ceremonyclient/node/execution/engines/token_execution_engine.go
2025-11-04 04:57:38 -06:00

916 lines
23 KiB
Go

package engines
import (
"bytes"
"encoding/binary"
"encoding/hex"
"math/big"
"slices"
"strings"
"sync"
"github.com/pkg/errors"
"go.uber.org/zap"
"source.quilibrium.com/quilibrium/monorepo/lifecycle"
"source.quilibrium.com/quilibrium/monorepo/node/execution/fees"
"source.quilibrium.com/quilibrium/monorepo/node/execution/intrinsics/token"
"source.quilibrium.com/quilibrium/monorepo/protobufs"
"source.quilibrium.com/quilibrium/monorepo/types/crypto"
"source.quilibrium.com/quilibrium/monorepo/types/execution"
"source.quilibrium.com/quilibrium/monorepo/types/execution/intrinsics"
"source.quilibrium.com/quilibrium/monorepo/types/execution/state"
"source.quilibrium.com/quilibrium/monorepo/types/hypergraph"
"source.quilibrium.com/quilibrium/monorepo/types/keys"
"source.quilibrium.com/quilibrium/monorepo/types/store"
)
// ExecutionMode defines whether the engine is running in global or application
// mode
type ExecutionMode int
const (
// GlobalMode - only deploy messages are valid
GlobalMode ExecutionMode = iota
// ApplicationMode - both deploy and invoke messages are valid
ApplicationMode
)
type TokenExecutionEngine struct {
logger *zap.Logger
hypergraph hypergraph.Hypergraph
clockStore store.ClockStore
keyManager keys.KeyManager
inclusionProver crypto.InclusionProver
bulletproofProver crypto.BulletproofProver
verEnc crypto.VerifiableEncryptor
decafConstructor crypto.DecafConstructor
// State
intrinsics map[string]intrinsics.Intrinsic
intrinsicsMutex sync.RWMutex
mode ExecutionMode
mu sync.RWMutex
ctx lifecycle.SignalerContext
}
func NewTokenExecutionEngine(
logger *zap.Logger,
hypergraph hypergraph.Hypergraph,
clockStore store.ClockStore,
keyManager keys.KeyManager,
inclusionProver crypto.InclusionProver,
bulletproofProver crypto.BulletproofProver,
verEnc crypto.VerifiableEncryptor,
decafConstructor crypto.DecafConstructor,
mode ExecutionMode,
) (*TokenExecutionEngine, error) {
return &TokenExecutionEngine{
logger: logger,
hypergraph: hypergraph,
clockStore: clockStore,
keyManager: keyManager,
inclusionProver: inclusionProver,
bulletproofProver: bulletproofProver,
verEnc: verEnc,
decafConstructor: decafConstructor,
intrinsics: make(map[string]intrinsics.Intrinsic),
mode: mode,
}, nil
}
func (e *TokenExecutionEngine) GetName() string {
return "token"
}
// Prove implements execution.ShardExecutionEngine.
