2 This file is part of GNUnet.
3 Copyright (C) 2012-2016 GNUnet e.V.
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., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, 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_set_service.h"
33 #define LOG(kind,...) GNUNET_log_from (kind, "set-api",__VA_ARGS__)
37 struct SetCopyRequest *next;
39 struct SetCopyRequest *prev;
43 GNUNET_SET_CopyReadyCallback cb;
47 * Opaque handle to a set.
49 struct GNUNET_SET_Handle
52 * Message queue for @e client.
54 struct GNUNET_MQ_Handle *mq;
57 * Linked list of operations on the set.
59 struct GNUNET_SET_OperationHandle *ops_head;
62 * Linked list of operations on the set.
64 struct GNUNET_SET_OperationHandle *ops_tail;
67 * Callback for the current iteration over the set,
68 * NULL if no iterator is active.
70 GNUNET_SET_ElementIterator iterator;
73 * Closure for @e iterator
78 * Should the set be destroyed once all operations are gone?
80 int destroy_requested;
83 * Has the set become invalid (e.g. service died)?
88 * Both client and service count the number of iterators
89 * created so far to match replies with iterators.
91 uint16_t iteration_id;
94 * Configuration, needed when creating (lazy) copies.
96 const struct GNUNET_CONFIGURATION_Handle *cfg;
99 * Doubly linked list of copy requests.
101 struct SetCopyRequest *copy_req_head;
104 * Doubly linked list of copy requests.
106 struct SetCopyRequest *copy_req_tail;
111 * Handle for a set operation request from another peer.
113 struct GNUNET_SET_Request
116 * Id of the request, used to identify the request when
117 * accepting/rejecting it.
122 * Has the request been accepted already?
123 * #GNUNET_YES/#GNUNET_NO
130 * Handle to an operation. Only known to the service after committing
131 * the handle with a set.
133 struct GNUNET_SET_OperationHandle
136 * Function to be called when we have a result,
139 GNUNET_SET_ResultIterator result_cb;
142 * Closure for @e result_cb.
147 * Local set used for the operation,
148 * NULL if no set has been provided by conclude yet.
150 struct GNUNET_SET_Handle *set;
153 * Message sent to the server on calling conclude,
154 * NULL if conclude has been called.
156 struct GNUNET_MQ_Envelope *conclude_mqm;
159 * Address of the request if in the conclude message,
160 * used to patch the request id into the message when the set is known.
162 uint32_t *request_id_addr;
165 * Handles are kept in a linked list.
167 struct GNUNET_SET_OperationHandle *prev;
170 * Handles are kept in a linked list.
172 struct GNUNET_SET_OperationHandle *next;
175 * Request ID to identify the operation within the set.
182 * Opaque handle to a listen operation.
184 struct GNUNET_SET_ListenHandle
188 * Message queue for the client.
190 struct GNUNET_MQ_Handle* mq;
193 * Configuration handle for the listener, stored
194 * here to be able to reconnect transparently on
195 * connection failure.
197 const struct GNUNET_CONFIGURATION_Handle *cfg;
200 * Function to call on a new incoming request,
203 GNUNET_SET_ListenCallback listen_cb;
206 * Closure for @e listen_cb.
211 * Application ID we listen for.
213 struct GNUNET_HashCode app_id;
216 * Time to wait until we try to reconnect on failure.
218 struct GNUNET_TIME_Relative reconnect_backoff;
221 * Task for reconnecting when the listener fails.
223 struct GNUNET_SCHEDULER_Task *reconnect_task;
226 * Operation we listen for.
228 enum GNUNET_SET_OperationType operation;
232 /* mutual recursion with handle_copy_lazy */
233 static struct GNUNET_SET_Handle *
234 create_internal (const struct GNUNET_CONFIGURATION_Handle *cfg,
235 enum GNUNET_SET_OperationType op,
236 const uint32_t *cookie);
240 * Handle element for iteration over the set. Notifies the
241 * iterator and sends an acknowledgement to the service.
