2 This file is part of GNUnet
3 Copyright (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.
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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.
21 #ifndef GNUNET_NSE_SERVICE_H_
22 #define GNUNET_NSE_SERVICE_H_
25 * @author Nathan Evans
28 * API to retrieve the current network size estimate
30 * @defgroup nse NSE service
31 * Network Size Estimation
33 * Provides an API to retrieve the current network size estimate,
34 * also to register for notifications whenever a new
35 * network size estimate is calculated.
43 #if 0 /* keep Emacsens' auto-indent happy */
48 #include "gnunet_util_lib.h"
51 * Version of the network size estimation API.
53 #define GNUNET_NSE_VERSION 0x00000000
56 * Handle for the network size estimation service.
58 struct GNUNET_NSE_Handle;
61 * Callback to call when network size estimate is updated.
64 * @param timestamp time when the estimate was received from the server (or created by the server)
65 * @param logestimate the log(Base 2) value of the current network size estimate
66 * @param std_dev standard deviation for the estimate
69 typedef void (*GNUNET_NSE_Callback) (void *cls,
70 struct GNUNET_TIME_Absolute timestamp,
71 double logestimate, double std_dev);
75 * Convert the logarithmic estimated returned to the 'GNUNET_NSE_Callback'
76 * into an absolute estimate in terms of the number of peers in the network.
78 * @param loge logarithmic estimate
79 * @return absolute number of peers in the network (estimated)
81 #define GNUNET_NSE_log_estimate_to_n(loge) pow(2.0, (loge))
85 * Connect to the network size estimation service.
87 * @param cfg the configuration to use
88 * @param func funtion to call with network size estimate
89 * @param func_cls closure to pass to @a func
90 * @return handle to use in #GNUNET_NSE_disconnect to stop NSE from invoking the callbacks
92 struct GNUNET_NSE_Handle *
93 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
94 GNUNET_NSE_Callback func, void *func_cls);
98 * Disconnect from network size estimation service
100 * @param h handle to destroy
103 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h);
106 #if 0 /* keep Emacsens' auto-indent happy */
113 /** @} */ /* end of group nse */
115 #endif /* GNUNET_NSE_SERVICE_H_ */