2 This file is part of GNUnet.
3 (C) 2012-2014 Christian Grothoff (and other contributing authors)
5 GNUnet is free software; you can redistribute it and/or modify
6 it under the terms of the GNU General Public License as published
7 by the Free Software Foundation; either version 3, or (at your
8 option) any later version.
10 GNUnet is distributed in the hope that it will be useful, but
11 WITHOUT ANY WARRANTY; without even the implied warranty of
12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
13 General Public License for more details.
15 You should have received a copy of the GNU General Public License
16 along with GNUnet; see the file COPYING. If not, write to the
17 Free Software Foundation, Inc., 59 Temple Place - Suite 330,
18 Boston, MA 02111-1307, USA.
22 * @brief api for the set service
23 * @author Florian Dold
24 * @author Christian Grothoff
27 #include "gnunet_util_lib.h"
28 #include "gnunet_protocols.h"
29 #include "gnunet_client_lib.h"
30 #include "gnunet_set_service.h"
34 #define LOG(kind,...) GNUNET_log_from (kind, "set-api",__VA_ARGS__)
37 * Opaque handle to a set.
39 struct GNUNET_SET_Handle
42 * Client connected to the set service.
44 struct GNUNET_CLIENT_Connection *client;
47 * Message queue for @e client.
49 struct GNUNET_MQ_Handle *mq;
52 * Linked list of operations on the set.
54 struct GNUNET_SET_OperationHandle *ops_head;
57 * Linked list of operations on the set.
59 struct GNUNET_SET_OperationHandle *ops_tail;
62 * Callback for the current iteration over the set,
63 * NULL if no iterator is active.
65 GNUNET_SET_ElementIterator iterator;
68 * Closure for @e iterator
73 * Should the set be destroyed once all operations are gone?
75 int destroy_requested;
78 * Has the set become invalid (e.g. service died)?
83 * Both client and service count the number of iterators
84 * created so far to match replies with iterators.
86 uint16_t iteration_id;
91 * Handle for a set operation request from another peer.
93 struct GNUNET_SET_Request
96 * Id of the request, used to identify the request when
97 * accepting/rejecting it.
102 * Has the request been accepted already?
103 * #GNUNET_YES/#GNUNET_NO
110 * Handle to an operation. Only known to the service after committing
111 * the handle with a set.
113 struct GNUNET_SET_OperationHandle
116 * Function to be called when we have a result,
119 GNUNET_SET_ResultIterator result_cb;
122 * Closure for @e result_cb.
127 * Local set used for the operation,
128 * NULL if no set has been provided by conclude yet.
130 struct GNUNET_SET_Handle *set;
133 * Message sent to the server on calling conclude,
134 * NULL if conclude has been called.
136 struct GNUNET_MQ_Envelope *conclude_mqm;
139 * Address of the request if in the conclude message,
140 * used to patch the request id into the message when the set is known.
142 uint32_t *request_id_addr;
145 * Handles are kept in a linked list.
147 struct GNUNET_SET_OperationHandle *prev;
150 * Handles are kept in a linked list.
152 struct GNUNET_SET_OperationHandle *next;
155 * Request ID to identify the operation within the set.
162 * Opaque handle to a listen operation.
164 struct GNUNET_SET_ListenHandle
167 * Connection to the service.
169 struct GNUNET_CLIENT_Connection *client;
172 * Message queue for the client.
174 struct GNUNET_MQ_Handle* mq;
177 * Configuration handle for the listener, stored
178 * here to be able to reconnect transparently on
179 * connection failure.
181 const struct GNUNET_CONFIGURATION_Handle *cfg;
184 * Function to call on a new incoming request,
187 GNUNET_SET_ListenCallback listen_cb;
190 * Closure for @e listen_cb.
195 * Application ID we listen for.
197 struct GNUNET_HashCode app_id;
200 * Time to wait until we try to reconnect on failure.
