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 * Maximum size of a context message for set operation requests.
47 #define GNUNET_SET_CONTEXT_MESSAGE_MAX_SIZE ((1<<16) - 1024)
51 * Opaque handle to a set.
53 struct GNUNET_SET_Handle;
56 * Opaque handle to a set operation request from another peer.
58 struct GNUNET_SET_Request;
61 * Opaque handle to a listen operation.
63 struct GNUNET_SET_ListenHandle;
66 * Opaque handle to a set operation.
68 struct GNUNET_SET_OperationHandle;
72 * The operation that a set set supports.
74 enum GNUNET_SET_OperationType
77 * Set intersection, only return elements that are in both sets.
79 GNUNET_SET_OPERATION_INTERSECTION,
81 * Set union, return all elements that are in at least one of the sets.
83 GNUNET_SET_OPERATION_UNION
87 * Status for the result callback
89 enum GNUNET_SET_Status
97 * There was a timeout.
99 GNUNET_SET_STATUS_TIMEOUT,
102 * The other peer refused to to the operation with us,
103 * or something went wrong.
105 GNUNET_SET_STATUS_FAILURE,
108 * Success, all elements have been returned (but the other
109 * peer might still be receiving some from us, so we are not done).
111 GNUNET_SET_STATUS_HALF_DONE,
114 * Success, all elements have been sent (and received).
116 GNUNET_SET_STATUS_DONE
120 * The way results are given to the client.
122 enum GNUNET_SET_ResultMode
125 * Client gets every element in the resulting set.
127 GNUNET_SET_RESULT_FULL,
129 * Client gets only elements that have been added to the set.
130 * Only works with set union.
132 GNUNET_SET_RESULT_ADDED,
134 * Client gets only elements that have been removed from the set.
135 * Only works with set intersection.
137 GNUNET_SET_RESULT_REMOVED
141 * Element stored in a set.
143 struct GNUNET_SET_Element
146 * Number of bytes in the buffer pointed to by data.
151 * Application-specific element type.
156 * Actual data of the element
163 * Continuation used for some of the set operations
167 typedef void (*GNUNET_SET_Continuation) (void *cls);
171 * Callback for set operation results. Called for each element
175 * @param element a result element, only valid if status is GNUNET_SET_STATUS_OK
176 * @param status see enum GNUNET_SET_Status
178 typedef void (*GNUNET_SET_ResultIterator) (void *cls,
179 const struct GNUNET_SET_Element *element,
180 enum GNUNET_SET_Status status);
184 * Called when another peer wants to do a set operation with the
188 * @param other_peer the other peer
189 * @param context_msg message with application specific information from
191 * @param request request from the other peer, use GNUNET_SET_accept
192 * to accept it, otherwise the request will be refused
193 * Note that we don't use a return value here, as it is also
194 * necessary to specify the set we want to do the operation with,
195 * whith sometimes can be derived from the context message.
196 * Also necessary to specify the timeout.
199 (*GNUNET_SET_ListenCallback) (void *cls,
200 const struct GNUNET_PeerIdentity *other_peer,
201 const struct GNUNET_MessageHeader *context_msg,
202 struct GNUNET_SET_Request *request);
207 * Create an empty set, supporting the specified operation.
209 * @param cfg configuration to use for connecting to the
211 * @param op operation supported by the set
212 * Note that the operation has to be specified
213 * beforehand, as certain set operations need to maintain
214 * data structures spefific to the operation
215 * @return a handle to the set
217 struct GNUNET_SET_Handle *
218 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
219 enum GNUNET_SET_OperationType op);
223 * Add an element to the given set.
224 * After the element has been added (in the sense of being
225 * transmitted to the set service), cont will be called.
226 * Calls to add_element can be queued
228 * @param set set to add element to
229 * @param element element to add to the set
230 * @param cont continuation called after the element has been added
231 * @param cont_cls closure for cont
234 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
235 const struct GNUNET_SET_Element *element,
236 GNUNET_SET_Continuation cont,
241 * Remove an element to the given set.
