prysm-pulse/beacon-chain/rpc/proposer_server.go
Raul Jordan e0e3dada7b
Abstract Usage of Deposit Cache Into Interface (#3443)
* deposit cache refactor begin

* use interface for has chain  started

* use deposit fetcher interface instead

* use moar interfaces

* comment

* gaz

* fix breaking build

* lint

* implement chainstart fetcher

* allow start to work

* fix broken tests
2019-09-11 23:30:04 -05:00

377 lines
15 KiB
Go

package rpc
import (
"context"
"fmt"
"math/big"
"github.com/pkg/errors"
"github.com/prysmaticlabs/go-ssz"
"github.com/prysmaticlabs/prysm/beacon-chain/blockchain"
"github.com/prysmaticlabs/prysm/beacon-chain/cache/depositcache"
"github.com/prysmaticlabs/prysm/beacon-chain/core/blocks"
"github.com/prysmaticlabs/prysm/beacon-chain/core/helpers"
"github.com/prysmaticlabs/prysm/beacon-chain/core/state"
"github.com/prysmaticlabs/prysm/beacon-chain/db"
"github.com/prysmaticlabs/prysm/beacon-chain/operations"
"github.com/prysmaticlabs/prysm/beacon-chain/powchain"
pbp2p "github.com/prysmaticlabs/prysm/proto/beacon/p2p/v1"
pb "github.com/prysmaticlabs/prysm/proto/beacon/rpc/v1"
ethpb "github.com/prysmaticlabs/prysm/proto/eth/v1alpha1"
"github.com/prysmaticlabs/prysm/shared/bytesutil"
"github.com/prysmaticlabs/prysm/shared/hashutil"
"github.com/prysmaticlabs/prysm/shared/params"
"github.com/prysmaticlabs/prysm/shared/trieutil"
"github.com/sirupsen/logrus"
"go.opencensus.io/trace"
)
// ProposerServer defines a server implementation of the gRPC Proposer service,
// providing RPC endpoints for computing state transitions and state roots, proposing
// beacon blocks to a beacon node, and more.
type ProposerServer struct {
beaconDB db.Database
headFetcher blockchain.HeadFetcher
blockReceiver blockchain.BlockReceiver
mockEth1Votes bool
chainStartFetcher powchain.ChainStartFetcher
eth1InfoFetcher powchain.ChainInfoFetcher
eth1BlockFetcher powchain.POWBlockFetcher
pool operations.Pool
canonicalStateChan chan *pbp2p.BeaconState
depositFetcher depositcache.DepositFetcher
pendingDepositsFetcher depositcache.PendingDepositsFetcher
}
// RequestBlock is called by a proposer during its assigned slot to request a block to sign
// by passing in the slot and the signed randao reveal of the slot.
func (ps *ProposerServer) RequestBlock(ctx context.Context, req *pb.BlockRequest) (*ethpb.BeaconBlock, error) {
ctx, span := trace.StartSpan(ctx, "ProposerServer.RequestBlock")
defer span.End()
span.AddAttributes(trace.Int64Attribute("slot", int64(req.Slot)))
// Retrieve the parent block as the current head of the canonical chain
parent := ps.headFetcher.HeadBlock()
parentRoot, err := ssz.SigningRoot(parent)
if err != nil {
return nil, errors.Wrap(err, "could not get parent block signing root")
}
eth1Data, err := ps.eth1Data(ctx, req.Slot)
if err != nil {
return nil, errors.Wrap(err, "could not get ETH1 data")
}
// Pack ETH1 deposits which have not been included in the beacon chain.
deposits, err := ps.deposits(ctx, eth1Data)
if err != nil {
return nil, errors.Wrap(err, "could not get eth1 deposits")
}
// Pack aggregated attestations which have not been included in the beacon chain.
attestations, err := ps.attestations(ctx, req.Slot)
if err != nil {
return nil, errors.Wrap(err, "could not get pending attestations")
}
// Use zero hash as stub for state root to compute later.
stateRoot := params.BeaconConfig().ZeroHash[:]
emptySig := make([]byte, 96)
blk := &ethpb.BeaconBlock{
Slot: req.Slot,
ParentRoot: parentRoot[:],
StateRoot: stateRoot,
Body: &ethpb.BeaconBlockBody{
Eth1Data: eth1Data,
Deposits: deposits,
Attestations: attestations,
RandaoReveal: req.RandaoReveal,
// TODO(2766): Implement rest of the retrievals for beacon block operations
