2 This file is part of GNUnet.
3 (C) 2011 Christian Grothoff (and other contributing authors)
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22 * @file ats/gnunet-service-ats_normalization.c
23 * @brief ats service address: management of ATS properties and preferences normalization
24 * @author Matthias Wachs
25 * @author Christian Grothoff
28 #include "gnunet_ats_service.h"
29 #include "gnunet-service-ats_normalization.h"
36 struct PreferenceClient
41 struct PreferenceClient *prev;
47 struct PreferenceClient *next;
55 * Total preference for this peer
57 double f_abs_sum[GNUNET_ATS_PreferenceCount];
60 * List of peer preferences for this client
66 struct PreferencePeer *p_head;
71 struct PreferencePeer *p_tail;
83 struct PreferencePeer *next;
88 struct PreferencePeer *prev;
93 struct PreferenceClient *client;
98 struct GNUNET_PeerIdentity id;
101 * Absolute preference values
103 double f_abs[GNUNET_ATS_PreferenceCount];
106 * Relative preference values
108 double f_rel[GNUNET_ATS_PreferenceCount];
113 GNUNET_SCHEDULER_TaskIdentifier aging_task;
117 * Relative preferences for a peer
122 * Relative preference values
124 double f_rel[GNUNET_ATS_PreferenceCount];
129 struct GNUNET_PeerIdentity id;
134 * Callback to call on changing preference values
136 static GAS_Normalization_preference_changed_cb pref_changed_cb;
140 * Closure for callback to call on changing preference values
142 static void *pref_changed_cb_cls;
146 * Hashmap to store peer information
148 static struct GNUNET_CONTAINER_MultiHashMap *peers;
152 * Clients in DLL: head
154 static struct PreferenceClient *pc_head;
158 * Clients in DLL: tail
160 static struct PreferenceClient *pc_tail;
166 static struct PeerRelative defvalues;
172 * @pram kind the kind
175 update_peers (struct GNUNET_PeerIdentity *id,
176 enum GNUNET_ATS_PreferenceKind kind)
178 struct PreferenceClient *c_cur;
179 struct PreferencePeer *p_cur;
180 struct PeerRelative *rp;
188 /* For all clients */
189 for (c_cur = pc_head; NULL != c_cur; c_cur = c_cur->next)
191 /* Find peer with id */
192 for (p_cur = c_cur->p_head; NULL != p_cur; p_cur = p_cur->next)
194 if (0 == memcmp (id, &p_cur->id, sizeof (struct GNUNET_PeerIdentity)))
199 /* Found peer with id */
200 f_rel_total += p_cur->f_rel[kind];
206 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
207 "%u clients have a total relative preference for peer `%s''s `%s' of %.3f\n",
210 GNUNET_ATS_print_preference_type (kind),
212 if (NULL != (rp = GNUNET_CONTAINER_multihashmap_get (peers, &id->hashPubKey)))
214 backup = rp->f_rel[kind];
217 rp->f_rel[kind] = f_rel_total / count;
221 rp->f_rel[kind] = DEFAULT_REL_PREFERENCE;
226 return DEFAULT_REL_PREFERENCE;
229 if ((backup != rp->f_rel[kind]) && (NULL != pref_changed_cb))
231 pref_changed_cb (pref_changed_cb_cls, &rp->id, kind, rp->f_rel[kind]);
234 return rp->f_rel[kind];
239 * Recalculate preference for a specific ATS property
241 * @param c the preference client
243 * @param kind the preference kind
247 recalculate_rel_preferences (struct PreferenceClient *c,
248 struct PreferencePeer *p,
249 enum GNUNET_ATS_PreferenceKind kind)
251 struct PreferencePeer *p_cur;
252 struct PeerRelative *rp;
257 /* For this client: sum preferences to total preference */
258 c->f_abs_sum[kind] = 0;
259 for (p_cur = c->p_head; NULL != p_cur; p_cur = p_cur->next)
260 c->f_abs_sum[kind] += p_cur->f_abs[kind];
261 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