243 * @param cls the `struct GNUNET_SET_Handle *`
244 * @param msg the message
247 handle_copy_lazy (void *cls,
248 const struct GNUNET_SET_CopyLazyResponseMessage *msg)
250 struct GNUNET_SET_Handle *set = cls;
251 struct SetCopyRequest *req;
252 struct GNUNET_SET_Handle *new_set;
254 req = set->copy_req_head;
257 /* Service sent us unsolicited lazy copy response */
262 LOG (GNUNET_ERROR_TYPE_DEBUG,
263 "Handling response to lazy copy\n");
264 GNUNET_CONTAINER_DLL_remove (set->copy_req_head,
267 // We pass none as operation here, since it doesn't matter when
269 new_set = create_internal (set->cfg,
270 GNUNET_SET_OPERATION_NONE,
272 req->cb (req->cls, new_set);
278 * Check that the given @a msg is well-formed.
281 * @param msg message to check
282 * @return #GNUNET_OK if message is well-formed
285 check_iter_element (void *cls,
286 const struct GNUNET_SET_IterResponseMessage *msg)
288 /* minimum size was already checked, everything else is OK! */
294 * Handle element for iteration over the set. Notifies the
295 * iterator and sends an acknowledgement to the service.
297 * @param cls the `struct GNUNET_SET_Handle *`
298 * @param mh the message
301 handle_iter_element (void *cls,
302 const struct GNUNET_SET_IterResponseMessage *msg)
304 struct GNUNET_SET_Handle *set = cls;
305 GNUNET_SET_ElementIterator iter = set->iterator;
306 struct GNUNET_SET_Element element;
307 struct GNUNET_SET_IterAckMessage *ack_msg;
308 struct GNUNET_MQ_Envelope *ev;
311 msize = ntohs (msg->header.size);
312 if (set->iteration_id != ntohs (msg->iteration_id))
314 /* element from a previous iteration, skip! */
319 element.size = msize - sizeof (struct GNUNET_SET_IterResponseMessage);
320 element.element_type = ntohs (msg->element_type);
321 element.data = &msg[1];
322 iter (set->iterator_cls,
325 ev = GNUNET_MQ_msg (ack_msg,
326 GNUNET_MESSAGE_TYPE_SET_ITER_ACK);
327 ack_msg->send_more = htonl ((NULL != iter));
328 GNUNET_MQ_send (set->mq, ev);
333 * Handle message signalling conclusion of iteration over the set.
334 * Notifies the iterator that we are done.
337 * @param mh the message
340 handle_iter_done (void *cls,
341 const struct GNUNET_MessageHeader *mh)
343 struct GNUNET_SET_Handle *set = cls;
344 GNUNET_SET_ElementIterator iter = set->iterator;
348 set->iterator = NULL;
350 iter (set->iterator_cls,
356 * Check that the given @a msg is well-formed.
359 * @param msg message to check
360 * @return #GNUNET_OK if message is well-formed
363 check_result (void *cls,
364 const struct GNUNET_SET_ResultMessage *msg)
366 /* minimum size was already checked, everything else is OK! */
372 * Handle result message for a set operation.
