2 This file is part of GNUnet.
3 (C) 2011 Christian Grothoff (and other contributing authors)
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22 * @file fs/gnunet-service-fs_pe.c
23 * @brief API to manage query plan
24 * @author Christian Grothoff
27 #include "gnunet-service-fs.h"
28 #include "gnunet-service-fs_cp.h"
29 #include "gnunet-service-fs_pe.h"
30 #include "gnunet-service-fs_pr.h"
34 * List of GSF_PendingRequests this request plan
37 struct PendingRequestList;
40 * Transmission plan for a peer.
46 * DLL of request plans a particular pending request is
49 struct GSF_RequestPlanReference
53 * This is a doubly-linked list.
55 struct GSF_RequestPlanReference *next;
58 * This is a doubly-linked list.
60 struct GSF_RequestPlanReference *prev;
63 * Associated request plan.
65 struct GSF_RequestPlan *rp;
68 * Corresponding PendingRequestList.
70 struct PendingRequestList *prl;
75 * List of GSF_PendingRequests this request plan
78 struct PendingRequestList
82 * This is a doubly-linked list.
84 struct PendingRequestList *next;
87 * This is a doubly-linked list.
89 struct PendingRequestList *prev;
92 * Associated pending request.
94 struct GSF_PendingRequest *pr;
97 * Corresponding GSF_RequestPlanReference.
99 struct GSF_RequestPlanReference *rpr;
105 * Information we keep per request per peer. This is a doubly-linked
106 * list (with head and tail in the 'struct GSF_PendingRequestData')
107 * with one entry in each heap of each 'struct PeerPlan'. Each
108 * entry tracks information relevant for this request and this peer.
110 struct GSF_RequestPlan
114 * This is a doubly-linked list.
116 struct GSF_RequestPlan *next;
119 * This is a doubly-linked list.
121 struct GSF_RequestPlan *prev;
124 * Heap node associated with this request and this peer.
126 struct GNUNET_CONTAINER_HeapNode *hn;
129 * The transmission plan for a peer that this request is associated with.
134 * Head of list of associated pending requests.
136 struct PendingRequestList *prl_head;
139 * Tail of list of associated pending requests.
141 struct PendingRequestList *prl_tail;
144 * Earliest time we'd be happy to (re)transmit this request.
146 struct GNUNET_TIME_Absolute earliest_transmission;
149 * When was the last time we transmitted this request to this peer? 0 for never.
151 struct GNUNET_TIME_Absolute last_transmission;
154 * Current priority for this request for this target.
159 * How often did we transmit this request to this peer?
161 unsigned int transmission_counter;
167 * Transmission plan for a peer.
172 * Heap with pending queries (struct GSF_RequestPlan), higher weights mean higher priority.
174 struct GNUNET_CONTAINER_Heap *priority_heap;
177 * Heap with pending queries (struct GSF_RequestPlan), by transmission time, lowest first.
179 struct GNUNET_CONTAINER_Heap *delay_heap;
182 * Map of queries to plan entries. All entries in the priority_heap or delay_heap
183 * should be in the plan map. Note that it IS possible for the plan map to have
184 * multiple entries for the same query.
186 struct GNUNET_CONTAINER_MultiHashMap *plan_map;
189 * Current transmission request handle.
191 struct GSF_PeerTransmitHandle *pth;
194 * Peer for which this is the plan.
196 struct GSF_ConnectedPeer *cp;
199 * Current task for executing the plan.
201 GNUNET_SCHEDULER_TaskIdentifier task;
206 * Hash map from peer identities to PeerPlans.
208 static struct GNUNET_CONTAINER_MultiHashMap *plans;
211 * Sum of all transmission counters (equals total delay for all plan entries).
213 static unsigned long long total_delay;
216 * Number of plan entries.
218 static unsigned long long plan_count;
222 * Return the query (key in the plan_map) for the given request plan.
223 * Note that this key may change as there can be multiple pending
224 * requests for the same key and we just return _one_ of them; this
225 * particular one might complete while another one might still be
226 * active, hence the lifetime of the returned hash code is NOT
227 * necessarily identical to that of the 'struct GSF_RequestPlan'
230 * @param rp a request plan
231 * @return the associated query
233 static const struct GNUNET_HashCode *
234 get_rp_key (struct GSF_RequestPlan *rp)
236 return &GSF_pending_request_get_data_ (rp->prl_head->pr)->query;
241 * Figure out when and how to transmit to the given peer.
