From 0a35e9659b7a4c7f5ed7402bdea6d6b7e3f328d4 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?=C5=81ukasz=20Magiera?= <magik6k@gmail.com>
Date: Wed, 1 Feb 2023 17:51:12 +0100
Subject: [PATCH] feat: shed: Add a tool to read data from sectors

---
 cmd/lotus-shed/sectors.go | 140 ++++++++++++++++++++++++++++++++++++++
 1 file changed, 140 insertions(+)

diff --git a/cmd/lotus-shed/sectors.go b/cmd/lotus-shed/sectors.go
index 52d07f5b6..ee2f58c6b 100644
--- a/cmd/lotus-shed/sectors.go
+++ b/cmd/lotus-shed/sectors.go
@@ -18,6 +18,7 @@ import (
 	"github.com/ipfs/go-cid"
 	"github.com/urfave/cli/v2"
 	"golang.org/x/xerrors"
+	"gopkg.in/cheggaaa/pb.v1"
 
 	"github.com/filecoin-project/go-address"
 	"github.com/filecoin-project/go-bitfield"
@@ -31,6 +32,11 @@ import (
 	"github.com/filecoin-project/lotus/chain/types"
 	lcli "github.com/filecoin-project/lotus/cli"
 	"github.com/filecoin-project/lotus/lib/parmap"
+	"github.com/filecoin-project/lotus/node/repo"
+	"github.com/filecoin-project/lotus/storage/paths"
+	"github.com/filecoin-project/lotus/storage/sealer/fr32"
+	"github.com/filecoin-project/lotus/storage/sealer/fsutil"
+	"github.com/filecoin-project/lotus/storage/sealer/storiface"
 )
 
 var sectorsCmd = &cli.Command{
@@ -42,6 +48,7 @@ var sectorsCmd = &cli.Command{
 		terminateSectorPenaltyEstimationCmd,
 		visAllocatedSectorsCmd,
 		dumpRLESectorCmd,
+		sectorReadCmd,
 	},
 }
 
@@ -563,3 +570,136 @@ func rleToPng(rleBytes []byte) ([]byte, error) {
 
 	return buf.Bytes(), nil
 }
+
+var sectorReadCmd = &cli.Command{
+	Name:      "read",
+	Usage:     "read data from a sector into stdout",
+	ArgsUsage: "[sector num] [padded length] [padded offset]",
+	Description: `Read data from a sector.
+
+TIP: to get sectornum/len/offset for a piece you can use 'boostd pieces piece-info [cid]'
+
+fr32 padding is removed from the output.`,
+	Action: func(cctx *cli.Context) error {
+		if cctx.NArg() != 3 {
+			return xerrors.Errorf("must pass sectornum/len/offset")
+		}
+
+		sectorNum, err := strconv.ParseUint(cctx.Args().Get(0), 10, 64)
+		if err != nil {
+			return xerrors.Errorf("parsing sector number: %w", err)
+		}
+
+		length, err := strconv.ParseUint(cctx.Args().Get(1), 10, 64)
+		if err != nil {
+			return xerrors.Errorf("parsing length: %w", err)
+		}
+
+		offset, err := strconv.ParseUint(cctx.Args().Get(2), 10, 64)
+		if err != nil {
+			return xerrors.Errorf("parsing offset: %w", err)
+		}
+
+		ctx := lcli.ReqContext(cctx)
+		api, closer, err := lcli.GetStorageMinerAPI(cctx)
+		if err != nil {
+			return err
+		}
+
+		maddr, err := api.ActorAddress(ctx)
+		if err != nil {
+			return xerrors.Errorf("getting miner actor address: %w", err)
+		}
+
+		mid, err := address.IDFromAddress(maddr)
+		if err != nil {
+			return xerrors.Errorf("getting miner id: %w", err)
+		}
+
+		sid := abi.SectorID{
+			Miner:  abi.ActorID(mid),
+			Number: abi.SectorNumber(sectorNum),
+		}
+
+		si, err := api.SectorsStatus(ctx, sid.Number, false)
+		if err != nil {
+			return xerrors.Errorf("getting sector status: %w", err)
+		}
+
+		sref := storiface.SectorRef{
+			ID:        sid,
+			ProofType: si.SealProof,
+		}
+
+		defer closer()
+
+		// Setup remote sector store
+		sminfo, err := lcli.GetAPIInfo(cctx, repo.StorageMiner)
+		if err != nil {
+			return xerrors.Errorf("could not get api info: %w", err)
+		}
+
+		localStore, err := paths.NewLocal(ctx, &emptyLocalStorage{}, api, []string{})
+		if err != nil {
+			return err
+		}
+
+		remote := paths.NewRemote(localStore, api, sminfo.AuthHeader(), 10,
+			&paths.DefaultPartialFileHandler{})
+
+		readStarter, err := remote.Reader(ctx, sref, abi.PaddedPieceSize(offset), abi.PaddedPieceSize(length))
+		if err != nil {
+			return xerrors.Errorf("getting reader: %w", err)
+		}
+
+		rd, err := readStarter(0)
+		if err != nil {
+			return xerrors.Errorf("starting reader: %w", err)
+		}
+
+		upr, err := fr32.NewUnpadReaderBuf(rd, abi.PaddedPieceSize(length), make([]byte, 1<<20))
+		if err != nil {
+			return xerrors.Errorf("creating unpadded reader: %w", err)
+		}
+
+		l := int64(abi.PaddedPieceSize(length).Unpadded())
+
+		bar := pb.New64(l)
+		br := bar.NewProxyReader(upr)
+		bar.ShowTimeLeft = true
+		bar.ShowPercent = true
+		bar.ShowSpeed = true
+		bar.Units = pb.U_BYTES
+		bar.Output = os.Stderr
+		bar.Start()
+
+		_, err = io.CopyN(os.Stdout, br, l)
+		if err != nil {
+			return xerrors.Errorf("reading data: %w", err)
+		}
+
+		return nil
+	},
+}
+
+type emptyLocalStorage struct {
+}
+
+func (e *emptyLocalStorage) GetStorage() (storiface.StorageConfig, error) {
+	return storiface.StorageConfig{}, nil
+}
+
+func (e *emptyLocalStorage) SetStorage(f func(*storiface.StorageConfig)) error {
+	panic("don't call")
+}
+
+func (e *emptyLocalStorage) Stat(path string) (fsutil.FsStat, error) {
+	//TODO implement me
+	panic("don't call")
+}
+
+func (e *emptyLocalStorage) DiskUsage(path string) (int64, error) {
+	panic("don't call")
+}
+
+var _ paths.LocalStorage = &emptyLocalStorage{}