375 * @param mh the message
378 handle_result (void *cls,
379 const struct GNUNET_SET_ResultMessage *msg)
381 struct GNUNET_SET_Handle *set = cls;
382 struct GNUNET_SET_OperationHandle *oh;
383 struct GNUNET_SET_Element e;
384 enum GNUNET_SET_Status result_status;
386 GNUNET_assert (NULL != set->mq);
387 result_status = ntohs (msg->result_status);
388 LOG (GNUNET_ERROR_TYPE_DEBUG,
389 "Got result message with status %d\n",
392 oh = GNUNET_MQ_assoc_get (set->mq,
393 ntohl (msg->request_id));
396 /* 'oh' can be NULL if we canceled the operation, but the service
397 did not get the cancel message yet. */
398 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
399 "Ignoring result from canceled operation\n");
403 switch (result_status)
405 case GNUNET_SET_STATUS_OK:
406 case GNUNET_SET_STATUS_ADD_LOCAL:
407 case GNUNET_SET_STATUS_ADD_REMOTE:
409 case GNUNET_SET_STATUS_FAILURE:
410 case GNUNET_SET_STATUS_DONE:
412 case GNUNET_SET_STATUS_HALF_DONE:
413 /* not used anymore */
418 LOG (GNUNET_ERROR_TYPE_DEBUG,
419 "Treating result as final status\n");
420 GNUNET_MQ_assoc_remove (set->mq,
421 ntohl (msg->request_id));
422 GNUNET_CONTAINER_DLL_remove (set->ops_head,
425 if (NULL != oh->result_cb)
427 oh->result_cb (oh->result_cls,
433 LOG (GNUNET_ERROR_TYPE_DEBUG,
434 "No callback for final status\n");
436 if ( (GNUNET_YES == set->destroy_requested) &&
437 (NULL == set->ops_head) )
438 GNUNET_SET_destroy (set);
443 LOG (GNUNET_ERROR_TYPE_DEBUG,
444 "Treating result as element\n");
446 e.size = ntohs (msg->header.size) - sizeof (struct GNUNET_SET_ResultMessage);
447 e.element_type = ntohs (msg->element_type);
448 if (NULL != oh->result_cb)
449 oh->result_cb (oh->result_cls,
456 * Destroy the given set operation.
458 * @param oh set operation to destroy
461 set_operation_destroy (struct GNUNET_SET_OperationHandle *oh)
463 struct GNUNET_SET_Handle *set = oh->set;
464 struct GNUNET_SET_OperationHandle *h_assoc;
466 if (NULL != oh->conclude_mqm)
467 GNUNET_MQ_discard (oh->conclude_mqm);
468 /* is the operation already commited? */
471 GNUNET_CONTAINER_DLL_remove (set->ops_head,
474 h_assoc = GNUNET_MQ_assoc_remove (set->mq,
476 GNUNET_assert ((NULL == h_assoc) || (h_assoc == oh));
483 * Cancel the given set operation. We need to send an explicit cancel
484 * message, as all operations one one set communicate using one
487 * @param oh set operation to cancel
490 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh)
492 struct GNUNET_SET_Handle *set = oh->set;
493 struct GNUNET_SET_CancelMessage *m;
494 struct GNUNET_MQ_Envelope *mqm;
498 mqm = GNUNET_MQ_msg (m, GNUNET_MESSAGE_TYPE_SET_CANCEL);
499 m->request_id = htonl (oh->request_id);
500 GNUNET_MQ_send (set->mq, mqm);
502 set_operation_destroy (oh);
503 if ( (NULL != set) &&
504 (GNUNET_YES == set->destroy_requested) &&
505 (NULL == set->ops_head) )
507 LOG (GNUNET_ERROR_TYPE_DEBUG,
508 "Destroying set after operation cancel\n");
509 GNUNET_SET_destroy (set);
515 * We encountered an error communicating with the set service while
516 * performing a set operation. Report to the application.
