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 * A purely local set that does not support any
80 GNUNET_SET_OPERATION_NONE,
83 * Set intersection, only return elements that are in both sets.
85 GNUNET_SET_OPERATION_INTERSECTION,
88 * Set union, return all elements that are in at least one of the sets.
90 GNUNET_SET_OPERATION_UNION
94 * Status for the result callback
96 enum GNUNET_SET_Status
101 GNUNET_SET_STATUS_OK,
104 * There was a timeout.
106 GNUNET_SET_STATUS_TIMEOUT,
109 * The other peer refused to to the operation with us,
110 * or something went wrong.
112 GNUNET_SET_STATUS_FAILURE,
115 * Success, all elements have been returned (but the other
116 * peer might still be receiving some from us, so we are not done).
118 GNUNET_SET_STATUS_HALF_DONE,
121 * Success, all elements have been sent (and received).
123 GNUNET_SET_STATUS_DONE
128 * The way results are given to the client.
130 enum GNUNET_SET_ResultMode
133 * Client gets every element in the resulting set.
135 GNUNET_SET_RESULT_FULL,
137 * Client gets only elements that have been added to the set.
138 * Only works with set union.
140 GNUNET_SET_RESULT_ADDED,
142 * Client gets only elements that have been removed from the set.
143 * Only works with set intersection.
145 GNUNET_SET_RESULT_REMOVED
150 * Element stored in a set.
152 struct GNUNET_SET_Element
155 * Number of bytes in the buffer pointed to by data.
160 * Application-specific element type.
165 * Actual data of the element
172 * Continuation used for some of the set operations
176 typedef void (*GNUNET_SET_Continuation) (void *cls);
180 * Callback for set operation results. Called for each element
184 * @param element a result element, only valid if status is GNUNET_SET_STATUS_OK
185 * @param status see enum GNUNET_SET_Status
187 typedef void (*GNUNET_SET_ResultIterator) (void *cls,
188 const struct GNUNET_SET_Element *element,
189 enum GNUNET_SET_Status status);
193 * Called when another peer wants to do a set operation with the
194 * local peer. If a listen error occurs, the 'request' is NULL.
197 * @param other_peer the other peer
198 * @param context_msg message with application specific information from
200 * @param request request from the other peer, use GNUNET_SET_accept
201 * Will be NULL if the listener failed.
202 * to accept it, otherwise the request will be refused
203 * Note that we can't just return value from the listen callback,
204 * as it is also necessary to specify the set we want to do the
205 * operation with, whith sometimes can be derived from the context
206 * message. It's necessary to specify the timeout.
209 (*GNUNET_SET_ListenCallback) (void *cls,
210 const struct GNUNET_PeerIdentity *other_peer,
211 const struct GNUNET_MessageHeader *context_msg,
212 struct GNUNET_SET_Request *request);
217 * Create an empty set, supporting the specified operation.
219 * @param cfg configuration to use for connecting to the
221 * @param op operation supported by the set
222 * Note that the operation has to be specified
223 * beforehand, as certain set operations need to maintain
224 * data structures spefific to the operation
225 * @return a handle to the set
227 struct GNUNET_SET_Handle *
228 GNUNET_SET_create (const struct GNUNET_CONFIGURATION_Handle *cfg,
229 enum GNUNET_SET_OperationType op);
233 * Add an element to the given set.
234 * After the element has been added (in the sense of being
235 * transmitted to the set service), cont will be called.
236 * Calls to add_element can be queued
238 * @param set set to add element to
239 * @param element element to add to the set
240 * @param cont continuation called after the element has been added
241 * @param cont_cls closure for cont
244 GNUNET_SET_add_element (struct GNUNET_SET_Handle *set,
245 const struct GNUNET_SET_Element *element,
246 GNUNET_SET_Continuation cont,
251 * Remove an element to the given set.
252 * After the element has been removed (in the sense of the
253 * request being transmitted to the set service), cont will be called.
