From e473571dfbea7249150f611521d750aa403333e6 Mon Sep 17 00:00:00 2001 From: Aayush Date: Fri, 15 Dec 2023 14:02:17 -0500 Subject: [PATCH] feat: syncer: optimize syncFork for one-epoch forks --- chain/sync.go | 29 +++++++++++++++++++++++++++++ 1 file changed, 29 insertions(+) diff --git a/chain/sync.go b/chain/sync.go index 1b9a302f75d..c61c9f31094 100644 --- a/chain/sync.go +++ b/chain/sync.go @@ -886,6 +886,35 @@ func (syncer *Syncer) syncFork(ctx context.Context, incoming *types.TipSet, know } } + incomingParentsTsk := incoming.Parents() + commonParent := false + for _, incomingParent := range incomingParentsTsk.Cids() { + if known.Contains(incomingParent) { + commonParent = true + } + } + + if commonParent { + // known contains at least one of incoming's Parents => the common ancestor is known's Parents (incoming's Grandparents) + // in this case, we need to return {incoming, incoming.Parents()} + incomingParents, err := syncer.store.LoadTipSet(ctx, incomingParentsTsk) + if err != nil { + // fallback onto the network + tips, err := syncer.Exchange.GetBlocks(ctx, incoming.Parents(), 1) + if err != nil { + return nil, xerrors.Errorf("failed to fetch incomingParents from the network: %w", err) + } + + if len(tips) == 0 { + return nil, xerrors.Errorf("network didn't return any tipsets") + } + + incomingParents = tips[0] + } + + return []*types.TipSet{incoming, incomingParents}, nil + } + // TODO: Does this mean we always ask for ForkLengthThreshold blocks from the network, even if we just need, like, 2? Yes. // Would it not be better to ask in smaller chunks, given that an ~ForkLengthThreshold is very rare? tips, err := syncer.Exchange.GetBlocks(ctx, incoming.Parents(), int(build.ForkLengthThreshold))