lotus/storage/sealer/piece_provider.go
2022-06-15 12:06:22 +02:00

214 lines
8.2 KiB
Go

package sealer
import (
"bufio"
"context"
"io"
"github.com/ipfs/go-cid"
"golang.org/x/xerrors"
"github.com/filecoin-project/dagstore/mount"
"github.com/filecoin-project/go-state-types/abi"
"github.com/filecoin-project/specs-storage/storage"
"github.com/filecoin-project/lotus/storage/paths"
"github.com/filecoin-project/lotus/storage/sealer/fr32"
"github.com/filecoin-project/lotus/storage/sealer/storiface"
)
type Unsealer interface {
// SectorsUnsealPiece will Unseal a Sealed sector file for the given sector.
SectorsUnsealPiece(ctx context.Context, sector storage.SectorRef, offset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize, randomness abi.SealRandomness, commd *cid.Cid) error
}
type PieceProvider interface {
// ReadPiece is used to read an Unsealed piece at the given offset and of the given size from a Sector
// pieceOffset + pieceSize specify piece bounds for unsealing (note: with SDR the entire sector will be unsealed by
// default in most cases, but this might matter with future PoRep)
// startOffset is added to the pieceOffset to get the starting reader offset.
// The number of bytes that can be read is pieceSize-startOffset
ReadPiece(ctx context.Context, sector storage.SectorRef, pieceOffset storiface.UnpaddedByteIndex, pieceSize abi.UnpaddedPieceSize, ticket abi.SealRandomness, unsealed cid.Cid) (mount.Reader, bool, error)
IsUnsealed(ctx context.Context, sector storage.SectorRef, offset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize) (bool, error)
}
var _ PieceProvider = &pieceProvider{}
type pieceProvider struct {
storage *paths.Remote
index paths.SectorIndex
uns Unsealer
}
func NewPieceProvider(storage *paths.Remote, index paths.SectorIndex, uns Unsealer) PieceProvider {
return &pieceProvider{
storage: storage,
index: index,
uns: uns,
}
}
// IsUnsealed checks if we have the unsealed piece at the given offset in an already
// existing unsealed file either locally or on any of the workers.
func (p *pieceProvider) IsUnsealed(ctx context.Context, sector storage.SectorRef, offset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize) (bool, error) {
if err := offset.Valid(); err != nil {
return false, xerrors.Errorf("offset is not valid: %w", err)
}
if err := size.Validate(); err != nil {
return false, xerrors.Errorf("size is not a valid piece size: %w", err)
}
ctxLock, cancel := context.WithCancel(ctx)
defer cancel()
if err := p.index.StorageLock(ctxLock, sector.ID, storiface.FTUnsealed, storiface.FTNone); err != nil {
return false, xerrors.Errorf("acquiring read sector lock: %w", err)
}
return p.storage.CheckIsUnsealed(ctxLock, sector, abi.PaddedPieceSize(offset.Padded()), size.Padded())
}
// tryReadUnsealedPiece will try to read the unsealed piece from an existing unsealed sector file for the given sector from any worker that has it.
// It will NOT try to schedule an Unseal of a sealed sector file for the read.
//
// Returns a nil reader if the piece does NOT exist in any unsealed file or there is no unsealed file for the given sector on any of the workers.
func (p *pieceProvider) tryReadUnsealedPiece(ctx context.Context, pc cid.Cid, sector storage.SectorRef, pieceOffset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize) (mount.Reader, error) {
// acquire a lock purely for reading unsealed sectors
ctx, cancel := context.WithCancel(ctx)
if err := p.index.StorageLock(ctx, sector.ID, storiface.FTUnsealed, storiface.FTNone); err != nil {
cancel()
return nil, xerrors.Errorf("acquiring read sector lock: %w", err)
}
// Reader returns a reader getter for an unsealed piece at the given offset in the given sector.
