lotus/chain/beacon/mock.go

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2020-04-08 22:12:36 +00:00
package beacon
import (
"bytes"
"context"
"encoding/binary"
"time"
"github.com/filecoin-project/lotus/chain/types"
"github.com/filecoin-project/specs-actors/actors/abi"
"github.com/minio/blake2b-simd"
"golang.org/x/xerrors"
)
// Mock beacon assumes that filecoin rounds are 1:1 mapped with the beacon rounds
type mockBeacon struct {
interval time.Duration
}
func NewMockBeacon(interval time.Duration) RandomBeacon {
mb := &mockBeacon{interval: interval}
return mb
}
func (mb *mockBeacon) RoundTime() time.Duration {
return mb.interval
}
func (mb *mockBeacon) entryForIndex(index uint64) types.BeaconEntry {
buf := make([]byte, 8)
binary.BigEndian.PutUint64(buf, index)
rval := blake2b.Sum256(buf)
return types.BeaconEntry{
Round: index,
Data: rval[:],
}
}
func (mb *mockBeacon) Entry(ctx context.Context, index uint64) <-chan Response {
e := mb.entryForIndex(index)
out := make(chan Response, 1)
out <- Response{Entry: e}
return out
}
func (mb *mockBeacon) VerifyEntry(from types.BeaconEntry, to types.BeaconEntry) error {
// TODO: cache this, especially for bls
oe := mb.entryForIndex(from.Round)
if !bytes.Equal(from.Data, oe.Data) {
return xerrors.Errorf("mock beacon entry was invalid!")
}
return nil
}
func (mb *mockBeacon) IsEntryForEpoch(e types.BeaconEntry, epoch abi.ChainEpoch, nulls int) (bool, error) {
return int64(e.Round) <= int64(epoch) && int64(epoch)-int64(nulls) >= int64(e.Round), nil
}
func (mb *mockBeacon) MaxBeaconRoundForEpoch(epoch abi.ChainEpoch, prevEntry types.BeaconEntry) uint64 {
return uint64(epoch)
}
var _ RandomBeacon = (*mockBeacon)(nil)