Addressing feedback

config/stored_requests.go

@@ -20,7 +20,7 @@ type StoredRequests struct {
 	// Lazy-load the data.
 	//   false (default): preload all the files in cache
 	//   true: load data only when incoming requests ask for the stored resource
-	LazyLoad bool `mapstructure:"lazy_load"`
+	FilesLazyLoad bool `mapstructure:"filesystem_lazy_load"`
 	// Postgres configures Fetchers and EventProducers which read from a Postgres DB.
 	// Fetchers are in stored_requests/backends/db_fetcher/postgres.go
 	// EventProducers are in stored_requests/events/postgres
@@ -142,7 +142,7 @@ func (cfg *StoredRequests) validate(errs configErrors) configErrors {
 		if cfg.Postgres.CacheInitialization.Query != "" {
 			errs = append(errs, errors.New("stored_requests.postgres.initialize_caches.query must be empty if stored_requests.in_memory_cache=none"))
 		}
-		if cfg.Files && !cfg.LazyLoad {
+		if cfg.Files && !cfg.FilesLazyLoad {
 			// auto configure an in-memory static cache to replicate previous behavior (load and store all)
 			cfg.InMemoryCache.Type = "unbounded"
 		}

stored_requests/backends/file_fetcher/fetcher.go

@@ -13,14 +13,14 @@ import (
 )
 
 // NewFileFetcher lazy-loads various kinds of objects from the given directory
-// Expected directory structure:
+// Expected directory structure depends on data type - stored requests or categories,
+// and may include:
 // - stored_requests/{id}.json for stored requests
 // - stored_imps/{id}.json for stored imps
 // - {adserver}.json non-publisher specific primary adserver categories
 // - {adserver}/{adserver}_{account_id}.json publisher specific categories for primary adserver
 func NewFileFetcher(directory string) (stored_requests.AllFetcher, error) {
-	_, err := ioutil.ReadDir(directory)
-	if err != nil {
+	if _, err := ioutil.ReadDir(directory); err != nil {
 		return &fileFetcher{}, err
 	}
 	return &fileFetcher{

stored_requests/config/config.go

@@ -145,7 +145,7 @@ func resolvedStoredRequestsConfig(cfg *config.Configuration) (auc, amp config.St
 	// Auction endpoint uses non-Amp fields so can just copy the slin data
 	auc.Files.Enabled = sr.Files
 	auc.Files.Path = sr.Path
-	auc.Files.LazyLoad = sr.LazyLoad
+	auc.Files.LazyLoad = sr.FilesLazyLoad
 	auc.Postgres.ConnectionInfo = sr.Postgres.ConnectionInfo
 	auc.Postgres.FetcherQueries.QueryTemplate = sr.Postgres.FetcherQueries.QueryTemplate
 	auc.Postgres.CacheInitialization.Timeout = sr.Postgres.CacheInitialization.Timeout
@@ -195,6 +195,7 @@ func newFetcher(cfg *config.StoredRequestsSlim, client *http.Client, db *sql.DB)
 	if cfg.Files.Enabled {
 		fFetcher := newFilesystem(cfg.Files.Path)
 		if !cfg.Files.LazyLoad {
+			// Permanently load all categories in fetcher's internal static map
 			fFetcher.(stored_requests.CategoryFetcher).FetchAllCategories(context.Background())
 		}
 		idList = append(idList, fFetcher)