[chain] Remove Parent Block Dependency during Verify (#427)

* add TODO

* remove parent fetch

* remove parent block from innerVerify

* add verify context

* cleanup VerifyContext call

* working on clarifying GetVerifyContext/View

* keep cleaning up

* add specific conditional for height

* update verification context handling

* update wording in view to explain why we need accepted handling

* add more comments to main path

* update interface

* use preferred block directly

* drop verify

* fix lint

* update state manager

* add note about GetBlockIDByHeight

* finish comment about handling blocks

* make sure keys in set

* add todo for genesis handling

* update genesis block handling

* add more logs

* e2e passing

* address chain nits

* better comment genesis

* extra VM comments

* add TODO

* clarify note about verification status

chain/builder.go

@@ -12,7 +12,6 @@ import (
 	"time"
 
 	"github.com/ava-labs/avalanchego/database"
-	"github.com/ava-labs/avalanchego/ids"
 	smblock "github.com/ava-labs/avalanchego/snow/engine/snowman/block"
 	"github.com/ava-labs/avalanchego/utils/logging"
 	"github.com/ava-labs/avalanchego/utils/math"
@@ -61,19 +60,17 @@ func HandlePreExecute(log logging.Logger, err error) bool {
 func BuildBlock(
 	ctx context.Context,
 	vm VM,
-	preferred ids.ID,
+	parent *StatelessBlock,
 	blockContext *smblock.Context,
 ) (*StatelessBlock, error) {
 	ctx, span := vm.Tracer().Start(ctx, "chain.BuildBlock")
 	defer span.End()
 	log := vm.Logger()
 
-	// Setup new block
-	parent, err := vm.GetStatelessBlock(ctx, preferred)
-	if err != nil {
-		log.Warn("block building failed: couldn't get parent", zap.Error(err))
-		return nil, err
-	}
+	// We don't need to fetch the [VerifyContext] because
+	// we will always have a block to build on.
+
+	// Select next timestamp
 	nextTime := time.Now().UnixMilli()
 	r := vm.Rules(nextTime)
 	if nextTime < parent.Tmstmp+r.GetMinBlockGap() {
@@ -82,10 +79,13 @@ func BuildBlock(
 	}
 	b := NewBlock(vm, parent, nextTime)
 
-	// Fetch state to build on
+	// Fetch view where we will apply block state transitions
+	//
+	// If the parent block is not yet verified, we will attempt to
+	// execute it.
 	mempoolSize := vm.Mempool().Len(ctx)
 	changesEstimate := math.Min(mempoolSize, maxViewPreallocation)
-	parentView, err := parent.View(ctx, nil)
+	parentView, err := parent.View(ctx, nil, true)
 	if err != nil {
 		log.Warn("block building failed: couldn't get parent db", zap.Error(err))
 		return nil, err
@@ -454,21 +454,23 @@ func BuildBlock(
 		vm.RecordEmptyBlockBuilt()
 	}
 
-	// Set scope for [tstate] changes
+	// Update chain metadata
 	heightKey := HeightKey(sm.HeightKey())
 	heightKeyStr := string(heightKey)
+	timestampKey := TimestampKey(b.vm.StateManager().TimestampKey())
+	timestampKeyStr := string(timestampKey)
 	feeKeyStr := string(feeKey)
-	ts.SetScope(ctx, set.Of(heightKeyStr, feeKeyStr), map[string][]byte{
-		heightKeyStr: binary.BigEndian.AppendUint64(nil, parent.Hght),
-		feeKeyStr:    parentFeeManager.Bytes(),
+	ts.SetScope(ctx, set.Of(heightKeyStr, timestampKeyStr, feeKeyStr), map[string][]byte{
+		heightKeyStr:    binary.BigEndian.AppendUint64(nil, parent.Hght),
+		timestampKeyStr: binary.BigEndian.AppendUint64(nil, uint64(parent.Tmstmp)),
+		feeKeyStr:       parentFeeManager.Bytes(),
 	})
-
-	// Store height in state to prevent duplicate roots
 	if err := ts.Insert(ctx, heightKey, binary.BigEndian.AppendUint64(nil, b.Hght)); err != nil {
 		return nil, fmt.Errorf("%w: unable to insert height", err)
 	}
-
-	// Store fee parameters
+	if err := ts.Insert(ctx, timestampKey, binary.BigEndian.AppendUint64(nil, uint64(b.Tmstmp))); err != nil {
+		return nil, fmt.Errorf("%w: unable to insert timestamp", err)
+	}
 	if err := ts.Insert(ctx, feeKey, feeManager.Bytes()); err != nil {
 		return nil, fmt.Errorf("%w: unable to insert fees", err)
 	}

chain/consts.go

@@ -32,13 +32,18 @@ const (
 	// ranges (so, we can't expose a way to modify this over time).
 	MaxOutgoingWarpChunks = 4
 	HeightKeyChunks       = 1
+	TimestampKeyChunks    = 1
 	FeeKeyChunks          = 8 // 96 (per dimension) * 5 (num dimensions)
 )
 
 func HeightKey(prefix []byte) []byte {
 	return keys.EncodeChunks(prefix, HeightKeyChunks)
 }
 