518 * @param cls the `struct GNUNET_SET_Handle`
519 * @param error error code
522 handle_client_set_error (void *cls,
523 enum GNUNET_MQ_Error error)
525 struct GNUNET_SET_Handle *set = cls;
526 GNUNET_SET_ElementIterator iter = set->iterator;
528 LOG (GNUNET_ERROR_TYPE_DEBUG,
529 "Handling client set error %d\n",
531 while (NULL != set->ops_head)
533 if (NULL != set->ops_head->result_cb)
534 set->ops_head->result_cb (set->ops_head->result_cls,
536 GNUNET_SET_STATUS_FAILURE);
537 set_operation_destroy (set->ops_head);
539 set->iterator = NULL;
542 iter (set->iterator_cls,
544 set->invalid = GNUNET_YES;
545 if (GNUNET_YES == set->destroy_requested)
547 LOG (GNUNET_ERROR_TYPE_DEBUG,
548 "Destroying set after operation failure\n");
549 GNUNET_SET_destroy (set);
554 static struct GNUNET_SET_Handle *
555 create_internal (const struct GNUNET_CONFIGURATION_Handle *cfg,
556 enum GNUNET_SET_OperationType op,
557 const uint32_t *cookie)
559 GNUNET_MQ_hd_var_size (result,
560 GNUNET_MESSAGE_TYPE_SET_RESULT,
561 struct GNUNET_SET_ResultMessage);
562 GNUNET_MQ_hd_var_size (iter_element,
563 GNUNET_MESSAGE_TYPE_SET_ITER_ELEMENT,
564 struct GNUNET_SET_IterResponseMessage);
565 GNUNET_MQ_hd_fixed_size (iter_done,
566 GNUNET_MESSAGE_TYPE_SET_ITER_DONE,
567 struct GNUNET_MessageHeader);
568 GNUNET_MQ_hd_fixed_size (copy_lazy,
569 GNUNET_MESSAGE_TYPE_SET_COPY_LAZY_RESPONSE,
570 struct GNUNET_SET_CopyLazyResponseMessage);
571 struct GNUNET_SET_Handle *set = GNUNET_new (struct GNUNET_SET_Handle);
572 struct GNUNET_MQ_MessageHandler mq_handlers[] = {
573 make_result_handler (set),
574 make_iter_element_handler (set),
575 make_iter_done_handler (set),
576 make_copy_lazy_handler (set),
577 GNUNET_MQ_handler_end ()
579 struct GNUNET_MQ_Envelope *mqm;
580 struct GNUNET_SET_CreateMessage *create_msg;
581 struct GNUNET_SET_CopyLazyConnectMessage *copy_msg;
584 set->mq = GNUNET_CLIENT_connecT (cfg,
587 &handle_client_set_error,
596 LOG (GNUNET_ERROR_TYPE_DEBUG,
597 "Creating new set (operation %u)\n",
599 mqm = GNUNET_MQ_msg (create_msg,
600 GNUNET_MESSAGE_TYPE_SET_CREATE);
601 create_msg->operation = htonl (op);
605 LOG (GNUNET_ERROR_TYPE_DEBUG,
606 "Creating new set (lazy copy)\n",
608 mqm = GNUNET_MQ_msg (copy_msg,
609 GNUNET_MESSAGE_TYPE_SET_COPY_LAZY_CONNECT);
610 copy_msg->cookie = *cookie;
612 GNUNET_MQ_send (set->mq, mqm);
618 * Create an empty set, supporting the specified operation.
