[GH-13074] Migrate TermsOfServiceCache from store/sqlstore/terms_of_service.go to the new store/localcachelayer (#13205)

* migrated termsOfServiceCache from sqlstore to localcachelayer, and mocked store tests

* revert gitignore local change

* fixed caching in termsOfService Get, and added basic tests for termsOfServiceCache

* added a test for cache save, and fixed call to Store tests

* fixed GeLatest termsOfService from cache test

* added license headers to terms_of_service cache files

* using doStandardReadFromCache and doStandardAddToCache when reading and writing to cache

* removed unused variable, termsOfServiceCacheName

* added special key for the latest termsOfService value in termsOfServiceCache

* updated license information on localcachelayer termsOfServiceCache files

* fixed not updating latest termsOfServiceCache on Get by ID, and invalidating cache cluster on termsOfServiceCache save

Co-authored-by: mattermod <mattermod@users.noreply.github.com>

store/sqlstore/terms_of_service_store.go

@@ -10,7 +10,6 @@ import (
 	"github.com/mattermost/mattermost-server/v5/einterfaces"
 	"github.com/mattermost/mattermost-server/v5/model"
 	"github.com/mattermost/mattermost-server/v5/store"
-	"github.com/mattermost/mattermost-server/v5/utils"
 )
 
 type SqlTermsOfServiceStore struct {
@@ -18,12 +17,6 @@ type SqlTermsOfServiceStore struct {
 	metrics einterfaces.MetricsInterface
 }
 
-var termsOfServiceCache = utils.NewLru(model.TERMS_OF_SERVICE_CACHE_SIZE)
-
-const (
-	termsOfServiceCacheName = "TermsOfServiceStore"
-)
-
 func NewSqlTermsOfServiceStore(sqlStore SqlStore, metrics einterfaces.MetricsInterface) store.TermsOfServiceStore {
 	s := SqlTermsOfServiceStore{sqlStore, metrics}
 
@@ -55,28 +48,10 @@ func (s SqlTermsOfServiceStore) Save(termsOfService *model.TermsOfService) (*mod
 		return nil, model.NewAppError("SqlTermsOfServiceStore.Save", "store.sql_terms_of_service.save.app_error", nil, "terms_of_service_id="+termsOfService.Id+",err="+err.Error(), http.StatusInternalServerError)
 	}
 
-	termsOfServiceCache.AddWithDefaultExpires(termsOfService.Id, termsOfService)
-
 	return termsOfService, nil
 }
 
 func (s SqlTermsOfServiceStore) GetLatest(allowFromCache bool) (*model.TermsOfService, *model.AppError) {
-	if allowFromCache {
-		if termsOfServiceCache.Len() != 0 {
-			if cacheItem, ok := termsOfServiceCache.Get(termsOfServiceCache.Keys()[0]); ok {
-				if s.metrics != nil {
-					s.metrics.IncrementMemCacheHitCounter(termsOfServiceCacheName)
-				}
-
-				return cacheItem.(*model.TermsOfService), nil
-			}
-		}
-	}
-
-	if s.metrics != nil {
-		s.metrics.IncrementMemCacheMissCounter(termsOfServiceCacheName)
-	}
-
 	var termsOfService *model.TermsOfService
 
 	err := s.GetReplica().SelectOne(&termsOfService, "SELECT * FROM TermsOfService ORDER BY CreateAt DESC LIMIT 1")
@@ -87,28 +62,10 @@ func (s SqlTermsOfServiceStore) GetLatest(allowFromCache bool) (*model.TermsOfSe
 		return nil, model.NewAppError("SqlTermsOfServiceStore.GetLatest", "store.sql_terms_of_service_store.get.app_error", nil, "err="+err.Error(), http.StatusInternalServerError)
 	}
 
-	if allowFromCache {
-		termsOfServiceCache.AddWithDefaultExpires(termsOfService.Id, termsOfService)
-	}
 	return termsOfService, nil
 }
 
 func (s SqlTermsOfServiceStore) Get(id string, allowFromCache bool) (*model.TermsOfService, *model.AppError) {
-	if allowFromCache {
-		if termsOfServiceCache.Len() != 0 {
-			if cacheItem, ok := termsOfServiceCache.Get(id); ok {
-				if s.metrics != nil {
-					s.metrics.IncrementMemCacheHitCounter(termsOfServiceCacheName)
-				}
-
-				return cacheItem.(*model.TermsOfService), nil
-			}
-		}
-	}
-	if s.metrics != nil {
-		s.metrics.IncrementMemCacheMissCounter(termsOfServiceCacheName)
-	}
-
 	obj, err := s.GetReplica().Get(model.TermsOfService{}, id)
 	if err != nil {
 		return nil, model.NewAppError("SqlTermsOfServiceStore.Get", "store.sql_terms_of_service_store.get.app_error", nil, "err="+err.Error(), http.StatusInternalServerError)