+func TimestampKey(prefix []byte) []byte {
+	return keys.EncodeChunks(prefix, TimestampKeyChunks)
+}
+
 func FeeKey(prefix []byte) []byte {
 	return keys.EncodeChunks(prefix, FeeKeyChunks)
 }

chain/dependencies.go

@@ -48,6 +48,8 @@ type VM interface {
 	SetLastAccepted(*StatelessBlock) error
 	GetStatelessBlock(context.Context, ids.ID) (*StatelessBlock, error)
 
+	GetVerifyContext(ctx context.Context, blockHeight uint64, parent ids.ID) (VerifyContext, error)
+
 	State() (merkledb.MerkleDB, error)
 	StateManager() StateManager
 	ValidatorState() validators.State
@@ -82,6 +84,11 @@ type VM interface {
 	RecordClearedMempool()
 }
 
+type VerifyContext interface {
+	View(ctx context.Context, blockRoot *ids.ID, verify bool) (state.View, error)
+	IsRepeat(ctx context.Context, oldestAllowed int64, txs []*Transaction, marker set.Bits, stop bool) (set.Bits, error)
+}
+
 type Mempool interface {
 	Len(context.Context) int  // items
 	Size(context.Context) int // bytes
@@ -156,6 +163,7 @@ type Rules interface {
 // use. This will be handled by the hypersdk.
 type StateManager interface {
 	HeightKey() []byte
+	TimestampKey() []byte
 	FeeKey() []byte
 
 	IncomingWarpKeyPrefix(sourceChainID ids.ID, msgID ids.ID) []byte

chain/errors.go

@@ -27,6 +27,7 @@ var (
 	ErrInvalidSurplus       = errors.New("invalid surplus fee")
 	ErrStateRootMismatch    = errors.New("state root mismatch")
 	ErrInvalidResult        = errors.New("invalid result")
+	ErrInvalidBlockHeight   = errors.New("invalid block height")
 
 	// Tx Correctness
 	ErrInvalidSignature     = errors.New("invalid signature")

examples/morpheusvm/storage/state_manager.go

@@ -13,6 +13,10 @@ func (*StateManager) HeightKey() []byte {
 	return HeightKey()
 }
 
+func (*StateManager) TimestampKey() []byte {
+	return TimestampKey()
+}
+
 func (*StateManager) FeeKey() []byte {
 	return FeeKey()
 }

examples/morpheusvm/storage/storage.go

@@ -33,9 +33,10 @@ type ReadState func(context.Context, [][]byte) ([][]byte, []error)
 // 0x0/ (balance)
 //   -> [owner] => balance
 // 0x1/ (hypersdk-height)
-// 0x2/ (hypersdk-fee)
-// 0x3/ (hypersdk-incoming warp)
-// 0x4/ (hypersdk-outgoing warp)
+// 0x2/ (hypersdk-timestamp)
+// 0x3/ (hypersdk-fee)
+// 0x4/ (hypersdk-incoming warp)
+// 0x5/ (hypersdk-outgoing warp)
 
 const (
 	// metaDB
@@ -44,18 +45,20 @@ const (
 	// stateDB
 	balancePrefix      = 0x0
 	heightPrefix       = 0x1
-	feePrefix          = 0x2
-	incomingWarpPrefix = 0x3
-	outgoingWarpPrefix = 0x4
+	timestampPrefix    = 0x2
+	feePrefix          = 0x3
+	incomingWarpPrefix = 0x4
+	outgoingWarpPrefix = 0x5
 )
 
 const BalanceChunks uint16 = 1
 
 var (
-	failureByte = byte(0x0)
-	successByte = byte(0x1)
-	heightKey   = []byte{heightPrefix}
-	feeKey      = []byte{feePrefix}
+	failureByte  = byte(0x0)
+	successByte  = byte(0x1)
+	heightKey    = []byte{heightPrefix}
+	timestampKey = []byte{timestampPrefix}
+	feeKey       = []byte{feePrefix}
 
 	balanceKeyPool = sync.Pool{
 		New: func() any {
@@ -256,6 +259,10 @@ func HeightKey() (k []byte) {
 	return heightKey
 }
 
