2 This file is part of GNUnet
3 (C) 2013 Christian Grothoff (and other contributing authors)
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22 * @file include/gnunet_set_service.h
23 * @brief two-peer set operations
24 * @author Florian Dold
25 * @author Christian Grothoff
28 #ifndef GNUNET_SET_SERVICE_H
29 #define GNUNET_SET_SERVICE_H
34 #if 0 /* keep Emacsens' auto-indent happy */
39 #include "gnunet_common.h"
40 #include "gnunet_time_lib.h"
41 #include "gnunet_configuration_lib.h"
45 * Opaque handle to a set.
47 struct GNUNET_SET_Handle;
50 * Opaque handle to a set operation request from another peer.
52 struct GNUNET_SET_Request;
55 * Opaque handle to a listen operation.
57 struct GNUNET_SET_ListenHandle;
60 * Opaque handle to a set operation.
62 struct GNUNET_SET_OperationHandle;
66 * The operation that a set set supports.
68 enum GNUNET_SET_OperationType
71 * Set intersection, only return elements that are in both sets.
73 GNUNET_SET_OPERATION_INTERSECTION,
75 * Set union, return all elements that are in at least one of the sets.
77 GNUNET_SET_OPERATION_UNION
81 * Status for the result callback
83 enum GNUNET_SET_Status
91 * There was a timeout.
93 GNUNET_SET_STATUS_TIMEOUT,
96 * The other peer refused to to the operation with us,
97 * or something went wrong.
99 GNUNET_SET_STATUS_FAILURE,
102 * Success, all elements have been returned (but the other
103 * peer might still be receiving some from us, so we are not done).
105 GNUNET_SET_STATUS_HALF_DONE,
108 * Success, all elements have been sent (and received).
110 GNUNET_SET_STATUS_DONE
114 * The way results are given to the client.
116 enum GNUNET_SET_ResultMode
119 * Client gets every element in the resulting set.
121 GNUNET_SET_RESULT_FULL,
123 * Client gets only elements that have been added to the set.
124 * Only works with set union.
126 GNUNET_SET_RESULT_ADDED,
128 * Client gets only elements that have been removed from the set.
129 * Only works with set intersection.
131 GNUNET_SET_RESULT_REMOVED
135 * Element stored in a set.
137 struct GNUNET_SET_Element
140 * Number of bytes in the buffer pointed to by data.
145 * Application-specific element type.
150 * Actual data of the element
157 * Continuation used for some of the set operations
161 typedef void (*GNUNET_SET_Continuation) (void *cls);
165 * Callback for set operation results. Called for each element
169 * @param element a result element, only valid if status is GNUNET_SET_STATUS_OK
170 * @param status see enum GNUNET_SET_Status
172 typedef void (*GNUNET_SET_ResultIterator) (void *cls,
173 const struct GNUNET_SET_Element *element,
174 enum GNUNET_SET_Status status);
178 * Called when another peer wants to do a set operation with the
182 * @param other_peer the other peer
183 * @param context_msg message with application specific information from
185 * @param request request from the other peer, use GNUNET_SET_accept
186 * to accept it, otherwise the request will be refused
187 * Note that we don't use a return value here, as it is also
188 * necessary to specify the set we want to do the operation with,
189 * whith sometimes can be derived from the context message.
190 * Also necessary to specify the timeout.
193 (*GNUNET_SET_ListenCallback) (void *cls,
194 const struct GNUNET_PeerIdentity *other_peer,
195 const struct GNUNET_MessageHeader *context_msg,
196 struct GNUNET_SET_Request *request);
201 * Create an empty set, supporting the specified operation.
203 * @param cfg configuration to use for connecting to the
205 * @param op operation supported by the set
206 * Note that the operation has to be specified
207 * beforehand, as certain set operations need to maintain
208 * data structures spefific to the operation
209 * @return a handle to the set
211 struct GNUNET_SET_Handle *
212 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
213 enum GNUNET_SET_OperationType op);
217 * Add an element to the given set.