202 struct GNUNET_TIME_Relative reconnect_backoff;
205 * Task for reconnecting when the listener fails.
207 struct GNUNET_SCHEDULER_Task * reconnect_task;
210 * Operation we listen for.
212 enum GNUNET_SET_OperationType operation;
217 * Handle element for iteration over the set. Notifies the
218 * iterator and sends an acknowledgement to the service.
220 * @param cls the `struct GNUNET_SET_Handle *`
221 * @param mh the message
224 handle_iter_element (void *cls,
225 const struct GNUNET_MessageHeader *mh)
227 struct GNUNET_SET_Handle *set = cls;
228 GNUNET_SET_ElementIterator iter = set->iterator;
229 struct GNUNET_SET_Element element;
230 const struct GNUNET_SET_IterResponseMessage *msg;
231 struct GNUNET_SET_IterAckMessage *ack_msg;
232 struct GNUNET_MQ_Envelope *ev;
235 msize = ntohs (mh->size);
236 if (msize < sizeof (sizeof (struct GNUNET_SET_IterResponseMessage)))
238 /* message malformed */
240 set->iterator = NULL;
242 iter (set->iterator_cls,
246 msg = (const struct GNUNET_SET_IterResponseMessage *) mh;
247 if (set->iteration_id != ntohs (msg->iteration_id))
249 /* element from a previous iteration, skip! */
254 element.size = msize - sizeof (struct GNUNET_SET_IterResponseMessage);
255 element.element_type = htons (msg->element_type);
256 element.data = &msg[1];
257 iter (set->iterator_cls,
260 ev = GNUNET_MQ_msg (ack_msg,
261 GNUNET_MESSAGE_TYPE_SET_ITER_ACK);
262 ack_msg->send_more = htonl ((NULL != iter));
263 GNUNET_MQ_send (set->mq, ev);
268 * Handle message signalling conclusion of iteration over the set.
269 * Notifies the iterator that we are done.
272 * @param mh the message
275 handle_iter_done (void *cls,
276 const struct GNUNET_MessageHeader *mh)
278 struct GNUNET_SET_Handle *set = cls;
279 GNUNET_SET_ElementIterator iter = set->iterator;
283 set->iterator = NULL;
285 iter (set->iterator_cls,
291 * Handle result message for a set operation.
294 * @param mh the message
297 handle_result (void *cls,
298 const struct GNUNET_MessageHeader *mh)
300 struct GNUNET_SET_Handle *set = cls;
301 const struct GNUNET_SET_ResultMessage *msg;
302 struct GNUNET_SET_OperationHandle *oh;
303 struct GNUNET_SET_Element e;
304 enum GNUNET_SET_Status result_status;
306 msg = (const struct GNUNET_SET_ResultMessage *) mh;
307 GNUNET_assert (NULL != set->mq);
308 result_status = ntohs (msg->result_status);
309 LOG (GNUNET_ERROR_TYPE_DEBUG,
310 "Got result message with status %d\n",
313 oh = GNUNET_MQ_assoc_get (set->mq,
314 ntohl (msg->request_id));
317 /* 'oh' can be NULL if we canceled the operation, but the service
318 did not get the cancel message yet. */
319 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
320 "Ignoring result from canceled operation\n");
323 if (GNUNET_SET_STATUS_OK != result_status)
325 /* status is not #GNUNET_SET_STATUS_OK => there's no attached element,
326 * and this is the last result message we get */
327 GNUNET_MQ_assoc_remove (set->mq, ntohl (msg->request_id));
328 GNUNET_CONTAINER_DLL_remove (set->ops_head,
331 if ( (GNUNET_YES == set->destroy_requested) &&
332 (NULL == set->ops_head) )
333 GNUNET_SET_destroy (set);
334 if (NULL != oh->result_cb)
335 oh->result_cb (oh->result_cls,
338 switch (result_status)
340 case GNUNET_SET_STATUS_OK:
342 case GNUNET_SET_STATUS_FAILURE:
343 oh->result_cb = NULL;
345 case GNUNET_SET_STATUS_HALF_DONE:
347 case GNUNET_SET_STATUS_DONE:
348 oh->result_cb = NULL;
355 e.size = ntohs (mh->size) - sizeof (struct GNUNET_SET_ResultMessage);
356 e.element_type = msg->element_type;
357 if (NULL != oh->result_cb)
358 oh->result_cb (oh->result_cls,
365 * Destroy the given set operation.