254 * Calls to remove_element can be queued
256 * @param set set to remove element from
257 * @param element element to remove from the set
258 * @param cont continuation called after the element has been removed
259 * @param cont_cls closure for cont
262 GNUNET_SET_remove_element (struct GNUNET_SET_Handle *set,
263 const struct GNUNET_SET_Element *element,
264 GNUNET_SET_Continuation cont,
269 * Destroy the set handle, and free all associated resources.
272 GNUNET_SET_destroy (struct GNUNET_SET_Handle *set);
276 * Prepare a set operation to be evaluated with another peer.
277 * The evaluation will not start until the client provides
278 * a local set with GNUNET_SET_commit.
280 * @param other_peer peer with the other set
281 * @param app_id hash for the application using the set
282 * @param context_msg additional information for the request
283 * @param salt salt used for the set operation; sometimes set operations
284 * fail due to hash collisions, using a different salt for each operation
285 * makes it harder for an attacker to exploit this
286 * @param result_mode specified how results will be returned,
287 * see 'GNUNET_SET_ResultMode'.
288 * @param result_cb called on error or success
289 * @param result_cls closure for result_cb
290 * @return a handle to cancel the operation
292 struct GNUNET_SET_OperationHandle *
293 GNUNET_SET_prepare (const struct GNUNET_PeerIdentity *other_peer,
294 const struct GNUNET_HashCode *app_id,
295 const struct GNUNET_MessageHeader *context_msg,
297 enum GNUNET_SET_ResultMode result_mode,
298 GNUNET_SET_ResultIterator result_cb,
303 * Wait for set operation requests for the given application id
305 * @param cfg configuration to use for connecting to
307 * @param operation operation we want to listen for
308 * @param app_id id of the application that handles set operation requests
309 * @param listen_cb called for each incoming request matching the operation
311 * @param listen_cls handle for listen_cb
312 * @return a handle that can be used to cancel the listen operation
314 struct GNUNET_SET_ListenHandle *
315 GNUNET_SET_listen (const struct GNUNET_CONFIGURATION_Handle *cfg,
316 enum GNUNET_SET_OperationType op_type,
317 const struct GNUNET_HashCode *app_id,
318 GNUNET_SET_ListenCallback listen_cb,
323 * Cancel the given listen operation.
325 * @param lh handle for the listen operation
328 GNUNET_SET_listen_cancel (struct GNUNET_SET_ListenHandle *lh);
332 * Accept a request we got via GNUNET_SET_listen. Must be called during
333 * GNUNET_SET_listen, as the 'struct GNUNET_SET_Request' becomes invalid
335 * Call GNUNET_SET_commit to provide the local set to use for the operation,
336 * and to begin the exchange with the remote peer.
338 * @param request request to accept
339 * @param result_mode specified how results will be returned,
340 * see 'GNUNET_SET_ResultMode'.
341 * @param result_cb callback for the results
342 * @param result_cls closure for result_cb
343 * @return a handle to cancel the operation
345 struct GNUNET_SET_OperationHandle *
346 GNUNET_SET_accept (struct GNUNET_SET_Request *request,
347 enum GNUNET_SET_ResultMode result_mode,
348 GNUNET_SET_ResultIterator result_cb,
353 * Commit a set to be used with a set operation.
354 * This function is called once we have fully constructed
355 * the set that we want to use for the operation. At this
356 * time, the P2P protocol can then begin to exchange the
357 * set information and call the result callback with the
358 * result information.
360 * @param oh handle to the set operation
361 * @param set the set to use for the operation
364 GNUNET_SET_commit (struct GNUNET_SET_OperationHandle *oh,
365 struct GNUNET_SET_Handle *set);
369 * Cancel the given set operation.
370 * May not be called after the operation's GNUNET_SET_ResultIterator has been
371 * called with a status that indicates error, timeout or done.
373 * @param oh set operation to cancel
376 GNUNET_SET_operation_cancel (struct GNUNET_SET_OperationHandle *oh);
379 #if 0 /* keep Emacsens' auto-indent happy */