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20 * @file fs/gnunet-service-fs_pe.c
21 * @brief API to manage query plan
22 * @author Christian Grothoff
25 #include "gnunet-service-fs.h"
26 #include "gnunet-service-fs_cp.h"
27 #include "gnunet-service-fs_pe.h"
28 #include "gnunet-service-fs_pr.h"
31 * Collect an instane number of statistics? May cause excessive IPC.
33 #define INSANE_STATISTICS GNUNET_NO
36 * List of GSF_PendingRequests this request plan
39 struct PendingRequestList;
42 * Transmission plan for a peer.
48 * M:N binding of plans to pending requests.
49 * Each pending request can be in a number of plans,
50 * and each plan can have a number of pending requests.
51 * Objects of this type indicate a mapping of a plan to
52 * a particular pending request.
54 * The corresponding head and tail of the "PE" MDLL
55 * are stored in a `struct GSF_RequestPlan`. (We need
56 * to be able to lookup all pending requests corresponding
57 * to a given plan entry.)
59 * Similarly head and tail of the "PR" MDLL are stored
60 * with the `struct GSF_PendingRequest`. (We need
61 * to be able to lookup all plan entries corresponding
62 * to a given pending request.)
64 struct GSF_PendingRequestPlanBijection
68 * This is a doubly-linked list.
70 struct GSF_PendingRequestPlanBijection *next_PR;
73 * This is a doubly-linked list.
75 struct GSF_PendingRequestPlanBijection *prev_PR;
78 * This is a doubly-linked list.
80 struct GSF_PendingRequestPlanBijection *next_PE;
83 * This is a doubly-linked list.
85 struct GSF_PendingRequestPlanBijection *prev_PE;
88 * Associated request plan (tells us one of the peers that
89 * we plan to forward the request to).
91 struct GSF_RequestPlan *rp;
94 * Associated pending request (identifies request details
95 * and one of the origins of the request).
97 struct GSF_PendingRequest *pr;
103 * Information we keep per request per peer. This is a doubly-linked
104 * list (with head and tail in the `struct GSF_PendingRequestData`)
105 * with one entry in each heap of each `struct PeerPlan`. Each
106 * entry tracks information relevant for this request and this peer.
108 struct GSF_RequestPlan
112 * This is a doubly-linked list.
114 struct GSF_RequestPlan *next;
117 * This is a doubly-linked list.
119 struct GSF_RequestPlan *prev;
122 * Heap node associated with this request and this peer.
124 struct GNUNET_CONTAINER_HeapNode *hn;
127 * The transmission plan for a peer that this request is associated with.
132 * Head of list of associated pending requests. This tells us
133 * which incoming requests from other peers this plan entry
136 struct GSF_PendingRequestPlanBijection *pe_head;
139 * Tail of list of associated pending requests.
141 struct GSF_PendingRequestPlanBijection *pe_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 @e priority_heap
183 * or @e delay_heap should be in the @e plan_map. Note that it is
184 * possible for the @e plan_map to have multiple entries for the same
187 struct GNUNET_CONTAINER_MultiHashMap *plan_map;
190 * Peer for which this is the plan.
192 struct GSF_ConnectedPeer *cp;
195 * Current task for executing the plan.
197 struct GNUNET_SCHEDULER_Task *task;
200 * Current message under transmission for the plan.
202 struct GNUNET_MQ_Envelope *env;
208 * Hash map from peer identities to PeerPlans.
210 static struct GNUNET_CONTAINER_MultiPeerMap *plans;
213 * Sum of all transmission counters (equals total delay for all plan entries).
215 static unsigned long long total_delay;
218 * Number of plan entries.
220 static unsigned long long plan_count;
224 * Return the query (key in the plan_map) for the given request plan.
225 * Note that this key may change as there can be multiple pending
226 * requests for the same key and we just return _one_ of them; this
227 * particular one might complete while another one might still be
228 * active, hence the lifetime of the returned hash code is NOT
229 * necessarily identical to that of the `struct GSF_RequestPlan`
232 * @param rp a request plan
233 * @return the associated query
235 static const struct GNUNET_HashCode *
236 get_rp_key (struct GSF_RequestPlan *rp)
238 return &GSF_pending_request_get_data_ (rp->pe_head->pr)->query;
243 * Insert the given request plan into the heap with the appropriate weight.
