allow exporting a number of recent chain state trees

api/api_full.go

@@ -109,7 +109,10 @@ type FullNode interface {
 	ChainGetPath(ctx context.Context, from types.TipSetKey, to types.TipSetKey) ([]*HeadChange, error)
 
 	// ChainExport returns a stream of bytes with CAR dump of chain data.
-	ChainExport(context.Context, types.TipSetKey) (<-chan []byte, error)
+	// The exported chain data includes the header chain from the given tipset
+	// back to genesis, the entire genesis state, and the most recent 'nroots'
+	// state trees.
+	ChainExport(ctx context.Context, nroots abi.ChainEpoch, tsk types.TipSetKey) (<-chan []byte, error)
 
 	// MethodGroup: Beacon
 	// The Beacon method group contains methods for interacting with the random beacon (DRAND)

api/apistruct/struct.go

@@ -86,7 +86,7 @@ type FullNodeStruct struct {
 		ChainGetNode                  func(ctx context.Context, p string) (*api.IpldObject, error)                                                       `perm:"read"`
 		ChainGetMessage               func(context.Context, cid.Cid) (*types.Message, error)                                                             `perm:"read"`
 		ChainGetPath                  func(context.Context, types.TipSetKey, types.TipSetKey) ([]*api.HeadChange, error)                                 `perm:"read"`
-		ChainExport                   func(context.Context, types.TipSetKey) (<-chan []byte, error)                                                      `perm:"read"`
+		ChainExport                   func(context.Context, abi.ChainEpoch, types.TipSetKey) (<-chan []byte, error)                                      `perm:"read"`
 
 		BeaconGetEntry func(ctx context.Context, epoch abi.ChainEpoch) (*types.BeaconEntry, error) `perm:"read"`
 
@@ -654,8 +654,8 @@ func (c *FullNodeStruct) ChainGetPath(ctx context.Context, from types.TipSetKey,
 	return c.Internal.ChainGetPath(ctx, from, to)
 }
 
-func (c *FullNodeStruct) ChainExport(ctx context.Context, tsk types.TipSetKey) (<-chan []byte, error) {
-	return c.Internal.ChainExport(ctx, tsk)
+func (c *FullNodeStruct) ChainExport(ctx context.Context, nroots abi.ChainEpoch, tsk types.TipSetKey) (<-chan []byte, error) {
+	return c.Internal.ChainExport(ctx, nroots, tsk)
 }
 
 func (c *FullNodeStruct) BeaconGetEntry(ctx context.Context, epoch abi.ChainEpoch) (*types.BeaconEntry, error) {

chain/store/store.go

@@ -1114,7 +1114,7 @@ func (cs *ChainStore) GetTipsetByHeight(ctx context.Context, h abi.ChainEpoch, t
 	return cs.LoadTipSet(lbts.Parents())
 }
 
-func recurseLinks(bs bstore.Blockstore, root cid.Cid, in []cid.Cid) ([]cid.Cid, error) {
+func recurseLinks(bs bstore.Blockstore, walked *cid.Set, root cid.Cid, in []cid.Cid) ([]cid.Cid, error) {
 	if root.Prefix().Codec != cid.DagCBOR {
 		return in, nil
 	}
@@ -1131,9 +1131,14 @@ func recurseLinks(bs bstore.Blockstore, root cid.Cid, in []cid.Cid) ([]cid.Cid,
 			return
 		}
 
+		// traversed this already...
+		if !walked.Visit(c) {
+			return
+		}
+
 		in = append(in, c)
 		var err error
-		in, err = recurseLinks(bs, c, in)
+		in, err = recurseLinks(bs, walked, c, in)
 		if err != nil {
 			rerr = err
 		}
@@ -1145,12 +1150,13 @@ func recurseLinks(bs bstore.Blockstore, root cid.Cid, in []cid.Cid) ([]cid.Cid,
 	return in, rerr
 }
 
