Merkle-ize X-Chain state

Signed-off-by: Joshua Kim <20001595+joshua-kim@users.noreply.github.com>

Author: joshua-kim

database/memdb/db.go

@@ -5,6 +5,7 @@ package memdb
 
 import (
 	"context"
+	"fmt"
 	"slices"
 	"strings"
 	"sync"
@@ -38,6 +39,21 @@ func New() *Database {
 	return NewWithSize(DefaultSize)
 }
 
+// Copy returns a Database with the same key-value pairs as db
+func Copy(db *Database) (*Database, error) {
+	db.lock.Lock()
+	defer db.lock.Unlock()
+
+	result := New()
+	for k, v := range db.db {
+		if err := result.Put([]byte(k), v); err != nil {
+			return nil, fmt.Errorf("failed to insert key: %w", err)
+		}
+	}
+
+	return result, nil
+}
+
 // NewWithSize returns a map pre-allocated to the provided size with the
 // Database interface methods implemented.
 func NewWithSize(size int) *Database {

vms/avm/block/executor/block.go

@@ -201,7 +201,7 @@ func (b *Block) Verify(context.Context) error {
 	return nil
 }
 
-func (b *Block) Accept(context.Context) error {
+func (b *Block) Accept(ctx context.Context) error {
 	blkID := b.ID()
 	defer b.manager.free(blkID)
 
@@ -246,12 +246,16 @@ func (b *Block) Accept(context.Context) error {
 		return err
 	}
 
+	checksum, err := b.manager.state.Checksum(ctx)
+	if err != nil {
+		return fmt.Errorf("failed to get checksum: %w", err)
+	}
 	b.manager.backend.Ctx.Log.Trace(
 		"accepted block",
 		zap.Stringer("blkID", blkID),
 		zap.Uint64("height", b.Height()),
 		zap.Stringer("parentID", b.Parent()),
-		zap.Stringer("checksum", b.manager.state.Checksum()),
+		zap.Stringer("checksum", checksum),
 	)
 	return nil
 }

vms/avm/block/executor/block_test.go

@@ -749,7 +749,7 @@ func TestBlockAccept(t *testing.T) {
 				// because we mock the call to shared memory
 				mockManagerState.EXPECT().CommitBatch().Return(nil, nil)
 				mockManagerState.EXPECT().Abort()
-				mockManagerState.EXPECT().Checksum().Return(ids.Empty)
+				mockManagerState.EXPECT().Checksum(gomock.Any()).Return(ids.Empty, nil)
 
 				mockSharedMemory := atomicmock.NewSharedMemory(ctrl)
 				mockSharedMemory.EXPECT().Apply(gomock.Any(), gomock.Any()).Return(nil)

vms/avm/environment_test.go

@@ -113,7 +113,8 @@ func setup(tb testing.TB, c *envConfig) *environment {
 	}
 
 	vm := &VM{
-		Config: vmStaticConfig,
+		Config:                vmStaticConfig,
+		StateMigrationFactory: NoStateMigrationFactory{},
 	}
 
 	vmDynamicConfig := DefaultConfig