func (e *TokenExecutionEngine) Prove(
domain []byte,
frameNumber uint64,
message []byte,
) (*protobufs.MessageRequest, error) {
if len(message) < 4 {
return nil, errors.Wrap(errors.New("invalid message"), "prove")
}
request := &protobufs.MessageRequest{}
err := request.FromCanonicalBytes(message)
if err != nil {
return nil, errors.Wrap(err, "prove")
}
switch req := request.Request.(type) {
case *protobufs.MessageRequest_Transaction:
transaction, err := token.TransactionFromProtobuf(
req.Transaction,
e.inclusionProver,
)
if err != nil {
return nil, errors.Wrap(err, "prove")
}
if err := transaction.Prove(frameNumber); err != nil {
return nil, errors.Wrap(err, "prove")
}
return &protobufs.MessageRequest{
Request: &protobufs.MessageRequest_Transaction{
Transaction: transaction.ToProtobuf(),
},
}, nil
case *protobufs.MessageRequest_PendingTransaction:
pendingTransaction, err := token.PendingTransactionFromProtobuf(
req.PendingTransaction,
e.inclusionProver,
)
if err != nil {
return nil, errors.Wrap(err, "prove")
}
if err := pendingTransaction.Prove(frameNumber); err != nil {
return nil, errors.Wrap(err, "prove")
}
return &protobufs.MessageRequest{
Request: &protobufs.MessageRequest_PendingTransaction{
PendingTransaction: pendingTransaction.ToProtobuf(),
},
}, nil
case *protobufs.MessageRequest_MintTransaction:
mintTransaction, err := token.MintTransactionFromProtobuf(
req.MintTransaction,
)
if err != nil {
return nil, errors.Wrap(err, "prove")
}
if err := mintTransaction.Prove(frameNumber); err != nil {
return nil, errors.Wrap(err, "prove")
}
return &protobufs.MessageRequest{
Request: &protobufs.MessageRequest_MintTransaction{
MintTransaction: mintTransaction.ToProtobuf(),
},
}, nil
}
return nil, errors.Wrap(errors.New("invalid type"), "prove")
}
func (e *TokenExecutionEngine) GetCost(message []byte) (*big.Int, error) {
if len(message) < 4 {
return nil, errors.Wrap(errors.New("invalid message"), "get cost")
}
request := &protobufs.MessageRequest{}
err := request.FromCanonicalBytes(message)
if err != nil {
return nil, errors.Wrap(err, "get cost")
}
switch req := request.Request.(type) {
case *protobufs.MessageRequest_TokenDeploy:
configBytes, err := req.TokenDeploy.Config.ToCanonicalBytes()
if err != nil {
return nil, errors.Wrap(err, "get cost")
}
return big.NewInt(int64(
len(configBytes),
)), nil
case *protobufs.MessageRequest_TokenUpdate:
configBytes, err := req.TokenUpdate.Config.ToCanonicalBytes()
if err != nil {
return nil, errors.Wrap(err, "get cost")
}
return big.NewInt(int64(
len(configBytes),
)), nil
case *protobufs.MessageRequest_Transaction:
transaction, err := token.TransactionFromProtobuf(
req.Transaction,
e.inclusionProver,
)
if err != nil {
return nil, errors.Wrap(err, "get cost")
}
return transaction.GetCost()
case *protobufs.MessageRequest_PendingTransaction:
pendingTransaction, err := token.PendingTransactionFromProtobuf(
req.PendingTransaction,
e.inclusionProver,
)
if err != nil {
return nil, errors.Wrap(err, "get cost")
}
return pendingTransaction.GetCost()
case *protobufs.MessageRequest_MintTransaction:
mintTransaction, err := token.MintTransactionFromProtobuf(
req.MintTransaction,
)
if err != nil {
return nil, errors.Wrap(err, "get cost")
}
return mintTransaction.GetCost()
}
return big.NewInt(0), nil
}
func (e *TokenExecutionEngine) GetCapabilities() []*protobufs.Capability {
// Protocol identifier: 0x00040001 (token protocol v1)
// High 3 bytes: 0x000400 = token protocol
// Low byte: 0x01 = version 1
return []*protobufs.Capability{
{
ProtocolIdentifier: 0x00040001,
AdditionalMetadata: []byte{},
},
// Double Ratchet protocol (0x0101 = 257 = 1<<8 + 1)
{
ProtocolIdentifier: 0x0101,
AdditionalMetadata: []byte{},
},
// Triple Ratchet protocol (0x0201 = 513 = 2<<8 + 1)
{
ProtocolIdentifier: 0x0201,
AdditionalMetadata: []byte{},
},
// Onion Routing protocol (0x0301 = 769 = 3<<8 + 1)
{
ProtocolIdentifier: 0x0301,
AdditionalMetadata: []byte{},
},
}
}
func (e *TokenExecutionEngine) Start(
ctx lifecycle.SignalerContext,
ready lifecycle.ReadyFunc,
) {
e.ctx = ctx
e.logger.Info("starting token execution engine")
ready()
<-e.ctx.Done()
e.logger.Info("stopping token execution engine")
}
func (e *TokenExecutionEngine) ValidateMessage(
frameNumber uint64,
address []byte,
message []byte,
) error {
if len(message) < 4 {
return errors.Wrap(errors.New("invalid message"), "validate message")
