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22 * @file rps/gnunet-service-rps_sampler.c
23 * @brief sampler implementation
24 * @author Julius Bünger
27 #include "gnunet_util_lib.h"
30 #include "gnunet-service-rps_sampler.h"
35 #define LOG(kind, ...) GNUNET_log(kind, __VA_ARGS__)
37 // multiple 'clients'?
39 // TODO check for overflows
41 // TODO align message structs
43 // hist_size_init, hist_size_max
45 /***********************************************************************
46 * WARNING: This section needs to be reviewed regarding the use of
47 * functions providing (pseudo)randomness!
48 ***********************************************************************/
50 // TODO care about invalid input of the caller (size 0 or less...)
59 * A sampler element sampling one PeerID at a time.
61 struct RPS_SamplerElement
64 * Min-wise linear permutation used by this sampler.
66 * This is an key later used by a hmac.
68 struct GNUNET_CRYPTO_AuthKey auth_key;
71 * The PeerID this sampler currently samples.
73 struct GNUNET_PeerIdentity peer_id;
76 * The according hash value of this PeerID.
78 struct GNUNET_HashCode peer_id_hash;
81 * Time of last request.
83 struct GNUNET_TIME_Absolute last_request;
86 * Flag that indicates that we are not holding a valid PeerID right now.
88 enum RPS_SamplerEmpty is_empty;
92 * Sampler with its own array of SamplerElements
97 * Number of sampler elements we hold.
99 unsigned int sampler_size;
103 * All Samplers in one array.
105 struct RPS_SamplerElement **sampler_elements;
108 * Index to a sampler element.
110 * Gets cycled on every hist_request.
112 uint64_t sampler_elem_index;
115 * Callback to be called when a peer gets inserted into a sampler.
117 RPS_sampler_insert_cb insert_cb;
120 * Closure to the insert_cb.
125 * Callback to be called when a peer gets inserted into a sampler.
127 RPS_sampler_remove_cb remove_cb;
130 * Closure to the remove_cb.
136 * Global sampler variable.
138 struct RPS_Sampler *sampler;
142 * The minimal size for the extended sampler elements.
144 static size_t min_size;
147 * The maximal size the extended sampler elements should grow to.
149 static size_t max_size;
152 * The size the extended sampler elements currently have.
154 //static size_t extra_size;
157 * Inedex to the sampler element that is the next to be returned
159 static uint64_t client_get_index;
163 * Reinitialise a previously initialised sampler element.
165 * @param sampler pointer to the memory that keeps the value.
168 RPS_sampler_elem_reinit (struct RPS_SamplerElement *sampler_el)
170 sampler_el->is_empty = EMPTY;
172 // I guess I don't need to call GNUNET_CRYPTO_hmac_derive_key()...
173 GNUNET_CRYPTO_random_block(GNUNET_CRYPTO_QUALITY_STRONG,
174 &(sampler_el->auth_key.key),
175 GNUNET_CRYPTO_HASH_LENGTH);
177 sampler_el->last_request = GNUNET_TIME_UNIT_FOREVER_ABS;
179 /* We might want to keep the previous peer */
181 //GNUNET_CRYPTO_hmac(&sampler_el->auth_key, sampler_el->peer_id,
182 // sizeof(struct GNUNET_PeerIdentity),
183 // &sampler_el->peer_id_hash);
188 * (Re)Initialise given Sampler with random min-wise independent function.
190 * In this implementation this means choosing an auth_key for later use in
193 * @return a newly created RPS_SamplerElement which currently holds no id.
195 struct RPS_SamplerElement *
196 RPS_sampler_elem_create (void)
198 struct RPS_SamplerElement *s;
200 s = GNUNET_new (struct RPS_SamplerElement);
202 RPS_sampler_elem_reinit (s);
203 LOG (GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: initialised with empty PeerID\n");
210 * Input an PeerID into the given sampler.