367 * @param oh set operation to destroy
370 set_operation_destroy (struct GNUNET_SET_OperationHandle *oh)
372 struct GNUNET_SET_Handle *set = oh->set;
373 struct GNUNET_SET_OperationHandle *h_assoc;
375 if (NULL != oh->conclude_mqm)
376 GNUNET_MQ_discard (oh->conclude_mqm);
377 /* is the operation already commited? */
380 GNUNET_CONTAINER_DLL_remove (set->ops_head,
383 h_assoc = GNUNET_MQ_assoc_remove (set->mq,
385 GNUNET_assert ((NULL == h_assoc) || (h_assoc == oh));
392 * Cancel the given set operation. We need to send an explicit cancel
393 * message, as all operations one one set communicate using one
396 * @param oh set operation to cancel
399 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh)
401 struct GNUNET_SET_Handle *set = oh->set;
402 struct GNUNET_SET_CancelMessage *m;
403 struct GNUNET_MQ_Envelope *mqm;
407 mqm = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_SET_CANCEL);
408 m->request_id = htonl (oh->request_id);
409 GNUNET_MQ_send (set->mq, mqm);
411 set_operation_destroy (oh);
412 if ( (NULL != set) &&
413 (GNUNET_YES == set->destroy_requested) &&
414 (NULL == set->ops_head) )
416 LOG (GNUNET_ERROR_TYPE_DEBUG,
417 "Destroying set after operation cancel\n");
418 GNUNET_SET_destroy (set);
424 * We encountered an error communicating with the set service while
425 * performing a set operation. Report to the application.
427 * @param cls the `struct GNUNET_SET_Handle`
428 * @param error error code
431 handle_client_set_error (void *cls,
432 enum GNUNET_MQ_Error error)
434 struct GNUNET_SET_Handle *set = cls;
436 LOG (GNUNET_ERROR_TYPE_DEBUG,
437 "Handling client set error %d\n",
439 while (NULL != set->ops_head)
441 if (NULL != set->ops_head->result_cb)
442 set->ops_head->result_cb (set->ops_head->result_cls,
444 GNUNET_SET_STATUS_FAILURE);
445 set_operation_destroy (set->ops_head);
447 set->invalid = GNUNET_YES;
448 if (GNUNET_YES == set->destroy_requested)
450 LOG (GNUNET_ERROR_TYPE_DEBUG,
451 "Destroying set after operation failure\n");
452 GNUNET_SET_destroy (set);
458 * Create an empty set, supporting the specified operation.