}
// Read the type prefix to determine if it's a bundle or individual operation
typePrefix := binary.BigEndian.Uint32(message[:4])
// Check if it's a message bundle
if typePrefix == protobufs.MessageBundleType {
err := e.validateBundle(frameNumber, address, message)
if err != nil {
return errors.Wrap(err, "validate message")
}
return nil
} else if typePrefix != protobufs.MessageRequestType {
return errors.Wrap(
errors.New("unsupported message type"),
"validate message",
)
}
request := &protobufs.MessageRequest{}
err := request.FromCanonicalBytes(message)
if err != nil {
return errors.Wrap(err, "validate message")
}
// Otherwise, delegate to individual message validation
err = e.validateIndividualMessage(frameNumber, address, request, false)
if err != nil {
return errors.Wrap(err, "validate message")
}
return nil
}
func (e *TokenExecutionEngine) validateBundle(
frameNumber uint64,
address []byte,
message []byte,
) error {
// Parse the bundle
bundle := &protobufs.MessageBundle{}
if err := bundle.FromCanonicalBytes(message); err != nil {
return errors.Wrap(err, "validate bundle")
}
// Validate fees distribute correctly
feeQueue := fees.CollectBundleFees(bundle, DefaultFeeMarket)
consumers := fees.CountFeeConsumers(bundle, DefaultFeeMarket)
if err := fees.SanityCheck(feeQueue, consumers); err != nil {
return errors.Wrap(err, "validate bundle")
}
// Validate each operation in the bundle sequentially
for i, op := range bundle.Requests {
select {
case <-e.ctx.Done():
return errors.Wrap(errors.New("context canceled"), "validate bundle")
default:
e.logger.Debug(
"validating bundled operation",
zap.Int("operation", i),
zap.String("address", hex.EncodeToString(address)),
)
// Check if this is a hypergraph operation type
isHypergraphOp := op.GetTokenDeploy() != nil ||
op.GetTokenUpdate() != nil ||
op.GetTransaction() != nil ||
op.GetMintTransaction() != nil ||
op.GetPendingTransaction() != nil
if !isHypergraphOp {
// Skip non-token operations
e.logger.Debug(
"skipping non-token operation in bundle",
zap.Int("operation", i),
)
continue
}
// Validate this operation individually
err := e.validateIndividualMessage(
frameNumber,
address,
op,
true,
)
if err != nil {
return errors.Wrap(err, "validate bundle")
}
}
}
return nil
}
// validateIndividualMessage validates a single message without bundle handling
func (e *TokenExecutionEngine) validateIndividualMessage(
frameNumber uint64,
address []byte,
message *protobufs.MessageRequest,
fromBundle bool,
) error {
isTokenOp := false
isUpdate := false
switch message.Request.(type) {
case *protobufs.MessageRequest_TokenDeploy:
isTokenOp = true
isUpdate = true
case *protobufs.MessageRequest_TokenUpdate:
isTokenOp = true
isUpdate = true
case *protobufs.MessageRequest_MintTransaction:
isTokenOp = true
case *protobufs.MessageRequest_PendingTransaction:
isTokenOp = true
case *protobufs.MessageRequest_Transaction:
isTokenOp = true
}
if !isTokenOp {
return errors.Wrap(
errors.New("invalid type"),
"validate individual message",
)
}
// For token deploy operations, just validate the structure
if isUpdate && fromBundle {
return errors.Wrap(message.Validate(), "validate individual message")
}
// For other operations, try to load the intrinsic and validate
intrinsic, err := e.tryGetIntrinsic(address)
if err != nil {
return errors.Wrap(err, "validate individual message")
}
payload := []byte{}
switch message.Request.(type) {
case *protobufs.MessageRequest_TokenDeploy:
err = errors.New("deployments must be bundled")
case *protobufs.MessageRequest_TokenUpdate:
err = errors.New("updates must be bundled")
case *protobufs.MessageRequest_MintTransaction:
payload, err = message.GetMintTransaction().ToCanonicalBytes()
case *protobufs.MessageRequest_PendingTransaction:
payload, err = message.GetPendingTransaction().ToCanonicalBytes()
case *protobufs.MessageRequest_Transaction:
payload, err = message.GetTransaction().ToCanonicalBytes()
default:
err = errors.New("unsupported message type")
}
if err != nil {
return errors.Wrap(err, "validate individual message")
}
// Validate the operation
err = intrinsic.Validate(frameNumber, payload)
return errors.Wrap(err, "validate individual message")
}
func (e *TokenExecutionEngine) ProcessMessage(
frameNumber uint64,
feeMultiplier *big.Int,
address []byte,
message []byte,
state state.State,
) (*execution.ProcessMessageResult, error) {
