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3 Copyright (C) 2009, 2010, 2011, 2016 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,
8 or (at your 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 Affero General Public License for more details.
15 You should have received a copy of the GNU Affero General Public License
16 along with this program. If not, see <http://www.gnu.org/licenses/>.
18 SPDX-License-Identifier: AGPL3.0-or-later
23 * @brief api to get information from the network size estimation service
24 * @author Nathan Evans
27 #include "gnunet_constants.h"
28 #include "gnunet_arm_service.h"
29 #include "gnunet_hello_lib.h"
30 #include "gnunet_protocols.h"
31 #include "gnunet_util_lib.h"
32 #include "gnunet_nse_service.h"
35 #define LOG(kind, ...) GNUNET_log_from (kind, "nse-api", __VA_ARGS__)
38 * Handle for talking with the NSE service.
40 struct GNUNET_NSE_Handle
43 * Configuration to use.
45 const struct GNUNET_CONFIGURATION_Handle *cfg;
48 * Message queue (if available).
50 struct GNUNET_MQ_Handle *mq;
53 * Task doing exponential back-off trying to reconnect.
55 struct GNUNET_SCHEDULER_Task *reconnect_task;
58 * Time for next connect retry.
60 struct GNUNET_TIME_Relative reconnect_delay;
63 * Callback function to call when message is received.
65 GNUNET_NSE_Callback recv_cb;
68 * Closure to pass to @e recv_cb callback.
75 * Try again to connect to network size estimation service.
77 * @param cls closure with the `struct GNUNET_NSE_Handle *`
80 reconnect (void *cls);
84 * Generic error handler, called with the appropriate
85 * error code and the same closure specified at the creation of
87 * Not every message queue implementation supports an error handler.
89 * @param cls closure with the `struct GNUNET_NSE_Handle *`
90 * @param error error code
93 mq_error_handler (void *cls, enum GNUNET_MQ_Error error)
95 struct GNUNET_NSE_Handle *h = cls;
98 GNUNET_MQ_destroy (h->mq);
101 GNUNET_SCHEDULER_add_delayed (h->reconnect_delay, &reconnect, h);
102 h->reconnect_delay = GNUNET_TIME_STD_BACKOFF (h->reconnect_delay);
107 * Type of a function to call when we receive a message
111 * @param client_msg message received
114 handle_estimate (void *cls, const struct GNUNET_NSE_ClientMessage *client_msg)
116 struct GNUNET_NSE_Handle *h = cls;
118 h->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
119 h->recv_cb (h->recv_cb_cls,
120 GNUNET_TIME_absolute_ntoh (client_msg->timestamp),
121 GNUNET_ntoh_double (client_msg->size_estimate),
122 GNUNET_ntoh_double (client_msg->std_deviation));
127 * Try again to connect to network size estimation service.
129 * @param cls the `struct GNUNET_NSE_Handle *`
132 reconnect (void *cls)
134 struct GNUNET_NSE_Handle *h = cls;
135 struct GNUNET_MQ_MessageHandler handlers[] =
136 {GNUNET_MQ_hd_fixed_size (estimate,
137 GNUNET_MESSAGE_TYPE_NSE_ESTIMATE,
138 struct GNUNET_NSE_ClientMessage,
140 GNUNET_MQ_handler_end ()};
141 struct GNUNET_MessageHeader *msg;
142 struct GNUNET_MQ_Envelope *env;
144 h->reconnect_task = NULL;
145 LOG (GNUNET_ERROR_TYPE_DEBUG,
146 "Connecting to network size estimation service.\n");
147 GNUNET_assert (NULL == h->mq);
148 h->mq = GNUNET_CLIENT_connect (h->cfg, "nse", handlers, &mq_error_handler, h);
151 env = GNUNET_MQ_msg (msg, GNUNET_MESSAGE_TYPE_NSE_START);
152 GNUNET_MQ_send (h->mq, env);
157 * Connect to the network size estimation service.
159 * @param cfg the configuration to use
160 * @param func funtion to call with network size estimate
161 * @param func_cls closure to pass to @a func
162 * @return handle to use
164 struct GNUNET_NSE_Handle *
165 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
166 GNUNET_NSE_Callback func,
169 struct GNUNET_NSE_Handle *h;
171 GNUNET_assert (NULL != func);
172 h = GNUNET_new (struct GNUNET_NSE_Handle);
175 h->recv_cb_cls = func_cls;
176 h->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
188 * Disconnect from network size estimation service
190 * @param h handle to destroy
193 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h)
195 if (NULL != h->reconnect_task)
197 GNUNET_SCHEDULER_cancel (h->reconnect_task);
198 h->reconnect_task = NULL;
202 GNUNET_MQ_destroy (h->mq);
208 /* end of nse_api.c */