262 "Client %p has total preference for %s of %.3f\n",
264 GNUNET_ATS_print_preference_type (kind),
267 ret = DEFAULT_REL_PREFERENCE;
268 /* For all peers: calculate relative preference */
269 for (p_cur = c->p_head; NULL != p_cur; p_cur = p_cur->next)
271 /* Calculate relative preference for specific kind */
272 backup = p_cur->f_rel[kind];
273 if (DEFAULT_ABS_PREFERENCE == c->f_abs_sum[kind])
274 /* No peer has a preference for this property,
275 * so set default preference */
276 p_cur->f_rel[kind] = DEFAULT_REL_PREFERENCE;
278 p_cur->f_rel[kind] = (c->f_abs_sum[kind] + p_cur->f_abs[kind]) /
281 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
282 "Client %p: peer `%s' has relative preference for %s of %.3f\n",
284 GNUNET_i2s (&p_cur->id),
285 GNUNET_ATS_print_preference_type (kind),
289 if (p_cur->f_rel[kind] != backup)
291 /* Value changed, recalculate */
292 res = update_peers (&p_cur->id,kind);
293 if (0 == memcmp (&p->id, &p_cur->id, sizeof (struct GNUNET_PeerIdentity)))
298 /* Value did not chang, return old value*/
299 GNUNET_assert (NULL != (rp = GNUNET_CONTAINER_multihashmap_get (peers,
300 &p->id.hashPubKey)));
301 ret = rp->f_rel[kind];
309 * Update the absolute preference value for a peer
311 * @param kind the kind
312 * @return the new relative preference value
315 update_preference (struct PreferenceClient *c,
316 struct PreferencePeer *p,
317 enum GNUNET_ATS_PreferenceKind kind,
320 double score = score_abs;
322 /* Update preference value according to type */
324 case GNUNET_ATS_PREFERENCE_BANDWIDTH:
325 case GNUNET_ATS_PREFERENCE_LATENCY:
326 p->f_abs[kind] = (p->f_abs[kind] + score) / 2;
328 case GNUNET_ATS_PREFERENCE_END:
333 return recalculate_rel_preferences (c, p, kind);
338 * Reduce absolute preferences since they got old
340 * @param cls the PreferencePeer
344 preference_aging (void *cls, const struct GNUNET_SCHEDULER_TaskContext *tc)
348 struct PreferencePeer *p = cls;
349 GNUNET_assert (NULL != p);
351 p->aging_task = GNUNET_SCHEDULER_NO_TASK;
353 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Aging preferences for peer `%s'\n",
354 GNUNET_i2s (&p->id));
356 /* Aging absolute values: */
357 for (i = 0; i < GNUNET_ATS_PreferenceCount; i++)
359 backup = p->f_abs[i];
360 if (p->f_abs[i] > DEFAULT_ABS_PREFERENCE)
361 p->f_abs[i] *= PREF_AGING_FACTOR;
362 if (backup != p->f_abs[i])
364 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Aged preference for peer `%s' from %.3f to %.3f\n",
365 GNUNET_i2s (&p->id), backup, p->f_abs[i]);
366 recalculate_rel_preferences (p->client, p, i);
369 p->aging_task = GNUNET_SCHEDULER_add_delayed (PREF_AGING_INTERVAL,
370 &preference_aging, p);
375 * Normalize an updated preference value
377 * @param src the client with this preference
378 * @param peer the peer to change the preference for
379 * @param kind the kind to change the preference
380 * @param score_abs the normalized score
383 GAS_normalization_change_preference (void *src,
384 const struct GNUNET_PeerIdentity *peer,
385 enum GNUNET_ATS_PreferenceKind kind,
389 struct PreferenceClient *c_cur;
390 struct PreferencePeer *p_cur;
391 struct PeerRelative *r_cur;
395 GNUNET_assert (NULL != src);
396 GNUNET_assert (NULL != peer);
398 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
399 "Client %p changes preference for peer `%s' for `%s' to %.2f\n",
402 GNUNET_ATS_print_preference_type (kind),
405 if (kind >= GNUNET_ATS_PreferenceCount)
411 /* Find preference client */