242 * After the element has been removed (in the sense of the
243 * request being transmitted to the set service), cont will be called.
244 * Calls to remove_element can be queued
246 * @param set set to remove element from
247 * @param element element to remove from the set
248 * @param cont continuation called after the element has been removed
249 * @param cont_cls closure for cont
252 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
253 const struct GNUNET_SET_Element *element,
254 GNUNET_SET_Continuation cont,
259 * Destroy the set handle, and free all associated resources.
262 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set);
266 * Prepare a set operation to be evaluated with another peer.
267 * The evaluation will not start until the client provides
268 * a local set with GNUNET_SET_commit.
270 * @param other_peer peer with the other set
271 * @param app_id hash for the application using the set
272 * @param context_msg additional information for the request
273 * @param salt salt used for the set operation; sometimes set operations
274 * fail due to hash collisions, using a different salt for each operation
275 * makes it harder for an attacker to exploit this
276 * @param result_mode specified how results will be returned,
277 * see 'GNUNET_SET_ResultMode'.
278 * @param result_cb called on error or success
279 * @param result_cls closure for result_cb
280 * @return a handle to cancel the operation
282 struct GNUNET_SET_OperationHandle *
283 GNUNET_SET_prepare (const struct GNUNET_PeerIdentity *other_peer,
284 const struct GNUNET_HashCode *app_id,
285 const struct GNUNET_MessageHeader *context_msg,
287 enum GNUNET_SET_ResultMode result_mode,
288 GNUNET_SET_ResultIterator result_cb,
293 * Wait for set operation requests for the given application id
295 * @param cfg configuration to use for connecting to
297 * @param operation operation we want to listen for
298 * @param app_id id of the application that handles set operation requests
299 * @param listen_cb called for each incoming request matching the operation
301 * @param listen_cls handle for listen_cb
302 * @return a handle that can be used to cancel the listen operation
304 struct GNUNET_SET_ListenHandle *
305 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
306 enum GNUNET_SET_OperationType op_type,
307 const struct GNUNET_HashCode *app_id,
308 GNUNET_SET_ListenCallback listen_cb,
313 * Cancel the given listen operation.
315 * @param lh handle for the listen operation
318 GNUNET_SET_listen_cancel (struct GNUNET_SET_ListenHandle *lh);
322 * Accept a request we got via GNUNET_SET_listen. Must be called during
323 * GNUNET_SET_listen, as the 'struct GNUNET_SET_Request' becomes invalid
325 * Call GNUNET_SET_commit to provide the local set to use for the operation,
326 * and to begin the exchange with the remote peer.
328 * @param request request to accept
329 * @param result_mode specified how results will be returned,
330 * see 'GNUNET_SET_ResultMode'.
331 * @param result_cb callback for the results
332 * @param result_cls closure for result_cb
333 * @return a handle to cancel the operation
335 struct GNUNET_SET_OperationHandle *
336 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
337 enum GNUNET_SET_ResultMode result_mode,
338 GNUNET_SET_ResultIterator result_cb,
343 * Commit a set to be used with a set operation.
344 * This function is called once we have fully constructed
345 * the set that we want to use for the operation. At this
346 * time, the P2P protocol can then begin to exchange the
347 * set information and call the result callback with the
348 * result information.
350 * @param oh handle to the set operation
351 * @param set the set to use for the operation
354 GNUNET_SET_commit (struct GNUNET_SET_OperationHandle *oh,
355 struct GNUNET_SET_Handle *set);
359 * Cancel the given set operation.
360 * May not be called after the operation's GNUNET_SET_ResultIterator has been
361 * called with a status that indicates error, timeout or done.
363 * @param oh set operation to cancel
366 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh);
369 #if 0 /* keep Emacsens' auto-indent happy */