lotus/markets/dagstore/mount.go
2021-12-08 23:20:20 +01:00

92 lines
2.2 KiB
Go

package dagstore
import (
"context"
"net/url"
"github.com/ipfs/go-cid"
"golang.org/x/xerrors"
"github.com/filecoin-project/dagstore/mount"
)
const lotusScheme = "lotus"
var _ mount.Mount = (*LotusMount)(nil)
// mountTemplate returns a templated LotusMount containing the supplied API.
//
// It is called when registering a mount type with the mount registry
// of the DAG store. It is used to reinstantiate mounts after a restart.
//
// When the registry needs to deserialize a mount it clones the template then
// calls Deserialize on the cloned instance, which will have a reference to the
// lotus mount API supplied here.
func mountTemplate(api MinerAPI) *LotusMount {
return &LotusMount{API: api}
}
// LotusMount is a DAGStore mount implementation that fetches deal data
// from a PieceCID.
type LotusMount struct {
API MinerAPI
PieceCid cid.Cid
}
func NewLotusMount(pieceCid cid.Cid, api MinerAPI) (*LotusMount, error) {
return &LotusMount{
PieceCid: pieceCid,
API: api,
}, nil
}
func (l *LotusMount) Serialize() *url.URL {
return &url.URL{
Host: l.PieceCid.String(),
}
}
func (l *LotusMount) Deserialize(u *url.URL) error {
pieceCid, err := cid.Decode(u.Host)
if err != nil {
return xerrors.Errorf("failed to parse PieceCid from host '%s': %w", u.Host, err)
}
l.PieceCid = pieceCid
return nil
}
func (l *LotusMount) Fetch(ctx context.Context) (mount.Reader, error) {
return l.API.FetchUnsealedPiece(ctx, l.PieceCid)
}
func (l *LotusMount) Info() mount.Info {
return mount.Info{
Kind: mount.KindRemote,
AccessSequential: true,
AccessSeek: true,
AccessRandom: true,
}
}
func (l *LotusMount) Close() error {
return nil
}
func (l *LotusMount) Stat(ctx context.Context) (mount.Stat, error) {
size, err := l.API.GetUnpaddedCARSize(ctx, l.PieceCid)
if err != nil {
return mount.Stat{}, xerrors.Errorf("failed to fetch piece size for piece %s: %w", l.PieceCid, err)
}
isUnsealed, err := l.API.IsUnsealed(ctx, l.PieceCid)
if err != nil {
return mount.Stat{}, xerrors.Errorf("failed to verify if we have the unsealed piece %s: %w", l.PieceCid, err)
}
// TODO Mark false when storage deal expires.
return mount.Stat{
Exists: true,
Size: int64(size),
Ready: isUnsealed,
}, nil
}