218 * After the element has been added (in the sense of being
219 * transmitted to the set service), cont will be called.
220 * Calls to add_element can be queued
222 * @param set set to add element to
223 * @param element element to add to the set
224 * @param cont continuation called after the element has been added
225 * @param cont_cls closure for cont
228 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
229 const struct GNUNET_SET_Element *element,
230 GNUNET_SET_Continuation cont,
235 * Remove an element to the given set.
236 * After the element has been removed (in the sense of the
237 * request being transmitted to the set service), cont will be called.
238 * Calls to remove_element can be queued
240 * @param set set to remove element from
241 * @param element element to remove from the set
242 * @param cont continuation called after the element has been removed
243 * @param cont_cls closure for cont
246 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
247 const struct GNUNET_SET_Element *element,
248 GNUNET_SET_Continuation cont,
253 * Destroy the set handle, and free all associated resources.
256 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set);
260 * Prepare a set operation to be evaluated with another peer.
261 * The evaluation will not start until the client provides
262 * a local set with GNUNET_SET_commit.
264 * @param other_peer peer with the other set
265 * @param app_id hash for the application using the set
266 * @param context_msg additional information for the request
267 * @param salt salt used for the set operation; sometimes set operations
268 * fail due to hash collisions, using a different salt for each operation
269 * makes it harder for an attacker to exploit this
270 * @param result_mode specified how results will be returned,
271 * see 'GNUNET_SET_ResultMode'.
272 * @param result_cb called on error or success
273 * @param result_cls closure for result_cb
274 * @return a handle to cancel the operation
276 struct GNUNET_SET_OperationHandle *
277 GNUNET_SET_prepare (const struct GNUNET_PeerIdentity *other_peer,
278 const struct GNUNET_HashCode *app_id,
279 const struct GNUNET_MessageHeader *context_msg,
281 enum GNUNET_SET_ResultMode result_mode,
282 GNUNET_SET_ResultIterator result_cb,
287 * Wait for set operation requests for the given application id
289 * @param cfg configuration to use for connecting to
291 * @param operation operation we want to listen for
292 * @param app_id id of the application that handles set operation requests
293 * @param listen_cb called for each incoming request matching the operation
295 * @param listen_cls handle for listen_cb
296 * @return a handle that can be used to cancel the listen operation
298 struct GNUNET_SET_ListenHandle *
299 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
300 enum GNUNET_SET_OperationType op_type,
301 const struct GNUNET_HashCode *app_id,
302 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);
316 * Accept a request we got via GNUNET_SET_listen. Must be called during
317 * GNUNET_SET_listen, as the 'struct GNUNET_SET_Request' becomes invalid
319 * Call GNUNET_SET_commit to provide the local set to use for the operation,
320 * and to begin the exchange with the remote peer.
322 * @param request request to accept
323 * @param result_mode specified how results will be returned,
324 * see 'GNUNET_SET_ResultMode'.
325 * @param result_cb callback for the results
326 * @param result_cls closure for result_cb
327 * @return a handle to cancel the operation
329 struct GNUNET_SET_OperationHandle *
330 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
331 enum GNUNET_SET_ResultMode result_mode,
332 GNUNET_SET_ResultIterator result_cb,
337 * Commit a set to be used with a set operation.
338 * This function is called once we have fully constructed
339 * the set that we want to use for the operation. At this
340 * time, the P2P protocol can then begin to exchange the
341 * set information and call the result callback with the
342 * result information.
344 * @param oh handle to the set operation
345 * @param set the set to use for the operation
348 GNUNET_SET_commit (struct GNUNET_SET_OperationHandle *oh,
349 struct GNUNET_SET_Handle *set);
353 * Cancel the given set operation.
354 * May not be called after the operation's GNUNET_SET_ResultIterator has been
355 * called with a status that indicates error, timeout or done.
357 * @param oh set operation to cancel
360 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh);
363 #if 0 /* keep Emacsens' auto-indent happy */