245 * @param pp associated peer's plan
246 * @param rp request to plan
249 plan (struct PeerPlan *pp,
250 struct GSF_RequestPlan *rp)
252 #define N ((double)128.0)
254 * Running average delay we currently impose.
256 static double avg_delay;
258 struct GSF_PendingRequestData *prd;
259 struct GNUNET_TIME_Relative delay;
261 GNUNET_assert (rp->pp == pp);
262 GNUNET_STATISTICS_set (GSF_stats,
263 gettext_noop ("# average retransmission delay (ms)"),
264 total_delay * 1000LL / plan_count, GNUNET_NO);
265 prd = GSF_pending_request_get_data_ (rp->pe_head->pr);
267 if (rp->transmission_counter < 8)
269 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
270 rp->transmission_counter);
271 else if (rp->transmission_counter < 32)
273 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
275 (1LL << (rp->transmission_counter - 8)));
278 GNUNET_TIME_relative_multiply (GNUNET_TIME_UNIT_SECONDS,
281 GNUNET_CRYPTO_random_u32 (GNUNET_CRYPTO_QUALITY_WEAK,
282 delay.rel_value_us + 1);
283 /* Add 0.01 to avg_delay to avoid division-by-zero later */
284 avg_delay = (((avg_delay * (N - 1.0)) + delay.rel_value_us) / N) + 0.01;
287 * For the priority, we need to consider a few basic rules:
288 * 1) if we just started requesting (delay is small), we should
289 * virtually always have a priority of zero.
290 * 2) for requests with average latency, our priority should match
291 * the average priority observed on the network
292 * 3) even the longest-running requests should not be WAY out of
293 * the observed average (thus we bound by a factor of 2)
294 * 4) we add +1 to the observed average priority to avoid everyone
295 * staying put at zero (2 * 0 = 0...).
297 * Using the specific calculation below, we get:
299 * delay = 0 => priority = 0;
300 * delay = avg delay => priority = running-average-observed-priority;
301 * delay >> avg_delay => priority = 2 * running-average-observed-priority;
303 * which satisfies all of the rules above.
305 * Note: M_PI_4 = PI/4 = arctan(1)
308 round ((GSF_current_priorities +
309 1.0) * atan (delay.rel_value_us / avg_delay)) / M_PI_4;
310 /* Note: usage of 'round' and 'atan' requires -lm */
312 if (rp->transmission_counter != 0)
313 delay.rel_value_us += TTL_DECREMENT * 1000;
314 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
315 "Considering (re)transmission number %u in %s\n",
316 (unsigned int) rp->transmission_counter,
317 GNUNET_STRINGS_relative_time_to_string (delay,
319 rp->earliest_transmission = GNUNET_TIME_relative_to_absolute (delay);
320 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
321 "Earliest (re)transmission for `%s' in %us\n",
322 GNUNET_h2s (&prd->query),
323 rp->transmission_counter);
324 GNUNET_assert (rp->hn == NULL);
325 if (0 == GNUNET_TIME_absolute_get_remaining (rp->earliest_transmission).rel_value_us)
326 rp->hn = GNUNET_CONTAINER_heap_insert (pp->priority_heap,
331 GNUNET_CONTAINER_heap_insert (pp->delay_heap,
333 rp->earliest_transmission.abs_value_us);
334 GNUNET_assert (GNUNET_YES ==
335 GNUNET_CONTAINER_multihashmap_contains_value (pp->plan_map,
343 * Get the pending request with the highest TTL from the given plan.
