lotus/cmd/lotus-sim/simulation/block.go
Steven Allen 52261fb814 refactor(lotus-sim): enterprise grade
While the previous version "worked", this version nicely separates out
the state for the separate stages. Hopefully, we'll be able to use this
to build different pipelines with different configs.
2021-06-18 15:44:36 -07:00

94 lines
3.0 KiB
Go

package simulation
import (
"context"
"crypto/sha256"
"encoding/binary"
"time"
"golang.org/x/xerrors"
"github.com/filecoin-project/go-state-types/abi"
"github.com/filecoin-project/lotus/build"
"github.com/filecoin-project/lotus/chain/types"
)
const beaconPrefix = "mockbeacon:"
// nextBeaconEntries returns a fake beacon entries for the next block.
func (sim *Simulation) nextBeaconEntries() []types.BeaconEntry {
parentBeacons := sim.head.Blocks()[0].BeaconEntries
lastBeacon := parentBeacons[len(parentBeacons)-1]
beaconRound := lastBeacon.Round + 1
buf := make([]byte, len(beaconPrefix)+8)
copy(buf, beaconPrefix)
binary.BigEndian.PutUint64(buf[len(beaconPrefix):], beaconRound)
beaconRand := sha256.Sum256(buf)
return []types.BeaconEntry{{
Round: beaconRound,
Data: beaconRand[:],
}}
}
// nextTicket returns a fake ticket for the next block.
func (sim *Simulation) nextTicket() *types.Ticket {
newProof := sha256.Sum256(sim.head.MinTicket().VRFProof)
return &types.Ticket{
VRFProof: newProof[:],
}
}
// makeTipSet generates and executes the next tipset from the given messages. This method:
//
// 1. Stores the given messages in the Chainstore.
// 2. Creates and persists a single block mined by the same miner as the parent.
// 3. Creates a tipset from this block and executes it.
// 4. Returns the resulting tipset.
//
// This method does _not_ mutate local state (although it does add blocks to the datastore).
func (sim *Simulation) makeTipSet(ctx context.Context, messages []*types.Message) (*types.TipSet, error) {
parentTs := sim.head
parentState, parentRec, err := sim.StateManager.TipSetState(ctx, parentTs)
if err != nil {
return nil, xerrors.Errorf("failed to compute parent tipset: %w", err)
}
msgsCid, err := sim.storeMessages(ctx, messages)
if err != nil {
return nil, xerrors.Errorf("failed to store block messages: %w", err)
}
uts := parentTs.MinTimestamp() + build.BlockDelaySecs
blks := []*types.BlockHeader{{
Miner: parentTs.MinTicketBlock().Miner, // keep reusing the same miner.
Ticket: sim.nextTicket(),
BeaconEntries: sim.nextBeaconEntries(),
Parents: parentTs.Cids(),
Height: parentTs.Height() + 1,
ParentStateRoot: parentState,
ParentMessageReceipts: parentRec,
Messages: msgsCid,
ParentBaseFee: abi.NewTokenAmount(0),
Timestamp: uts,
ElectionProof: &types.ElectionProof{WinCount: 1},
}}
err = sim.Chainstore.PersistBlockHeaders(blks...)
if err != nil {
return nil, xerrors.Errorf("failed to persist block headers: %w", err)
}
newTipSet, err := types.NewTipSet(blks)
if err != nil {
return nil, xerrors.Errorf("failed to create new tipset: %w", err)
}
now := time.Now()
_, _, err = sim.StateManager.TipSetState(ctx, newTipSet)
if err != nil {
return nil, xerrors.Errorf("failed to compute new tipset: %w", err)
}
duration := time.Since(now)
log.Infow("computed tipset", "duration", duration, "height", newTipSet.Height())
return newTipSet, nil
}