2 This file is part of GNUnet
3 Copyright (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., 51 Franklin Street, Fifth Floor,
18 Boston, MA 02110-1301, USA.
22 * @file include/gnunet_consensus_service.h
23 * @brief multi-peer set reconciliation
24 * @author Florian Dold
27 #ifndef GNUNET_CONSENSUS_SERVICE_H
28 #define GNUNET_CONSENSUS_SERVICE_H
33 #if 0 /* keep Emacsens' auto-indent happy */
39 #include "gnunet_common.h"
40 #include "gnunet_time_lib.h"
41 #include "gnunet_configuration_lib.h"
42 #include "gnunet_set_service.h"
46 * Elements inserted into the consensus set by the client
47 * may not be larger than this constant, since types in
48 * the upper range are used by CONSENSUS internally.
50 #define GNUNET_CONSENSUS_ELEMENT_TYPE_USER_MAX 0xFFF0
54 * Called when a new element was received from another peer, or an error occured.
55 * May deliver duplicate values.
56 * Elements given to a consensus operation by the local peer are NOT given
60 * @param element new element, NULL on error
62 typedef void (*GNUNET_CONSENSUS_ElementCallback) (void *cls,
63 const struct GNUNET_SET_Element *element);
68 * Opaque handle for the consensus service.
70 struct GNUNET_CONSENSUS_Handle;
74 * Create a consensus session. The set being reconciled is initially
79 * @param peers array of peers participating in this consensus session
80 * Inclusion of the local peer is optional.
81 * @param session_id session identifier
82 * Allows a group of peers to have more than consensus session.
83 * @param start start time of the consensus, conclude should be called before
85 * @param deadline time when the consensus should have concluded
86 * @param new_element_cb callback, called when a new element is added to the set by
87 * another peer. Also called when an error occurs.
88 * @param new_element_cls closure for new_element
89 * @return handle to use, NULL on error
91 struct GNUNET_CONSENSUS_Handle *
92 GNUNET_CONSENSUS_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
93 unsigned int num_peers,
94 const struct GNUNET_PeerIdentity *peers,
95 const struct GNUNET_HashCode *session_id,
96 struct GNUNET_TIME_Absolute start,
97 struct GNUNET_TIME_Absolute deadline,
98 GNUNET_CONSENSUS_ElementCallback new_element_cb,
99 void *new_element_cls);
103 * Called when an insertion (transmission to consensus service, which
104 * does not imply fully consensus on this element with all other
105 * peers) was successful. May not call GNUNET_CONSENSUS_destroy();
106 * schedule a task to call GNUNET_CONSENSUS_destroy() instead (if
110 * @param success #GNUNET_OK on success, #GNUNET_SYSERR if
111 * the insertion and thus the consensus failed for good
113 typedef void (*GNUNET_CONSENSUS_InsertDoneCallback) (void *cls,
118 * Insert an element in the set being reconsiled. Only transmit changes to
119 * other peers if GNUNET_CONSENSUS_begin() has been called.
120 * Must not be called after GNUNET_CONSENSUS_conclude().
121 * May not call GNUNET_CONSENSUS_destroy(); schedule a task to call
122 * GNUNET_CONSENSUS_destroy() instead (if needed).
124 * @param consensus handle for the consensus session
125 * @param element the element to be inserted
126 * @param idc function called when we are done with this element and it
127 * is thus allowed to call GNUNET_CONSENSUS_insert() again
128 * @param idc_cls closure for @a idc
131 GNUNET_CONSENSUS_insert (struct GNUNET_CONSENSUS_Handle *consensus,
132 const struct GNUNET_SET_Element *element,
133 GNUNET_CONSENSUS_InsertDoneCallback idc,
139 * Called when a conclusion was successful.
143 typedef void (*GNUNET_CONSENSUS_ConcludeCallback) (void *cls);
147 * We are finished inserting new elements into the consensus;
148 * try to conclude the consensus within a given time window.
150 * @param consensus consensus session
151 * @param conclude called when the conclusion was successful
152 * @param conclude_cls closure for the conclude callback
155 GNUNET_CONSENSUS_conclude (struct GNUNET_CONSENSUS_Handle *consensus,
156 GNUNET_CONSENSUS_ConcludeCallback conclude,
161 * Destroy a consensus handle (free all state associated with
162 * it, no longer call any of the callbacks).
164 * @param consensus handle to destroy
167 GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *consensus);
170 #if 0 /* keep Emacsens' auto-indent happy */