Transfers: []*ethpb.Transfer{},
ProposerSlashings: []*ethpb.ProposerSlashing{},
AttesterSlashings: []*ethpb.AttesterSlashing{},
VoluntaryExits: []*ethpb.VoluntaryExit{},
Graffiti: []byte{},
},
Signature: emptySig,
}
// Compute state root with the newly constructed block.
stateRoot, err = ps.computeStateRoot(ctx, blk)
if err != nil {
return nil, errors.Wrap(err, "could not get compute state root")
}
blk.StateRoot = stateRoot
return blk, nil
}
// ProposeBlock is called by a proposer during its assigned slot to create a block in an attempt
// to get it processed by the beacon node as the canonical head.
func (ps *ProposerServer) ProposeBlock(ctx context.Context, blk *ethpb.BeaconBlock) (*pb.ProposeResponse, error) {
// TODO(#78): To protect against blk not filling, this will be handled within the SSZ code codebase.
// https://github.com/prysmaticlabs/go-ssz/issues/78
blk.Body.Graffiti = make([]byte, 32)
root, err := ssz.SigningRoot(blk)
if err != nil {
return nil, errors.Wrap(err, "could not tree hash block")
}
log.WithField("blockRoot", fmt.Sprintf("%#x", bytesutil.Trunc(root[:]))).Debugf(
"Block proposal received via RPC")
if err := ps.blockReceiver.ReceiveBlock(ctx, blk); err != nil {
return nil, errors.Wrap(err, "could not process beacon block")
}
return &pb.ProposeResponse{BlockRoot: root[:]}, nil
}
// attestations retrieves aggregated attestations kept in the beacon node's operations pool which have
// not yet been included into the beacon chain. Proposers include these pending attestations in their
// proposed blocks when performing their responsibility. If desired, callers can choose to filter pending
// attestations which are ready for inclusion. That is, attestations that satisfy:
// attestation.slot + MIN_ATTESTATION_INCLUSION_DELAY <= state.slot.
func (ps *ProposerServer) attestations(ctx context.Context, expectedSlot uint64) ([]*ethpb.Attestation, error) {
beaconState := ps.headFetcher.HeadState()
atts, err := ps.pool.AttestationPool(ctx, expectedSlot)
if err != nil {
return nil, errors.Wrap(err, "could not retrieve pending attestations from operations service")
}
// advance slot, if it is behind
if beaconState.Slot < expectedSlot {
beaconState, err = state.ProcessSlots(ctx, beaconState, expectedSlot)
if err != nil {
return nil, err
}
}
var attsReadyForInclusion []*ethpb.Attestation
for _, att := range atts {
slot, err := helpers.AttestationDataSlot(beaconState, att.Data)
if err != nil {
return nil, errors.Wrap(err, "could not get attestation slot")
}
if slot+params.BeaconConfig().MinAttestationInclusionDelay <= beaconState.Slot &&
beaconState.Slot <= slot+params.BeaconConfig().SlotsPerEpoch {
attsReadyForInclusion = append(attsReadyForInclusion, att)
}
}
validAtts := make([]*ethpb.Attestation, 0, len(attsReadyForInclusion))
for _, att := range attsReadyForInclusion {
slot, err := helpers.AttestationDataSlot(beaconState, att.Data)
if err != nil {
return nil, errors.Wrap(err, "could not get attestation slot")
}
if _, err := blocks.ProcessAttestationNoVerify(beaconState, att); err != nil {
if ctx.Err() != nil {
return nil, ctx.Err()
}
log.WithError(err).WithFields(logrus.Fields{
"slot": slot,
"headRoot": fmt.Sprintf("%#x", bytesutil.Trunc(att.Data.BeaconBlockRoot))}).Info(
"Deleting failed pending attestation from DB")
root, err := ssz.HashTreeRoot(att.Data)
if err != nil {
return nil, err
}
if err := ps.beaconDB.DeleteAttestation(ctx, root); err != nil {
return nil, errors.Wrap(err, "could not delete failed attestation")
}
continue
}
validAtts = append(validAtts, att)
}
return validAtts, nil
}
// eth1Data determines the appropriate eth1data for a block proposal. The algorithm for this method