213 RPS_sampler_elem_next (struct RPS_SamplerElement *s_elem, const struct GNUNET_PeerIdentity *other,
214 RPS_sampler_insert_cb insert_cb, void *insert_cls,
215 RPS_sampler_remove_cb remove_cb, void *remove_cls)
217 struct GNUNET_HashCode other_hash;
219 if ( 0 == GNUNET_CRYPTO_cmp_peer_identity(other, &(s_elem->peer_id)) )
221 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Got PeerID %s\n",
223 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Have already PeerID %s\n",
224 GNUNET_i2s(&(s_elem->peer_id)));
228 GNUNET_CRYPTO_hmac(&s_elem->auth_key,
230 sizeof(struct GNUNET_PeerIdentity),
233 if ( EMPTY == s_elem->is_empty )
234 { // Or whatever is a valid way to say
235 // "we have no PeerID at the moment"
236 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Got PeerID %s; Simply accepting (was empty previously).\n",
238 s_elem->peer_id = *other;
239 //s_elem->peer_id = other;
240 s_elem->peer_id_hash = other_hash;
241 if (NULL != sampler->insert_cb)
243 sampler->insert_cb(sampler->insert_cls, &(s_elem->peer_id));
246 else if ( 0 > GNUNET_CRYPTO_hash_cmp(&other_hash, &s_elem->peer_id_hash) )
248 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Got PeerID %s\n",
250 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Discarding old PeerID %s\n",
251 GNUNET_i2s(&s_elem->peer_id));
253 if ( NULL != sampler->remove_cb )
255 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Removing old PeerID %s with the remove callback.\n",
256 GNUNET_i2s(&s_elem->peer_id));
257 sampler->remove_cb(sampler->remove_cls, &s_elem->peer_id);
260 memcpy(&s_elem->peer_id, other, sizeof(struct GNUNET_PeerIdentity));
261 //s_elem->peer_id = other;
262 s_elem->peer_id_hash = other_hash;
264 if ( NULL != sampler->insert_cb )
266 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Inserting new PeerID %s with the insert callback.\n",
267 GNUNET_i2s(&s_elem->peer_id));
268 sampler->insert_cb(sampler->insert_cls, &s_elem->peer_id);
273 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Got PeerID %s\n",
275 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Keeping old PeerID %s\n",
276 GNUNET_i2s(&s_elem->peer_id));
279 s_elem->is_empty = NOT_EMPTY;
284 * Grow or shrink the size of the sampler.
286 * @param new_size the new size of the sampler
289 RPS_sampler_resize (unsigned int new_size)
291 unsigned int old_size;
293 struct RPS_SamplerElement **rem_list;
295 // TODO check min and max size
297 old_size = sampler->sampler_size;
299 if (old_size > new_size)
301 /* Temporary store those to properly call the removeCB on those later */
302 rem_list = GNUNET_malloc ((old_size - new_size) * sizeof (struct RPS_SamplerElement *));
304 &sampler->sampler_elements[new_size],
305 (old_size - new_size) * sizeof (struct RPS_SamplerElement *));
307 LOG (GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Shrinking sampler %d -> %d\n", old_size, new_size);
308 GNUNET_array_grow (sampler->sampler_elements, sampler->sampler_size, new_size);
309 LOG (GNUNET_ERROR_TYPE_DEBUG,
310 "SAMPLER: sampler->sampler_elements now points to %p\n",
311 sampler->sampler_elements);
313 for (i = 0 ; i < old_size - new_size ; i++)
314 {/* Remove unneeded rest */
315 LOG (GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Removing %" PRIX64 ". sampler\n", i);
316 if (NULL != sampler->remove_cb)
317 sampler->remove_cb (sampler->remove_cls, &rem_list[i]->peer_id);
318 GNUNET_free (rem_list[i]);
320 GNUNET_free (rem_list);
322 else if (old_size < new_size)
324 LOG (GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Growing sampler %d -> %d\n", old_size, new_size);
325 GNUNET_array_grow (sampler->sampler_elements, sampler->sampler_size, new_size);
326 LOG (GNUNET_ERROR_TYPE_DEBUG,
327 "SAMPLER: sampler->sampler_elements now points to %p\n",
328 sampler->sampler_elements);
330 for ( i = old_size ; i < new_size ; i++ )
331 { /* Add new sampler elements */
332 sampler->sampler_elements[i] = RPS_sampler_elem_create ();
333 if (NULL != sampler->insert_cb)
334 sampler->insert_cb (sampler->insert_cls, &sampler->sampler_elements[i]->peer_id);
335 LOG (GNUNET_ERROR_TYPE_DEBUG,
336 "SAMPLER: Added %" PRIX64 ". sampler, now pointing to %p, contains %s\n",
337 i, &sampler->sampler_elements[i], GNUNET_i2s (&sampler->sampler_elements[i]->peer_id));
342 LOG (GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Size remains the same -- nothing to do\n");
346 GNUNET_assert(sampler->sampler_size == new_size);
347 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Finished growing/shrinking.\n"); // remove
352 * Initialise a tuple of sampler elements.
