2 This file is part of GNUnet.
3 (C) 2012 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 * @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 * Client connected to the consensus service, may be NULL if not connected.
50 struct GNUNET_CLIENT_Connection *client;
53 * Callback for new elements. Not called for elements added locally.
55 GNUNET_CONSENSUS_ElementCallback new_element_cb;
58 * Closure for new_element_cb
60 void *new_element_cls;
63 * The (local) session identifier for the consensus session.
65 struct GNUNET_HashCode session_id;
68 * GNUNES_YES iff the join message has been sent to the service.
73 * Called when the conclude operation finishes or fails.
75 GNUNET_CONSENSUS_ConcludeCallback conclude_cb;
78 * Closure for the conclude callback.
83 * Deadline for the conclude operation.
85 struct GNUNET_TIME_Absolute conclude_deadline;
88 * Message queue for the client.
90 struct GNUNET_MQ_Handle *mq;
94 * FIXME: this should not bee necessary when the API
95 * issue has been fixed
99 GNUNET_CONSENSUS_InsertDoneCallback idc;
105 * Called when the server has sent is a new element
107 * @param cls consensus handle
108 * @param mh element message
111 handle_new_element (void *cls,
112 const struct GNUNET_MessageHeader *mh)
114 struct GNUNET_CONSENSUS_Handle *consensus = cls;
115 const struct GNUNET_CONSENSUS_ElementMessage *msg
116 = (const struct GNUNET_CONSENSUS_ElementMessage *) mh;
117 struct GNUNET_SET_Element element;
119 LOG (GNUNET_ERROR_TYPE_DEBUG, "received new element\n");
121 element.type = msg->element_type;
122 element.size = ntohs (msg->header.size) - sizeof (struct GNUNET_CONSENSUS_ElementMessage);
123 element.data = &msg[1];
125 consensus->new_element_cb (consensus->new_element_cls, &element);
130 * Called when the server has announced
131 * that the conclusion is over.
133 * @param cls consensus handle
134 * @param msg conclude done message
137 handle_conclude_done (void *cls,
138 const struct GNUNET_MessageHeader *msg)
140 struct GNUNET_CONSENSUS_Handle *consensus = cls;
142 GNUNET_CONSENSUS_ConcludeCallback cc;
144 GNUNET_MQ_destroy (consensus->mq);
145 consensus->mq = NULL;
147 GNUNET_CLIENT_disconnect (consensus->client);
148 consensus->client = NULL;
151 GNUNET_assert (NULL != (cc = consensus->conclude_cb));
152 consensus->conclude_cb = NULL;
153 cc (consensus->conclude_cls);
158 * Generic error handler, called with the appropriate
159 * error code and the same closure specified at the creation of
161 * Not every message queue implementation supports an error handler.
163 * @param cls closure, same closure as for the message handlers
164 * @param error error code
167 mq_error_handler (void *cls, enum GNUNET_MQ_Error error)
169 LOG (GNUNET_ERROR_TYPE_WARNING, "consensus service disconnected us\n");
174 * Create a consensus session.
176 * @param cfg configuration to use for connecting to the consensus service
177 * @param num_peers number of peers in the peers array
178 * @param peers array of peers participating in this consensus session
179 * Inclusion of the local peer is optional.
180 * @param session_id session identifier
181 * Allows a group of peers to have more than consensus session.