243 * @param cls the 'struct GSF_ConnectedPeer' for transmission
244 * @param tc scheduler context
247 schedule_peer_transmission (void *cls,
248 const struct GNUNET_SCHEDULER_TaskContext *tc);
252 * Insert the given request plan into the heap with the appropriate weight.
254 * @param pp associated peer's plan
255 * @param rp request to plan
258 plan (struct PeerPlan *pp, struct GSF_RequestPlan *rp)
260 #define N ((double)128.0)
262 * Running average delay we currently impose.
264 static double avg_delay;
266 struct GSF_PendingRequestData *prd;
267 struct GNUNET_TIME_Relative delay;
269 GNUNET_assert (rp->pp == pp);
270 GNUNET_STATISTICS_set (GSF_stats,
271 gettext_noop ("# average retransmission delay (ms)"),
272 total_delay * 1000LL / plan_count, GNUNET_NO);
273 prd = GSF_pending_request_get_data_ (rp->prl_head->pr);
275 if (rp->transmission_counter < 8)
277 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
278 rp->transmission_counter);
279 else if (rp->transmission_counter < 32)
281 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
283 (1LL << (rp->transmission_counter - 8)));
286 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
289 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
290 delay.rel_value + 1);
291 /* Add 0.01 to avg_delay to avoid division-by-zero later */
292 avg_delay = (((avg_delay * (N - 1.0)) + delay.rel_value) / N) + 0.01;
295 * For the priority, we need to consider a few basic rules:
296 * 1) if we just started requesting (delay is small), we should
297 * virtually always have a priority of zero.
298 * 2) for requests with average latency, our priority should match
299 * the average priority observed on the network
300 * 3) even the longest-running requests should not be WAY out of
301 * the observed average (thus we bound by a factor of 2)
302 * 4) we add +1 to the observed average priority to avoid everyone
303 * staying put at zero (2 * 0 = 0...).
305 * Using the specific calculation below, we get:
307 * delay = 0 => priority = 0;
308 * delay = avg delay => priority = running-average-observed-priority;
309 * delay >> avg_delay => priority = 2 * running-average-observed-priority;
311 * which satisfies all of the rules above.
313 * Note: M_PI_4 = PI/4 = arctan(1)
316 round ((GSF_current_priorities +
317 1.0) * atan (delay.rel_value / avg_delay)) / M_PI_4;
318 /* Note: usage of 'round' and 'atan' requires -lm */
320 if (rp->transmission_counter != 0)
321 delay.rel_value += TTL_DECREMENT;
322 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
323 "Considering (re)transmission number %u in %llu ms\n",
324 (unsigned int) rp->transmission_counter,
325 (unsigned long long) delay.rel_value);
326 rp->earliest_transmission = GNUNET_TIME_relative_to_absolute (delay);
327 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
328 "Earliest (re)transmission for `%s' in %us\n",
329 GNUNET_h2s (&prd->query), rp->transmission_counter);
330 GNUNET_assert (rp->hn == NULL);
331 if (GNUNET_TIME_absolute_get_remaining (rp->earliest_transmission).rel_value
333 rp->hn = GNUNET_CONTAINER_heap_insert (pp->priority_heap, rp, rp->priority);
336 GNUNET_CONTAINER_heap_insert (pp->delay_heap, rp,
337 rp->earliest_transmission.abs_value);
338 GNUNET_assert (GNUNET_YES ==
339 GNUNET_CONTAINER_multihashmap_contains_value (pp->plan_map,
342 if (GNUNET_SCHEDULER_NO_TASK != pp->task)
343 GNUNET_SCHEDULER_cancel (pp->task);
344 pp->task = GNUNET_SCHEDULER_add_now (&schedule_peer_transmission, pp);
350 * Get the pending request with the highest TTL from the given plan.
352 * @param rp plan to investigate
353 * @return pending request with highest TTL
355 struct GSF_PendingRequest *
356 get_latest (const struct GSF_RequestPlan *rp)
358 struct GSF_PendingRequest *ret;
359 struct PendingRequestList *prl;
366 if (GSF_pending_request_get_data_ (prl->pr)->ttl.abs_value >
367 GSF_pending_request_get_data_ (ret)->ttl.abs_value)
376 * Function called to get a message for transmission.
