move Settings and Viewed to separate json files

server/settings/dbreadcache.go

@@ -0,0 +1,60 @@
+package settings
+
+type DBReadCache struct {
+	db        TorrServerDB
+	listCache map[string][]string
+	dataCache map[[2]string][]byte
+}
+
+func NewDBReadCache(db TorrServerDB) TorrServerDB {
+	cdb := &DBReadCache{
+		db:        db,
+		listCache: map[string][]string{},
+		dataCache: map[[2]string][]byte{},
+	}
+	return cdb
+}
+
+func (v *DBReadCache) CloseDB() {
+	v.db.CloseDB()
+	v.db = nil
+	v.listCache = nil
+	v.dataCache = nil
+}
+
+func (v *DBReadCache) Get(xPath, name string) []byte {
+	cacheKey := v.makeDataCacheKey(xPath, name)
+	if data, ok := v.dataCache[cacheKey]; ok {
+		return data
+	}
+	data := v.db.Get(xPath, name)
+	v.dataCache[cacheKey] = data
+	return data
+}
+
+func (v *DBReadCache) Set(xPath, name string, value []byte) {
+	cacheKey := v.makeDataCacheKey(xPath, name)
+	v.dataCache[cacheKey] = value
+	delete(v.listCache, xPath)
+	v.db.Set(xPath, name, value)
+}
+
+func (v *DBReadCache) List(xPath string) []string {
+	if names, ok := v.listCache[xPath]; ok {
+		return names
+	}
+	names := v.db.List(xPath)
+	v.listCache[xPath] = names
+	return names
+}
+
+func (v *DBReadCache) Rem(xPath, name string) {
+	cacheKey := v.makeDataCacheKey(xPath, name)
+	delete(v.dataCache, cacheKey)
+	delete(v.listCache, xPath)
+	v.db.Rem(xPath, name)
+}
+
+func (v *DBReadCache) makeDataCacheKey(xPath, name string) [2]string {
+	return [2]string{xPath, name}
+}