lotus/cmd/lotus-shed/export.go
Raúl Kripalani 3795cc2bd2 segregate chain and state blockstores.
This paves the way for better object lifetime management.

Concretely, it makes it possible to:
- have different stores backing chain and state data.
- having the same datastore library, but using different parameters.
- attach different caching layers/policies to each class of data, e.g.
  sizing caches differently.
- specifying different retention policies for chain and state data.

This separation is important because:
- access patterns/frequency of chain and state data are different.
- state is derivable from chain, so one could never expunge the chain
  store, and only retain state objects reachable from the last finality
  in the state store.
2021-02-28 22:49:44 +00:00

133 lines
2.8 KiB
Go

package main
import (
"context"
"fmt"
"io"
"os"
"github.com/urfave/cli/v2"
"golang.org/x/xerrors"
"github.com/filecoin-project/go-state-types/abi"
"github.com/filecoin-project/lotus/chain/store"
"github.com/filecoin-project/lotus/chain/types"
lcli "github.com/filecoin-project/lotus/cli"
"github.com/filecoin-project/lotus/node/repo"
)
var exportChainCmd = &cli.Command{
Name: "export",
Description: "Export chain from repo (requires node to be offline)",
Flags: []cli.Flag{
&cli.StringFlag{
Name: "repo",
Value: "~/.lotus",
},
&cli.StringFlag{
Name: "tipset",
Usage: "tipset to export from",
},
&cli.Int64Flag{
Name: "recent-stateroots",
},
&cli.BoolFlag{
Name: "full-state",
},
&cli.BoolFlag{
Name: "skip-old-msgs",
},
},
Action: func(cctx *cli.Context) error {
if !cctx.Args().Present() {
return lcli.ShowHelp(cctx, fmt.Errorf("must specify file name to write export to"))
}
ctx := context.TODO()
r, err := repo.NewFS(cctx.String("repo"))
if err != nil {
return xerrors.Errorf("opening fs repo: %w", err)
}
exists, err := r.Exists()
if err != nil {
return err
}
if !exists {
return xerrors.Errorf("lotus repo doesn't exist")
}
lr, err := r.Lock(repo.FullNode)
if err != nil {
return err
}
defer lr.Close() //nolint:errcheck
fi, err := os.Create(cctx.Args().First())
if err != nil {
return xerrors.Errorf("opening the output file: %w", err)
}
defer fi.Close() //nolint:errcheck
bs, err := lr.Blockstore(ctx, repo.UniversalBlockstore)
if err != nil {
return fmt.Errorf("failed to open blockstore: %w", err)
}
defer func() {
if c, ok := bs.(io.Closer); ok {
if err := c.Close(); err != nil {
log.Warnf("failed to close blockstore: %s", err)
}
}
}()
mds, err := lr.Datastore(context.Background(), "/metadata")
if err != nil {
return err
}
cs := store.NewChainStore(bs, bs, mds, nil, nil)
defer cs.Close() //nolint:errcheck
if err := cs.Load(); err != nil {
return err
}
nroots := abi.ChainEpoch(cctx.Int64("recent-stateroots"))
fullstate := cctx.Bool("full-state")
skipoldmsgs := cctx.Bool("skip-old-msgs")
var ts *types.TipSet
if tss := cctx.String("tipset"); tss != "" {
cids, err := lcli.ParseTipSetString(tss)
if err != nil {
return xerrors.Errorf("failed to parse tipset (%q): %w", tss, err)
}
tsk := types.NewTipSetKey(cids...)
selts, err := cs.LoadTipSet(tsk)
if err != nil {
return xerrors.Errorf("loading tipset: %w", err)
}
ts = selts
} else {
ts = cs.GetHeaviestTipSet()
}
if fullstate {
nroots = ts.Height() + 1
}
if err := cs.Export(ctx, ts, nroots, skipoldmsgs, fi); err != nil {
return xerrors.Errorf("export failed: %w", err)
}
return nil
},
}