Revert removing events for cachekv (#396)

## Describe your changes and provide context
This PR reverts the change in
#353 and
#391 until we have OCC
fully enabled.

## Testing performed to validate your change
Unit test coverage

store/cachekv/mergeiterator.go

@@ -16,10 +16,11 @@ import (
 //
 // TODO: Optimize by memoizing.
 type cacheMergeIterator struct {
-	parent    types.Iterator
-	cache     types.Iterator
-	ascending bool
-	storeKey  sdktypes.StoreKey
+	parent       types.Iterator
+	cache        types.Iterator
+	ascending    bool
+	storeKey     sdktypes.StoreKey
+	eventManager *sdktypes.EventManager
 }
 
 var _ types.Iterator = (*cacheMergeIterator)(nil)
@@ -28,12 +29,14 @@ func NewCacheMergeIterator(
 	parent, cache types.Iterator,
 	ascending bool,
 	storeKey sdktypes.StoreKey,
+	eventManager *sdktypes.EventManager,
 ) *cacheMergeIterator {
 	iter := &cacheMergeIterator{
-		parent:    parent,
-		cache:     cache,
-		ascending: ascending,
-		storeKey:  storeKey,
+		parent:       parent,
+		cache:        cache,
+		ascending:    ascending,
+		storeKey:     storeKey,
+		eventManager: eventManager,
 	}
 
 	return iter
@@ -135,12 +138,14 @@ func (iter *cacheMergeIterator) Value() []byte {
 	// If parent is invalid, get the cache value.
 	if !iter.parent.Valid() {
 		value := iter.cache.Value()
+		iter.eventManager.EmitResourceAccessReadEvent("iterator", iter.storeKey, iter.cache.Key(), value)
 		return value
 	}
 
 	// If cache is invalid, get the parent value.
 	if !iter.cache.Valid() {
 		value := iter.parent.Value()
+		iter.eventManager.EmitResourceAccessReadEvent("iterator", iter.storeKey, iter.parent.Key(), value)
 		return value
 	}
 
@@ -151,9 +156,11 @@ func (iter *cacheMergeIterator) Value() []byte {
 	switch cmp {
 	case -1: // parent < cache
 		value := iter.parent.Value()
+		iter.eventManager.EmitResourceAccessReadEvent("iterator", iter.storeKey, keyP, value)
 		return value
 	case 0, 1: // parent >= cache
 		value := iter.cache.Value()
+		iter.eventManager.EmitResourceAccessReadEvent("iterator", iter.storeKey, keyC, value)
 		return value
 	default:
 		panic("invalid comparison result")

store/cachekv/mergeiterator_test.go

@@ -6,13 +6,15 @@ import (
 	"github.com/cosmos/cosmos-sdk/store/cachekv"
 	"github.com/cosmos/cosmos-sdk/store/dbadapter"
 	"github.com/cosmos/cosmos-sdk/store/types"
+	sdktypes "github.com/cosmos/cosmos-sdk/types"
 	"github.com/stretchr/testify/require"
 	dbm "github.com/tendermint/tm-db"
 )
 
 func TestMangerIterator(t *testing.T) {
 	// initiate mock kvstore
 	mem := dbadapter.Store{DB: dbm.NewMemDB()}
+	eventManager := sdktypes.NewEventManager()
 	kvstore := cachekv.NewStore(mem, types.NewKVStoreKey("CacheKvTest"), types.DefaultCacheSizeLimit)
 	value := randSlice(defaultValueSizeBz)
 	startKey := randSlice(32)
@@ -27,13 +29,27 @@ func TestMangerIterator(t *testing.T) {
 	cache := kvstore.Iterator(nil, nil)
 	for ; cache.Valid(); cache.Next() {
 	}
-	iter := cachekv.NewCacheMergeIterator(parent, cache, true, types.NewKVStoreKey("CacheKvTest"))
+	iter := cachekv.NewCacheMergeIterator(parent, cache, true, types.NewKVStoreKey("CacheKvTest"), eventManager)
 
-	// get the next value and it should not be nil
-	nextValue := iter.Value()
-	require.NotNil(t, nextValue)
+	// get the next value
+	iter.Value()
+
+	// assert the resource access is still emitted correctly when the cache store is unavailable
+	require.Equal(t, "access_type", string(eventManager.Events()[0].Attributes[0].Key))
+	require.Equal(t, "read", string(eventManager.Events()[0].Attributes[0].Value))
+	require.Equal(t, "store_key", string(eventManager.Events()[0].Attributes[1].Key))
+	require.Equal(t, "CacheKvTest", string(eventManager.Events()[0].Attributes[1].Value))
+
+	// assert event emission when cache is available
+	cache = kvstore.Iterator(keys[1], keys[2])
+	iter = cachekv.NewCacheMergeIterator(parent, cache, true, types.NewKVStoreKey("CacheKvTest"), eventManager)
 
 	// get the next value
-	nextValue = iter.Value()
-	require.NotNil(t, nextValue)
+	iter.Value()
+
+	// assert the resource access is still emitted correctly when the cache store is available
+	require.Equal(t, "access_type", string(eventManager.Events()[0].Attributes[0].Key))
+	require.Equal(t, "read", string(eventManager.Events()[0].Attributes[0].Value))
+	require.Equal(t, "store_key", string(eventManager.Events()[0].Attributes[1].Key))
+	require.Equal(t, "CacheKvTest", string(eventManager.Events()[0].Attributes[1].Value))
 }

store/cachekv/store.go

@@ -56,6 +56,8 @@ func (store *Store) GetEvents() []abci.Event {
 
 // Implements Store
 func (store *Store) ResetEvents() {
+	store.mtx.Lock()
+	defer store.mtx.Unlock()
 	store.eventManager = sdktypes.NewEventManager()
 }
 
@@ -75,6 +77,7 @@ func (store *Store) getFromCache(key []byte) []byte {
 // Get implements types.KVStore.
 func (store *Store) Get(key []byte) (value []byte) {
 	types.AssertValidKey(key)
+	store.eventManager.EmitResourceAccessReadEvent("get", store.storeKey, key, value)
 	return store.getFromCache(key)
 }
 
@@ -83,11 +86,13 @@ func (store *Store) Set(key []byte, value []byte) {
 	types.AssertValidKey(key)
 	types.AssertValidValue(value)
 	store.setCacheValue(key, value, false, true)
+	store.eventManager.EmitResourceAccessWriteEvent("set", store.storeKey, key, value)
 }
 
 // Has implements types.KVStore.
 func (store *Store) Has(key []byte) bool {
 	value := store.Get(key)
+	store.eventManager.EmitResourceAccessReadEvent("has", store.storeKey, key, value)
 	return value != nil
 }
 
@@ -189,7 +194,7 @@ func (store *Store) iterator(start, end []byte, ascending bool) types.Iterator {
 	}()
 	store.dirtyItems(start, end)
 	cache = newMemIterator(start, end, store.sortedCache, store.deleted, ascending, store.eventManager, store.storeKey)
-	return NewCacheMergeIterator(parent, cache, ascending, store.storeKey)
+	return NewCacheMergeIterator(parent, cache, ascending, store.storeKey, store.eventManager)
 }
 
 func (store *Store) VersionExists(version int64) bool {