Merge pull request #7378 from filecoin-project/asr/weight

ChainStore: Add a tiebreaker rule for tipsets of equal weight
This commit is contained in:
Aayush Rajasekaran 2021-09-27 12:34:16 -04:00 committed by GitHub
commit d9e711eac5
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@ -424,7 +424,13 @@ func (cs *ChainStore) MaybeTakeHeavierTipSet(ctx context.Context, ts *types.TipS
return err
}
if w.GreaterThan(heaviestW) {
heavier := w.GreaterThan(heaviestW)
if w.Equals(heaviestW) && !ts.Equals(cs.heaviest) {
log.Errorw("weight draw", "currTs", cs.heaviest, "ts", ts)
heavier = breakWeightTie(ts, cs.heaviest)
}
if heavier {
// TODO: don't do this for initial sync. Now that we don't have a
// difference between 'bootstrap sync' and 'caught up' sync, we need
// some other heuristic.
@ -438,9 +444,8 @@ func (cs *ChainStore) MaybeTakeHeavierTipSet(ctx context.Context, ts *types.TipS
}
return cs.takeHeaviestTipSet(ctx, ts)
} else if w.Equals(heaviestW) && !ts.Equals(cs.heaviest) {
log.Errorw("weight draw", "currTs", cs.heaviest, "ts", ts)
}
return nil
}
@ -1165,3 +1170,22 @@ func (cs *ChainStore) GetTipsetByHeight(ctx context.Context, h abi.ChainEpoch, t
func (cs *ChainStore) Weight(ctx context.Context, hts *types.TipSet) (types.BigInt, error) { // todo remove
return cs.weight(ctx, cs.StateBlockstore(), hts)
}
// true if ts1 wins according to the filecoin tie-break rule
func breakWeightTie(ts1, ts2 *types.TipSet) bool {
s := len(ts1.Blocks())
if s > len(ts2.Blocks()) {
s = len(ts2.Blocks())
}
// blocks are already sorted by ticket
for i := 0; i < s; i++ {
if ts1.Blocks()[i].Ticket.Less(ts2.Blocks()[i].Ticket) {
log.Infof("weight tie broken in favour of %s", ts1.Key())
return true
}
}
log.Infof("weight tie left unbroken, default to %s", ts2.Key())
return false
}