Add support for offsetting the voting interval in order to bootstrap faster.

A new option TestingV3AuthVotingStartOffset is added which offsets the
starting time of the voting interval. This is possible only when
TestingTorNetwork is set.

This patch makes run_scheduled_events() check for new consensus
downloads every second when TestingTorNetwork, instead of every
minute. This should be fine, see #8532 for reasoning.

This patch also brings MIN_VOTE_SECONDS and MIN_DIST_SECONDS down from
20 to 2 seconds, unconditionally. This makes sanity checking of
misconfiguration slightly less sane.

Addresses #8532.

1 files changed, 14 insertions, 7 deletions

diff --git a/src/or/dirvote.c b/src/or/dirvote.c
index 0c386e604..4f0ab6833 100644
--- a/src/or/dirvote.c
+++ b/src/or/dirvote.c
@@ -2523,12 +2523,13 @@ dirvote_get_preferred_voting_intervals(vote_timing_t *timing_out)
   timing_out->dist_delay = options->V3AuthDistDelay;
 }
 
-/** Return the start of the next interval of size <b>interval</b> (in seconds)
- * after <b>now</b>.  Midnight always starts a fresh interval, and if the last
- * interval of a day would be truncated to less than half its size, it is
- * rolled into the previous interval. */
+/** Return the start of the next interval of size <b>interval</b> (in
+ * seconds) after <b>now</b>, plus <b>offset</b>. Midnight always
+ * starts a fresh interval, and if the last interval of a day would be
+ * truncated to less than half its size, it is rolled into the
+ * previous interval. */
 time_t
-dirvote_get_start_of_next_interval(time_t now, int interval)
+dirvote_get_start_of_next_interval(time_t now, int interval, int offset)
 {
   struct tm tm;
   time_t midnight_today=0;
@@ -2556,6 +2557,10 @@ dirvote_get_start_of_next_interval(time_t now, int interval)
   if (next + interval/2 > midnight_tomorrow)
     next = midnight_tomorrow;
 
+  next += offset;
+  if (next - interval > now)
+    next -= interval;
+
   return next;
 }
 
@@ -2619,8 +2624,10 @@ dirvote_recalculate_timing(const or_options_t *options, time_t now)
     vote_delay = dist_delay = interval / 4;
 
   start = voting_schedule.interval_starts =
-    dirvote_get_start_of_next_interval(now,interval);
-  end = dirvote_get_start_of_next_interval(start+1, interval);
+    dirvote_get_start_of_next_interval(now,interval,
+                                      options->TestingV3AuthVotingStartOffset);
+  end = dirvote_get_start_of_next_interval(start+1, interval,
+                                      options->TestingV3AuthVotingStartOffset);
 
   tor_assert(end > start);