2 This file is part of GNUnet
3 (C) 2011 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.
21 #ifndef GNUNET_NSE_SERVICE_H_
22 #define GNUNET_NSE_SERVICE_H_
25 * @file include/gnunet_nse_service.h
26 * @brief API to retrieve the current network size estimate,
27 * also to register for notifications whenever a new
28 * network size estimate is calculated.
29 * @author Nathan Evans
30 * @defgroup nse network size estimation service
37 #if 0 /* keep Emacsens' auto-indent happy */
42 #include "gnunet_common.h"
43 #include "gnunet_configuration_lib.h"
44 #include "gnunet_scheduler_lib.h"
47 * Version of the network size estimation API.
49 #define GNUNET_NSE_VERSION 0x00000000
52 * Handle for the network size estimation service.
54 struct GNUNET_NSE_Handle;
57 * Callback to call when network size estimate is updated.
60 * @param timestamp time when the estimate was received from the server (or created by the server)
61 * @param logestimate the log(Base 2) value of the current network size estimate
62 * @param std_dev standard deviation for the estimate
65 typedef void (*GNUNET_NSE_Callback) (void *cls,
66 struct GNUNET_TIME_Absolute timestamp,
67 double logestimate, double std_dev);
71 * Convert the logarithmic estimated returned to the 'GNUNET_NSE_Callback'
72 * into an absolute estimate in terms of the number of peers in the network.
74 * @param loge logarithmic estimate
75 * @return absolute number of peers in the network (estimated)
77 #define GNUNET_NSE_log_estimate_to_n(loge) pow(2.0, (loge))
81 * Connect to the network size estimation service.
83 * @param cfg the configuration to use
84 * @param func funtion to call with network size estimate
85 * @param func_cls closure to pass to @a func
86 * @return handle to use in #GNUNET_NSE_disconnect to stop NSE from invoking the callbacks
88 struct GNUNET_NSE_Handle *
89 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
90 GNUNET_NSE_Callback func, void *func_cls);
94 * Disconnect from network size estimation service
96 * @param h handle to destroy
99 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h);
102 #if 0 /* keep Emacsens' auto-indent happy */
109 /** @} */ /* end of group nse */
111 #endif /* GNUNET_NSE_SERVICE_H_ */