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3 (C) 2001-2013 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_client_lib.h
23 * @brief functions related to accessing services
24 * @author Christian Grothoff
25 * @defgroup client Generic client-side communication with services
29 #ifndef GNUNET_CLIENT_LIB_H
30 #define GNUNET_CLIENT_LIB_H
35 #if 0 /* keep Emacsens' auto-indent happy */
42 * Opaque handle for a connection to a service.
44 struct GNUNET_CLIENT_Connection;
47 * Get a connection with a service.
49 * @param service_name name of the service
50 * @param cfg configuration to use
51 * @return NULL on error (service unknown to configuration)
53 struct GNUNET_CLIENT_Connection *
54 GNUNET_CLIENT_connect (const char *service_name,
55 const struct GNUNET_CONFIGURATION_Handle *cfg);
59 * Destroy connection with the service. This will automatically
60 * cancel any pending "receive" request (however, the handler will
61 * *NOT* be called, not even with a NULL message). Any pending
62 * transmission request will also be cancelled UNLESS the callback for
63 * the transmission request has already been called, in which case the
64 * transmission 'finish_pending_write' argument determines whether or
65 * not the write is guaranteed to complete before the socket is fully
66 * destroyed (unless, of course, there is an error with the server in
67 * which case the message may still be lost).
69 * @param client handle to the service connection
72 GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client);
76 * Type of a function to call when we receive a message
80 * @param msg message received, NULL on timeout or fatal error
82 typedef void (*GNUNET_CLIENT_MessageHandler) (void *cls,
83 const struct GNUNET_MessageHeader *msg);
87 * Read from the service.
89 * @param client connection to the service
90 * @param handler function to call with the message
91 * @param handler_cls closure for @a handler
92 * @param timeout how long to wait until timing out
95 GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
96 GNUNET_CLIENT_MessageHandler handler, void *handler_cls,
97 struct GNUNET_TIME_Relative timeout);
101 * Transmit handle for client connections.
103 struct GNUNET_CLIENT_TransmitHandle;
107 * Ask the client to call us once the specified number of bytes
108 * are free in the transmission buffer. May call the notify
109 * method immediately if enough space is available.
111 * @param client connection to the service
112 * @param size number of bytes to send
113 * @param timeout after how long should we give up (and call
114 * @a notify with buf NULL and size 0)?
115 * @param auto_retry if the connection to the service dies, should we
116 * automatically re-connect and retry (within the timeout period)
117 * or should we immediately fail in this case? Pass #GNUNET_YES
118 * if the caller does not care about temporary connection errors,
119 * for example because the protocol is stateless
120 * @param notify function to call
121 * @param notify_cls closure for @a notify
122 * @return NULL if someone else is already waiting to be notified
123 * non-NULL if the notify callback was queued (can be used to cancel
124 * using #GNUNET_CONNECTION_notify_transmit_ready_cancel)
126 struct GNUNET_CLIENT_TransmitHandle *
127 GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
129 struct GNUNET_TIME_Relative timeout,
131 GNUNET_CONNECTION_TransmitReadyNotify notify,
136 * Cancel a request for notification.
138 * @param th handle from the original request.
141 GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
146 * Convenience API that combines sending a request
147 * to the service and waiting for a response.
148 * If either operation times out, the callback
149 * will be called with a "NULL" response (in which
150 * case the connection should probably be destroyed).
152 * @param client connection to use
153 * @param hdr message to transmit
154 * @param timeout when to give up (for both transmission
155 * and for waiting for a response)
156 * @param auto_retry if the connection to the service dies, should we
157 * automatically re-connect and retry (within the timeout period)
158 * or should we immediately fail in this case? Pass #GNUNET_YES
159 * if the caller does not care about temporary connection errors,
160 * for example because the protocol is stateless
161 * @param rn function to call with the response
162 * @param rn_cls closure for @a rn
163 * @return #GNUNET_OK on success, #GNUNET_SYSERR if a request
167 GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
168 const struct GNUNET_MessageHeader *hdr,
169 struct GNUNET_TIME_Relative timeout,
171 GNUNET_CLIENT_MessageHandler rn,
176 * Handle for a test to check if a service is running.
178 struct GNUNET_CLIENT_TestHandle;
181 * Function called with the result on the service test.
184 * @param result #GNUNET_YES if the service is running,
185 * #GNUNET_NO if the service is not running
186 * #GNUNET_SYSERR if the configuration is invalid
188 typedef void (*GNUNET_CLIENT_TestResultCallback)(void *cls,
193 * Test if the service is running. If we are given a UNIXPATH or a
194 * local address, we do this NOT by trying to connect to the service,
195 * but by trying to BIND to the same port. If the BIND fails, we know
196 * the service is running.
198 * @param service name of the service to wait for
199 * @param cfg configuration to use
200 * @param timeout how long to wait at most
201 * @param cb function to call with the result
202 * @param cb_cls closure for @a cb
203 * @return handle to cancel the test
205 struct GNUNET_CLIENT_TestHandle *
206 GNUNET_CLIENT_service_test (const char *service,
207 const struct GNUNET_CONFIGURATION_Handle *cfg,
208 struct GNUNET_TIME_Relative timeout,
209 GNUNET_CLIENT_TestResultCallback cb, void *cb_cls);
213 * Abort testing for service.
215 * @param th test handle
218 GNUNET_CLIENT_service_test_cancel (struct GNUNET_CLIENT_TestHandle *th);
221 #if 0 /* keep Emacsens' auto-indent happy */
228 /** @} */ /* end of group client */
230 /* ifndef GNUNET_CLIENT_LIB_H */
232 /* end of gnunet_client_lib.h */