feat: stateconf.SnapshotUpdateOption

Author: ARR4N

core/state/snapshot/snapshot.go

@@ -27,6 +27,7 @@ import (
 	"github.com/ava-labs/libevm/core/rawdb"
 	"github.com/ava-labs/libevm/core/types"
 	"github.com/ava-labs/libevm/ethdb"
+	"github.com/ava-labs/libevm/libevm/stateconf"
 	"github.com/ava-labs/libevm/log"
 	"github.com/ava-labs/libevm/metrics"
 	"github.com/ava-labs/libevm/rlp"
@@ -348,7 +349,9 @@ func (t *Tree) Snapshots(root common.Hash, limits int, nodisk bool) []Snapshot {
 
 // Update adds a new snapshot into the tree, if that can be linked to an existing
 // old parent. It is disallowed to insert a disk layer (the origin of all).
-func (t *Tree) Update(blockRoot common.Hash, parentRoot common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte) error {
+//
+// libevm: Options are ignored and only included to match an interface method.
+func (t *Tree) Update(blockRoot common.Hash, parentRoot common.Hash, destructs map[common.Hash]struct{}, accounts map[common.Hash][]byte, storage map[common.Hash]map[common.Hash][]byte, _ ...stateconf.SnapshotUpdateOption) error {
 	// Reject noop updates to avoid self-loops in the snapshot tree. This is a
 	// special case that can only happen for Clique networks where empty blocks
 	// don't modify the state (0 block subsidy).

core/state/statedb.go

@@ -27,6 +27,7 @@ import (
 	"github.com/ava-labs/libevm/core/state/snapshot"
 	"github.com/ava-labs/libevm/core/types"
 	"github.com/ava-labs/libevm/crypto"
+	"github.com/ava-labs/libevm/libevm/stateconf"
 	"github.com/ava-labs/libevm/log"
 	"github.com/ava-labs/libevm/metrics"
 	"github.com/ava-labs/libevm/params"
@@ -1163,7 +1164,7 @@ func (s *StateDB) handleDestruction(nodes *trienode.MergedNodeSet) (map[common.A
 //
 // The associated block number of the state transition is also provided
 // for more chain context.
-func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool) (common.Hash, error) {
+func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool, opts ...stateconf.SnapshotUpdateOption) (common.Hash, error) {
 	// Short circuit in case any database failure occurred earlier.
 	if s.dbErr != nil {
 		return common.Hash{}, fmt.Errorf("commit aborted due to earlier error: %v", s.dbErr)
@@ -1253,7 +1254,7 @@ func (s *StateDB) Commit(block uint64, deleteEmptyObjects bool) (common.Hash, er
 		start := time.Now()
 		// Only update if there's a state transition (skip empty Clique blocks)
 		if parent := s.snap.Root(); parent != root {
-			if err := s.snaps.Update(root, parent, s.convertAccountSet(s.stateObjectsDestruct), s.accounts, s.storages); err != nil {
+			if err := s.snaps.Update(root, parent, s.convertAccountSet(s.stateObjectsDestruct), s.accounts, s.storages, opts...); err != nil {
 				log.Warn("Failed to update snapshot tree", "from", parent, "to", root, "err", err)
 			}
 			// Keep 128 diff layers in the memory, persistent layer is 129th.

core/state/statedb.libevm.go

@@ -21,6 +21,7 @@ import (
 
 	"github.com/ava-labs/libevm/common"
 	"github.com/ava-labs/libevm/core/state/snapshot"
+	"github.com/ava-labs/libevm/libevm/stateconf"
 )
 
 // SnapshotTree mirrors the functionality of a [snapshot.Tree], allowing for
@@ -35,6 +36,7 @@ type SnapshotTree interface {
 		destructs map[common.Hash]struct{},
 		accounts map[common.Hash][]byte,
 		storage map[common.Hash]map[common.Hash][]byte,
+		opts ...stateconf.SnapshotUpdateOption,
 	) error
 }
 

libevm/stateconf/conf.go

@@ -0,0 +1,44 @@
+// Copyright 2024 the libevm authors.
+//
+// The libevm additions to go-ethereum are free software: you can redistribute
+// them and/or modify them under the terms of the GNU Lesser General Public License
+// as published by the Free Software Foundation, either version 3 of the License,
+// or (at your option) any later version.
+//
+// The libevm additions are distributed in the hope that they will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU Lesser
+// General Public License for more details.
+//
+// You should have received a copy of the GNU Lesser General Public License
+// along with the go-ethereum library. If not, see
+// <http://www.gnu.org/licenses/>.
+
+// Package stateconf configures state management.
+package stateconf
+
+import "github.com/ava-labs/libevm/libevm/options"
+
+// A SnapshotUpdateOption configures the behaviour of
+// state.SnapshotTree.Update() implementations.
+type SnapshotUpdateOption = options.Option[snapshotUpdateConfig]
+
+type snapshotUpdateConfig struct {
+	payload any
+}
+
+// WithUpdatePayload returns a SnapshotUpdateOption carrying an arbitrary
+// payload. It acts only as a carrier to exploit existing function plumbing and
+// the effect on behaviour is left to the implementation receiving it.
+func WithUpdatePayload(p any) SnapshotUpdateOption {
+	return options.Func[snapshotUpdateConfig](func(c *snapshotUpdateConfig) {
+		c.payload = p
+	})
+}
+
+// ExtractUpdatePayload returns the payload carried by a [WithUpdatePayload]
+// option. Only one such option can be used at once; behaviour is otherwise
+// undefined.
+func ExtractUpdatePayload(opts ...SnapshotUpdateOption) any {
+	return options.As(opts...).payload
+}