2 This file is part of GNUnet.
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 {
42 * Configuration to use.
44 const struct GNUNET_CONFIGURATION_Handle *cfg;
47 * Message queue (if available).
49 struct GNUNET_MQ_Handle *mq;
52 * Task doing exponential back-off trying to reconnect.
54 struct GNUNET_SCHEDULER_Task *reconnect_task;
57 * Time for next connect retry.
59 struct GNUNET_TIME_Relative reconnect_delay;
62 * Callback function to call when message is received.
64 GNUNET_NSE_Callback recv_cb;
67 * Closure to pass to @e recv_cb callback.
74 * Try again to connect to network size estimation service.
76 * @param cls closure with the `struct GNUNET_NSE_Handle *`
83 * Generic error handler, called with the appropriate
84 * error code and the same closure specified at the creation of
86 * Not every message queue implementation supports an error handler.
88 * @param cls closure with the `struct GNUNET_NSE_Handle *`
89 * @param error error code
92 mq_error_handler(void *cls, enum GNUNET_MQ_Error error)
94 struct GNUNET_NSE_Handle *h = cls;
97 GNUNET_MQ_destroy(h->mq);
100 GNUNET_SCHEDULER_add_delayed(h->reconnect_delay, &reconnect, h);
101 h->reconnect_delay = GNUNET_TIME_STD_BACKOFF(h->reconnect_delay);
106 * Type of a function to call when we receive a message
110 * @param client_msg message received
113 handle_estimate(void *cls, const struct GNUNET_NSE_ClientMessage *client_msg)
115 struct GNUNET_NSE_Handle *h = cls;
117 h->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
118 h->recv_cb(h->recv_cb_cls,
119 GNUNET_TIME_absolute_ntoh(client_msg->timestamp),
120 GNUNET_ntoh_double(client_msg->size_estimate),
121 GNUNET_ntoh_double(client_msg->std_deviation));
126 * Try again to connect to network size estimation service.
128 * @param cls the `struct GNUNET_NSE_Handle *`
133 struct GNUNET_NSE_Handle *h = cls;
134 struct GNUNET_MQ_MessageHandler handlers[] =
135 { GNUNET_MQ_hd_fixed_size(estimate,
136 GNUNET_MESSAGE_TYPE_NSE_ESTIMATE,
137 struct GNUNET_NSE_ClientMessage,
139 GNUNET_MQ_handler_end() };
140 struct GNUNET_MessageHeader *msg;
141 struct GNUNET_MQ_Envelope *env;
143 h->reconnect_task = NULL;
144 LOG(GNUNET_ERROR_TYPE_DEBUG,
145 "Connecting to network size estimation service.\n");
146 GNUNET_assert(NULL == h->mq);
147 h->mq = GNUNET_CLIENT_connect(h->cfg, "nse", handlers, &mq_error_handler, h);
150 env = GNUNET_MQ_msg(msg, GNUNET_MESSAGE_TYPE_NSE_START);
151 GNUNET_MQ_send(h->mq, env);
156 * Connect to the network size estimation service.
158 * @param cfg the configuration to use
159 * @param func funtion to call with network size estimate
160 * @param func_cls closure to pass to @a func
161 * @return handle to use
163 struct GNUNET_NSE_Handle *
164 GNUNET_NSE_connect(const struct GNUNET_CONFIGURATION_Handle *cfg,
165 GNUNET_NSE_Callback func,
168 struct GNUNET_NSE_Handle *h;
170 GNUNET_assert(NULL != func);
171 h = GNUNET_new(struct GNUNET_NSE_Handle);
174 h->recv_cb_cls = func_cls;
175 h->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
187 * Disconnect from network size estimation service
189 * @param h handle to destroy
192 GNUNET_NSE_disconnect(struct GNUNET_NSE_Handle *h)
194 if (NULL != h->reconnect_task)
196 GNUNET_SCHEDULER_cancel(h->reconnect_task);
197 h->reconnect_task = NULL;
201 GNUNET_MQ_destroy(h->mq);
207 /* end of nse_api.c */