2 This file is part of GNUnet
3 Copyright (C) 2012 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/>.
20 * @author Florian Dold
23 * Multi-peer set reconciliation
25 * @defgroup consensus Consensus service
26 * Multi-peer set reconciliation
30 #ifndef GNUNET_CONSENSUS_SERVICE_H
31 #define GNUNET_CONSENSUS_SERVICE_H
36 #if 0 /* keep Emacsens' auto-indent happy */
41 #include "gnunet_common.h"
42 #include "gnunet_time_lib.h"
43 #include "gnunet_configuration_lib.h"
44 #include "gnunet_set_service.h"
48 * Elements inserted into the consensus set by the client
49 * may not be larger than this constant, since types in
50 * the upper range are used by CONSENSUS internally.
52 #define GNUNET_CONSENSUS_ELEMENT_TYPE_USER_MAX 0xFFF0
56 * Called when a new element was received from another peer, or an error occurred.
57 * May deliver duplicate values.
58 * Elements given to a consensus operation by the local peer are NOT given
62 * @param element new element, NULL on error
64 typedef void (*GNUNET_CONSENSUS_ElementCallback) (void *cls,
65 const struct GNUNET_SET_Element *element);
70 * Opaque handle for the consensus service.
72 struct GNUNET_CONSENSUS_Handle;
76 * Create a consensus session. The set being reconciled is initially
81 * @param peers array of peers participating in this consensus session
82 * Inclusion of the local peer is optional.
83 * @param session_id session identifier
84 * Allows a group of peers to have more than consensus session.
85 * @param start start time of the consensus, conclude should be called before
87 * @param deadline time when the consensus should have concluded
88 * @param new_element_cb callback, called when a new element is added to the set by
89 * another peer. Also called when an error occurs.
90 * @param new_element_cls closure for new_element
91 * @return handle to use, NULL on error
93 struct GNUNET_CONSENSUS_Handle *
94 GNUNET_CONSENSUS_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
95 unsigned int num_peers,
96 const struct GNUNET_PeerIdentity *peers,
97 const struct GNUNET_HashCode *session_id,
98 struct GNUNET_TIME_Absolute start,
99 struct GNUNET_TIME_Absolute deadline,
100 GNUNET_CONSENSUS_ElementCallback new_element_cb,
101 void *new_element_cls);
105 * Called when an insertion (transmission to consensus service, which
106 * does not imply fully consensus on this element with all other
107 * peers) was successful. May not call GNUNET_CONSENSUS_destroy();
108 * schedule a task to call GNUNET_CONSENSUS_destroy() instead (if
112 * @param success #GNUNET_OK on success, #GNUNET_SYSERR if
113 * the insertion and thus the consensus failed for good
115 typedef void (*GNUNET_CONSENSUS_InsertDoneCallback) (void *cls,
120 * Insert an element in the set being reconsiled. Only transmit changes to
121 * other peers if GNUNET_CONSENSUS_begin() has been called.
122 * Must not be called after GNUNET_CONSENSUS_conclude().
123 * May not call GNUNET_CONSENSUS_destroy(); schedule a task to call
124 * GNUNET_CONSENSUS_destroy() instead (if needed).
126 * @param consensus handle for the consensus session
127 * @param element the element to be inserted
128 * @param idc function called when we are done with this element and it
129 * is thus allowed to call GNUNET_CONSENSUS_insert() again
130 * @param idc_cls closure for @a idc
133 GNUNET_CONSENSUS_insert (struct GNUNET_CONSENSUS_Handle *consensus,
134 const struct GNUNET_SET_Element *element,
135 GNUNET_CONSENSUS_InsertDoneCallback idc,
141 * Called when a conclusion was successful.
145 typedef void (*GNUNET_CONSENSUS_ConcludeCallback) (void *cls);
149 * We are finished inserting new elements into the consensus;
150 * try to conclude the consensus within a given time window.
152 * @param consensus consensus session
153 * @param conclude called when the conclusion was successful
154 * @param conclude_cls closure for the conclude callback
157 GNUNET_CONSENSUS_conclude (struct GNUNET_CONSENSUS_Handle *consensus,
158 GNUNET_CONSENSUS_ConcludeCallback conclude,
163 * Destroy a consensus handle (free all state associated with
164 * it, no longer call any of the callbacks).
166 * @param consensus handle to destroy
169 GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *consensus);
172 #if 0 /* keep Emacsens' auto-indent happy */
181 /** @} */ /* end of group */