/*
This file is part of GNUnet
- (C) 2012 Christian Grothoff (and other contributing authors)
+ Copyright (C) 2012 GNUnet e.V.
GNUnet is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published
- by the Free Software Foundation; either version 2, or (at your
+ by the Free Software Foundation; either version 3, or (at your
option) any later version.
GNUnet is distributed in the hope that it will be useful, but
You should have received a copy of the GNU General Public License
along with GNUnet; see the file COPYING. If not, write to the
- Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- Boston, MA 02111-1307, USA.
+ Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
+ Boston, MA 02110-1301, USA.
*/
/**
- * @file include/gnunet_consensus_service.h
- * @brief
* @author Florian Dold
+ *
+ * @file
+ * Multi-peer set reconciliation
+ *
+ * @defgroup consensus Consensus service
+ * Multi-peer set reconciliation
+ * @{
*/
#ifndef GNUNET_CONSENSUS_SERVICE_H
#endif
#endif
-#include "platform.h"
#include "gnunet_common.h"
#include "gnunet_time_lib.h"
+#include "gnunet_configuration_lib.h"
+#include "gnunet_set_service.h"
/**
- * Called when a new element was received from another peer.
- *
- * @return GNUNET_YES to keep the new value, GNUNET_NO to discard it
+ * Elements inserted into the consensus set by the client
+ * may not be larger than this constant, since types in
+ * the upper range are used by CONSENSUS internally.
*/
-typedef int (*GNUNET_CONSENSUS_NewElementCallback) (void *cls,
- struct GNUNET_PeerIdentity *source,
- uint8_t *new_data);
+#define GNUNET_CONSENSUS_ELEMENT_TYPE_USER_MAX 0xFFF0
/**
- * Called when a conclusion was successful.
+ * Called when a new element was received from another peer, or an error occured.
+ * May deliver duplicate values.
+ * Elements given to a consensus operation by the local peer are NOT given
+ * to this callback.
*
- * TODO: A way to get to the set elements at the point of conclusion
+ * @param cls closure
+ * @param element new element, NULL on error
*/
-typedef void (*GNUNET_CONSENSUS_ConcludeCallback) (void *cls, int success);
+typedef void (*GNUNET_CONSENSUS_ElementCallback) (void *cls,
+ const struct GNUNET_SET_Element *element);
-/**
- * Opaque handle for the consensus service.
- */
-struct GNUNET_CONSENSUS_Handle;
/**
* Opaque handle for the consensus service.
*/
-struct GNUNET_CONSENSUS_ConcludeHandle;
+struct GNUNET_CONSENSUS_Handle;
/**
- * Create a consensus session.
+ * Create a consensus session. The set being reconciled is initially
+ * empty.
*
- * @param peers zero-terminated list of peers participating in this consensus session
+ * @param cfg
+ * @param num_peers
+ * @param peers array of peers participating in this consensus session
+ * Inclusion of the local peer is optional.
* @param session_id session identifier
* Allows a group of peers to have more than consensus session.
- * @param element_size size of the elements in the reconciled set in bytes
- * @param new_element callback, called when a new element is added to the set by
- * another peer
- * @param cls closure for new_element
- *
- * @return handle to use
+ * @param start start time of the consensus, conclude should be called before
+ * the start time.
+ * @param deadline time when the consensus should have concluded
+ * @param new_element_cb callback, called when a new element is added to the set by
+ * another peer. Also called when an error occurs.
+ * @param new_element_cls closure for new_element
+ * @return handle to use, NULL on error
*/
struct GNUNET_CONSENSUS_Handle *
-GNUNET_CONSENSUS_create (struct GNUNET_PeerIdentity *peers,
- uint32_t session_id,
- int element_size,
- uint8_t **initial_elements,
- GNUNET_CONSENSUS_NewElementCallback new_element,
- void *cls);
+GNUNET_CONSENSUS_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
+ unsigned int num_peers,
+ const struct GNUNET_PeerIdentity *peers,
+ const struct GNUNET_HashCode *session_id,
+ struct GNUNET_TIME_Absolute start,
+ struct GNUNET_TIME_Absolute deadline,
+ GNUNET_CONSENSUS_ElementCallback new_element_cb,
+ void *new_element_cls);
/**
- * Try to reach a short-term consensus with all other peers in the consensus session.
- *
- * @param consensus consensus session
- * @param timeout timeout after which the conculde callback
- * will be called with success=GNUNET_NO
- * @param conclude called when the conclusion was successful
- * @param cls closure for the conclude callback
+ * Called when an insertion (transmission to consensus service, which
+ * does not imply fully consensus on this element with all other
+ * peers) was successful. May not call GNUNET_CONSENSUS_destroy();
+ * schedule a task to call GNUNET_CONSENSUS_destroy() instead (if
+ * needed).
*
+ * @param cls
+ * @param success #GNUNET_OK on success, #GNUNET_SYSERR if
+ * the insertion and thus the consensus failed for good
*/
-struct GNUNET_CONSENSUS_ConcludeHandle
-GNUNET_CONSENSUS_conclude(struct GNUNET_CONSENSUS_Handle *consensus,
- struct GNUNET_TIME_Relative timeout,
- GNUNET_CONSENSUS_ConcludeCallback conclude,
- void *cls);
+typedef void (*GNUNET_CONSENSUS_InsertDoneCallback) (void *cls,
+ int success);
/**
- * Insert an element in the set being reconsiled.
+ * Insert an element in the set being reconsiled. Only transmit changes to
+ * other peers if GNUNET_CONSENSUS_begin() has been called.
+ * Must not be called after GNUNET_CONSENSUS_conclude().
+ * May not call GNUNET_CONSENSUS_destroy(); schedule a task to call
+ * GNUNET_CONSENSUS_destroy() instead (if needed).
*
- * @param handle handle for the consensus session
+ * @param consensus handle for the consensus session
* @param element the element to be inserted
- *
+ * @param idc function called when we are done with this element and it
+ * is thus allowed to call GNUNET_CONSENSUS_insert() again
+ * @param idc_cls closure for @a idc
*/
void
-GNUNET_CONSENSUS_insert(struct GNUNET_CONSENSUS_Handle, uint8_t *element);
+GNUNET_CONSENSUS_insert (struct GNUNET_CONSENSUS_Handle *consensus,
+ const struct GNUNET_SET_Element *element,
+ GNUNET_CONSENSUS_InsertDoneCallback idc,
+ void *idc_cls);
+
/**
- * Destroy a consensus handle (free all state associated with
- * it).
+ * Called when a conclusion was successful.
*
- * @param h consensus handle to destroy
+ * @param cls
*/
-void
-GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *h);
+typedef void (*GNUNET_CONSENSUS_ConcludeCallback) (void *cls);
+/**
+ * We are finished inserting new elements into the consensus;
+ * try to conclude the consensus within a given time window.
+ *
+ * @param consensus consensus session
+ * @param conclude called when the conclusion was successful
+ * @param conclude_cls closure for the conclude callback
+ */
+void
+GNUNET_CONSENSUS_conclude (struct GNUNET_CONSENSUS_Handle *consensus,
+ GNUNET_CONSENSUS_ConcludeCallback conclude,
+ void *conclude_cls);
+/**
+ * Destroy a consensus handle (free all state associated with
+ * it, no longer call any of the callbacks).
+ *
+ * @param consensus handle to destroy
+ */
+void
+GNUNET_CONSENSUS_destroy (struct GNUNET_CONSENSUS_Handle *consensus);
+
#if 0 /* keep Emacsens' auto-indent happy */
{
#endif
#endif
+
+/** @} */ /* end of group */