fix: state listener could observe discarded writes (backport #13459)

CHANGELOG.md

@@ -42,14 +42,15 @@ Ref: https://keepachangelog.com/en/1.0.0/
 * [#13369](https://github.com/cosmos/cosmos-sdk/pull/13369) Improve UX for `keyring.List` by returning all retrieved keys.
 * [#13323](https://github.com/cosmos/cosmos-sdk/pull/13323) Ensure `withdraw_rewards` rewards are emitted from all actions that result in rewards being withdrawn.
 * [#13321](https://github.com/cosmos/cosmos-sdk/pull/13321) Add flag to disable fast node migration and usage.
+* (store) [#13326](https://github.com/cosmos/cosmos-sdk/pull/13326) Implementation of ADR-038 file StreamingService, backport #8664.
 
 ### API Breaking Changes
 
 - (cli) [#13089](https://github.com/cosmos/cosmos-sdk/pull/13089) Fix rollback command don't actually delete multistore versions, added method `RollbackToVersion` to interface `CommitMultiStore` and added method `CommitMultiStore` to `Application` interface.
 
-### Improvements
+### Bug Fixes
 
-* (store) [\#13326](https://github.com/cosmos/cosmos-sdk/pull/13326) Implementation of ADR-038 file StreamingService, backport #8664
+* (store) [#13459](https://github.com/cosmos/cosmos-sdk/pull/13459) Don't let state listener observe the uncommitted writes.
 
 ## v0.45.8 - 2022-08-25
 

store/cachemulti/store.go

@@ -41,6 +41,9 @@ func NewFromKVStore(
 	keys map[string]types.StoreKey, traceWriter io.Writer, traceContext types.TraceContext,
 	listeners map[types.StoreKey][]types.WriteListener,
 ) Store {
+	if listeners == nil {
+		listeners = make(map[types.StoreKey][]types.WriteListener)
+	}
 	cms := Store{
 		db:           cachekv.NewStore(store),
 		stores:       make(map[types.StoreKey]types.CacheWrap, len(stores)),
@@ -78,7 +81,8 @@ func newCacheMultiStoreFromCMS(cms Store) Store {
 		stores[k] = v
 	}
 
-	return NewFromKVStore(cms.db, stores, nil, cms.traceWriter, cms.traceContext, cms.listeners)
+	// don't pass listeners to nested cache store.
+	return NewFromKVStore(cms.db, stores, nil, cms.traceWriter, cms.traceContext, nil)
 }
 
 // SetTracer sets the tracer for the MultiStore that the underlying

store/rootmulti/store_test.go

@@ -813,3 +813,52 @@ func hashStores(stores map[types.StoreKey]types.CommitKVStore) []byte {
 	}
 	return sdkmaps.HashFromMap(m)
 }
+
+type MockListener struct {
+	stateCache []types.StoreKVPair
+}
+
+func (tl *MockListener) OnWrite(storeKey types.StoreKey, key []byte, value []byte, delete bool) error {
+	tl.stateCache = append(tl.stateCache, types.StoreKVPair{
+		StoreKey: storeKey.Name(),
+		Key:      key,
+		Value:    value,
+		Delete:   delete,
+	})
+	return nil
+}
+
+func TestStateListeners(t *testing.T) {
+	var db dbm.DB = dbm.NewMemDB()
+	ms := newMultiStoreWithMounts(db, pruningtypes.NewPruningOptions(pruningtypes.PruningNothing))
+
+	listener := &MockListener{}
+	ms.AddListeners(testStoreKey1, []types.WriteListener{listener})
+
+	require.NoError(t, ms.LoadLatestVersion())
+	cacheMulti := ms.CacheMultiStore()
+
+	store1 := cacheMulti.GetKVStore(testStoreKey1)
+	store1.Set([]byte{1}, []byte{1})
+	require.Empty(t, listener.stateCache)
+
+	// writes are observed when cache store commit.
+	cacheMulti.Write()
+	require.Equal(t, 1, len(listener.stateCache))
+
+	// test nested cache store
+	listener.stateCache = []types.StoreKVPair{}
+	nested := cacheMulti.CacheMultiStore()
+
+	store1 = nested.GetKVStore(testStoreKey1)
+	store1.Set([]byte{1}, []byte{1})
+	require.Empty(t, listener.stateCache)
+
+	// writes are not observed when nested cache store commit
+	nested.Write()
+	require.Empty(t, listener.stateCache)
+
+	// writes are observed when inner cache store commit
+	cacheMulti.Write()
+	require.Equal(t, 1, len(listener.stateCache))
+}