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 2, 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 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"
45 * An element of the consensus set.
47 struct GNUNET_CONSENSUS_Element
50 * The actual data of the element.
55 * Size of the element's data.
60 * Application specific element type
67 * Called when a new element was received from another peer, or an error occured.
68 * May deliver duplicate values.
69 * Elements given to a consensus operation by the local peer are NOT given
73 * @param element new element, NULL on error
74 * @return GNUNET_OK if the valid is well-formed and should be added to the consensus,
75 * GNUNET_SYSERR if the element should be ignored and not be propagated
77 typedef int (*GNUNET_CONSENSUS_ElementCallback) (void *cls,
78 const struct GNUNET_CONSENSUS_Element *element);
83 * Opaque handle for the consensus service.
85 struct GNUNET_CONSENSUS_Handle;
89 * Create a consensus session. The set being reconciled is initially
90 * empty. Only reconcile with other peers after
91 * GNUNET_CONSENSUS_reconcile has been called.
95 * @param peers array of peers participating in this consensus session
96 * Inclusion of the local peer is optional.
97 * @param session_id session identifier
98 * Allows a group of peers to have more than consensus session.
99 * @param new_element_cb callback, called when a new element is added to the set by
101 * @param new_element_cls closure for new_element
102 * @return handle to use, NULL on error
104 struct GNUNET_CONSENSUS_Handle *
105 GNUNET_CONSENSUS_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
106 unsigned int num_peers,
107 const struct GNUNET_PeerIdentity *peers,
108 const struct GNUNET_HashCode *session_id,
109 GNUNET_CONSENSUS_ElementCallback new_element_cb,
110 void *new_element_cls);
114 * Called when an insertion (transmission to consensus service,
115 * which does not imply fully consensus on this element with
116 * all other peers) was successful.
117 * May not call GNUNET_CONSENSUS_destroy; schedule a task to call
118 * GNUNET_CONSENSUS_destroy instead.
121 * @param success GNUNET_OK on success, GNUNET_SYSERR if
122 * the insertion and thus the consensus failed for good
124 typedef void (*GNUNET_CONSENSUS_InsertDoneCallback) (void *cls,
129 * Insert an element in the set being reconsiled. Only transmit changes to
130 * other peers if "GNUNET_CONSENSUS_begin" has been called.
131 * Must not be called after "GNUNET_CONSENSUS_conclude".
132 * May not call GNUNET_CONSENSUS_destroy; schedule a task to call
133 * GNUNET_CONSENSUS_destroy instead.
135 * @param consensus handle for the consensus session
136 * @param element the element to be inserted
137 * @param idc function called when we are done with this element and it
138 * is thus allowed to call GNUNET_CONSENSUS_insert again
139 * @param idc_cls closure for 'idc'
142 GNUNET_CONSENSUS_insert (struct GNUNET_CONSENSUS_Handle *consensus,
143 const struct GNUNET_CONSENSUS_Element *element,
144 GNUNET_CONSENSUS_InsertDoneCallback idc,
148 struct GNUNET_CONSENSUS_DeltaRequest;
153 * @param consensus consensus session
154 * @param remove_element_cb callback that receives the removed elements
155 * @return a handle to cancel the request
157 struct GNUNET_CONSENSUS_DeltaRequest *
158 GNUNET_CONSENSUS_get_delta (struct GNUNET_CONSENSUS_Handle *consensus,
159 GNUNET_CONSENSUS_ElementCallback remove_element_cb,
160 void *remove_element_cb_cls);
164 GNUNET_CONSENSUS_get_delta_cancel (struct GNUNET_CONSENSUS_DeltaRequest *dr);
167 struct GNUNET_CONSENSUS_Group
169 unsigned int num_members;
170 uint64_t total_elements_in_group;
171 const struct GNUNET_PeerIdentity **members;
176 * Called when a conclusion was successful.
181 typedef void (*GNUNET_CONSENSUS_ConcludeCallback) (void *cls, const struct GNUNET_CONSENSUS_Group *group);
185 * We are finished inserting new elements into the consensus;
186 * try to conclude the consensus within a given time window.
188 * @param consensus consensus session
189 * @param timeout timeout after which the conculde callback
191 * @param conclude called when the conclusion was successful
192 * @param conclude_cls closure for the conclude callback
195 GNUNET_CONSENSUS_conclude (struct GNUNET_CONSENSUS_Handle *consensus,
196 struct GNUNET_TIME_Relative timeout,
197 unsigned int min_group_size_in_consensus,
198 GNUNET_CONSENSUS_ConcludeCallback conclude,
203 * Destroy a consensus handle (free all state associated with
204 * it, no longer call any of the callbacks).
206 * @param consensus handle to destroy
209 GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *consensus);
212 #if 0 /* keep Emacsens' auto-indent happy */