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13 General Public License for more details.
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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 * Socket (if available).
50 struct GNUNET_CLIENT_Connection *client;
53 * Currently pending transmission request.
55 struct GNUNET_CLIENT_TransmitHandle *th;
58 * Task doing exponential back-off trying to reconnect.
60 struct GNUNET_SCHEDULER_Task * reconnect_task;
63 * Time for next connect retry.
65 struct GNUNET_TIME_Relative reconnect_delay;
68 * Callback function to call when message is received.
70 GNUNET_NSE_Callback recv_cb;
73 * Closure to pass to @e recv_cb callback.
81 * Try again to connect to network size estimation service.
83 * @param cls the handle to the transport service
86 reconnect (void *cls);
90 * Type of a function to call when we receive a message
94 * @param msg message received, NULL on timeout or fatal error
97 message_handler (void *cls,
98 const struct GNUNET_MessageHeader *msg)
100 struct GNUNET_NSE_Handle *h = cls;
101 const struct GNUNET_NSE_ClientMessage *client_msg;
105 /* Error, timeout, death */
106 GNUNET_CLIENT_disconnect (h->client);
109 GNUNET_SCHEDULER_add_delayed (h->reconnect_delay,
113 if ((ntohs (msg->size) != sizeof (struct GNUNET_NSE_ClientMessage)) ||
114 (ntohs (msg->type) != GNUNET_MESSAGE_TYPE_NSE_ESTIMATE))
119 client_msg = (const struct GNUNET_NSE_ClientMessage *) msg;
120 h->recv_cb (h->recv_cb_cls, GNUNET_TIME_absolute_ntoh (client_msg->timestamp),
121 GNUNET_ntoh_double (client_msg->size_estimate),
122 GNUNET_ntoh_double (client_msg->std_deviation));
123 GNUNET_CLIENT_receive (h->client, &message_handler, h,
124 GNUNET_TIME_UNIT_FOREVER_REL);
129 * Reschedule a connect attempt to the service.
131 * @param h transport service to reconnect
134 reschedule_connect (struct GNUNET_NSE_Handle *h)
136 GNUNET_assert (h->reconnect_task == NULL);
140 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
143 if (NULL != h->client)
145 GNUNET_CLIENT_disconnect (h->client);
149 LOG (GNUNET_ERROR_TYPE_DEBUG,
150 "Scheduling task to reconnect to nse service in %s.\n",
151 GNUNET_STRINGS_relative_time_to_string (h->reconnect_delay,
154 GNUNET_SCHEDULER_add_delayed (h->reconnect_delay,
156 h->reconnect_delay = GNUNET_TIME_STD_BACKOFF (h->reconnect_delay);
161 * Transmit START message to service.
163 * @param cls the `struct GNUNET_NSE_Handle *`
164 * @param size number of bytes available in @a buf
165 * @param buf where to copy the message
166 * @return number of bytes copied to @a buf
169 send_start (void *cls, size_t size, void *buf)
171 struct GNUNET_NSE_Handle *h = cls;
172 struct GNUNET_MessageHeader *msg;
177 /* Connect error... */
178 LOG (GNUNET_ERROR_TYPE_DEBUG,
179 "Error while trying to transmit `%s' request.\n",
181 reschedule_connect (h);
184 LOG (GNUNET_ERROR_TYPE_DEBUG,
185 "Transmitting `%s' request.\n",
187 GNUNET_assert (size >= sizeof (struct GNUNET_MessageHeader));
189 msg = (struct GNUNET_MessageHeader *) buf;
190 msg->size = htons (sizeof (struct GNUNET_MessageHeader));
191 msg->type = htons (GNUNET_MESSAGE_TYPE_NSE_START);
192 GNUNET_CLIENT_receive (h->client, &message_handler, h,
193 GNUNET_TIME_UNIT_FOREVER_REL);
194 return sizeof (struct GNUNET_MessageHeader);
199 * Try again to connect to network size estimation service.
201 * @param cls the `struct GNUNET_NSE_Handle *`
204 reconnect (void *cls)
206 struct GNUNET_NSE_Handle *h = cls;
208 h->reconnect_task = NULL;
209 LOG (GNUNET_ERROR_TYPE_DEBUG,
210 "Connecting to network size estimation service.\n");
211 GNUNET_assert (NULL == h->client);
212 h->client = GNUNET_CLIENT_connect ("nse", h->cfg);
213 GNUNET_assert (NULL != h->client);
214 GNUNET_assert (NULL == h->th);
216 GNUNET_CLIENT_notify_transmit_ready (h->client,
217 sizeof (struct GNUNET_MessageHeader),
218 GNUNET_TIME_UNIT_FOREVER_REL,
219 GNUNET_NO, &send_start, h);
220 GNUNET_assert (NULL != h->th);
225 * Connect to the network size estimation service.
227 * @param cfg the configuration to use
228 * @param func funtion to call with network size estimate
229 * @param func_cls closure to pass to @a func
230 * @return handle to use
232 struct GNUNET_NSE_Handle *
233 GNUNET_NSE_connect (const struct GNUNET_CONFIGURATION_Handle *cfg,
234 GNUNET_NSE_Callback func, void *func_cls)
236 struct GNUNET_NSE_Handle *ret;
238 GNUNET_assert (func != NULL);
239 ret = GNUNET_new (struct GNUNET_NSE_Handle);
242 ret->recv_cb_cls = func_cls;
243 ret->reconnect_delay = GNUNET_TIME_UNIT_ZERO;
244 ret->reconnect_task = GNUNET_SCHEDULER_add_now (&reconnect, ret);
250 * Disconnect from network size estimation service
252 * @param h handle to destroy
255 GNUNET_NSE_disconnect (struct GNUNET_NSE_Handle *h)
257 GNUNET_assert (NULL != h);
258 if (h->reconnect_task != NULL)
260 GNUNET_SCHEDULER_cancel (h->reconnect_task);
261 h->reconnect_task = NULL;
265 GNUNET_CLIENT_notify_transmit_ready_cancel (h->th);
268 if (NULL != h->client)
270 GNUNET_CLIENT_disconnect (h->client);
276 /* end of nse_api.c */