e.mu.RLock()
defer e.mu.RUnlock()
if len(message) < 4 {
return nil, errors.Wrap(errors.New("invalid message"), "process message")
}
// Read the type prefix to determine if it's a bundle or individual operation
typePrefix := binary.BigEndian.Uint32(message[:4])
// Check if it's a message bundle
if typePrefix == protobufs.MessageBundleType {
result, err := e.handleBundle(
frameNumber,
feeMultiplier,
address,
message,
state,
)
if err != nil {
return nil, errors.Wrap(err, "process message")
}
return result, nil
} else if typePrefix != protobufs.MessageRequestType {
return nil, errors.Wrap(
errors.New("unsupported message type"),
"process message",
)
}
// Parse the bundle
request := &protobufs.MessageRequest{}
if err := request.FromCanonicalBytes(message); err != nil {
return nil, errors.Wrap(err, "process message")
}
// Otherwise, delegate to individual message processing
result, err := e.processIndividualMessage(
frameNumber,
big.NewInt(0),
feeMultiplier,
address,
request,
false,
state,
)
if err != nil {
return nil, errors.Wrap(err, "process message")
}
return result, nil
}
func (e *TokenExecutionEngine) Lock(
frameNumber uint64,
address []byte,
message []byte,
) ([][]byte, error) {
intrinsic, err := e.tryGetIntrinsic(address)
if err != nil {
// non-applicable
return nil, nil
}
if len(message) > 4 &&
binary.BigEndian.Uint32(message[:4]) == protobufs.MessageBundleType {
bundle := &protobufs.MessageBundle{}
err = bundle.FromCanonicalBytes(message)
if err != nil {
return nil, errors.Wrap(err, "lock")
}
addresses := [][]byte{}
for _, r := range bundle.Requests {
req, err := r.ToCanonicalBytes()
if err != nil {
return nil, errors.Wrap(err, "lock")
}
addrs, err := intrinsic.Lock(frameNumber, req[8:])
if err != nil {
return nil, err
}
addresses = append(addresses, addrs...)
}
return addresses, nil
}
return intrinsic.Lock(frameNumber, message)
}
func (e *TokenExecutionEngine) Unlock() error {
e.intrinsicsMutex.RLock()
errs := []string{}
for _, intrinsic := range e.intrinsics {
err := intrinsic.Unlock()
if err != nil {
errs = append(errs, err.Error())
}
}
e.intrinsicsMutex.RUnlock()
if len(errs) != 0 {
return errors.Wrap(
errors.Errorf("multiple errors: %s", strings.Join(errs, ", ")),
"unlock",
)
}
return nil
}
func (e *TokenExecutionEngine) handleBundle(
frameNumber uint64,
feeMultiplier *big.Int,
address []byte,
payload []byte,
state state.State,
) (*execution.ProcessMessageResult, error) {
// Parse the bundle
bundle := &protobufs.MessageBundle{}
if err := bundle.FromCanonicalBytes(payload); err != nil {
return nil, errors.Wrap(err, "handle bundle")
}
// Validate fees distribute correctly
feeQueue := fees.CollectBundleFees(bundle, DefaultFeeMarket)
consumers := fees.CountFeeConsumers(bundle, DefaultFeeMarket)
if err := fees.SanityCheck(feeQueue, consumers); err != nil {
return nil, errors.Wrap(err, "handle bundle")
}
responses := &execution.ProcessMessageResult{}
// Process each operation in the bundle sequentially
for i, op := range bundle.Requests {
e.logger.Debug(
"processing bundled operation",
zap.Int("operation", i),
zap.String("address", hex.EncodeToString(address)),
)
// Check if this is a token operation type
isTokenOp := op.GetTokenDeploy() != nil ||
op.GetTokenUpdate() != nil ||
op.GetTransaction() != nil ||
op.GetMintTransaction() != nil ||
op.GetPendingTransaction() != nil
if !isTokenOp {
if fees.NeedsOneFee(op, DefaultFeeMarket) {
_ = fees.PopFee(&feeQueue)
}
// Skip non-token operations
// They are retained in the bundle for reference but not processed here
e.logger.Debug(
"skipping non-token operation in bundle",
zap.Int("operation", i),
)
continue
}
feeForOp := big.NewInt(0)
if fees.NeedsOneFee(op, DefaultFeeMarket) {
// Pre-checked; defensive guard helpful for future policy changes
if len(feeQueue) == 0 {
return nil, errors.Wrapf(
errors.New("fee underflow"),
"handle bundle: op %d required a fee but none left",
i,
)
}
feeForOp = fees.PopFee(&feeQueue)
}
// Process the individual operation by calling ProcessMessage recursively
// but with the individual operation payload
opResponses, err := e.processIndividualMessage(
frameNumber,
feeForOp,
feeMultiplier,
address,
op,
true,
state,
)
if err != nil {
return nil, errors.Wrapf(err, "handle bundle: operation %d failed", i)
}
// Collect responses
responses.Messages = append(responses.Messages, opResponses.Messages...)