460 * @param cfg configuration to use for connecting to the
462 * @param op operation supported by the set
463 * Note that the operation has to be specified
464 * beforehand, as certain set operations need to maintain
465 * data structures spefific to the operation
466 * @return a handle to the set
468 struct GNUNET_SET_Handle *
469 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
470 enum GNUNET_SET_OperationType op)
472 static const struct GNUNET_MQ_MessageHandler mq_handlers[] = {
474 GNUNET_MESSAGE_TYPE_SET_RESULT,
476 { &handle_iter_element,
477 GNUNET_MESSAGE_TYPE_SET_ITER_ELEMENT,
480 GNUNET_MESSAGE_TYPE_SET_ITER_DONE,
481 sizeof (struct GNUNET_MessageHeader) },
482 GNUNET_MQ_HANDLERS_END
484 struct GNUNET_SET_Handle *set;
485 struct GNUNET_MQ_Envelope *mqm;
486 struct GNUNET_SET_CreateMessage *msg;
488 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
489 "Creating new set (operation %u)\n",
491 set = GNUNET_new (struct GNUNET_SET_Handle);
492 set->client = GNUNET_CLIENT_connect ("set", cfg);
493 if (NULL == set->client)
498 set->mq = GNUNET_MQ_queue_for_connection_client (set->client,
500 &handle_client_set_error,
502 GNUNET_assert (NULL != set->mq);
503 mqm = GNUNET_MQ_msg (msg,
504 GNUNET_MESSAGE_TYPE_SET_CREATE);
505 msg->operation = htonl (op);
506 GNUNET_MQ_send (set->mq, mqm);
512 * Add an element to the given set. After the element has been added
513 * (in the sense of being transmitted to the set service), @a cont
514 * will be called. Multiple calls to GNUNET_SET_add_element() can be
517 * @param set set to add element to
518 * @param element element to add to the set
519 * @param cont continuation called after the element has been added
520 * @param cont_cls closure for @a cont
521 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the
522 * set is invalid (e.g. the set service crashed)
525 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
526 const struct GNUNET_SET_Element *element,
527 GNUNET_SET_Continuation cont,
530 struct GNUNET_MQ_Envelope *mqm;
531 struct GNUNET_SET_ElementMessage *msg;
533 if (GNUNET_YES == set->invalid)
537 return GNUNET_SYSERR;
539 mqm = GNUNET_MQ_msg_extra (msg, element->size,
540 GNUNET_MESSAGE_TYPE_SET_ADD);
541 msg->element_type = element->element_type;
545 GNUNET_MQ_notify_sent (mqm,
547 GNUNET_MQ_send (set->mq, mqm);
553 * Remove an element to the given set. After the element has been
554 * removed (in the sense of the request being transmitted to the set
555 * service), @a cont will be called. Multiple calls to
556 * GNUNET_SET_remove_element() can be queued
558 * @param set set to remove element from
559 * @param element element to remove from the set
560 * @param cont continuation called after the element has been removed
561 * @param cont_cls closure for @a cont
562 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the
563 * set is invalid (e.g. the set service crashed)
566 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
567 const struct GNUNET_SET_Element *element,
568 GNUNET_SET_Continuation cont,
571 struct GNUNET_MQ_Envelope *mqm;
572 struct GNUNET_SET_ElementMessage *msg;
574 if (GNUNET_YES == set->invalid)
578 return GNUNET_SYSERR;
580 mqm = GNUNET_MQ_msg_extra (msg,
582 GNUNET_MESSAGE_TYPE_SET_REMOVE);
583 msg->element_type = element->element_type;
587 GNUNET_MQ_notify_sent (mqm,
589 GNUNET_MQ_send (set->mq, mqm);
595 * Destroy the set handle if no operations are left, mark the set
596 * for destruction otherwise.
598 * @param set set handle to destroy
601 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set)
603 /* destroying set while iterator is active is currently
604 not supported; we should expand the API to allow
605 clients to explicitly cancel the iteration! */
606 GNUNET_assert (NULL == set->iterator);
607 if (NULL != set->ops_head)
609 LOG (GNUNET_ERROR_TYPE_DEBUG,
610 "Set operations are pending, delaying set destruction\n");
611 set->destroy_requested = GNUNET_YES;
614 LOG (GNUNET_ERROR_TYPE_DEBUG,
615 "Really destroying set\n");
616 if (NULL != set->client)
618 GNUNET_CLIENT_disconnect (set->client);
623 GNUNET_MQ_destroy (set->mq);
631 * Prepare a set operation to be evaluated with another peer.
632 * The evaluation will not start until the client provides
633 * a local set with #GNUNET_SET_commit().
635 * @param other_peer peer with the other set
636 * @param app_id hash for the application using the set
637 * @param context_msg additional information for the request
638 * @param result_mode specified how results will be returned,
639 * see `enum GNUNET_SET_ResultMode`.
