Decouple tstate from merkledb

chain/builder.go

@@ -439,8 +439,8 @@ func (c *Builder) BuildBlock(ctx context.Context, parentView state.View, parent
 		return nil, nil, nil, err
 	}
 
-	// Get view from [tstate] after writing all changed keys
-	view, err := ts.ExportMerkleDBView(ctx, c.tracer, parentView)
+	// Calculate new view from parent and state diff
+	view, err := createView(ctx, c.tracer, parentView, ts.ChangedKeys())
 	if err != nil {
 		return nil, nil, nil, err
 	}

chain/processor.go

@@ -13,8 +13,10 @@ import (
 	"github.com/ava-labs/avalanchego/ids"
 	"github.com/ava-labs/avalanchego/trace"
 	"github.com/ava-labs/avalanchego/utils/logging"
+	"github.com/ava-labs/avalanchego/utils/maybe"
 	"github.com/ava-labs/avalanchego/utils/set"
 	"github.com/ava-labs/avalanchego/x/merkledb"
+	"go.opentelemetry.io/otel/attribute"
 	"go.uber.org/zap"
 
 	"github.com/ava-labs/hypersdk/internal/executor"
@@ -23,6 +25,8 @@ import (
 	"github.com/ava-labs/hypersdk/internal/workers"
 	"github.com/ava-labs/hypersdk/state"
 	"github.com/ava-labs/hypersdk/state/tstate"
+
+	oteltrace "go.opentelemetry.io/otel/trace"
 )
 
 type ExecutionBlock struct {
@@ -242,7 +246,8 @@ func (p *Processor) Execute(
 	// Get view from [tstate] after processing all state transitions
 	p.metrics.stateChanges.Add(float64(ts.PendingChanges()))
 	p.metrics.stateOperations.Add(float64(ts.OpIndex()))
-	view, err := ts.ExportMerkleDBView(ctx, p.tracer, parentView)
+
+	view, err := createView(ctx, p.tracer, parentView, ts.ChangedKeys())
 	if err != nil {
 		return nil, nil, err
 	}
@@ -409,3 +414,18 @@ func (p *Processor) AsyncVerify(ctx context.Context, block *ExecutionBlock) erro
 	}
 	return nil
 }
+
+func createView(ctx context.Context, tracer trace.Tracer, parentView state.View, stateDiff map[string]maybe.Maybe[[]byte]) (merkledb.View, error) {
+	ctx, span := tracer.Start(
+		ctx, "Chain.CreateView",
+		oteltrace.WithAttributes(
+			attribute.Int("items", len(stateDiff)),
+		),
+	)
+	defer span.End()
+
+	return parentView.NewView(ctx, merkledb.ViewChanges{
+		MapOps:       stateDiff,
+		ConsumeBytes: true,
+	})
+}

state/tstate/tstate.go

@@ -7,14 +7,7 @@ import (
 	"context"
 	"sync"
 
-	"github.com/ava-labs/avalanchego/trace"
 	"github.com/ava-labs/avalanchego/utils/maybe"
-	"github.com/ava-labs/avalanchego/x/merkledb"
-	"go.opentelemetry.io/otel/attribute"
-
-	"github.com/ava-labs/hypersdk/state"
-
-	oteltrace "go.opentelemetry.io/otel/trace"
 )
 
 // TState defines a struct for storing temporary state.
@@ -60,23 +53,9 @@ func (ts *TState) OpIndex() int {
 	return ts.ops
 }
 
-// ExportMerkleDBView creates a slice of [database.BatchOp] of all
-// changes in [TState] that can be used to commit to [merkledb].
-func (ts *TState) ExportMerkleDBView(
-	ctx context.Context,
-	t trace.Tracer, //nolint:interfacer
-	view state.View,
-) (merkledb.View, error) {
+func (ts *TState) ChangedKeys() map[string]maybe.Maybe[[]byte] {
 	ts.l.RLock()
 	defer ts.l.RUnlock()
 
-	ctx, span := t.Start(
-		ctx, "TState.ExportMerkleDBView",
-		oteltrace.WithAttributes(
-			attribute.Int("items", len(ts.changedKeys)),
-		),
-	)
-	defer span.End()
-
-	return view.NewView(ctx, merkledb.ViewChanges{MapOps: ts.changedKeys, ConsumeBytes: true})
+	return ts.changedKeys
 }

state/tstate/tstate_test.go

@@ -9,13 +9,9 @@ import (
 	"testing"
 