responses.State = state
}
e.logger.Info(
"processed message bundle",
zap.Int("operations", len(bundle.Requests)),
zap.String("address", hex.EncodeToString(address)),
zap.Int("responses", len(responses.Messages)),
)
return responses, nil
}
// processIndividualMessage processes a single message without bundle handling
func (e *TokenExecutionEngine) processIndividualMessage(
frameNumber uint64,
feePaid *big.Int,
feeMultiplier *big.Int,
address []byte,
message *protobufs.MessageRequest,
fromBundle bool,
state state.State,
) (*execution.ProcessMessageResult, error) {
payload := []byte{}
var err error
domain := address
switch message.Request.(type) {
case *protobufs.MessageRequest_TokenDeploy:
payload, err = message.GetTokenDeploy().ToCanonicalBytes()
case *protobufs.MessageRequest_TokenUpdate:
payload, err = message.GetTokenUpdate().ToCanonicalBytes()
case *protobufs.MessageRequest_MintTransaction:
payload, err = message.GetMintTransaction().ToCanonicalBytes()
domain = message.GetMintTransaction().Domain
case *protobufs.MessageRequest_PendingTransaction:
payload, err = message.GetPendingTransaction().ToCanonicalBytes()
domain = message.GetPendingTransaction().Domain
case *protobufs.MessageRequest_Transaction:
payload, err = message.GetTransaction().ToCanonicalBytes()
domain = message.GetTransaction().Domain
default:
err = errors.New("unsupported message type")
}
if err != nil {
return nil, errors.Wrap(err, "process individual message")
}
// Read the type prefix to determine if it's a deploy or operation
typePrefix := binary.BigEndian.Uint32(payload[:4])
// Check if it's a token deploy or update
if typePrefix == protobufs.TokenDeploymentType ||
typePrefix == protobufs.TokenUpdateType {
if fromBundle {
return e.handleDeploy(domain, payload, frameNumber, feePaid, state)
} else {
return nil, errors.Wrap(
errors.New("deploy or update messages must be bundled"),
"process individual message",
)
}
}
// In global mode, only deploy messages are valid after deployment has
// occurred (but bundles can contain mixed operations)
if e.mode == GlobalMode {
_, err := e.hypergraph.GetVertex(
[64]byte(slices.Concat(domain, bytes.Repeat([]byte{0xff}, 32))),
)
if err == nil || !fromBundle {
return nil, errors.Wrap(
errors.New("non-deploy messages not allowed in global mode"),
"process individual message",
)
}
}
// Otherwise, try to handle it as an operation on existing intrinsic
intrinsic, err := e.tryGetIntrinsic(domain)
if err != nil {
return nil, errors.Wrap(err, "process individual message")
}
err = e.validateIndividualMessage(frameNumber, domain, message, fromBundle)
if err != nil {
return nil, errors.Wrap(err, "process individual message")
}
// Process the operation
newState, err := intrinsic.InvokeStep(
frameNumber,
payload,
feePaid,
feeMultiplier,
state,
)
if err != nil {
return nil, errors.Wrap(err, "process individual message")
}
e.logger.Debug(
"processed individual message",
zap.String("address", hex.EncodeToString(address)),
)
return &execution.ProcessMessageResult{
Messages: []*protobufs.Message{},
State: newState,
}, nil
}
func (e *TokenExecutionEngine) handleDeploy(
address []byte,
payload []byte,
frameNumber uint64,
feePaid *big.Int,
state state.State,
) (*execution.ProcessMessageResult, error) {