-func (cs *ChainStore) Export(ctx context.Context, ts *types.TipSet, w io.Writer) error {
+func (cs *ChainStore) Export(ctx context.Context, ts *types.TipSet, inclRecentRoots abi.ChainEpoch, w io.Writer) error {
 	if ts == nil {
 		ts = cs.GetHeaviestTipSet()
 	}
 
 	seen := cid.NewSet()
+	walked := cid.NewSet()
 
 	h := &car.CarHeader{
 		Roots:   ts.Cids(),
@@ -1182,7 +1188,7 @@ func (cs *ChainStore) Export(ctx context.Context, ts *types.TipSet, w io.Writer)
 			return xerrors.Errorf("unmarshaling block header (cid=%s): %w", blk, err)
 		}
 
-		cids, err := recurseLinks(cs.bs, b.Messages, []cid.Cid{b.Messages})
+		cids, err := recurseLinks(cs.bs, walked, b.Messages, []cid.Cid{b.Messages})
 		if err != nil {
 			return xerrors.Errorf("recursing messages failed: %w", err)
 		}
@@ -1198,8 +1204,8 @@ func (cs *ChainStore) Export(ctx context.Context, ts *types.TipSet, w io.Writer)
 
 		out := cids
 
-		if b.Height == 0 {
-			cids, err := recurseLinks(cs.bs, b.ParentStateRoot, []cid.Cid{b.ParentStateRoot})
+		if b.Height == 0 || b.Height > ts.Height()-inclRecentRoots {
+			cids, err := recurseLinks(cs.bs, walked, b.ParentStateRoot, []cid.Cid{b.ParentStateRoot})
 			if err != nil {
 				return xerrors.Errorf("recursing genesis state failed: %w", err)
 			}

chain/store/store_test.go

@@ -96,7 +96,7 @@ func TestChainExportImport(t *testing.T) {
 	}
 
 	buf := new(bytes.Buffer)
-	if err := cg.ChainStore().Export(context.TODO(), last, buf); err != nil {
+	if err := cg.ChainStore().Export(context.TODO(), last, 0, buf); err != nil {
 		t.Fatal(err)
 	}
 

chain/store/weight.go

@@ -41,7 +41,7 @@ func (cs *ChainStore) Weight(ctx context.Context, ts *types.TipSet) (types.BigIn
 
 		var st power.State
 		if err := cst.Get(ctx, act.Head, &st); err != nil {
-			return types.NewInt(0), xerrors.Errorf("get power actor head: %w", err)
+			return types.NewInt(0), xerrors.Errorf("get power actor head (%s, height=%d): %w", act.Head, ts.Height(), err)
 		}
 		tpow = st.TotalQualityAdjPower // TODO: REVIEW: Is this correct?
 	}

cli/chain.go

@@ -859,6 +859,10 @@ var chainExportCmd = &cli.Command{
 		&cli.StringFlag{
 			Name: "tipset",
 		},
+		&cli.Int64Flag{
+			Name:  "recent-stateroots",
+			Usage: "specify the number of recent state roots to include in the export",
+		},
 	},
 	Action: func(cctx *cli.Context) error {
 		api, closer, err := GetFullNodeAPI(cctx)
@@ -872,6 +876,11 @@ var chainExportCmd = &cli.Command{
 			return fmt.Errorf("must specify filename to export chain to")
 		}
 
+		rsrs := abi.ChainEpoch(cctx.Int64("recent-stateroots"))
+		if cctx.IsSet("recent-stateroots") && rsrs < build.Finality {
+			return fmt.Errorf("\"recent-stateroots\" has to be greater than %d", build.Finality)
+		}
+
 		fi, err := os.Create(cctx.Args().First())
 		if err != nil {
 			return err
@@ -888,7 +897,7 @@ var chainExportCmd = &cli.Command{
 			return err
 		}
 