 	"github.com/ava-labs/avalanchego/database"
-	"github.com/ava-labs/avalanchego/database/memdb"
 	"github.com/ava-labs/avalanchego/utils/maybe"
-	"github.com/ava-labs/avalanchego/utils/units"
-	"github.com/ava-labs/avalanchego/x/merkledb"
 	"github.com/stretchr/testify/require"
 
-	"github.com/ava-labs/hypersdk/internal/trace"
 	"github.com/ava-labs/hypersdk/keys"
 	"github.com/ava-labs/hypersdk/state"
 )
@@ -576,19 +572,6 @@ func TestCreateView(t *testing.T) {
 
 	ctx := context.TODO()
 	ts := New(10)
-	tracer, err := trace.New(&trace.Config{Enabled: false})
-	require.NoError(err)
-	db, err := merkledb.New(ctx, memdb.New(), merkledb.Config{
-		BranchFactor:                merkledb.BranchFactor16,
-		RootGenConcurrency:          1,
-		HistoryLength:               100,
-		ValueNodeCacheSize:          units.MiB,
-		IntermediateNodeCacheSize:   units.MiB,
-		IntermediateWriteBufferSize: units.KiB,
-		IntermediateWriteBatchSize:  units.KiB,
-		Tracer:                      tracer,
-	})
-	require.NoError(err)
 	keys := [][]byte{key1, key2, key3}
 	keySet := state.Keys{
 		key1str: state.All,
@@ -629,15 +612,13 @@ func TestCreateView(t *testing.T) {
 	require.Empty(allocates)
 	require.Equal(map[string]uint16{key1str: 1}, writes)
 
-	// Create merkle view
-	view, err := ts.ExportMerkleDBView(ctx, tracer, db)
-	require.NoError(err, "error writing changes")
-	require.NoError(view.CommitToDB(ctx))
-
-	// Check if db was updated correctly
+	// Extract state diff
+	stateDiff := ts.ChangedKeys()
+	// Check if diff includes the correct keys
 	for i, key := range keys {
-		val, _ := db.GetValue(ctx, key)
-		require.Equal(vals[i], val, "value not updated in db")
+		maybeValue := stateDiff[string(key)]
+		require.True(maybeValue.HasValue())
+		require.Equal(vals[i], maybeValue.Value())
 	}
 
 	// Remove
@@ -660,14 +641,13 @@ func TestCreateView(t *testing.T) {
 	tsv.Commit()
 
 	// Create merkle view
-	view, err = tsv.ts.ExportMerkleDBView(ctx, tracer, db)
-	require.NoError(err, "error writing changes")
-	require.NoError(view.CommitToDB(ctx))
+	stateDiff = ts.ChangedKeys()
 
-	// Check if db was updated correctly
+	// Check if state diff was updated correctly
 	for _, key := range keys {
-		_, err := db.GetValue(ctx, key)
-		require.ErrorIs(err, database.ErrNotFound, "value not removed from db")
+		maybeValue := stateDiff[string(key)]
+		require.NotNil(maybeValue)
+		require.False(maybeValue.HasValue())
 	}
 }
 

vm/resolutions.go

@@ -28,7 +28,6 @@ import (
 	"github.com/ava-labs/hypersdk/internal/validitywindow"
 	"github.com/ava-labs/hypersdk/internal/workers"
 	"github.com/ava-labs/hypersdk/state"
-	"github.com/ava-labs/hypersdk/state/tstate"
 
 	internalfees "github.com/ava-labs/hypersdk/internal/fees"
 )
@@ -120,12 +119,12 @@ func (vm *VM) State() (merkledb.MerkleDB, error) {
 }
 
 func (vm *VM) ImmutableState(ctx context.Context) (state.Immutable, error) {
-	ts := tstate.New(0)
 	state, err := vm.State()
 	if err != nil {
 		return nil, err
 	}
-	return ts.ExportMerkleDBView(ctx, vm.tracer, state)
+
+	return state.NewView(ctx, merkledb.ViewChanges{MapOps: nil, ConsumeBytes: true})
 }
 
 func (vm *VM) Mempool() chain.Mempool {