQ_destroy_notify().
1129 * @param dnh handle for registration to cancel
1132 GNUNET_MQ_destroy_notify_cancel (struct GNUNET_MQ_DestroyNotificationHandle *dnh)
1134 struct GNUNET_MQ_Handle *mq = dnh->mq;
1136 GNUNET_CONTAINER_DLL_remove (mq->dnh_head,
1144 * Insert @a env into the envelope DLL starting at @a env_head
1145 * Note that @a env must not be in any MQ while this function
1146 * is used with DLLs defined outside of the MQ module. This
1147 * is just in case some application needs to also manage a
1148 * FIFO of envelopes independent of MQ itself and wants to
1149 * re-use the pointers internal to @a env. Use with caution.
1151 * @param[in|out] env_head of envelope DLL
1152 * @param[in|out] env_tail tail of envelope DLL
1153 * @param[in|out] env element to insert at the tail
1156 GNUNET_MQ_dll_insert_tail (struct GNUNET_MQ_Envelope **env_head,
1157 struct GNUNET_MQ_Envelope **env_tail,
1158 struct GNUNET_MQ_Envelope *env)
1160 GNUNET_CONTAINER_DLL_insert_tail (*env_head,
1167 * Remove @a env from the envelope DLL starting at @a env_head.
1168 * Note that @a env must not be in any MQ while this function
1169 * is used with DLLs defined outside of the MQ module. This
1170 * is just in case some application needs to also manage a
1171 * FIFO of envelopes independent of MQ itself and wants to
1172 * re-use the pointers internal to @a env. Use with caution.
1174 * @param[in|out] env_head of envelope DLL
1175 * @param[in|out] env_tail tail of envelope DLL
1176 * @param[in|out] env element to remove from the DLL
1179 GNUNET_MQ_dll_remove (struct GNUNET_MQ_Envelope **env_head,
1180 struct GNUNET_MQ_Envelope **env_tail,
1181 struct GNUNET_MQ_Envelope *env)
1183 GNUNET_CONTAINER_DLL_remove (*env_head,
1190 * Copy an array of handlers.
1192 * Useful if the array has been delared in local memory and needs to be
1193 * persisted for future use.
1195 * @param handlers Array of handlers to be copied. Can be NULL (nothing done).
1196 * @return A newly allocated array of handlers.
1197 * Needs to be freed with #GNUNET_free.
1199 struct GNUNET_MQ_MessageHandler *
1200 GNUNET_MQ_copy_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
1202 struct GNUNET_MQ_MessageHandler *copy;
1205 if (NULL == handlers)
1208 count = GNUNET_MQ_count_handlers (handlers);
1209 copy = GNUNET_new_array (count + 1,
1210 struct GNUNET_MQ_MessageHandler);
1211 GNUNET_memcpy (copy,
1213 count * sizeof (struct GNUNET_MQ_MessageHandler));
1219 * Copy an array of handlers, appending AGPL handler.
1221 * Useful if the array has been delared in local memory and needs to be
1222 * persisted for future use.
1224 * @param handlers Array of handlers to be copied. Can be NULL (nothing done).
1225 * @param agpl_handler function to call for AGPL handling
1226 * @param agpl_cls closure for @a agpl_handler
1227 * @return A newly allocated array of handlers.
1228 * Needs to be freed with #GNUNET_free.
1230 struct GNUNET_MQ_MessageHandler *
1231 GNUNET_MQ_copy_handlers2 (const struct GNUNET_MQ_MessageHandler *handlers,
1232 GNUNET_MQ_MessageCallback agpl_handler,
1235 struct GNUNET_MQ_MessageHandler *copy;
1238 if (NULL == handlers)
1240 count = GNUNET_MQ_count_handlers (handlers);
1241 copy = GNUNET_new_array (count + 2,
1242 struct GNUNET_MQ_MessageHandler);
1243 GNUNET_memcpy (copy,
1245 count * sizeof (struct GNUNET_MQ_MessageHandler));
1246 copy[count].mv = NULL;
1247 copy[count].cb = agpl_handler;
1248 copy[count].cls = agpl_cls;
1249 copy[count].type = GNUNET_MESSAGE_TYPE_REQUEST_AGPL;
1250 copy[count].expected_size = sizeof (struct GNUNET_MessageHeader);
1256 * Count the handlers in a handler array.
1258 * @param handlers Array of handlers to be counted.
1259 * @return The number of handlers in the array.
1262 GNUNET_MQ_count_handlers (const struct GNUNET_MQ_MessageHandler *handlers)
1266 if (NULL == handlers)
1269 for (i=0; NULL != handlers[i].cb; i++) ;
1276 * Convert an `enum GNUNET_MQ_PreferenceType` to a string
1278 * @param type the preference type
1279 * @return a string or NULL if invalid
1282 GNUNET_MQ_preference_to_string (enum GNUNET_MQ_PreferenceKind type)
1285 case GNUNET_MQ_PREFERENCE_NONE:
1287 case GNUNET_MQ_PREFERENCE_BANDWIDTH:
1289 case GNUNET_MQ_PREFERENCE_LATENCY:
1291 case GNUNET_MQ_PREFERENCE_RELIABILITY:
1292 return "RELIABILITY";