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 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,
8 or (at your 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 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 * @file consensus/consensus_api.c
24 * @author Florian Dold
27 #include "gnunet_util_lib.h"
28 #include "gnunet_protocols.h"
29 #include "gnunet_client_lib.h"
30 #include "gnunet_consensus_service.h"
31 #include "consensus.h"
34 #define LOG(kind, ...) GNUNET_log_from (kind, "consensus-api", __VA_ARGS__)
38 * Handle for the service.
40 struct GNUNET_CONSENSUS_Handle
43 * Configuration to use.
45 const struct GNUNET_CONFIGURATION_Handle *cfg;
48 * Callback for new elements. Not called for elements added locally.
50 GNUNET_CONSENSUS_ElementCallback new_element_cb;
53 * Closure for @e new_element_cb
55 void *new_element_cls;
58 * The (local) session identifier for the consensus session.
60 struct GNUNET_HashCode session_id;
63 * #GNUNET_YES iff the join message has been sent to the service.
68 * Called when the conclude operation finishes or fails.
70 GNUNET_CONSENSUS_ConcludeCallback conclude_cb;
73 * Closure for the @e conclude_cb callback.
78 * Deadline for the conclude operation.
80 struct GNUNET_TIME_Absolute conclude_deadline;
83 * Message queue for the client.
85 struct GNUNET_MQ_Handle *mq;
90 * FIXME: this should not bee necessary when the API
91 * issue has been fixed
95 GNUNET_CONSENSUS_InsertDoneCallback idc;
101 * Called when the server has sent is a new element
103 * @param cls consensus handle
104 * @param msg element message
107 check_new_element (void *cls,
108 const struct GNUNET_CONSENSUS_ElementMessage *msg)
110 /* any size is fine, elements are variable-size */
116 * Called when the server has sent is a new element
118 * @param cls consensus handle
119 * @param msg element message
122 handle_new_element (void *cls,
123 const struct GNUNET_CONSENSUS_ElementMessage *msg)
125 struct GNUNET_CONSENSUS_Handle *consensus = cls;
126 struct GNUNET_SET_Element element;
128 LOG (GNUNET_ERROR_TYPE_DEBUG,
129 "received new element\n");
130 element.element_type = msg->element_type;
131 element.size = ntohs (msg->header.size) - sizeof(struct
132 GNUNET_CONSENSUS_ElementMessage);
133 element.data = &msg[1];
134 consensus->new_element_cb (consensus->new_element_cls,
140 * Called when the server has announced
141 * that the conclusion is over.
143 * @param cls consensus handle
144 * @param msg conclude done message
147 handle_conclude_done (void *cls,
148 const struct GNUNET_MessageHeader *msg)
150 struct GNUNET_CONSENSUS_Handle *consensus = cls;
151 GNUNET_CONSENSUS_ConcludeCallback cc;
153 GNUNET_MQ_destroy (consensus->mq);
154 consensus->mq = NULL;
155 GNUNET_assert (NULL != (cc = consensus->conclude_cb));
156 consensus->conclude_cb = NULL;
157 cc (consensus->conclude_cls);
162 * Generic error handler, called with the appropriate
163 * error code and the same closure specified at the creation of
165 * Not every message queue implementation supports an error handler.
167 * @param cls closure, same closure as for the message handlers
168 * @param error error code
171 mq_error_handler (void *cls,
172 enum GNUNET_MQ_Error error)
174 LOG (GNUNET_ERROR_TYPE_WARNING,
175 "consensus service disconnected us\n");
180 * Create a consensus session.
182 * @param cfg configuration to use for connecting to the consensus service
183 * @param num_peers number of peers in the peers array
184 * @param peers array of peers participating in this consensus session
185 * Inclusion of the local peer is optional.
186 * @param session_id session identifier
187 * Allows a group of peers to have more than consensus session.