620 * @param cfg configuration to use for connecting to the
622 * @param op operation supported by the set
623 * Note that the operation has to be specified
624 * beforehand, as certain set operations need to maintain
625 * data structures spefific to the operation
626 * @return a handle to the set
628 struct GNUNET_SET_Handle *
629 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
630 enum GNUNET_SET_OperationType op)
632 return create_internal (cfg, op, NULL);
637 * Add an element to the given set. After the element has been added
638 * (in the sense of being transmitted to the set service), @a cont
639 * will be called. Multiple calls to GNUNET_SET_add_element() can be
642 * @param set set to add element to
643 * @param element element to add to the set
644 * @param cont continuation called after the element has been added
645 * @param cont_cls closure for @a cont
646 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the
647 * set is invalid (e.g. the set service crashed)
650 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
651 const struct GNUNET_SET_Element *element,
652 GNUNET_SET_Continuation cont,
655 struct GNUNET_MQ_Envelope *mqm;
656 struct GNUNET_SET_ElementMessage *msg;
658 if (GNUNET_YES == set->invalid)
662 return GNUNET_SYSERR;
664 mqm = GNUNET_MQ_msg_extra (msg, element->size,
665 GNUNET_MESSAGE_TYPE_SET_ADD);
666 msg->element_type = htons (element->element_type);
667 GNUNET_memcpy (&msg[1],
670 GNUNET_MQ_notify_sent (mqm,
672 GNUNET_MQ_send (set->mq, mqm);
678 * Remove an element to the given set. After the element has been
679 * removed (in the sense of the request being transmitted to the set
680 * service), @a cont will be called. Multiple calls to
681 * GNUNET_SET_remove_element() can be queued
683 * @param set set to remove element from
684 * @param element element to remove from the set
685 * @param cont continuation called after the element has been removed
686 * @param cont_cls closure for @a cont
687 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the
688 * set is invalid (e.g. the set service crashed)
691 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
692 const struct GNUNET_SET_Element *element,
693 GNUNET_SET_Continuation cont,
696 struct GNUNET_MQ_Envelope *mqm;
697 struct GNUNET_SET_ElementMessage *msg;
699 if (GNUNET_YES == set->invalid)
703 return GNUNET_SYSERR;
705 mqm = GNUNET_MQ_msg_extra (msg,
707 GNUNET_MESSAGE_TYPE_SET_REMOVE);
708 msg->element_type = htons (element->element_type);
709 GNUNET_memcpy (&msg[1],
712 GNUNET_MQ_notify_sent (mqm,
714 GNUNET_MQ_send (set->mq, mqm);
720 * Destroy the set handle if no operations are left, mark the set
721 * for destruction otherwise.
723 * @param set set handle to destroy
726 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set)
728 /* destroying set while iterator is active is currently
729 not supported; we should expand the API to allow
730 clients to explicitly cancel the iteration! */
731 GNUNET_assert (NULL == set->iterator);
732 if (NULL != set->ops_head)
734 LOG (GNUNET_ERROR_TYPE_DEBUG,
735 "Set operations are pending, delaying set destruction\n");
736 set->destroy_requested = GNUNET_YES;
739 LOG (GNUNET_ERROR_TYPE_DEBUG,
740 "Really destroying set\n");
743 GNUNET_MQ_destroy (set->mq);
751 * Prepare a set operation to be evaluated with another peer.
752 * The evaluation will not start until the client provides
753 * a local set with #GNUNET_SET_commit().
755 * @param other_peer peer with the other set
756 * @param app_id hash for the application using the set
757 * @param context_msg additional information for the request
758 * @param result_mode specified how results will be returned,
759 * see `enum GNUNET_SET_ResultMode`.
760 * @param result_cb called on error or success
761 * @param result_cls closure for @e result_cb
762 * @return a handle to cancel the operation
764 struct GNUNET_SET_OperationHandle *
765 GNUNET_SET_prepare (const struct GNUNET_PeerIdentity *other_peer,
766 const struct GNUNET_HashCode *app_id,
767 const struct GNUNET_MessageHeader *context_msg,
768 enum GNUNET_SET_ResultMode result_mode,
769 GNUNET_SET_ResultIterator result_cb,
772 struct GNUNET_MQ_Envelope *mqm;
773 struct GNUNET_SET_OperationHandle *oh;
774 struct GNUNET_SET_EvaluateMessage *msg;
776 oh = GNUNET_new (struct GNUNET_SET_OperationHandle);
777 oh->result_cb = result_cb;
778 oh->result_cls = result_cls;
779 mqm = GNUNET_MQ_msg_nested_mh (msg,
780 GNUNET_MESSAGE_TYPE_SET_EVALUATE,
782 msg->app_id = *app_id;
783 msg->result_mode = htonl (result_mode);
784 msg->target_peer = *other_peer;
785 oh->conclude_mqm = mqm;
786 oh->request_id_addr = &msg->request_id;
793 * Connect to the set service in order to listen for requests.