+func TimestampKey() (k []byte) {
+	return timestampKey
+}
+
 func FeeKey() (k []byte) {
 	return feeKey
 }

examples/tokenvm/controller/state_manager.go

@@ -14,6 +14,10 @@ func (*StateManager) HeightKey() []byte {
 	return storage.HeightKey()
 }
 
+func (*StateManager) TimestampKey() []byte {
+	return storage.TimestampKey()
+}
+
 func (*StateManager) FeeKey() []byte {
 	return storage.HeightKey()
 }

examples/tokenvm/storage/storage.go

@@ -37,9 +37,10 @@ type ReadState func(context.Context, [][]byte) ([][]byte, []error)
 // 0x3/ (loans)
 //   -> [assetID|destination] => amount
 // 0x4/ (hypersdk-height)
-// 0x5/ (hypersdk-fee)
-// 0x6/ (hypersdk-incoming warp)
-// 0x7/ (hypersdk-outgoing warp)
+// 0x5/ (hypersdk-timestamp)
+// 0x6/ (hypersdk-fee)
+// 0x7/ (hypersdk-incoming warp)
+// 0x8/ (hypersdk-outgoing warp)
 
 const (
 	// metaDB
@@ -51,9 +52,10 @@ const (
 	orderPrefix        = 0x2
 	loanPrefix         = 0x3
 	heightPrefix       = 0x4
-	feePrefix          = 0x5
-	incomingWarpPrefix = 0x6
-	outgoingWarpPrefix = 0x7
+	timestampPrefix    = 0x5
+	feePrefix          = 0x6
+	incomingWarpPrefix = 0x7
+	outgoingWarpPrefix = 0x8
 )
 
 const (
@@ -64,10 +66,11 @@ const (
 )
 
 var (
-	failureByte = byte(0x0)
-	successByte = byte(0x1)
-	heightKey   = []byte{heightPrefix}
-	feeKey      = []byte{feePrefix}
+	failureByte  = byte(0x0)
+	successByte  = byte(0x1)
+	heightKey    = []byte{heightPrefix}
+	timestampKey = []byte{timestampPrefix}
+	feeKey       = []byte{feePrefix}
 
 	balanceKeyPool = sync.Pool{
 		New: func() any {
@@ -538,6 +541,10 @@ func HeightKey() (k []byte) {
 	return heightKey
 }
 
+func TimestampKey() (k []byte) {
+	return timestampKey
+}
+
 func FeeKey() (k []byte) {
 	return feeKey
 }

vm/errors.go

@@ -8,9 +8,10 @@ import (
 )
 
 var (
-	ErrNotAdded     = errors.New("not added")
-	ErrDropped      = errors.New("dropped")
-	ErrNotReady     = errors.New("not ready")
-	ErrStateMissing = errors.New("state missing")
-	ErrStateSyncing = errors.New("state still syncing")
+	ErrNotAdded            = errors.New("not added")
+	ErrDropped             = errors.New("dropped")
+	ErrNotReady            = errors.New("not ready")
+	ErrStateMissing        = errors.New("state missing")
+	ErrStateSyncing        = errors.New("state still syncing")
+	ErrUnexpectedStateRoot = errors.New("unexpected state root")
 )

vm/resolutions.go

@@ -116,6 +116,7 @@ func (vm *VM) Verified(ctx context.Context, b *chain.StatelessBlock) {
 			zap.Stringer("blkID", b.ID()),
 			zap.Uint64("height", b.Hght),
 			zap.Int("txs", len(b.Txs)),
+			zap.Stringer("parent root", b.StateRoot),
 			zap.Bool("state ready", vm.StateReady()),
 			zap.Any("unit prices", fm.UnitPrices()),
 			zap.Any("units consumed", fm.UnitsConsumed()),
@@ -128,6 +129,7 @@ func (vm *VM) Verified(ctx context.Context, b *chain.StatelessBlock) {
 			zap.Stringer("blkID", b.ID()),
 			zap.Uint64("height", b.Hght),
 			zap.Int("txs", len(b.Txs)),
+			zap.Stringer("parent root", b.StateRoot),
 			zap.Bool("state ready", vm.StateReady()),
 		)
 	}
@@ -301,6 +303,7 @@ func (vm *VM) Accepted(ctx context.Context, b *chain.StatelessBlock) {
 		zap.Stringer("blkID", b.ID()),
 		zap.Uint64("height", b.Hght),
 		zap.Int("txs", len(b.Txs)),
+		zap.Stringer("parent root", b.StateRoot),
 		zap.Int("size", len(b.Bytes())),
 		zap.Int("dropped mempool txs", len(removed)),
 		zap.Bool("state ready", vm.StateReady()),