345 * @param rp plan to investigate
346 * @return pending request with highest TTL
348 struct GSF_PendingRequest *
349 get_latest (const struct GSF_RequestPlan *rp)
351 struct GSF_PendingRequest *ret;
352 struct GSF_PendingRequestPlanBijection *bi;
353 const struct GSF_PendingRequestData *rprd;
354 const struct GSF_PendingRequestData *prd;
358 return NULL; /* should never happen */
360 rprd = GSF_pending_request_get_data_ (ret);
361 for (bi = bi->next_PE; NULL != bi; bi = bi->next_PE)
363 GNUNET_break (GNUNET_YES ==
364 GSF_pending_request_test_active_ (bi->pr));
365 prd = GSF_pending_request_get_data_ (bi->pr);
366 if (prd->ttl.abs_value_us > rprd->ttl.abs_value_us)
377 * Figure out when and how to transmit to the given peer.
379 * @param cls the `struct PeerPlan`
382 schedule_peer_transmission (void *cls)
384 struct PeerPlan *pp = cls;
385 struct GSF_RequestPlan *rp;
386 struct GNUNET_TIME_Relative delay;
388 if (NULL != pp->task)
394 GNUNET_assert (NULL != pp->env);
397 /* move ready requests to priority queue */
398 while ((NULL != (rp = GNUNET_CONTAINER_heap_peek (pp->delay_heap))) &&
399 (0 == GNUNET_TIME_absolute_get_remaining
400 (rp->earliest_transmission).rel_value_us))
402 GNUNET_assert (rp == GNUNET_CONTAINER_heap_remove_root (pp->delay_heap));
403 rp->hn = GNUNET_CONTAINER_heap_insert (pp->priority_heap,
407 if (0 == GNUNET_CONTAINER_heap_get_size (pp->priority_heap))
409 /* priority heap (still) empty, check for delay... */
410 rp = GNUNET_CONTAINER_heap_peek (pp->delay_heap);
413 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
414 "No active requests for plan %p.\n",
416 return; /* both queues empty */
418 delay = GNUNET_TIME_absolute_get_remaining (rp->earliest_transmission);
419 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
420 "Sleeping for %s before retrying requests on plan %p.\n",
421 GNUNET_STRINGS_relative_time_to_string (delay,
424 GNUNET_STATISTICS_set (GSF_stats,
425 gettext_noop ("# delay heap timeout (ms)"),
426 delay.rel_value_us / 1000LL, GNUNET_NO);
429 = GNUNET_SCHEDULER_add_at (rp->earliest_transmission,
430 &schedule_peer_transmission,
434 #if INSANE_STATISTICS
435 GNUNET_STATISTICS_update (GSF_stats,
436 gettext_noop ("# query plans executed"),
440 /* process from priority heap */
441 rp = GNUNET_CONTAINER_heap_remove_root (pp->priority_heap);
442 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
443 "Executing query plan %p\n",
445 GNUNET_assert (NULL != rp);
447 rp->last_transmission = GNUNET_TIME_absolute_get ();
448 rp->transmission_counter++;
450 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
451 "Executing plan %p executed %u times, planning retransmission\n",
453 rp->transmission_counter);
454 GNUNET_assert (NULL == pp->env);
455 pp->env = GSF_pending_request_get_message_ (get_latest (rp));
456 GNUNET_MQ_notify_sent (pp->env,
457 &schedule_peer_transmission,
459 GSF_peer_transmit_ (pp->cp,
463 GNUNET_STATISTICS_update (GSF_stats,
464 gettext_noop ("# query messages sent to other peers"),
473 * Closure for merge_pr().
479 * Request we are trying to merge.
481 struct GSF_PendingRequest *pr;
484 * Set to #GNUNET_YES if we succeeded to merge.
492 * Iterator that checks if an equivalent request is already
493 * present for this peer.