795 * @param cls the `struct GNUNET_SET_ListenHandle *` to connect
798 listen_connect (void *cls);
802 * Check validity of request message for a listen operation
804 * @param cls the listen handle
805 * @param msg the message
806 * @return #GNUNET_OK if the message is well-formed
809 check_request (void *cls,
810 const struct GNUNET_SET_RequestMessage *msg)
812 const struct GNUNET_MessageHeader *context_msg;
814 if (ntohs (msg->header.size) == sizeof (*msg))
815 return GNUNET_OK; /* no context message is OK */
816 context_msg = GNUNET_MQ_extract_nested_mh (msg);
817 if (NULL == context_msg)
819 /* malformed context message is NOT ok */
821 return GNUNET_SYSERR;
828 * Handle request message for a listen operation
830 * @param cls the listen handle
831 * @param msg the message
834 handle_request (void *cls,
835 const struct GNUNET_SET_RequestMessage *msg)
837 struct GNUNET_SET_ListenHandle *lh = cls;
838 struct GNUNET_SET_Request req;
839 const struct GNUNET_MessageHeader *context_msg;
840 struct GNUNET_MQ_Envelope *mqm;
841 struct GNUNET_SET_RejectMessage *rmsg;
843 LOG (GNUNET_ERROR_TYPE_DEBUG,
844 "Processing incoming operation request\n");
845 /* we got another valid request => reset the backoff */
846 lh->reconnect_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
847 req.accept_id = ntohl (msg->accept_id);
848 req.accepted = GNUNET_NO;
849 context_msg = GNUNET_MQ_extract_nested_mh (msg);
850 /* calling #GNUNET_SET_accept() in the listen cb will set req->accepted */
851 lh->listen_cb (lh->listen_cls,
855 if (GNUNET_YES == req.accepted)
856 return; /* the accept-case is handled in #GNUNET_SET_accept() */
857 LOG (GNUNET_ERROR_TYPE_DEBUG,
858 "Rejecting request\n");
859 mqm = GNUNET_MQ_msg (rmsg,
860 GNUNET_MESSAGE_TYPE_SET_REJECT);
861 rmsg->accept_reject_id = msg->accept_id;
862 GNUNET_MQ_send (lh->mq, mqm);
867 * Our connection with the set service encountered an error,
868 * re-initialize with exponential back-off.
870 * @param cls the `struct GNUNET_SET_ListenHandle *`
871 * @param error reason for the disconnect
874 handle_client_listener_error (void *cls,
875 enum GNUNET_MQ_Error error)
877 struct GNUNET_SET_ListenHandle *lh = cls;
879 LOG (GNUNET_ERROR_TYPE_DEBUG,
880 "Listener broke down (%d), re-connecting\n",
882 GNUNET_MQ_destroy (lh->mq);
884 lh->reconnect_task = GNUNET_SCHEDULER_add_delayed (lh->reconnect_backoff,
887 lh->reconnect_backoff = GNUNET_TIME_STD_BACKOFF (lh->reconnect_backoff);
892 * Connect to the set service in order to listen for requests.