// is as follows:
// - Determine the timestamp for the start slot for the eth1 voting period.
// - Determine the most recent eth1 block before that timestamp.
// - Subtract that eth1block.number by ETH1_FOLLOW_DISTANCE.
// - This is the eth1block to use for the block proposal.
func (ps *ProposerServer) eth1Data(ctx context.Context, slot uint64) (*ethpb.Eth1Data, error) {
if ps.mockEth1Votes {
// If a mock eth1 data votes is specified, we use the following for the
// eth1data we provide to every proposer based on https://github.com/ethereum/eth2.0-pm/issues/62:
//
// slot_in_voting_period = current_slot % SLOTS_PER_ETH1_VOTING_PERIOD
// Eth1Data(
// DepositRoot = hash(current_epoch + slot_in_voting_period),
// DepositCount = state.eth1_deposit_index,
// BlockHash = hash(hash(current_epoch + slot_in_voting_period)),
// )
slotInVotingPeriod := slot % params.BeaconConfig().SlotsPerEth1VotingPeriod
headState := ps.headFetcher.HeadState()
enc, err := ssz.Marshal(helpers.SlotToEpoch(slot) + slotInVotingPeriod)
if err != nil {
return nil, err
}
depRoot := hashutil.Hash(enc)
blockHash := hashutil.Hash(depRoot[:])
return &ethpb.Eth1Data{
DepositRoot: depRoot[:],
DepositCount: headState.Eth1DepositIndex,
BlockHash: blockHash[:],
}, nil
}
eth1VotingPeriodStartTime, _ := ps.eth1InfoFetcher.Eth2GenesisPowchainInfo()
eth1VotingPeriodStartTime += (slot - (slot % params.BeaconConfig().SlotsPerEth1VotingPeriod)) * params.BeaconConfig().SecondsPerSlot
// Look up most recent block up to timestamp
blockNumber, err := ps.eth1BlockFetcher.BlockNumberByTimestamp(ctx, eth1VotingPeriodStartTime)
if err != nil {
return nil, err
}
return ps.defaultEth1DataResponse(ctx, blockNumber)
}
// computeStateRoot computes the state root after a block has been processed through a state transition and
// returns it to the validator client.
func (ps *ProposerServer) computeStateRoot(ctx context.Context, block *ethpb.BeaconBlock) ([]byte, error) {
beaconState, err := ps.beaconDB.HeadState(ctx)
if err != nil {
return nil, errors.Wrap(err, "could not retrieve beacon state")
}
s, err := state.ExecuteStateTransitionNoVerify(
ctx,
beaconState,
block,
)
if err != nil {
return nil, errors.Wrapf(err, "could not execute state transition for state at slot %d", beaconState.Slot)
}
root, err := ssz.HashTreeRoot(s)
if err != nil {
return nil, errors.Wrap(err, "could not tree hash beacon state")
}
log.WithField("beaconStateRoot", fmt.Sprintf("%#x", root)).Debugf("Computed state hash")
return root[:], nil
}
// deposits returns a list of pending deposits that are ready for inclusion in the next beacon
// block. Determining deposits depends on the current eth1data vote for the block and whether or not
// this eth1data has enough support to be considered for deposits inclusion. If current vote has
// enough support, then use that vote for basis of determining deposits, otherwise use current state
// eth1data.
func (ps *ProposerServer) deposits(ctx context.Context, currentVote *ethpb.Eth1Data) ([]*ethpb.Deposit, error) {
if ps.mockEth1Votes {
return []*ethpb.Deposit{}, nil
}
// Need to fetch if the deposits up to the state's latest eth 1 data matches
// the number of all deposits in this RPC call. If not, then we return nil.
beaconState := ps.headFetcher.HeadState()
canonicalEth1Data, latestEth1DataHeight, err := ps.canonicalEth1Data(ctx, beaconState, currentVote)
if err != nil {
return nil, err
}
_, genesisEth1Block := ps.eth1InfoFetcher.Eth2GenesisPowchainInfo()
if genesisEth1Block.Cmp(latestEth1DataHeight) == 0 {
return []*ethpb.Deposit{}, nil
}
upToEth1DataDeposits := ps.depositFetcher.AllDeposits(ctx, latestEth1DataHeight)
depositData := [][]byte{}
