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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.
37 * @see [Documentation](https://gnunet.org/gnunet-nse-subsystem)
45 #if 0 /* keep Emacsens' auto-indent happy */
50 #include "gnunet_util_lib.h"
53 * Version of the network size estimation API.
55 #define GNUNET_NSE_VERSION 0x00000000
58 * Handle for the network size estimation service.
60 struct GNUNET_NSE_Handle;
63 * Callback to call when network size estimate is updated.
66 * @param timestamp time when the estimate was received from the server (or created by the server)
67 * @param logestimate the log(Base 2) value of the current network size estimate
68 * @param std_dev standard deviation for the estimate
71 typedef void (*GNUNET_NSE_Callback) (void *cls,
72 struct GNUNET_TIME_Absolute timestamp,
73 double logestimate, double std_dev);
77 * Convert the logarithmic estimated returned to the 'GNUNET_NSE_Callback'
78 * into an absolute estimate in terms of the number of peers in the network.
80 * @param loge logarithmic estimate
81 * @return absolute number of peers in the network (estimated)
83 #define GNUNET_NSE_log_estimate_to_n(loge) pow(2.0, (loge))
87 * Connect to the network size estimation service.
89 * @param cfg the configuration to use
90 * @param func funtion to call with network size estimate
91 * @param func_cls closure to pass to @a func
92 * @return handle to use in #GNUNET_NSE_disconnect to stop NSE from invoking the callbacks
94 struct GNUNET_NSE_Handle *
95 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
96 GNUNET_NSE_Callback func, void *func_cls);
100 * Disconnect from network size estimation service
102 * @param h handle to destroy
105 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h);
108 #if 0 /* keep Emacsens' auto-indent happy */
115 /** @} */ /* end of group nse */
117 #endif /* GNUNET_NSE_SERVICE_H_ */