2 This file is part of GNUnet.
3 (C) 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2009 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
27 #ifndef GNUNET_CLIENT_LIB_H
28 #define GNUNET_CLIENT_LIB_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_common.h"
39 #include "gnunet_configuration_lib.h"
40 #include "gnunet_connection_lib.h"
41 #include "gnunet_scheduler_lib.h"
42 #include "gnunet_time_lib.h"
45 * Opaque handle for a connection to a service.
47 struct GNUNET_CLIENT_Connection;
50 * Get a connection with a service.
52 * @param service_name name of the service
53 * @param cfg configuration to use
54 * @return NULL on error (service unknown to configuration)
56 struct GNUNET_CLIENT_Connection *
57 GNUNET_CLIENT_connect (const char *service_name,
58 const struct GNUNET_CONFIGURATION_Handle *cfg);
62 * Destroy connection with the service. This will automatically
63 * cancel any pending "receive" request (however, the handler will
64 * *NOT* be called, not even with a NULL message). Any pending
65 * transmission request will also be cancelled UNLESS the callback for
66 * the transmission request has already been called, in which case the
67 * transmission 'finish_pending_write' argument determines whether or
68 * not the write is guaranteed to complete before the socket is fully
69 * destroyed (unless, of course, there is an error with the server in
70 * which case the message may still be lost).
72 * @param client handle to the service connection
75 GNUNET_CLIENT_disconnect (struct GNUNET_CLIENT_Connection *client);
79 * Type of a function to call when we receive a message
83 * @param msg message received, NULL on timeout or fatal error
85 typedef void (*GNUNET_CLIENT_MessageHandler) (void *cls,
86 const struct GNUNET_MessageHeader
91 * Type of a function to call when we have finished shutting
92 * down a service, or failed.
95 * @param reason what is the result of the shutdown
96 * GNUNET_NO on shutdown (not running)
97 * GNUNET_YES on running
98 * GNUNET_SYSERR on failure to transmit message
100 typedef void (*GNUNET_CLIENT_ShutdownTask) (void *cls, int reason);
104 * Read from the service.
106 * @param client connection to the service
107 * @param handler function to call with the message
108 * @param handler_cls closure for handler
109 * @param timeout how long to wait until timing out
112 GNUNET_CLIENT_receive (struct GNUNET_CLIENT_Connection *client,
113 GNUNET_CLIENT_MessageHandler handler, void *handler_cls,
114 struct GNUNET_TIME_Relative timeout);
118 * Transmit handle for client connections.
120 struct GNUNET_CLIENT_TransmitHandle;
124 * Ask the client to call us once the specified number of bytes
125 * are free in the transmission buffer. May call the notify
126 * method immediately if enough space is available.
128 * @param client connection to the service
129 * @param size number of bytes to send
130 * @param timeout after how long should we give up (and call
131 * notify with buf NULL and size 0)?
132 * @param auto_retry if the connection to the service dies, should we
133 * automatically re-connect and retry (within the timeout period)
134 * or should we immediately fail in this case? Pass GNUNET_YES
135 * if the caller does not care about temporary connection errors,
136 * for example because the protocol is stateless
137 * @param notify function to call
138 * @param notify_cls closure for notify
139 * @return NULL if someone else is already waiting to be notified
140 * non-NULL if the notify callback was queued (can be used to cancel
141 * using GNUNET_CONNECTION_notify_transmit_ready_cancel)
143 struct GNUNET_CLIENT_TransmitHandle *
144 GNUNET_CLIENT_notify_transmit_ready (struct GNUNET_CLIENT_Connection *client,
146 struct GNUNET_TIME_Relative timeout,
148 GNUNET_CONNECTION_TransmitReadyNotify
149 notify, void *notify_cls);
153 * Cancel a request for notification.
155 * @param th handle from the original request.
158 GNUNET_CLIENT_notify_transmit_ready_cancel (struct GNUNET_CLIENT_TransmitHandle
163 * Convenience API that combines sending a request
164 * to the service and waiting for a response.
165 * If either operation times out, the callback
166 * will be called with a "NULL" response (in which
167 * case the connection should probably be destroyed).
169 * @param client connection to use
170 * @param hdr message to transmit
171 * @param timeout when to give up (for both transmission
172 * and for waiting for a response)
173 * @param auto_retry if the connection to the service dies, should we
174 * automatically re-connect and retry (within the timeout period)
175 * or should we immediately fail in this case? Pass GNUNET_YES
176 * if the caller does not care about temporary connection errors,
177 * for example because the protocol is stateless
178 * @param rn function to call with the response
179 * @param rn_cls closure for rn
180 * @return GNUNET_OK on success, GNUNET_SYSERR if a request
184 GNUNET_CLIENT_transmit_and_get_response (struct GNUNET_CLIENT_Connection *client,
185 const struct GNUNET_MessageHeader *hdr,
186 struct GNUNET_TIME_Relative timeout,
188 GNUNET_CLIENT_MessageHandler rn,
193 * Wait until the service is running.
195 * @param service name of the service to wait for
196 * @param cfg configuration to use
197 * @param timeout how long to wait at most in ms
198 * @param task task to run if service is running
199 * (reason will be "PREREQ_DONE" (service running)
200 * or "TIMEOUT" (service not known to be running))
201 * @param task_cls closure for task
204 GNUNET_CLIENT_service_test (const char *service,
205 const struct GNUNET_CONFIGURATION_Handle *cfg,
206 struct GNUNET_TIME_Relative timeout,
207 GNUNET_SCHEDULER_Task task, void *task_cls);
210 #if 0 /* keep Emacsens' auto-indent happy */
217 /* ifndef GNUNET_CLIENT_LIB_H */
219 /* end of gnunet_client_lib.h */