for _, dep := range upToEth1DataDeposits {
depHash, err := ssz.HashTreeRoot(dep.Data)
if err != nil {
return nil, errors.Wrap(err, "could not hash deposit data")
}
depositData = append(depositData, depHash[:])
}
depositTrie, err := trieutil.GenerateTrieFromItems(depositData, int(params.BeaconConfig().DepositContractTreeDepth))
if err != nil {
return nil, errors.Wrap(err, "could not generate historical deposit trie from deposits")
}
allPendingContainers := ps.pendingDepositsFetcher.PendingContainers(ctx, latestEth1DataHeight)
// Deposits need to be received in order of merkle index root, so this has to make sure
// deposits are sorted from lowest to highest.
var pendingDeps []*depositcache.DepositContainer
for _, dep := range allPendingContainers {
if uint64(dep.Index) >= beaconState.Eth1DepositIndex && uint64(dep.Index) < canonicalEth1Data.DepositCount {
pendingDeps = append(pendingDeps, dep)
}
}
for i := range pendingDeps {
// Don't construct merkle proof if the number of deposits is more than max allowed in block.
if uint64(i) == params.BeaconConfig().MaxDeposits {
break
}
pendingDeps[i].Deposit, err = constructMerkleProof(depositTrie, pendingDeps[i].Index, pendingDeps[i].Deposit)
if err != nil {
return nil, err
}
}
// Limit the return of pending deposits to not be more than max deposits allowed in block.
var pendingDeposits []*ethpb.Deposit
for i := 0; i < len(pendingDeps) && i < int(params.BeaconConfig().MaxDeposits); i++ {
pendingDeposits = append(pendingDeposits, pendingDeps[i].Deposit)
}
return pendingDeposits, nil
}
// canonicalEth1Data determines the canonical eth1data and eth1 block height to use for determining deposits.
func (ps *ProposerServer) canonicalEth1Data(ctx context.Context, beaconState *pbp2p.BeaconState, currentVote *ethpb.Eth1Data) (*ethpb.Eth1Data, *big.Int, error) {
var eth1BlockHash [32]byte
// Add in current vote, to get accurate vote tally
beaconState.Eth1DataVotes = append(beaconState.Eth1DataVotes, currentVote)
hasSupport, err := blocks.Eth1DataHasEnoughSupport(beaconState, currentVote)
if err != nil {
return nil, nil, errors.Wrap(err, "could not determine if current eth1data vote has enough support")
}
var canonicalEth1Data *ethpb.Eth1Data
if hasSupport {
canonicalEth1Data = currentVote
eth1BlockHash = bytesutil.ToBytes32(currentVote.BlockHash)
} else {
canonicalEth1Data = beaconState.Eth1Data
eth1BlockHash = bytesutil.ToBytes32(beaconState.Eth1Data.BlockHash)
}
_, latestEth1DataHeight, err := ps.eth1BlockFetcher.BlockExists(ctx, eth1BlockHash)
if err != nil {
return nil, nil, errors.Wrap(err, "could not fetch eth1data height")
}
return canonicalEth1Data, latestEth1DataHeight, nil
}
// in case no vote for new eth1data vote considered best vote we
// default into returning the latest deposit root and the block
// hash of eth1 block hash that is FOLLOW_DISTANCE back from its
// latest block.
func (ps *ProposerServer) defaultEth1DataResponse(ctx context.Context, currentHeight *big.Int) (*ethpb.Eth1Data, error) {
eth1FollowDistance := int64(params.BeaconConfig().Eth1FollowDistance)
ancestorHeight := big.NewInt(0).Sub(currentHeight, big.NewInt(eth1FollowDistance))
blockHash, err := ps.eth1BlockFetcher.BlockHashByHeight(ctx, ancestorHeight)
if err != nil {
return nil, errors.Wrap(err, "could not fetch ETH1_FOLLOW_DISTANCE ancestor")
}
// Fetch all historical deposits up to an ancestor height.
depositsTillHeight, depositRoot := ps.depositFetcher.DepositsNumberAndRootAtHeight(ctx, ancestorHeight)
if depositsTillHeight == 0 {
return ps.chainStartFetcher.ChainStartEth1Data(), nil
}
return &ethpb.Eth1Data{
DepositRoot: depositRoot[:],
BlockHash: blockHash[:],
DepositCount: depositsTillHeight,
}, nil
}