379 * @param buf_size number of bytes available in buf
380 * @param buf where to copy the message, NULL on error (peer disconnect)
381 * @return number of bytes copied to 'buf', can be 0 (without indicating an error)
384 transmit_message_callback (void *cls, size_t buf_size, void *buf)
386 struct PeerPlan *pp = cls;
387 struct GSF_RequestPlan *rp;
393 /* failed, try again... */
394 pp->task = GNUNET_SCHEDULER_add_now (&schedule_peer_transmission, pp);
395 GNUNET_STATISTICS_update (GSF_stats,
397 ("# transmission failed (core has no bandwidth)"),
401 rp = GNUNET_CONTAINER_heap_peek (pp->priority_heap);
404 pp->task = GNUNET_SCHEDULER_add_now (&schedule_peer_transmission, pp);
407 msize = GSF_pending_request_get_message_ (get_latest (rp), buf_size, buf);
408 if (msize > buf_size)
410 /* buffer to small (message changed), try again */
411 pp->task = GNUNET_SCHEDULER_add_now (&schedule_peer_transmission, pp);
414 /* remove from root, add again elsewhere... */
415 GNUNET_assert (rp == GNUNET_CONTAINER_heap_remove_root (pp->priority_heap));
417 rp->last_transmission = GNUNET_TIME_absolute_get ();
418 rp->transmission_counter++;
420 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
421 "Executing plan %p executed %u times, planning retransmission\n",
422 rp, rp->transmission_counter);
424 GNUNET_STATISTICS_update (GSF_stats,
426 ("# query messages sent to other peers"), 1,
433 * Figure out when and how to transmit to the given peer.
435 * @param cls the 'struct PeerPlan'
436 * @param tc scheduler context
439 schedule_peer_transmission (void *cls,
440 const struct GNUNET_SCHEDULER_TaskContext *tc)
442 struct PeerPlan *pp = cls;
443 struct GSF_RequestPlan *rp;
445 struct GNUNET_TIME_Relative delay;
447 pp->task = GNUNET_SCHEDULER_NO_TASK;
450 GSF_peer_transmit_cancel_ (pp->pth);
453 /* move ready requests to priority queue */
454 while ((NULL != (rp = GNUNET_CONTAINER_heap_peek (pp->delay_heap))) &&
455 (GNUNET_TIME_absolute_get_remaining
456 (rp->earliest_transmission).rel_value == 0))
458 GNUNET_assert (rp == GNUNET_CONTAINER_heap_remove_root (pp->delay_heap));
459 rp->hn = GNUNET_CONTAINER_heap_insert (pp->priority_heap, rp, rp->priority);
461 if (0 == GNUNET_CONTAINER_heap_get_size (pp->priority_heap))
463 /* priority heap (still) empty, check for delay... */
464 rp = GNUNET_CONTAINER_heap_peek (pp->delay_heap);
467 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "No active requests for plan %p.\n",
469 return; /* both queues empty */
471 delay = GNUNET_TIME_absolute_get_remaining (rp->earliest_transmission);
472 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
473 "Sleeping for %llu ms before retrying requests on plan %p.\n",
474 (unsigned long long) delay.rel_value, pp);
475 GNUNET_STATISTICS_set (GSF_stats, gettext_noop ("# delay heap timeout"),
476 delay.rel_value, GNUNET_NO);
479 GNUNET_SCHEDULER_add_delayed (delay, &schedule_peer_transmission, pp);
482 GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# query plans executed"),
484 /* process from priority heap */
485 rp = GNUNET_CONTAINER_heap_peek (pp->priority_heap);
486 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG, "Executing query plan %p\n", rp);
487 GNUNET_assert (NULL != rp);
488 msize = GSF_pending_request_get_message_ (get_latest (rp), 0, NULL);
490 GSF_peer_transmit_ (pp->cp, GNUNET_YES, rp->priority,
491 GNUNET_TIME_UNIT_FOREVER_REL, msize,
492 &transmit_message_callback, pp);
493 GNUNET_assert (NULL != pp->pth);
498 * Closure for 'merge_pr'.
503 struct GSF_PendingRequest *pr;
511 * Iterator that checks if an equivalent request is already
512 * present for this peer.