354 * @param init_size the size the sampler is initialised with
355 * @param id with which all newly created sampler elements are initialised
356 * @param ins_cb the callback that will be called on every PeerID that is
357 * newly inserted into a sampler element
358 * @param ins_cls the closure given to #ins_cb
359 * @param rem_cb the callback that will be called on every PeerID that is
360 * removed from a sampler element
361 * @param rem_cls the closure given to #rem_cb
364 RPS_sampler_init (size_t init_size, const struct GNUNET_PeerIdentity *id,
365 RPS_sampler_insert_cb ins_cb, void *ins_cls,
366 RPS_sampler_remove_cb rem_cb, void *rem_cls)
368 //struct RPS_Sampler *sampler;
371 /* Initialise context around extended sampler */
372 min_size = 10; // TODO make input to _samplers_init()
373 max_size = 1000; // TODO make input to _samplers_init()
375 sampler = GNUNET_new (struct RPS_Sampler);
376 sampler->sampler_size = 0;
377 sampler->sampler_elements = NULL;
378 sampler->insert_cb = ins_cb;
379 sampler->insert_cls = ins_cls;
380 sampler->remove_cb = rem_cb;
381 sampler->remove_cls = rem_cls;
382 //sampler->sampler_elements = GNUNET_new_array(init_size, struct GNUNET_PeerIdentity);
383 //GNUNET_array_grow (sampler->sampler_elements, sampler->sampler_size, min_size);
384 RPS_sampler_resize (init_size);
385 RPS_sampler_update_list (id); // no super nice desing but ok for the moment
387 client_get_index = 0;
389 //GNUNET_assert (init_size == sampler->sampler_size);
394 * A fuction to update every sampler in the given list
396 * @param id the PeerID that is put in the sampler
399 RPS_sampler_update_list (const struct GNUNET_PeerIdentity *id)
403 for ( i = 0 ; i < sampler->sampler_size ; i++ )
404 RPS_sampler_elem_next (sampler->sampler_elements[i], id,
405 sampler->insert_cb, sampler->insert_cls,
406 sampler->remove_cb, sampler->remove_cls);
411 * Reinitialise all previously initialised sampler elements with the given value.
413 * Used to get rid of a PeerID.
415 * @param id the id of the sampler elements to update.
418 RPS_sampler_reinitialise_by_value (const struct GNUNET_PeerIdentity *id)
422 for ( i = 0 ; i < sampler->sampler_size ; i++ )
424 if ( 0 == GNUNET_CRYPTO_cmp_peer_identity(id, &(sampler->sampler_elements[i]->peer_id)) )
426 LOG(GNUNET_ERROR_TYPE_DEBUG, "SAMPLER: Reinitialising sampler\n");
427 RPS_sampler_elem_reinit (sampler->sampler_elements[i]);
434 * Get one random peer out of the sampled peers.
436 * We might want to reinitialise this sampler after giving the
437 * corrsponding peer to the client.
438 * Only used internally
440 const struct GNUNET_PeerIdentity *
441 RPS_sampler_get_rand_peer_ ()
444 const struct GNUNET_PeerIdentity *peer; // do we have to malloc that?
