2 This file is part of GNUnet
3 Copyright (C) 2011 GNUnet e.V.
5 GNUnet is free software: you can redistribute it and/or modify it
6 under the terms of the GNU Affero General Public License as published
7 by the Free Software Foundation, either version 3 of the License,
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13 Affero General Public License for more details.
16 #ifndef GNUNET_NSE_SERVICE_H_
17 #define GNUNET_NSE_SERVICE_H_
20 * @author Nathan Evans
23 * API to retrieve the current network size estimate
25 * @defgroup nse NSE service
26 * Network Size Estimation
28 * Provides an API to retrieve the current network size estimate,
29 * also to register for notifications whenever a new
30 * network size estimate is calculated.
32 * @see [Documentation](https://gnunet.org/gnunet-nse-subsystem)
40 #if 0 /* keep Emacsens' auto-indent happy */
45 #include "gnunet_util_lib.h"
48 * Version of the network size estimation API.
50 #define GNUNET_NSE_VERSION 0x00000000
53 * Handle for the network size estimation service.
55 struct GNUNET_NSE_Handle;
58 * Callback to call when network size estimate is updated.
61 * @param timestamp time when the estimate was received from the server (or created by the server)
62 * @param logestimate the log(Base 2) value of the current network size estimate
63 * @param std_dev standard deviation for the estimate
66 typedef void (*GNUNET_NSE_Callback) (void *cls,
67 struct GNUNET_TIME_Absolute timestamp,
68 double logestimate, double std_dev);
72 * Convert the logarithmic estimated returned to the 'GNUNET_NSE_Callback'
73 * into an absolute estimate in terms of the number of peers in the network.
75 * @param loge logarithmic estimate
76 * @return absolute number of peers in the network (estimated)
78 #define GNUNET_NSE_log_estimate_to_n(loge) pow(2.0, (loge))
82 * Connect to the network size estimation service.
84 * @param cfg the configuration to use
85 * @param func funtion to call with network size estimate
86 * @param func_cls closure to pass to @a func
87 * @return handle to use in #GNUNET_NSE_disconnect to stop NSE from invoking the callbacks
89 struct GNUNET_NSE_Handle *
90 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
91 GNUNET_NSE_Callback func, void *func_cls);
95 * Disconnect from network size estimation service
97 * @param h handle to destroy
100 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h);
103 #if 0 /* keep Emacsens' auto-indent happy */
110 /** @} */ /* end of group nse */
112 #endif /* GNUNET_NSE_SERVICE_H_ */