640 * @param result_cb called on error or success
641 * @param result_cls closure for @e result_cb
642 * @return a handle to cancel the operation
644 struct GNUNET_SET_OperationHandle *
645 GNUNET_SET_prepare (const struct GNUNET_PeerIdentity *other_peer,
646 const struct GNUNET_HashCode *app_id,
647 const struct GNUNET_MessageHeader *context_msg,
648 enum GNUNET_SET_ResultMode result_mode,
649 GNUNET_SET_ResultIterator result_cb,
652 struct GNUNET_MQ_Envelope *mqm;
653 struct GNUNET_SET_OperationHandle *oh;
654 struct GNUNET_SET_EvaluateMessage *msg;
656 oh = GNUNET_new (struct GNUNET_SET_OperationHandle);
657 oh->result_cb = result_cb;
658 oh->result_cls = result_cls;
659 mqm = GNUNET_MQ_msg_nested_mh (msg,
660 GNUNET_MESSAGE_TYPE_SET_EVALUATE,
662 msg->app_id = *app_id;
663 msg->result_mode = htonl (result_mode);
664 msg->target_peer = *other_peer;
665 oh->conclude_mqm = mqm;
666 oh->request_id_addr = &msg->request_id;
673 * Connect to the set service in order to listen for requests.
675 * @param cls the `struct GNUNET_SET_ListenHandle *` to connect
676 * @param tc task context if invoked as a task, NULL otherwise
679 listen_connect (void *cls,
680 const struct GNUNET_SCHEDULER_TaskContext *tc);
684 * Handle request message for a listen operation
686 * @param cls the listen handle
687 * @param mh the message
690 handle_request (void *cls,
691 const struct GNUNET_MessageHeader *mh)
693 struct GNUNET_SET_ListenHandle *lh = cls;
694 const struct GNUNET_SET_RequestMessage *msg;
695 struct GNUNET_SET_Request req;
696 const struct GNUNET_MessageHeader *context_msg;
698 struct GNUNET_MQ_Envelope *mqm;
699 struct GNUNET_SET_RejectMessage *rmsg;
701 LOG (GNUNET_ERROR_TYPE_DEBUG,
702 "Processing incoming operation request\n");
703 msize = ntohs (mh->size);
704 if (msize < sizeof (struct GNUNET_SET_RequestMessage))
707 GNUNET_CLIENT_disconnect (lh->client);
709 GNUNET_MQ_destroy (lh->mq);
711 lh->reconnect_task = GNUNET_SCHEDULER_add_delayed (lh->reconnect_backoff,
712 &listen_connect, lh);
713 lh->reconnect_backoff = GNUNET_TIME_STD_BACKOFF (lh->reconnect_backoff);
716 /* we got another valid request => reset the backoff */
717 lh->reconnect_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
718 msg = (const struct GNUNET_SET_RequestMessage *) mh;
719 req.accept_id = ntohl (msg->accept_id);
720 req.accepted = GNUNET_NO;
721 context_msg = GNUNET_MQ_extract_nested_mh (msg);
722 /* calling #GNUNET_SET_accept() in the listen cb will set req->accepted */
723 lh->listen_cb (lh->listen_cls,
727 if (GNUNET_YES == req.accepted)
728 return; /* the accept-case is handled in #GNUNET_SET_accept() */
729 LOG (GNUNET_ERROR_TYPE_DEBUG,
730 "Rejecting request\n");
731 mqm = GNUNET_MQ_msg (rmsg,
732 GNUNET_MESSAGE_TYPE_SET_REJECT);
733 rmsg->accept_reject_id = msg->accept_id;
734 GNUNET_MQ_send (lh->mq, mqm);
739 * Our connection with the set service encountered an error,
740 * re-initialize with exponential back-off.
