Merge pull request #1982 from filecoin-project/fix/interop-chain-idx-nulls

Fix/interop chain idx nulls

chain/store/index.go

@@ -91,15 +91,16 @@ func (ci *ChainIndex) fillCache(tsk types.TipSetKey) (*lbEntry, error) {
 		return nil, err
 	}
 
-	if parent.Height() > rheight {
-		return nil, xerrors.Errorf("cache is inconsistent")
-	}
-
 	rheight -= ci.skipLength
 
-	skipTarget, err := ci.walkBack(parent, rheight)
-	if err != nil {
-		return nil, err
+	var skipTarget *types.TipSet
+	if parent.Height() < rheight {
+		skipTarget = parent
+	} else {
+		skipTarget, err = ci.walkBack(parent, rheight)
+		if err != nil {
+			return nil, xerrors.Errorf("fillCache walkback: %w", err)
+		}
 	}
 
 	lbe := &lbEntry{
@@ -113,8 +114,9 @@ func (ci *ChainIndex) fillCache(tsk types.TipSetKey) (*lbEntry, error) {
 	return lbe, nil
 }
 
+// floors to nearest skipLength multiple
 func (ci *ChainIndex) roundHeight(h abi.ChainEpoch) abi.ChainEpoch {
-	return abi.ChainEpoch(h/ci.skipLength) * ci.skipLength
+	return (h/ci.skipLength) * ci.skipLength
 }
 
 func (ci *ChainIndex) roundDown(ts *types.TipSet) (*types.TipSet, error) {
@@ -146,6 +148,8 @@ func (ci *ChainIndex) walkBack(from *types.TipSet, to abi.ChainEpoch) (*types.Ti
 		}
 
 		if to > pts.Height() {
+			// in case pts is lower than the epoch we're looking for (null blocks)
+			// return a tipset above that height
 			return ts, nil
 		}
 		if to == pts.Height() {

chain/store/index_test.go

@@ -0,0 +1,80 @@
+package store_test
+
+import (
+	"bytes"
+	"context"
+	"testing"
+
+	"github.com/filecoin-project/lotus/chain/gen"
+	"github.com/filecoin-project/lotus/chain/store"
+	"github.com/filecoin-project/lotus/chain/types/mock"
+	"github.com/filecoin-project/specs-actors/actors/abi"
+	datastore "github.com/ipfs/go-datastore"
+	syncds "github.com/ipfs/go-datastore/sync"
+	blockstore "github.com/ipfs/go-ipfs-blockstore"
+	"github.com/stretchr/testify/assert"
+)
+
+func TestIndexSeeks(t *testing.T) {
+	cg, err := gen.NewGenerator()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gencar, err := cg.GenesisCar()
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	gen := cg.Genesis()
+
+	ctx := context.TODO()
+
+	nbs := blockstore.NewBlockstore(syncds.MutexWrap(datastore.NewMapDatastore()))
+	cs := store.NewChainStore(nbs, syncds.MutexWrap(datastore.NewMapDatastore()), nil)
+
+	_, err = cs.Import(bytes.NewReader(gencar))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	cur := mock.TipSet(gen)
+	if err := cs.PutTipSet(ctx, mock.TipSet(gen)); err != nil {
+		t.Fatal(err)
+	}
+	cs.SetGenesis(gen)
+
+	// Put 113 blocks from genesis
+	for i := 0; i < 113; i++ {
+		nextts := mock.TipSet(mock.MkBlock(cur, 1, 1))
+
+		if err := cs.PutTipSet(ctx, nextts); err != nil {
+			t.Fatal(err)
+		}
+		cur = nextts
+	}
+
+	// Put 50 null epochs + 1 block
+	skip := mock.MkBlock(cur, 1, 1)
+	skip.Height += 50
+
+	skipts := mock.TipSet(skip)
+
+	if err := cs.PutTipSet(ctx, skipts); err != nil {
+		t.Fatal(err)
+	}
+
+	ts, err := cs.GetTipsetByHeight(ctx, skip.Height-10, skipts, false)
+	if err != nil {
+		t.Fatal(err)
+	}
+	assert.Equal(t, abi.ChainEpoch(164), ts.Height())
+
+	for i := 0; i <= 113; i++ {
+		ts3, err := cs.GetTipsetByHeight(ctx, abi.ChainEpoch(i), skipts, false)
+		if err != nil {
+			t.Fatal(err)
+		}
+		assert.Equal(t, abi.ChainEpoch(i), ts3.Height())
+	}
+}

chain/types/mock/chain.go

@@ -49,6 +49,11 @@ func MkBlock(parents *types.TipSet, weightInc uint64, ticketNonce uint64) *types
 		panic(err)
 	}
 
+	pstateRoot := c
+	if parents != nil {
+		pstateRoot = parents.Blocks()[0].ParentStateRoot
+	}
+
 	var pcids []cid.Cid
 	var height abi.ChainEpoch
 	weight := types.NewInt(weightInc)
@@ -72,7 +77,7 @@ func MkBlock(parents *types.TipSet, weightInc uint64, ticketNonce uint64) *types
 		ParentWeight:          weight,
 		Messages:              c,
 		Height:                height,
-		ParentStateRoot:       c,
+		ParentStateRoot:       pstateRoot,
 		BlockSig:              &crypto.Signature{Type: crypto.SigTypeBLS, Data: []byte("boo! im a signature")},
 	}
 }