894 * @param cls the `struct GNUNET_SET_ListenHandle *` to connect
897 listen_connect (void *cls)
899 GNUNET_MQ_hd_var_size (request,
900 GNUNET_MESSAGE_TYPE_SET_REQUEST,
901 struct GNUNET_SET_RequestMessage);
902 struct GNUNET_SET_ListenHandle *lh = cls;
903 struct GNUNET_MQ_MessageHandler mq_handlers[] = {
904 make_request_handler (lh),
905 GNUNET_MQ_handler_end ()
907 struct GNUNET_MQ_Envelope *mqm;
908 struct GNUNET_SET_ListenMessage *msg;
910 lh->reconnect_task = NULL;
911 GNUNET_assert (NULL == lh->mq);
912 lh->mq = GNUNET_CLIENT_connecT (lh->cfg,
915 &handle_client_listener_error,
919 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_LISTEN);
920 msg->operation = htonl (lh->operation);
921 msg->app_id = lh->app_id;
922 GNUNET_MQ_send (lh->mq,
928 * Wait for set operation requests for the given application id
930 * @param cfg configuration to use for connecting to
931 * the set service, needs to be valid for the lifetime of the listen handle
932 * @param operation operation we want to listen for
933 * @param app_id id of the application that handles set operation requests
934 * @param listen_cb called for each incoming request matching the operation
936 * @param listen_cls handle for @a listen_cb
937 * @return a handle that can be used to cancel the listen operation
939 struct GNUNET_SET_ListenHandle *
940 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
941 enum GNUNET_SET_OperationType operation,
942 const struct GNUNET_HashCode *app_id,
943 GNUNET_SET_ListenCallback listen_cb,
946 struct GNUNET_SET_ListenHandle *lh;
948 lh = GNUNET_new (struct GNUNET_SET_ListenHandle);
949 lh->listen_cb = listen_cb;
950 lh->listen_cls = listen_cls;
952 lh->operation = operation;
953 lh->app_id = *app_id;
954 lh->reconnect_backoff = GNUNET_TIME_UNIT_MILLISECONDS;
966 * Cancel the given listen operation.
968 * @param lh handle for the listen operation
971 GNUNET_SET_listen_cancel (struct GNUNET_SET_ListenHandle *lh)
973 LOG (GNUNET_ERROR_TYPE_DEBUG,
974 "Canceling listener\n");
977 GNUNET_MQ_destroy (lh->mq);
980 if (NULL != lh->reconnect_task)
982 GNUNET_SCHEDULER_cancel (lh->reconnect_task);
983 lh->reconnect_task = NULL;
990 * Accept a request we got via #GNUNET_SET_listen. Must be called during
991 * #GNUNET_SET_listen, as the 'struct GNUNET_SET_Request' becomes invalid
993 * Call #GNUNET_SET_commit to provide the local set to use for the operation,
994 * and to begin the exchange with the remote peer.
996 * @param request request to accept
997 * @param result_mode specified how results will be returned,
998 * see `enum GNUNET_SET_ResultMode`.
999 * @param result_cb callback for the results
1000 * @param result_cls closure for @a result_cb
1001 * @return a handle to cancel the operation
1003 struct GNUNET_SET_OperationHandle *
1004 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
1005 enum GNUNET_SET_ResultMode result_mode,
1006 GNUNET_SET_ResultIterator result_cb,
1009 struct GNUNET_MQ_Envelope *mqm;
1010 struct GNUNET_SET_OperationHandle *oh;
1011 struct GNUNET_SET_AcceptMessage *msg;
1013 GNUNET_assert (GNUNET_NO == request->accepted);
1014 request->accepted = GNUNET_YES;
1015 mqm = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_SET_ACCEPT);
1016 msg->accept_reject_id = htonl (request->accept_id);
1017 msg->result_mode = htonl (result_mode);
1018 oh = GNUNET_new (struct GNUNET_SET_OperationHandle);
1019 oh->result_cb = result_cb;
1020 oh->result_cls = result_cls;
1021 oh->conclude_mqm = mqm;
1022 oh->request_id_addr = &msg->request_id;
1028 * Commit a set to be used with a set operation.
1029 * This function is called once we have fully constructed
1030 * the set that we want to use for the operation. At this
1031 * time, the P2P protocol can then begin to exchange the
1032 * set information and call the result callback with the
1033 * result information.