412 for (c_cur = pc_head; NULL != c_cur; c_cur = c_cur->next)
414 if (src == c_cur->client)
417 /* Not found: create new preference client */
420 c_cur = GNUNET_malloc (sizeof (struct PreferenceClient));
422 GNUNET_CONTAINER_DLL_insert (pc_head, pc_tail, c_cur);
425 /* Find entry for peer */
426 for (p_cur = c_cur->p_head; NULL != p_cur; p_cur = p_cur->next)
427 if (0 == memcmp (&p_cur->id, peer, sizeof (p_cur->id)))
430 /* Not found: create new peer entry */
433 p_cur = GNUNET_malloc (sizeof (struct PreferencePeer));
434 p_cur->client = c_cur;
436 for (i = 0; i < GNUNET_ATS_PreferenceCount; i++)
438 /* Default value per peer absolut preference for a quality:
439 * No value set, so absolute preference 0 */
440 p_cur->f_abs[i] = DEFAULT_ABS_PREFERENCE;
441 /* Default value per peer relative preference for a quality: 1.0 */
442 p_cur->f_rel[i] = DEFAULT_REL_PREFERENCE;
444 p_cur->aging_task = GNUNET_SCHEDULER_add_delayed (PREF_AGING_INTERVAL,
445 &preference_aging, p_cur);
446 GNUNET_CONTAINER_DLL_insert (c_cur->p_head, c_cur->p_tail, p_cur);
449 if (NULL == (r_cur = GNUNET_CONTAINER_multihashmap_get (peers,
452 r_cur = GNUNET_malloc (sizeof (struct PeerRelative));
454 for (i = 0; i < GNUNET_ATS_PreferenceCount; i++)
455 r_cur->f_rel[i] = DEFAULT_REL_PREFERENCE;
456 GNUNET_CONTAINER_multihashmap_put (peers, &r_cur->id.hashPubKey,
457 r_cur, GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
460 score_rel = update_preference (c_cur, p_cur, kind, score_abs);
466 * Get the normalized preference values for a specific peer or
467 * the default values if
470 * @return pointer to the values, can be indexed with GNUNET_ATS_PreferenceKind,
471 * default preferences if peer does not exist
474 GAS_normalization_get_preferences (const struct GNUNET_PeerIdentity *id)
476 GNUNET_assert (NULL != peers);
477 GNUNET_assert (NULL != id);
479 struct PeerRelative *rp;
480 if (NULL == (rp = GNUNET_CONTAINER_multihashmap_get (peers, &id->hashPubKey)))
482 return defvalues.f_rel;
489 * Start the normalization component
491 * @param pref_ch_cb callback to call on relative preference changing
492 * @param ref_ch_cb_cls cls for the callback
495 GAS_normalization_start (GAS_Normalization_preference_changed_cb pref_ch_cb,
496 void *pref_ch_cb_cls)
499 peers = GNUNET_CONTAINER_multihashmap_create(10, GNUNET_NO);
500 pref_changed_cb = pref_ch_cb;
501 pref_changed_cb_cls = pref_ch_cb_cls;
502 for (i = 0; i < GNUNET_ATS_PreferenceCount; i++)
503 defvalues.f_rel[i] = DEFAULT_REL_PREFERENCE;
513 * @param value RelativePeer
514 * @return GNUNET_OK to continue
517 free_peer (void *cls,
518 const struct GNUNET_HashCode * key,
521 struct PeerRelative *rp = value;
522 GNUNET_CONTAINER_multihashmap_remove (peers, key, value);
529 * Stop the normalization component and free all items
532 GAS_normalization_stop ()
534 struct PreferenceClient *pc;
535 struct PreferenceClient *next_pc;
536 struct PreferencePeer *p;
537 struct PreferencePeer *next_p;
540 while (NULL != (pc = next_pc))
543 GNUNET_CONTAINER_DLL_remove (pc_head, pc_tail, pc);
545 while (NULL != (p = next_p))
548 if (GNUNET_SCHEDULER_NO_TASK != p->aging_task)
550 GNUNET_SCHEDULER_cancel(p->aging_task);
551 p->aging_task = GNUNET_SCHEDULER_NO_TASK;
553 GNUNET_CONTAINER_DLL_remove (pc->p_head, pc->p_tail, p);
558 GNUNET_CONTAINER_multihashmap_iterate (peers, &free_peer, NULL);
559 GNUNET_CONTAINER_multihashmap_destroy (peers);
563 /* end of gnunet-service-ats_normalization.c */