// The returned reader will be nil if none of the workers has an unsealed sector file containing
// the unsealed piece.
rg, err := p.storage.Reader(ctx, sector, abi.PaddedPieceSize(pieceOffset.Padded()), size.Padded())
if err != nil {
cancel()
log.Debugf("did not get storage reader;sector=%+v, err:%s", sector.ID, err)
return nil, err
}
if rg == nil {
cancel()
return nil, nil
}
buf := make([]byte, fr32.BufSize(size.Padded()))
pr, err := (&pieceReader{
ctx: ctx,
getReader: func(ctx context.Context, startOffset uint64) (io.ReadCloser, error) {
startOffsetAligned := storiface.UnpaddedByteIndex(startOffset / 127 * 127) // floor to multiple of 127
r, err := rg(startOffsetAligned.Padded())
if err != nil {
return nil, xerrors.Errorf("getting reader at +%d: %w", startOffsetAligned, err)
}
upr, err := fr32.NewUnpadReaderBuf(r, size.Padded(), buf)
if err != nil {
r.Close() // nolint
return nil, xerrors.Errorf("creating unpadded reader: %w", err)
}
bir := bufio.NewReaderSize(upr, 127)
if startOffset > uint64(startOffsetAligned) {
if _, err := bir.Discard(int(startOffset - uint64(startOffsetAligned))); err != nil {
r.Close() // nolint
return nil, xerrors.Errorf("discarding bytes for startOffset: %w", err)
}
}
return struct {
io.Reader
io.Closer
}{
Reader: bir,
Closer: funcCloser(func() error {
return r.Close()
}),
}, nil
},
len: size,
onClose: cancel,
pieceCid: pc,
}).init()
if err != nil || pr == nil { // pr == nil to make sure we don't return typed nil
cancel()
return nil, err
}
return pr, err
}
type funcCloser func() error
func (f funcCloser) Close() error {
return f()
}
var _ io.Closer = funcCloser(nil)
// ReadPiece is used to read an Unsealed piece at the given offset and of the given size from a Sector
// If an Unsealed sector file exists with the Piece Unsealed in it, we'll use that for the read.
// Otherwise, we will Unseal a Sealed sector file for the given sector and read the Unsealed piece from it.
// If we do NOT have an existing unsealed file containing the given piece thus causing us to schedule an Unseal,
// the returned boolean parameter will be set to true.
// If we have an existing unsealed file containing the given piece, the returned boolean will be set to false.
func (p *pieceProvider) ReadPiece(ctx context.Context, sector storage.SectorRef, pieceOffset storiface.UnpaddedByteIndex, size abi.UnpaddedPieceSize, ticket abi.SealRandomness, unsealed cid.Cid) (mount.Reader, bool, error) {
if err := pieceOffset.Valid(); err != nil {
return nil, false, xerrors.Errorf("pieceOffset is not valid: %w", err)
}
if err := size.Validate(); err != nil {
return nil, false, xerrors.Errorf("size is not a valid piece size: %w", err)
}
r, err := p.tryReadUnsealedPiece(ctx, unsealed, sector, pieceOffset, size)
if xerrors.Is(err, storiface.ErrSectorNotFound) {
log.Debugf("no unsealed sector file with unsealed piece, sector=%+v, pieceOffset=%d, size=%d", sector, pieceOffset, size)
err = nil
}
if err != nil {
log.Errorf("returning error from ReadPiece:%s", err)
return nil, false, err
}
var uns bool
if r == nil {
// a nil reader means that none of the workers has an unsealed sector file
// containing the unsealed piece.
// we now need to unseal a sealed sector file for the given sector to read the unsealed piece from it.
uns = true
commd := &unsealed
if unsealed == cid.Undef {
commd = nil
}
if err := p.uns.SectorsUnsealPiece(ctx, sector, pieceOffset, size, ticket, commd); err != nil {
log.Errorf("failed to SectorsUnsealPiece: %s", err)
return nil, false, xerrors.Errorf("unsealing piece: %w", err)
}
log.Debugf("unsealed a sector file to read the piece, sector=%+v, pieceOffset=%d, size=%d", sector, pieceOffset, size)
r, err = p.tryReadUnsealedPiece(ctx, unsealed, sector, pieceOffset, size)
if err != nil {
log.Errorf("failed to tryReadUnsealedPiece after SectorsUnsealPiece: %s", err)
return nil, true, xerrors.Errorf("read after unsealing: %w", err)
}
if r == nil {
log.Errorf("got no reader after unsealing piece")
return nil, true, xerrors.Errorf("got no reader after unsealing piece")
}
log.Debugf("got a reader to read unsealed piece, sector=%+v, pieceOffset=%d, size=%d", sector, pieceOffset, size)
} else {
log.Debugf("unsealed piece already exists, no need to unseal, sector=%+v, pieceOffset=%d, size=%d", sector, pieceOffset, size)
}
log.Debugf("returning reader to read unsealed piece, sector=%+v, pieceOffset=%d, size=%d", sector, pieceOffset, size)
return r, uns, nil
}