if bytes.Equal(address, token.QUIL_TOKEN_ADDRESS) {
return nil, errors.Wrap(errors.New("reserved"), "handle deploy")
}
var intrinsic *token.TokenIntrinsic
if bytes.Equal(address, token.TOKEN_BASE_DOMAIN[:]) {
// Deserialize the deploy arguments
deployPb := &protobufs.TokenDeploy{}
err := deployPb.FromCanonicalBytes(payload)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
deployArgs, err := token.TokenDeployFromProtobuf(deployPb)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
// Create new token intrinsic
intrinsic, err = token.NewTokenIntrinsic(
deployArgs.Config,
e.hypergraph,
e.verEnc,
e.decafConstructor,
e.bulletproofProver,
e.inclusionProver,
e.keyManager,
)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
// Deploy the intrinsic
state, err = intrinsic.Deploy(
token.TOKEN_BASE_DOMAIN,
nil, // provers
nil, // creator
feePaid,
deployArgs.RDFSchema,
frameNumber,
state,
)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
// Get the deployed address
deployedAddress := intrinsic.Address()
// Store the intrinsic
e.intrinsicsMutex.Lock()
e.intrinsics[string(deployedAddress)] = intrinsic
e.intrinsicsMutex.Unlock()
e.logger.Info(
"deployed token intrinsic",
zap.String("address", hex.EncodeToString(deployedAddress)),
zap.String("name", deployArgs.Config.Name),
zap.String("symbol", deployArgs.Config.Symbol),
)
} else {
// Deserialize the update arguments
updatePb := &protobufs.TokenUpdate{}
err := updatePb.FromCanonicalBytes(payload)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
deployArgs, err := token.TokenUpdateFromProtobuf(updatePb)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
// Load existing token intrinsic
intrinsic, err = token.LoadTokenIntrinsic(
address,
e.hypergraph,
e.verEnc,
e.decafConstructor,
e.bulletproofProver,
e.inclusionProver,
e.keyManager,
e.clockStore,
)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
// Update the intrinsic
state, err = intrinsic.Deploy(
[32]byte(address),
nil, // provers
nil, // creator
feePaid,
payload,
frameNumber,
state,
)
if err != nil {
return nil, errors.Wrap(err, "handle deploy")
}
// Get the deployed address
deployedAddress := intrinsic.Address()
// Store the intrinsic
e.intrinsicsMutex.Lock()
e.intrinsics[string(deployedAddress)] = intrinsic
e.intrinsicsMutex.Unlock()
e.logger.Info(
"updated token intrinsic",
zap.String("address", hex.EncodeToString(deployedAddress)),
zap.String("name", deployArgs.Config.Name),
zap.String("symbol", deployArgs.Config.Symbol),
)
}
return &execution.ProcessMessageResult{
Messages: []*protobufs.Message{},
State: state,
}, nil
}
func (e *TokenExecutionEngine) tryGetIntrinsic(
address []byte,
) (intrinsics.Intrinsic, error) {
addressStr := string(address)
e.intrinsicsMutex.RLock()
intrinsic, exists := e.intrinsics[addressStr]
e.intrinsicsMutex.RUnlock()
if !exists { // Try to load existing intrinsic
loaded, err := token.LoadTokenIntrinsic(
address,
e.hypergraph,
e.verEnc,
e.decafConstructor,
e.bulletproofProver,
e.inclusionProver,
e.keyManager,
e.clockStore,
)
if err != nil {
return nil, errors.Wrap(err, "try get intrinsic")
}
e.intrinsicsMutex.Lock()
e.intrinsics[addressStr] = loaded
e.intrinsicsMutex.Unlock()
intrinsic = loaded
}
return intrinsic, nil
}
var _ execution.ShardExecutionEngine = (*TokenExecutionEngine)(nil)