515 * @param query the query
516 * @param element request plan stored at the node
517 * @return GNUNET_YES if we should continue to iterate,
518 * GNUNET_NO if not (merge success)
521 merge_pr (void *cls, const struct GNUNET_HashCode * query, void *element)
523 struct MergeContext *mpr = cls;
524 struct GSF_RequestPlan *rp = element;
525 struct GSF_PendingRequestData *prd;
526 struct GSF_RequestPlanReference *rpr;
527 struct PendingRequestList *prl;
528 struct GSF_PendingRequest *latest;
531 GSF_pending_request_is_compatible_ (mpr->pr, rp->prl_head->pr))
533 /* merge new request with existing request plan */
534 rpr = GNUNET_malloc (sizeof (struct GSF_RequestPlanReference));
535 prl = GNUNET_malloc (sizeof (struct PendingRequestList));
540 prd = GSF_pending_request_get_data_ (mpr->pr);
541 GNUNET_CONTAINER_DLL_insert (prd->rpr_head, prd->rpr_tail, rpr);
542 GNUNET_CONTAINER_DLL_insert (rp->prl_head, rp->prl_tail, prl);
543 mpr->merged = GNUNET_YES;
544 GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests merged"), 1,
546 latest = get_latest (rp);
547 if (GSF_pending_request_get_data_ (latest)->ttl.abs_value <
550 GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# requests refreshed"),
552 rp->transmission_counter = 0; /* reset */
559 * Create a new query plan entry.
561 * @param cp peer with the entry
562 * @param pr request with the entry
565 GSF_plan_add_ (struct GSF_ConnectedPeer *cp, struct GSF_PendingRequest *pr)
567 const struct GNUNET_PeerIdentity *id;
569 struct GSF_PendingRequestData *prd;
570 struct GSF_RequestPlan *rp;
571 struct GSF_RequestPlanReference *rpr;
572 struct PendingRequestList *prl;
573 struct MergeContext mpc;
575 GNUNET_assert (NULL != cp);
576 id = GSF_connected_peer_get_identity2_ (cp);
577 pp = GNUNET_CONTAINER_multihashmap_get (plans, &id->hashPubKey);
580 pp = GNUNET_malloc (sizeof (struct PeerPlan));
581 pp->plan_map = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
583 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MAX);
585 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
587 GNUNET_CONTAINER_multihashmap_put (plans,
589 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY);
591 mpc.merged = GNUNET_NO;
593 GNUNET_CONTAINER_multihashmap_get_multiple (pp->plan_map,
594 &GSF_pending_request_get_data_
595 (pr)->query, &merge_pr, &mpc); // 8 MB in 'merge_pr'
596 if (mpc.merged != GNUNET_NO)
598 GNUNET_CONTAINER_multihashmap_get_multiple (pp->plan_map,
599 &GSF_pending_request_get_data_
600 (pr)->query, &merge_pr, &mpc);
601 if (mpc.merged != GNUNET_NO)
604 GNUNET_STATISTICS_update (GSF_stats, gettext_noop ("# query plan entries"), 1,
606 prd = GSF_pending_request_get_data_ (pr);
607 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
608 "Planning transmission of query `%s' to peer `%s'\n",
609 GNUNET_h2s (&prd->query), GNUNET_i2s (id));
610 rp = GNUNET_malloc (sizeof (struct GSF_RequestPlan)); // 8 MB
611 rpr = GNUNET_malloc (sizeof (struct GSF_RequestPlanReference));
612 prl = GNUNET_malloc (sizeof (struct PendingRequestList));
617 GNUNET_CONTAINER_DLL_insert (prd->rpr_head, prd->rpr_tail, rpr);
618 GNUNET_CONTAINER_DLL_insert (rp->prl_head, rp->prl_tail, prl);
620 GNUNET_assert (GNUNET_YES ==
621 GNUNET_CONTAINER_multihashmap_put (pp->plan_map,
623 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE)); // 8 MB
624 plan (pp, rp); // +5 MB (plan/heap-insert)
629 * Notify the plan about a peer being no longer available;
630 * destroy all entries associated with this peer.