-		stream, err := api.ChainExport(ctx, ts.Key())
+		stream, err := api.ChainExport(ctx, rsrs, ts.Key())
 		if err != nil {
 			return err
 		}

cmd/lotus/daemon.go

@@ -100,7 +100,11 @@ var DaemonCmd = &cli.Command{
 		},
 		&cli.StringFlag{
 			Name:  "import-chain",
-			Usage: "on first run, load chain from given file",
+			Usage: "on first run, load chain from given file and validate",
+		},
+		&cli.StringFlag{
+			Name:  "import-snapshot",
+			Usage: "import chain state from a given chain export file",
 		},
 		&cli.BoolFlag{
 			Name:  "halt-after-import",
@@ -191,13 +195,23 @@ var DaemonCmd = &cli.Command{
 		}
 
 		chainfile := cctx.String("import-chain")
-		if chainfile != "" {
+		snapshot := cctx.String("import-snapshot")
+		if chainfile != "" || snapshot != "" {
+			if chainfile != "" && snapshot != "" {
+				return fmt.Errorf("cannot specify both 'import-snapshot' and 'import-chain'")
+			}
+			var issnapshot bool
+			if chainfile == "" {
+				chainfile = snapshot
+				issnapshot = true
+			}
+
 			chainfile, err := homedir.Expand(chainfile)
 			if err != nil {
 				return err
 			}
 
-			if err := ImportChain(r, chainfile); err != nil {
+			if err := ImportChain(r, chainfile, issnapshot); err != nil {
 				return err
 			}
 			if cctx.Bool("halt-after-import") {
@@ -312,7 +326,7 @@ func importKey(ctx context.Context, api api.FullNode, f string) error {
 	return nil
 }
 
-func ImportChain(r repo.Repo, fname string) error {
+func ImportChain(r repo.Repo, fname string, snapshot bool) error {
 	fi, err := os.Open(fname)
 	if err != nil {
 		return err
@@ -357,9 +371,11 @@ func ImportChain(r repo.Repo, fname string) error {
 
 	stm := stmgr.NewStateManager(cst)
 
-	log.Infof("validating imported chain...")
-	if err := stm.ValidateChain(context.TODO(), ts); err != nil {
-		return xerrors.Errorf("chain validation failed: %w", err)
+	if !snapshot {
+		log.Infof("validating imported chain...")
+		if err := stm.ValidateChain(context.TODO(), ts); err != nil {
+			return xerrors.Errorf("chain validation failed: %w", err)
+		}
 	}
 
 	log.Info("accepting %s as new head", ts.Cids())

documentation/en/api-methods.md

@@ -268,13 +268,17 @@ blockchain, but that do not require any form of state computation.
 
 ### ChainExport
 ChainExport returns a stream of bytes with CAR dump of chain data.
+The exported chain data includes the header chain from the given tipset
+back to genesis, the entire genesis state, and the most recent 'nroots'
+state trees.
 
 
 Perms: read
 
 Inputs:
 ```json
 [
+  10101,
   [
     {
       "/": "bafy2bzacea3wsdh6y3a36tb3skempjoxqpuyompjbmfeyf34fi3uy6uue42v4"

node/impl/full/chain.go

@@ -494,7 +494,7 @@ func (a *ChainAPI) ChainGetMessage(ctx context.Context, mc cid.Cid) (*types.Mess
 	return cm.VMMessage(), nil
 }
 
-func (a *ChainAPI) ChainExport(ctx context.Context, tsk types.TipSetKey) (<-chan []byte, error) {
+func (a *ChainAPI) ChainExport(ctx context.Context, nroots abi.ChainEpoch, tsk types.TipSetKey) (<-chan []byte, error) {
 	ts, err := a.Chain.GetTipSetFromKey(tsk)
 	if err != nil {
 		return nil, xerrors.Errorf("loading tipset %s: %w", tsk, err)
@@ -503,7 +503,7 @@ func (a *ChainAPI) ChainExport(ctx context.Context, tsk types.TipSetKey) (<-chan
 	out := make(chan []byte)
 	go func() {
 		defer w.Close() //nolint:errcheck // it is a pipe
-		if err := a.Chain.Export(ctx, ts, w); err != nil {
+		if err := a.Chain.Export(ctx, ts, nroots, w); err != nil {
 			log.Errorf("chain export call failed: %s", err)
 			return
 		}