446 // TODO implement extra logic
449 * Choose the r_index of the peer we want to return
450 * at random from the interval of the gossip list
452 r_index = GNUNET_CRYPTO_random_u64(GNUNET_CRYPTO_QUALITY_STRONG,
453 sampler->sampler_size);
455 //if ( EMPTY == sampler->sampler_elements[r_index]->is_empty )
456 // // TODO schedule for later
459 peer = &(sampler->sampler_elements[r_index]->peer_id);
460 sampler->sampler_elements[r_index]->last_request = GNUNET_TIME_absolute_get();
461 LOG(GNUNET_ERROR_TYPE_DEBUG, "Sgrp: Returning PeerID %s\n", GNUNET_i2s(peer));
468 * Get n random peers out of the sampled peers.
470 * We might want to reinitialise this sampler after giving the
471 * corrsponding peer to the client.
472 * Random with or without consumption?
473 * Only used internally
475 const struct GNUNET_PeerIdentity *
476 RPS_sampler_get_n_rand_peers_ (uint64_t n)
478 if ( 0 == sampler->sampler_size )
480 LOG (GNUNET_ERROR_TYPE_DEBUG,
481 "Sgrp: List empty - Returning NULL\n");
486 // TODO check if we have too much (distinct) sampled peers
487 // If we are not ready yet maybe schedule for later
488 struct GNUNET_PeerIdentity *peers;
491 peers = GNUNET_malloc (n * sizeof(struct GNUNET_PeerIdentity));
493 for ( i = 0 ; i < n ; i++ ) {
494 //peers[i] = RPS_sampler_get_rand_peer_(sampler->sampler_elements);
495 memcpy (&peers[i], RPS_sampler_get_rand_peer_ (), sizeof (struct GNUNET_PeerIdentity));
503 * Get one random peer out of the sampled peers.
505 * We might want to reinitialise this sampler after giving the
506 * corrsponding peer to the client.
508 * @return a random PeerID of the PeerIDs previously put into the sampler.
510 const struct GNUNET_PeerIdentity *
511 RPS_sampler_get_rand_peer ()
513 struct GNUNET_PeerIdentity *peer;
515 // use _get_rand_peer_ ?
516 peer = GNUNET_new (struct GNUNET_PeerIdentity);
517 *peer = sampler->sampler_elements[client_get_index]->peer_id;
518 RPS_sampler_elem_reinit (sampler->sampler_elements[client_get_index]);
519 if ( client_get_index == sampler->sampler_size )
520 client_get_index = 0;
528 * Get n random peers out of the sampled peers.
530 * We might want to reinitialise this sampler after giving the
531 * corrsponding peer to the client.
532 * Random with or without consumption?
534 * @return n random PeerIDs of the PeerIDs previously put into the sampler.
536 const struct GNUNET_PeerIdentity *
537 RPS_sampler_get_n_rand_peers (uint64_t n)
539 // use _get_rand_peers_ ?
540 if ( 0 == sampler->sampler_size )
542 LOG (GNUNET_ERROR_TYPE_DEBUG,
543 "Sgrp: List empty - Returning NULL\n");
548 // TODO check if we have too much (distinct) sampled peers
549 // If we are not ready yet maybe schedule for later
550 struct GNUNET_PeerIdentity *peers;
551 const struct GNUNET_PeerIdentity *peer;
554 peers = GNUNET_malloc (n * sizeof (struct GNUNET_PeerIdentity));
556 for ( i = 0 ; i < n ; i++ ) {
557 //peers[i] = RPS_sampler_get_rand_peer_(sampler->sampler_elements);
558 peer = RPS_sampler_get_rand_peer ();
559 memcpy (&peers[i], peer, sizeof (struct GNUNET_PeerIdentity));
560 //GNUNET_free (peer);
568 * Counts how many Samplers currently hold a given PeerID.
570 * @param id the PeerID to count.
572 * @return the number of occurrences of id.
575 RPS_sampler_count_id (const struct GNUNET_PeerIdentity *id)
581 for ( i = 0 ; i < sampler->sampler_size ; i++ )
583 if ( 0 == GNUNET_CRYPTO_cmp_peer_identity (&sampler->sampler_elements[i]->peer_id, id)
584 && EMPTY != sampler->sampler_elements[i]->is_empty)
592 * Cleans the sampler.
595 RPS_sampler_destroy ()
597 RPS_sampler_resize (0);
598 GNUNET_array_grow (sampler->sampler_elements, sampler->sampler_size, 0);
601 /* end of gnunet-service-rps.c */