From c45c8f34a16605a087bd4c6b5b022f8828784156 Mon Sep 17 00:00:00 2001
From: Aayush Rajasekaran <arajasek94@gmail.com>
Date: Wed, 30 Sep 2020 01:39:06 -0400
Subject: [PATCH] Parametrise whether sync validators should use cache

---
 chain/sync.go          | 28 ++++++++++++++++------------
 chain/sync_test.go     |  4 ++--
 node/impl/full/sync.go |  9 +--------
 3 files changed, 19 insertions(+), 22 deletions(-)

diff --git a/chain/sync.go b/chain/sync.go
index 78e5178d14e..b2e3bb7f1d1 100644
--- a/chain/sync.go
+++ b/chain/sync.go
@@ -597,7 +597,7 @@ func isPermanent(err error) bool {
 	return !errors.Is(err, ErrTemporal)
 }
 
-func (syncer *Syncer) ValidateTipSet(ctx context.Context, fts *store.FullTipSet) error {
+func (syncer *Syncer) ValidateTipSet(ctx context.Context, fts *store.FullTipSet, useCache bool) error {
 	ctx, span := trace.StartSpan(ctx, "validateTipSet")
 	defer span.End()
 
@@ -613,7 +613,7 @@ func (syncer *Syncer) ValidateTipSet(ctx context.Context, fts *store.FullTipSet)
 		b := b // rebind to a scoped variable
 
 		futures = append(futures, async.Err(func() error {
-			if err := syncer.ValidateBlock(ctx, b); err != nil {
+			if err := syncer.ValidateBlock(ctx, b, useCache); err != nil {
 				if isPermanent(err) {
 					syncer.bad.Add(b.Cid(), NewBadBlockReason([]cid.Cid{b.Cid()}, err.Error()))
 				}
@@ -680,7 +680,7 @@ func blockSanityChecks(h *types.BlockHeader) error {
 }
 
 // ValidateBlock should match up with 'Semantical Validation' in validation.md in the spec
-func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) (err error) {
+func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock, useCache bool) (err error) {
 	defer func() {
 		// b.Cid() could panic for empty blocks that are used in tests.
 		if rerr := recover(); rerr != nil {
@@ -689,13 +689,15 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) (er
 		}
 	}()
 
-	isValidated, err := syncer.store.IsBlockValidated(ctx, b.Cid())
-	if err != nil {
-		return xerrors.Errorf("check block validation cache %s: %w", b.Cid(), err)
-	}
+	if useCache {
+		isValidated, err := syncer.store.IsBlockValidated(ctx, b.Cid())
+		if err != nil {
+			return xerrors.Errorf("check block validation cache %s: %w", b.Cid(), err)
+		}
 
-	if isValidated {
-		return nil
+		if isValidated {
+			return nil
+		}
 	}
 
 	validationStart := build.Clock.Now()
@@ -959,8 +961,10 @@ func (syncer *Syncer) ValidateBlock(ctx context.Context, b *types.FullBlock) (er
 		return mulErr
 	}
 
-	if err := syncer.store.MarkBlockAsValidated(ctx, b.Cid()); err != nil {
-		return xerrors.Errorf("caching block validation %s: %w", b.Cid(), err)
+	if useCache {
+		if err := syncer.store.MarkBlockAsValidated(ctx, b.Cid()); err != nil {
+			return xerrors.Errorf("caching block validation %s: %w", b.Cid(), err)
+		}
 	}
 
 	return nil
@@ -1462,7 +1466,7 @@ func (syncer *Syncer) syncMessagesAndCheckState(ctx context.Context, headers []*
 
 	return syncer.iterFullTipsets(ctx, headers, func(ctx context.Context, fts *store.FullTipSet) error {
 		log.Debugw("validating tipset", "height", fts.TipSet().Height(), "size", len(fts.TipSet().Cids()))
-		if err := syncer.ValidateTipSet(ctx, fts); err != nil {
+		if err := syncer.ValidateTipSet(ctx, fts, true); err != nil {
 			log.Errorf("failed to validate tipset: %+v", err)
 			return xerrors.Errorf("message processing failed: %w", err)
 		}
diff --git a/chain/sync_test.go b/chain/sync_test.go
index 7a839be2bf1..1b06f604bdc 100644
--- a/chain/sync_test.go
+++ b/chain/sync_test.go
@@ -732,7 +732,7 @@ func TestSyncInputs(t *testing.T) {
 
 	err := s.ValidateBlock(context.TODO(), &types.FullBlock{
 		Header: &types.BlockHeader{},
-	})
+	}, false)
 	if err == nil {
 		t.Fatal("should error on empty block")
 	}
@@ -741,7 +741,7 @@ func TestSyncInputs(t *testing.T) {
 
 	h.ElectionProof = nil
 
-	err = s.ValidateBlock(context.TODO(), &types.FullBlock{Header: h})
+	err = s.ValidateBlock(context.TODO(), &types.FullBlock{Header: h}, false)
 	if err == nil {
 		t.Fatal("should error on block with nil election proof")
 	}
diff --git a/node/impl/full/sync.go b/node/impl/full/sync.go
index 221942673b9..1bd3af41517 100644
--- a/node/impl/full/sync.go
+++ b/node/impl/full/sync.go
@@ -138,14 +138,7 @@ func (a *SyncAPI) SyncValidateTipset(ctx context.Context, tsk types.TipSetKey) (
 		return false, err
 	}
 
-	for _, blk := range tsk.Cids() {
-		err = a.Syncer.ChainStore().UnmarkBlockAsValidated(ctx, blk)
-		if err != nil {
-			return false, err
-		}
-	}
-
-	err = a.Syncer.ValidateTipSet(ctx, fts)
+	err = a.Syncer.ValidateTipSet(ctx, fts, false)
 	if err != nil {
 		return false, err
 	}