632 * @param cp connected peer
635 GSF_plan_notify_peer_disconnect_ (const struct GSF_ConnectedPeer *cp)
637 const struct GNUNET_PeerIdentity *id;
639 struct GSF_RequestPlan *rp;
640 struct GSF_PendingRequestData *prd;
641 struct PendingRequestList *prl;
643 id = GSF_connected_peer_get_identity2_ (cp);
644 pp = GNUNET_CONTAINER_multihashmap_get (plans, &id->hashPubKey);
646 return; /* nothing was ever planned for this peer */
647 GNUNET_assert (GNUNET_YES ==
648 GNUNET_CONTAINER_multihashmap_remove (plans, &id->hashPubKey,
652 GSF_peer_transmit_cancel_ (pp->pth);
655 if (GNUNET_SCHEDULER_NO_TASK != pp->task)
657 GNUNET_SCHEDULER_cancel (pp->task);
658 pp->task = GNUNET_SCHEDULER_NO_TASK;
660 while (NULL != (rp = GNUNET_CONTAINER_heap_remove_root (pp->priority_heap)))
662 GNUNET_break (GNUNET_YES ==
663 GNUNET_CONTAINER_multihashmap_remove (pp->plan_map,
664 get_rp_key (rp), rp));
665 while (NULL != (prl = rp->prl_head))
667 GNUNET_CONTAINER_DLL_remove (rp->prl_head, rp->prl_tail, prl);
668 prd = GSF_pending_request_get_data_ (prl->pr);
669 GNUNET_CONTAINER_DLL_remove (prd->rpr_head, prd->rpr_tail, prl->rpr);
670 GNUNET_free (prl->rpr);
676 GNUNET_CONTAINER_heap_destroy (pp->priority_heap);
677 while (NULL != (rp = GNUNET_CONTAINER_heap_remove_root (pp->delay_heap)))
679 GNUNET_break (GNUNET_YES ==
680 GNUNET_CONTAINER_multihashmap_remove (pp->plan_map,
681 get_rp_key (rp), rp));
682 while (NULL != (prl = rp->prl_head))
684 GNUNET_CONTAINER_DLL_remove (rp->prl_head, rp->prl_tail, prl);
685 prd = GSF_pending_request_get_data_ (prl->pr);
686 GNUNET_CONTAINER_DLL_remove (prd->rpr_head, prd->rpr_tail, prl->rpr);
687 GNUNET_free (prl->rpr);
693 GNUNET_STATISTICS_set (GSF_stats, gettext_noop ("# query plan entries"),
694 plan_count, GNUNET_NO);
695 GNUNET_CONTAINER_heap_destroy (pp->delay_heap);
696 GNUNET_CONTAINER_multihashmap_destroy (pp->plan_map);
701 * Get the last transmission attempt time for the request plan list
702 * referenced by 'rpr_head', that was sent to 'sender'
704 * @param rpr_head request plan reference list to check.
705 * @param sender the peer that we've sent the request to.
706 * @param result the timestamp to fill.
707 * @return GNUNET_YES if 'result' was changed, GNUNET_NO otherwise.
710 GSF_request_plan_reference_get_last_transmission_ (
711 struct GSF_RequestPlanReference *rpr_head, struct GSF_ConnectedPeer *sender,
712 struct GNUNET_TIME_Absolute *result)
714 struct GSF_RequestPlanReference *rpr;
715 for (rpr = rpr_head; rpr; rpr = rpr->next)
717 if (rpr->rp->pp->cp == sender)
719 *result = rpr->rp->last_transmission;
727 * Notify the plan about a request being done; destroy all entries
728 * associated with this request.
730 * @param pr request that is done
733 GSF_plan_notify_request_done_ (struct GSF_PendingRequest *pr)
735 struct GSF_RequestPlan *rp;
736 struct GSF_PendingRequestData *prd;
737 struct GSF_RequestPlanReference *rpr;
739 prd = GSF_pending_request_get_data_ (pr);
740 while (NULL != (rpr = prd->rpr_head))
742 GNUNET_CONTAINER_DLL_remove (prd->rpr_head, prd->rpr_tail, rpr);
744 GNUNET_CONTAINER_DLL_remove (rp->prl_head, rp->prl_tail, rpr->prl);
745 if (NULL == rp->prl_head)
747 GNUNET_CONTAINER_heap_remove_node (rp->hn);
749 GNUNET_break (GNUNET_YES ==
750 GNUNET_CONTAINER_multihashmap_remove (rp->pp->plan_map,
755 GNUNET_free (rpr->prl);
758 GNUNET_STATISTICS_set (GSF_stats, gettext_noop ("# query plan entries"),
759 plan_count, GNUNET_NO);
764 * Initialize plan subsystem.
769 plans = GNUNET_CONTAINER_multihashmap_create (256, GNUNET_YES);
774 * Shutdown plan subsystem.
779 GNUNET_assert (0 == GNUNET_CONTAINER_multihashmap_size (plans));
780 GNUNET_CONTAINER_multihashmap_destroy (plans);
785 /* end of gnunet-service-fs_pe.h */