496 * @param query the query
497 * @param element request plan stored at the node
498 * @return #GNUNET_YES if we should continue to iterate,
499 * #GNUNET_NO if not (merge success)
503 const struct GNUNET_HashCode *query,
506 struct MergeContext *mpr = cls;
507 struct GSF_RequestPlan *rp = element;
508 struct GSF_PendingRequestData *prd;
509 struct GSF_PendingRequestPlanBijection *bi;
510 struct GSF_PendingRequest *latest;
512 GNUNET_break (GNUNET_YES ==
513 GSF_pending_request_test_active_ (mpr->pr));
515 GSF_pending_request_is_compatible_ (mpr->pr,
518 /* merge new request with existing request plan */
519 bi = GNUNET_new (struct GSF_PendingRequestPlanBijection);
522 prd = GSF_pending_request_get_data_ (mpr->pr);
523 GNUNET_CONTAINER_MDLL_insert (PR,
527 GNUNET_CONTAINER_MDLL_insert (PE,
531 mpr->merged = GNUNET_YES;
532 #if INSANE_STATISTICS
533 GNUNET_STATISTICS_update (GSF_stats,
534 gettext_noop ("# requests merged"),
538 latest = get_latest (rp);
539 if (GSF_pending_request_get_data_ (latest)->ttl.abs_value_us <
540 prd->ttl.abs_value_us)
542 #if INSANE_STATISTICS
543 GNUNET_STATISTICS_update (GSF_stats,
544 gettext_noop ("# requests refreshed"),
548 rp->transmission_counter = 0; /* reset */
555 * Create a new query plan entry.
557 * @param cp peer with the entry
558 * @param pr request with the entry
561 GSF_plan_add_ (struct GSF_ConnectedPeer *cp,
562 struct GSF_PendingRequest *pr)
564 const struct GNUNET_PeerIdentity *id;
566 struct GSF_PendingRequestData *prd;
567 struct GSF_RequestPlan *rp;
568 struct GSF_PendingRequestPlanBijection *bi;
569 struct MergeContext mpc;
571 GNUNET_assert (GNUNET_YES ==
572 GSF_pending_request_test_active_ (pr));
573 GNUNET_assert (NULL != cp);
574 id = GSF_connected_peer_get_identity2_ (cp);
575 pp = GNUNET_CONTAINER_multipeermap_get (plans, id);
578 pp = GNUNET_new (struct PeerPlan);
579 pp->plan_map = GNUNET_CONTAINER_multihashmap_create (128, GNUNET_NO);
581 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MAX);
583 GNUNET_CONTAINER_heap_create (GNUNET_CONTAINER_HEAP_ORDER_MIN);
585 GNUNET_assert (GNUNET_OK ==
586 GNUNET_CONTAINER_multipeermap_put (plans,
589 GNUNET_CONTAINER_MULTIHASHMAPOPTION_UNIQUE_ONLY));
590 pp->task = GNUNET_SCHEDULER_add_now (&schedule_peer_transmission,
593 mpc.merged = GNUNET_NO;
595 prd = GSF_pending_request_get_data_ (pr);
596 GNUNET_CONTAINER_multihashmap_get_multiple (pp->plan_map,
600 if (GNUNET_NO != mpc.merged)
603 GNUNET_STATISTICS_update (GSF_stats,
604 gettext_noop ("# query plan entries"),
607 GNUNET_log (GNUNET_ERROR_TYPE_DEBUG,
608 "Planning transmission of query `%s' to peer `%s'\n",
609 GNUNET_h2s (&prd->query),
611 rp = GNUNET_new (struct GSF_RequestPlan);
612 bi = GNUNET_new (struct GSF_PendingRequestPlanBijection);
615 GNUNET_CONTAINER_MDLL_insert (PR,
619 GNUNET_CONTAINER_MDLL_insert (PE,
624 GNUNET_assert (GNUNET_YES ==
625 GNUNET_CONTAINER_multihashmap_put (pp->plan_map,
628 GNUNET_CONTAINER_MULTIHASHMAPOPTION_MULTIPLE));
635 * Notify the plan about a peer being no longer available;
636 * destroy all entries associated with this peer.
