lotus/extern/storage-sealing/utils.go
2020-09-07 15:48:41 -04:00

58 lines
1.7 KiB
Go

package sealing
import (
"math/bits"
"github.com/filecoin-project/go-state-types/abi"
)
func fillersFromRem(in abi.UnpaddedPieceSize) ([]abi.UnpaddedPieceSize, error) {
// Convert to in-sector bytes for easier math:
//
// Sector size to user bytes ratio is constant, e.g. for 1024B we have 1016B
// of user-usable data.
//
// (1024/1016 = 128/127)
//
// Given that we can get sector size by simply adding 1/127 of the user
// bytes
//
// (we convert to sector bytes as they are nice round binary numbers)
toFill := uint64(in + (in / 127))
// We need to fill the sector with pieces that are powers of 2. Conveniently
// computers store numbers in binary, which means we can look at 1s to get
// all the piece sizes we need to fill the sector. It also means that number
// of pieces is the number of 1s in the number of remaining bytes to fill
out := make([]abi.UnpaddedPieceSize, bits.OnesCount64(toFill))
for i := range out {
// Extract the next lowest non-zero bit
next := bits.TrailingZeros64(toFill)
psize := uint64(1) << next
// e.g: if the number is 0b010100, psize will be 0b000100
// set that bit to 0 by XORing it, so the next iteration looks at the
// next bit
toFill ^= psize
// Add the piece size to the list of pieces we need to create
out[i] = abi.PaddedPieceSize(psize).Unpadded()
}
return out, nil
}
func (m *Sealing) ListSectors() ([]SectorInfo, error) {
var sectors []SectorInfo
if err := m.sectors.List(&sectors); err != nil {
return nil, err
}
return sectors, nil
}
func (m *Sealing) GetSectorInfo(sid abi.SectorNumber) (SectorInfo, error) {
var out SectorInfo
err := m.sectors.Get(uint64(sid)).Get(&out)
return out, err
}