182 * @param start start time of the consensus, conclude should be called before
184 * @param deadline time when the consensus should have concluded
185 * @param new_element_cb callback, called when a new element is added to the set by
187 * @param new_element_cls closure for new_element
188 * @return handle to use, NULL on error
190 struct GNUNET_CONSENSUS_Handle *
191 GNUNET_CONSENSUS_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
192 unsigned int num_peers,
193 const struct GNUNET_PeerIdentity *peers,
194 const struct GNUNET_HashCode *session_id,
195 struct GNUNET_TIME_Absolute start,
196 struct GNUNET_TIME_Absolute deadline,
197 GNUNET_CONSENSUS_ElementCallback new_element_cb,
198 void *new_element_cls)
200 struct GNUNET_CONSENSUS_Handle *consensus;
201 struct GNUNET_CONSENSUS_JoinMessage *join_msg;
202 struct GNUNET_MQ_Envelope *ev;
203 const static struct GNUNET_MQ_MessageHandler mq_handlers[] = {
205 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_RECEIVED_ELEMENT, 0},
206 {handle_conclude_done,
207 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_CONCLUDE_DONE, 0},
208 GNUNET_MQ_HANDLERS_END
211 consensus = GNUNET_new (struct GNUNET_CONSENSUS_Handle);
212 consensus->cfg = cfg;
213 consensus->new_element_cb = new_element_cb;
214 consensus->new_element_cls = new_element_cls;
215 consensus->session_id = *session_id;
216 consensus->client = GNUNET_CLIENT_connect ("consensus", cfg);
217 consensus->mq = GNUNET_MQ_queue_for_connection_client (consensus->client,
218 mq_handlers, mq_error_handler, consensus);
220 GNUNET_assert (consensus->client != NULL);
222 ev = GNUNET_MQ_msg_extra (join_msg,
223 (num_peers * sizeof (struct GNUNET_PeerIdentity)),
224 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_JOIN);
226 join_msg->session_id = consensus->session_id;
227 join_msg->start = GNUNET_TIME_absolute_hton (start);
228 join_msg->deadline = GNUNET_TIME_absolute_hton (deadline);
229 join_msg->num_peers = htonl (num_peers);
232 num_peers * sizeof (struct GNUNET_PeerIdentity));
234 GNUNET_MQ_send (consensus->mq, ev);
240 idc_adapter (void *cls)
242 struct InsertDoneInfo *i = cls;
243 i->idc (i->cls, GNUNET_OK);
248 * Insert an element in the set being reconsiled. Must not be called after
249 * "GNUNET_CONSENSUS_conclude".
251 * @param consensus handle for the consensus session
252 * @param element the element to be inserted
253 * @param idc function called when we are done with this element and it
254 * is thus allowed to call GNUNET_CONSENSUS_insert again
255 * @param idc_cls closure for 'idc'
258 GNUNET_CONSENSUS_insert (struct GNUNET_CONSENSUS_Handle *consensus,
259 const struct GNUNET_SET_Element *element,
260 GNUNET_CONSENSUS_InsertDoneCallback idc,
263 struct GNUNET_CONSENSUS_ElementMessage *element_msg;
264 struct GNUNET_MQ_Envelope *ev;
265 struct InsertDoneInfo *i;
267 LOG (GNUNET_ERROR_TYPE_DEBUG, "inserting, size=%llu\n", element->size);
269 ev = GNUNET_MQ_msg_extra (element_msg, element->size,
270 GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_INSERT);
272 memcpy (&element_msg[1], element->data, element->size);
276 i = GNUNET_new (struct InsertDoneInfo);
279 GNUNET_MQ_notify_sent (ev, idc_adapter, i);
281 GNUNET_MQ_send (consensus->mq, ev);
286 * We are done with inserting new elements into the consensus;
287 * try to conclude the consensus within a given time window.
288 * After conclude has been called, no further elements may be
289 * inserted by the client.
291 * @param consensus consensus session
292 * @param deadline deadline after which the conculde callback
294 * @param conclude called when the conclusion was successful
295 * @param conclude_cls closure for the conclude callback
298 GNUNET_CONSENSUS_conclude (struct GNUNET_CONSENSUS_Handle *consensus,
299 GNUNET_CONSENSUS_ConcludeCallback conclude,
302 struct GNUNET_MQ_Envelope *ev;
304 GNUNET_assert (NULL != conclude);
305 GNUNET_assert (NULL == consensus->conclude_cb);
307 consensus->conclude_cls = conclude_cls;
308 consensus->conclude_cb = conclude;
310 ev = GNUNET_MQ_msg_header (GNUNET_MESSAGE_TYPE_CONSENSUS_CLIENT_CONCLUDE);
311 GNUNET_MQ_send (consensus->mq, ev);
316 * Destroy a consensus handle (free all state associated with
317 * it, no longer call any of the callbacks).
319 * @param consensus handle to destroy
322 GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *consensus)
324 if (NULL != consensus->mq)
326 GNUNET_MQ_destroy (consensus->mq);
327 consensus->mq = NULL;
329 if (NULL != consensus->client)
331 GNUNET_CLIENT_disconnect (consensus->client);
332 consensus->client = NULL;
334 GNUNET_free (consensus);