Mono repo -> Master (#22553)

Combines the following repositories into one:

https://github.com/mattermost/mattermost-server
https://github.com/mattermost/mattermost-webapp
https://github.com/mattermost/focalboard
https://github.com/mattermost/mattermost-plugin-playbooks

server/channels/store/localcachelayer/reaction_layer.go

@@ -0,0 +1,61 @@
+// Copyright (c) 2015-present Mattermost, Inc. All Rights Reserved.
+// See LICENSE.txt for license information.
+
+package localcachelayer
+
+import (
+	"bytes"
+
+	"github.com/mattermost/mattermost-server/v6/model"
+	"github.com/mattermost/mattermost-server/v6/server/channels/store"
+)
+
+type LocalCacheReactionStore struct {
+	store.ReactionStore
+	rootStore *LocalCacheStore
+}
+
+func (s *LocalCacheReactionStore) handleClusterInvalidateReaction(msg *model.ClusterMessage) {
+	if bytes.Equal(msg.Data, clearCacheMessageData) {
+		s.rootStore.reactionCache.Purge()
+	} else {
+		s.rootStore.reactionCache.Remove(string(msg.Data))
+	}
+}
+
+func (s LocalCacheReactionStore) Save(reaction *model.Reaction) (*model.Reaction, error) {
+	defer s.rootStore.doInvalidateCacheCluster(s.rootStore.reactionCache, reaction.PostId)
+	return s.ReactionStore.Save(reaction)
+}
+
+func (s LocalCacheReactionStore) Delete(reaction *model.Reaction) (*model.Reaction, error) {
+	defer s.rootStore.doInvalidateCacheCluster(s.rootStore.reactionCache, reaction.PostId)
+	return s.ReactionStore.Delete(reaction)
+}
+
+func (s LocalCacheReactionStore) GetForPost(postId string, allowFromCache bool) ([]*model.Reaction, error) {
+	if !allowFromCache {
+		return s.ReactionStore.GetForPost(postId, false)
+	}
+
+	var reaction []*model.Reaction
+	if err := s.rootStore.doStandardReadCache(s.rootStore.reactionCache, postId, &reaction); err == nil {
+		return reaction, nil
+	}
+
+	reaction, err := s.ReactionStore.GetForPost(postId, false)
+	if err != nil {
+		return nil, err
+	}
+
+	s.rootStore.doStandardAddToCache(s.rootStore.reactionCache, postId, reaction)
+
+	return reaction, nil
+}
+
+func (s LocalCacheReactionStore) DeleteAllWithEmojiName(emojiName string) error {
+	// This could be improved. Right now we just clear the whole
+	// cache because we don't have a way find what post Ids have this emoji name.
+	defer s.rootStore.doClearCacheCluster(s.rootStore.reactionCache)
+	return s.ReactionStore.DeleteAllWithEmojiName(emojiName)
+}