1035 * @param oh handle to the set operation
1036 * @param set the set to use for the operation
1037 * @return #GNUNET_OK on success, #GNUNET_SYSERR if the
1038 * set is invalid (e.g. the set service crashed)
1041 GNUNET_SET_commit (struct GNUNET_SET_OperationHandle *oh,
1042 struct GNUNET_SET_Handle *set)
1044 if (NULL != oh->set)
1046 /* Some other set was already commited for this
1047 * operation, there is a logic bug in the client of this API */
1051 if (GNUNET_YES == set->invalid)
1052 return GNUNET_SYSERR;
1053 GNUNET_assert (NULL != oh->conclude_mqm);
1055 GNUNET_CONTAINER_DLL_insert (set->ops_head,
1058 oh->request_id = GNUNET_MQ_assoc_add (set->mq, oh);
1059 *oh->request_id_addr = htonl (oh->request_id);
1060 GNUNET_MQ_send (set->mq, oh->conclude_mqm);
1061 oh->conclude_mqm = NULL;
1062 oh->request_id_addr = NULL;
1068 * Iterate over all elements in the given set. Note that this
1069 * operation involves transferring every element of the set from the
1070 * service to the client, and is thus costly.
1072 * @param set the set to iterate over
1073 * @param iter the iterator to call for each element
1074 * @param iter_cls closure for @a iter
1075 * @return #GNUNET_YES if the iteration started successfuly,
1076 * #GNUNET_NO if another iteration is active
1077 * #GNUNET_SYSERR if the set is invalid (e.g. the server crashed, disconnected)
1080 GNUNET_SET_iterate (struct GNUNET_SET_Handle *set,
1081 GNUNET_SET_ElementIterator iter,
1084 struct GNUNET_MQ_Envelope *ev;
1086 GNUNET_assert (NULL != iter);
1087 if (GNUNET_YES == set->invalid)
1088 return GNUNET_SYSERR;
1089 if (NULL != set->iterator)
1091 LOG (GNUNET_ERROR_TYPE_DEBUG,
1092 "Iterating over set\n");
1093 set->iterator = iter;
1094 set->iterator_cls = iter_cls;
1095 ev = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_SET_ITER_REQUEST);
1096 GNUNET_MQ_send (set->mq, ev);
1102 GNUNET_SET_copy_lazy (struct GNUNET_SET_Handle *set,
1103 GNUNET_SET_CopyReadyCallback cb,
1106 struct GNUNET_MQ_Envelope *ev;
1107 struct SetCopyRequest *req;
1109 ev = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_SET_COPY_LAZY_PREPARE);
1110 GNUNET_MQ_send (set->mq, ev);
1112 req = GNUNET_new (struct SetCopyRequest);
1115 GNUNET_CONTAINER_DLL_insert (set->copy_req_head,
1122 * Create a copy of an element. The copy
1123 * must be GNUNET_free-d by the caller.
1125 * @param element the element to copy
1126 * @return the copied element
1128 struct GNUNET_SET_Element *
1129 GNUNET_SET_element_dup (const struct GNUNET_SET_Element *element)
1131 struct GNUNET_SET_Element *copy;
1133 copy = GNUNET_malloc (element->size + sizeof (struct GNUNET_SET_Element));
1134 copy->size = element->size;
1135 copy->element_type = element->element_type;
1136 copy->data = ©[1];
1137 GNUNET_memcpy (copy->data, element->data, copy->size);
1144 * Hash a set element.
1146 * @param element the element that should be hashed
1147 * @param[out] ret_hash a pointer to where the hash of @a element
1151 GNUNET_SET_element_hash (const struct GNUNET_SET_Element *element,
1152 struct GNUNET_HashCode *ret_hash)
1154 struct GNUNET_HashContext *ctx = GNUNET_CRYPTO_hash_context_start ();
1156 /* It's not guaranteed that the element data is always after the element header,
1157 so we need to hash the chunks separately. */
1158 GNUNET_CRYPTO_hash_context_read (ctx, &element->size, sizeof (uint16_t));
1159 GNUNET_CRYPTO_hash_context_read (ctx, &element->element_type, sizeof (uint16_t));
1160 GNUNET_CRYPTO_hash_context_read (ctx, element->data, element->size);
1161 GNUNET_CRYPTO_hash_context_finish (ctx, ret_hash);
1164 /* end of set_api.c */