188 * @param start start time of the consensus, conclude should be called before
190 * @param deadline time when the consensus should have concluded
191 * @param new_element_cb callback, called when a new element is added to the set by
193 * @param new_element_cls closure for new_element
194 * @return handle to use, NULL on error
196 struct GNUNET_CONSENSUS_Handle *
197 GNUNET_CONSENSUS_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
198 unsigned int num_peers,
199 const struct GNUNET_PeerIdentity *peers,
200 const struct GNUNET_HashCode *session_id,
201 struct GNUNET_TIME_Absolute start,
202 struct GNUNET_TIME_Absolute deadline,
203 GNUNET_CONSENSUS_ElementCallback new_element_cb,
204 void *new_element_cls)
206 struct GNUNET_CONSENSUS_Handle *consensus
207 = GNUNET_new (struct GNUNET_CONSENSUS_Handle);
208 struct GNUNET_MQ_MessageHandler mq_handlers[] = {
209 GNUNET_MQ_hd_var_size (new_element,
210 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_RECEIVED_ELEMENT,
211 struct GNUNET_CONSENSUS_ElementMessage,
213 GNUNET_MQ_hd_fixed_size (conclude_done,
214 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_CONCLUDE_DONE,
215 struct GNUNET_MessageHeader,
217 GNUNET_MQ_handler_end ()
219 struct GNUNET_CONSENSUS_JoinMessage *join_msg;
220 struct GNUNET_MQ_Envelope *ev;
222 consensus->cfg = cfg;
223 consensus->new_element_cb = new_element_cb;
224 consensus->new_element_cls = new_element_cls;
225 consensus->session_id = *session_id;
226 consensus->mq = GNUNET_CLIENT_connect (cfg,
231 if (NULL == consensus->mq)
233 GNUNET_free (consensus);
236 ev = GNUNET_MQ_msg_extra (join_msg,
237 (num_peers * sizeof(struct GNUNET_PeerIdentity)),
238 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_JOIN);
240 join_msg->session_id = consensus->session_id;
241 join_msg->start = GNUNET_TIME_absolute_hton (start);
242 join_msg->deadline = GNUNET_TIME_absolute_hton (deadline);
243 join_msg->num_peers = htonl (num_peers);
244 GNUNET_memcpy (&join_msg[1],
246 num_peers * sizeof(struct GNUNET_PeerIdentity));
248 GNUNET_MQ_send (consensus->mq, ev);
254 idc_adapter (void *cls)
256 struct InsertDoneInfo *i = cls;
258 i->idc (i->cls, GNUNET_OK);
264 * Insert an element in the set being reconsiled. Must not be called after
265 * "GNUNET_CONSENSUS_conclude".
267 * @param consensus handle for the consensus session
268 * @param element the element to be inserted
269 * @param idc function called when we are done with this element and it
270 * is thus allowed to call GNUNET_CONSENSUS_insert again
271 * @param idc_cls closure for 'idc'
274 GNUNET_CONSENSUS_insert (struct GNUNET_CONSENSUS_Handle *consensus,
275 const struct GNUNET_SET_Element *element,
276 GNUNET_CONSENSUS_InsertDoneCallback idc,
279 struct GNUNET_CONSENSUS_ElementMessage *element_msg;
280 struct GNUNET_MQ_Envelope *ev;
281 struct InsertDoneInfo *i;
283 LOG (GNUNET_ERROR_TYPE_DEBUG, "inserting, size=%llu\n", element->size);
285 ev = GNUNET_MQ_msg_extra (element_msg, element->size,
286 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_INSERT);
288 GNUNET_memcpy (&element_msg[1], element->data, element->size);
292 i = GNUNET_new (struct InsertDoneInfo);
295 GNUNET_MQ_notify_sent (ev, idc_adapter, i);
297 GNUNET_MQ_send (consensus->mq, ev);
302 * We are done with inserting new elements into the consensus;
303 * try to conclude the consensus within a given time window.
304 * After conclude has been called, no further elements may be
305 * inserted by the client.
307 * @param consensus consensus session
308 * @param deadline deadline after which the conculde callback
310 * @param conclude called when the conclusion was successful
311 * @param conclude_cls closure for the conclude callback
314 GNUNET_CONSENSUS_conclude (struct GNUNET_CONSENSUS_Handle *consensus,
315 GNUNET_CONSENSUS_ConcludeCallback conclude,
318 struct GNUNET_MQ_Envelope *ev;
320 GNUNET_assert (NULL != conclude);
321 GNUNET_assert (NULL == consensus->conclude_cb);
323 consensus->conclude_cls = conclude_cls;
324 consensus->conclude_cb = conclude;
326 ev = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_CONCLUDE);
327 GNUNET_MQ_send (consensus->mq, ev);
332 * Destroy a consensus handle (free all state associated with
333 * it, no longer call any of the callbacks).
335 * @param consensus handle to destroy
338 GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *consensus)
340 if (NULL != consensus->mq)
342 GNUNET_MQ_destroy (consensus->mq);
343 consensus->mq = NULL;
345 GNUNET_free (consensus);
349 /* end of consensus_api.c */