742 * @param cls the `struct GNUNET_SET_ListenHandle *`
743 * @param error reason for the disconnect
746 handle_client_listener_error (void *cls,
747 enum GNUNET_MQ_Error error)
749 struct GNUNET_SET_ListenHandle *lh = cls;
751 LOG (GNUNET_ERROR_TYPE_DEBUG,
752 "Listener broke down (%d), re-connecting\n",
754 GNUNET_CLIENT_disconnect (lh->client);
756 GNUNET_MQ_destroy (lh->mq);
758 lh->reconnect_task = GNUNET_SCHEDULER_add_delayed (lh->reconnect_backoff,
759 &listen_connect, lh);
760 lh->reconnect_backoff = GNUNET_TIME_STD_BACKOFF (lh->reconnect_backoff);
765 * Connect to the set service in order to listen for requests.
767 * @param cls the `struct GNUNET_SET_ListenHandle *` to connect
768 * @param tc task context if invoked as a task, NULL otherwise
771 listen_connect (void *cls,
772 const struct GNUNET_SCHEDULER_TaskContext *tc)
774 static const struct GNUNET_MQ_MessageHandler mq_handlers[] = {
775 { &handle_request, GNUNET_MESSAGE_TYPE_SET_REQUEST },
776 GNUNET_MQ_HANDLERS_END
778 struct GNUNET_SET_ListenHandle *lh = cls;
779 struct GNUNET_MQ_Envelope *mqm;
780 struct GNUNET_SET_ListenMessage *msg;
783 (0 != (tc->reason & GNUNET_SCHEDULER_REASON_SHUTDOWN)) )
785 LOG (GNUNET_ERROR_TYPE_DEBUG,
786 "Listener not reconnecting due to shutdown\n");
789 lh->reconnect_task = NULL;
790 GNUNET_assert (NULL == lh->client);
791 lh->client = GNUNET_CLIENT_connect ("set", lh->cfg);
792 if (NULL == lh->client)
794 GNUNET_assert (NULL == lh->mq);
795 lh->mq = GNUNET_MQ_queue_for_connection_client (lh->client,
797 &handle_client_listener_error, lh);
798 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_LISTEN);
799 msg->operation = htonl (lh->operation);
800 msg->app_id = lh->app_id;
801 GNUNET_MQ_send (lh->mq, mqm);
806 * Wait for set operation requests for the given application id
808 * @param cfg configuration to use for connecting to
809 * the set service, needs to be valid for the lifetime of the listen handle
810 * @param operation operation we want to listen for
811 * @param app_id id of the application that handles set operation requests
812 * @param listen_cb called for each incoming request matching the operation
814 * @param listen_cls handle for @a listen_cb
815 * @return a handle that can be used to cancel the listen operation
817 struct GNUNET_SET_ListenHandle *
818 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
819 enum GNUNET_SET_OperationType operation,
820 const struct GNUNET_HashCode *app_id,
821 GNUNET_SET_ListenCallback listen_cb,
824 struct GNUNET_SET_ListenHandle *lh;
826 lh = GNUNET_new (struct GNUNET_SET_ListenHandle);
827 lh->listen_cb = listen_cb;
828 lh->listen_cls = listen_cls;
830 lh->operation = operation;
831 lh->app_id = *app_id;
832 lh->reconnect_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
833 listen_connect (lh, NULL);
834 if (NULL == lh->client)
844 * Cancel the given listen operation.
846 * @param lh handle for the listen operation
849 GNUNET_SET_listen_cancel (struct GNUNET_SET_ListenHandle *lh)
851 LOG (GNUNET_ERROR_TYPE_DEBUG,
852 "Canceling listener\n");
855 GNUNET_MQ_destroy (lh->mq);
858 if (NULL != lh->client)
860 GNUNET_CLIENT_disconnect (lh->client);
863 if (NULL != lh->reconnect_task)
865 GNUNET_SCHEDULER_cancel (lh->reconnect_task);
866 lh->reconnect_task = NULL;
873 * Accept a request we got via #GNUNET_SET_listen. Must be called during
874 * #GNUNET_SET_listen, as the 'struct GNUNET_SET_Request' becomes invalid
876 * Call #GNUNET_SET_commit to provide the local set to use for the operation,
877 * and to begin the exchange with the remote peer.
