2 This file is part of GNUnet
3 (C) 2013 Christian Grothoff (and other contributing authors)
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13 General Public License for more details.
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22 * @file include/gnunet_set_service.h
23 * @brief two-peer set operations
24 * @author Florian Dold
27 #ifndef GNUNET_SET_SERVICE_H
28 #define GNUNET_SET_SERVICE_H
33 #if 0 /* keep Emacsens' auto-indent happy */
38 #include "gnunet_common.h"
39 #include "gnunet_time_lib.h"
40 #include "gnunet_configuration_lib.h"
44 * Opaque handle to a set.
46 struct GNUNET_SET_Handle;
49 * Opaque handle to a set operation request from another peer.
51 struct GNUNET_SET_Request;
54 * Opaque handle to a listen operation.
56 struct GNUNET_SET_ListenHandle;
59 * Opaque handle to a set operation.
61 struct GNUNET_SET_OperationHandle;
65 * The operation that a set set supports.
67 enum GNUNET_SET_OperationType
70 * Set intersection, only return elements that are in both sets.
72 GNUNET_SET_OPERATION_INTERSECTION,
74 * Set union, return all elements that are in at least one of the sets.
76 GNUNET_SET_OPERATION_UNION
80 * Status for the result callback
82 enum GNUNET_SET_Status
90 * There was a timeout.
92 GNUNET_SET_STATUS_TIMEOUT,
95 * The other peer refused to to the operation with us,
96 * or something went wrong.
98 GNUNET_SET_STATUS_FAILURE,
101 * Success, all elements have been returned (but the other
102 * peer might still be receiving some from us, so we are not done).
104 GNUNET_SET_STATUS_HALF_DONE,
107 * Success, all elements have been sent (and received).
109 GNUNET_SET_STATUS_DONE
113 * The way results are given to the client.
115 enum GNUNET_SET_ResultMode
118 * Client gets every element in the resulting set.
120 GNUNET_SET_RESULT_FULL,
122 * Client gets only elements that have been added to the set.
123 * Only works with set union.
125 GNUNET_SET_RESULT_ADDED,
127 * Client gets only elements that have been removed from the set.
128 * Only works with set intersection.
130 GNUNET_SET_RESULT_REMOVED
134 * Element stored in a set.
136 struct GNUNET_SET_Element
139 * Number of bytes in the buffer pointed to by data.
144 * Application-specific element type.
149 * Actual data of the element
156 * Continuation used for some of the set operations
160 typedef void (*GNUNET_SET_Continuation) (void *cls);
164 * Callback for set operation results. Called for each element
168 * @param element a result element, only valid if status is GNUNET_SET_STATUS_OK
169 * @param status see enum GNUNET_SET_Status
171 typedef void (*GNUNET_SET_ResultIterator) (void *cls,
172 const struct GNUNET_SET_Element *element,
173 enum GNUNET_SET_Status status);
177 * Called when another peer wants to do a set operation with the
180 * @param other_peer the other peer
181 * @param context_msg message with application specific information from
183 * @param request request from the other peer, use GNUNET_SET_accept
184 * to accept it, otherwise the request will be refused
185 * Note that we don't use a return value here, as it is also
186 * necessary to specify the set we want to do the operation with,
187 * whith sometimes can be derived from the context message.
188 * Also necessary to specify the timeout.
191 (*GNUNET_SET_ListenCallback) (void *cls,
192 const struct GNUNET_PeerIdentity *other_peer,
193 const struct GNUNET_MessageHeader *context_msg,
194 struct GNUNET_SET_Request *request);
199 * Create an empty set, supporting the specified operation.
201 * @param cfg configuration to use for connecting to the
203 * @param op operation supported by the set
204 * Note that the operation has to be specified
205 * beforehand, as certain set operations need to maintain
206 * data structures spefific to the operation
207 * @return a handle to the set
209 struct GNUNET_SET_Handle *
210 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
211 enum GNUNET_SET_OperationType op);
215 * Add an element to the given set.
216 * After the element has been added (in the sense of being
217 * transmitted to the set service), cont will be called.
218 * Calls to add_element can be queued
220 * @param set set to add element to
221 * @param element element to add to the set
222 * @param cont continuation called after the element has been added
223 * @param cont_cls closure for cont
226 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
227 const struct GNUNET_SET_Element *element,
228 GNUNET_SET_Continuation cont,
233 * Remove an element to the given set.
234 * After the element has been removed (in the sense of the
235 * request being transmitted to the set service), cont will be called.
236 * Calls to remove_element can be queued
238 * @param set set to remove element from
239 * @param element element to remove from the set
240 * @param cont continuation called after the element has been removed
241 * @param cont_cls closure for cont
244 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
245 const struct GNUNET_SET_Element *element,
246 GNUNET_SET_Continuation cont,
251 * Destroy the set handle, and free all associated resources.
254 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set);
258 * Evaluate a set operation with our set and the set of another peer.
260 * @param set set to use
261 * @param salt salt for HKDF (explain more here)
262 * @param other_peer peer with the other set
263 * @param app_id hash for the application using the set
264 * @param context_msg additional information for the request
265 * @param salt salt used for the set operation; sometimes set operations
266 * fail due to hash collisions, using a different salt for each operation
267 * makes it harder for an attacker to exploit this
268 * @param result_mode specified how results will be returned,
269 * see 'GNUNET_SET_ResultMode'.
270 * @param result_cb called on error or success
271 * @param result_cls closure for result_cb
272 * @return a handle to cancel the operation
274 struct GNUNET_SET_OperationHandle *
275 GNUNET_SET_evaluate (struct GNUNET_SET_Handle *set,
276 const struct GNUNET_PeerIdentity *other_peer,
277 const struct GNUNET_HashCode *app_id,
278 const struct GNUNET_MessageHeader *context_msg,
280 enum GNUNET_SET_ResultMode result_mode,
281 GNUNET_SET_ResultIterator result_cb,
286 * Wait for set operation requests for the given application id
288 * @param cfg configuration to use for connecting to
290 * @param operation operation we want to listen for
291 * @param app_id id of the application that handles set operation requests
292 * @param listen_cb called for each incoming request matching the operation
294 * @param listen_cls handle for listen_cb
295 * @return a handle that can be used to cancel the listen operation
297 struct GNUNET_SET_ListenHandle *
298 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
299 enum GNUNET_SET_OperationType op_type,
300 const struct GNUNET_HashCode *app_id,
301 GNUNET_SET_ListenCallback listen_cb,
307 * Cancel the given listen operation.
309 * @param lh handle for the listen operation
312 GNUNET_SET_listen_cancel (struct GNUNET_SET_ListenHandle *lh);
317 * Accept a request we got via GNUNET_SET_listen.
319 * @param request request to accept
320 * @param set set used for the requested operation
321 * @param result_mode specified how results will be returned,
322 * see 'GNUNET_SET_ResultMode'.
323 * @param result_cb callback for the results
324 * @param result_cls closure for result_cb
325 * @return a handle to cancel the operation
327 struct GNUNET_SET_OperationHandle *
328 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
329 struct GNUNET_SET_Handle *set,
330 enum GNUNET_SET_ResultMode result_mode,
331 GNUNET_SET_ResultIterator result_cb,
336 * Cancel the given set operation.
338 * @param oh set operation to cancel
341 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh);
344 #if 0 /* keep Emacsens' auto-indent happy */