638 * @param cp connected peer
641 GSF_plan_notify_peer_disconnect_ (const struct GSF_ConnectedPeer *cp)
643 const struct GNUNET_PeerIdentity *id;
645 struct GSF_RequestPlan *rp;
646 struct GSF_PendingRequestData *prd;
647 struct GSF_PendingRequestPlanBijection *bi;
649 id = GSF_connected_peer_get_identity2_ (cp);
650 pp = GNUNET_CONTAINER_multipeermap_get (plans, id);
652 return; /* nothing was ever planned for this peer */
653 GNUNET_assert (GNUNET_YES ==
654 GNUNET_CONTAINER_multipeermap_remove (plans, id,
656 if (NULL != pp->task)
658 GNUNET_SCHEDULER_cancel (pp->task);
661 while (NULL != (rp = GNUNET_CONTAINER_heap_remove_root (pp->priority_heap)))
663 GNUNET_break (GNUNET_YES ==
664 GNUNET_CONTAINER_multihashmap_remove (pp->plan_map,
667 while (NULL != (bi = rp->pe_head))
669 GNUNET_CONTAINER_MDLL_remove (PE,
673 prd = GSF_pending_request_get_data_ (bi->pr);
674 GNUNET_CONTAINER_MDLL_remove (PR,
683 GNUNET_CONTAINER_heap_destroy (pp->priority_heap);
684 while (NULL != (rp = GNUNET_CONTAINER_heap_remove_root (pp->delay_heap)))
686 GNUNET_break (GNUNET_YES ==
687 GNUNET_CONTAINER_multihashmap_remove (pp->plan_map,
690 while (NULL != (bi = rp->pe_head))
692 prd = GSF_pending_request_get_data_ (bi->pr);
693 GNUNET_CONTAINER_MDLL_remove (PE,
697 GNUNET_CONTAINER_MDLL_remove (PR,
706 GNUNET_STATISTICS_set (GSF_stats,
707 gettext_noop ("# query plan entries"),
710 GNUNET_CONTAINER_heap_destroy (pp->delay_heap);
711 GNUNET_CONTAINER_multihashmap_destroy (pp->plan_map);
717 * Get the last transmission attempt time for the request plan list
718 * referenced by @a pr_head, that was sent to @a sender
720 * @param pr_head request plan reference list to check.
721 * @param sender the peer that we've sent the request to.
722 * @param result the timestamp to fill, set to #GNUNET_TIME_UNIT_FOREVER_ABS if never transmitted
723 * @return #GNUNET_YES if @a result was changed, #GNUNET_NO otherwise.
726 GSF_request_plan_reference_get_last_transmission_ (struct GSF_PendingRequestPlanBijection *pr_head,
727 struct GSF_ConnectedPeer *sender,
728 struct GNUNET_TIME_Absolute *result)
730 struct GSF_PendingRequestPlanBijection *bi;
732 for (bi = pr_head; NULL != bi; bi = bi->next_PR)
734 if (bi->rp->pp->cp == sender)
736 if (0 == bi->rp->last_transmission.abs_value_us)
737 *result = GNUNET_TIME_UNIT_FOREVER_ABS;
739 *result = bi->rp->last_transmission;
748 * Notify the plan about a request being done; destroy all entries
749 * associated with this request.
751 * @param pr request that is done
754 GSF_plan_notify_request_done_ (struct GSF_PendingRequest *pr)
756 struct GSF_RequestPlan *rp;
757 struct GSF_PendingRequestData *prd;
758 struct GSF_PendingRequestPlanBijection *bi;
760 prd = GSF_pending_request_get_data_ (pr);
761 while (NULL != (bi = prd->pr_head))
764 GNUNET_CONTAINER_MDLL_remove (PR,
768 GNUNET_CONTAINER_MDLL_remove (PE,
772 GNUNET_assert (bi->pr == pr);
773 if (NULL == rp->pe_head)
775 GNUNET_CONTAINER_heap_remove_node (rp->hn);
777 GNUNET_break (GNUNET_YES ==
778 GNUNET_CONTAINER_multihashmap_remove (rp->pp->plan_map,
785 GNUNET_STATISTICS_set (GSF_stats,
786 gettext_noop ("# query plan entries"),
793 * Initialize plan subsystem.
798 plans = GNUNET_CONTAINER_multipeermap_create (256,
804 * Shutdown plan subsystem.
809 GNUNET_assert (0 == GNUNET_CONTAINER_multipeermap_size (plans));
810 GNUNET_CONTAINER_multipeermap_destroy (plans);
815 /* end of gnunet-service-fs_pe.h */