879 * @param request request to accept
880 * @param result_mode specified how results will be returned,
881 * see `enum GNUNET_SET_ResultMode`.
882 * @param result_cb callback for the results
883 * @param result_cls closure for @a result_cb
884 * @return a handle to cancel the operation
886 struct GNUNET_SET_OperationHandle *
887 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
888 enum GNUNET_SET_ResultMode result_mode,
889 GNUNET_SET_ResultIterator result_cb,
892 struct GNUNET_MQ_Envelope *mqm;
893 struct GNUNET_SET_OperationHandle *oh;
894 struct GNUNET_SET_AcceptMessage *msg;
896 GNUNET_assert (GNUNET_NO == request->accepted);
897 request->accepted = GNUNET_YES;
898 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_ACCEPT);
899 msg->accept_reject_id = htonl (request->accept_id);
900 msg->result_mode = htonl (result_mode);
901 oh = GNUNET_new (struct GNUNET_SET_OperationHandle);
902 oh->result_cb = result_cb;
903 oh->result_cls = result_cls;
904 oh->conclude_mqm = mqm;
905 oh->request_id_addr = &msg->request_id;
911 * Commit a set to be used with a set operation.
912 * This function is called once we have fully constructed
913 * the set that we want to use for the operation. At this
914 * time, the P2P protocol can then begin to exchange the
915 * set information and call the result callback with the
916 * result information.
918 * @param oh handle to the set operation
919 * @param set the set to use for the operation
920 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the
921 * set is invalid (e.g. the set service crashed)
924 GNUNET_SET_commit (struct GNUNET_SET_OperationHandle *oh,
925 struct GNUNET_SET_Handle *set)
927 GNUNET_assert (NULL == oh->set);
928 if (GNUNET_YES == set->invalid)
929 return GNUNET_SYSERR;
930 GNUNET_assert (NULL != oh->conclude_mqm);
932 GNUNET_CONTAINER_DLL_insert (set->ops_head,
935 oh->request_id = GNUNET_MQ_assoc_add (set->mq, oh);
936 *oh->request_id_addr = htonl (oh->request_id);
937 GNUNET_MQ_send (set->mq, oh->conclude_mqm);
938 oh->conclude_mqm = NULL;
939 oh->request_id_addr = NULL;
945 * Iterate over all elements in the given set. Note that this
946 * operation involves transferring every element of the set from the
947 * service to the client, and is thus costly.
949 * @param set the set to iterate over
950 * @param iter the iterator to call for each element
951 * @param iter_cls closure for @a iter
952 * @return #GNUNET_YES if the iteration started successfuly,
953 * #GNUNET_NO if another iteration is active
954 * #GNUNET_SYSERR if the set is invalid (e.g. the server crashed, disconnected)
957 GNUNET_SET_iterate (struct GNUNET_SET_Handle *set,
958 GNUNET_SET_ElementIterator iter,
961 struct GNUNET_MQ_Envelope *ev;
963 GNUNET_assert (NULL != iter);
964 if (GNUNET_YES == set->invalid)
965 return GNUNET_SYSERR;
966 if (NULL != set->iterator)
968 LOG (GNUNET_ERROR_TYPE_DEBUG,
969 "Iterating over set\n");
970 set->iterator = iter;
971 set->iterator_cls = iter_cls;
972 ev = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_SET_ITER_REQUEST);
973 GNUNET_MQ_send (set->mq, ev);
979 * Stop iteration over all elements in the given set. Can only
980 * be called before the iteration has "naturally" completed its
983 * @param set the set to stop iterating over
986 GNUNET_SET_iterate_cancel (struct GNUNET_SET_Handle *set)
988 GNUNET_assert (NULL != set->iterator);
989 set->iterator = NULL;
994 /* end of set_api.c */