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3 Copyright (C) 2011 GNUnet e.V.
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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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19 #ifndef GNUNET_NSE_SERVICE_H_
20 #define GNUNET_NSE_SERVICE_H_
23 * @author Nathan Evans
26 * API to retrieve the current network size estimate
28 * @defgroup nse NSE service
29 * Network Size Estimation
31 * Provides an API to retrieve the current network size estimate,
32 * also to register for notifications whenever a new
33 * network size estimate is calculated.
35 * @see [Documentation](https://gnunet.org/gnunet-nse-subsystem)
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_ */