Remove statistics and add frequent tags in memory

lib/database/database.go

@@ -22,22 +22,17 @@ type DB interface {
 	GetNews(num int, days int) (news []New, err error)
 	AddStats(stats interface{}) error
 	GetVisitedBooks() (books []Book, err error)
-	UpdateMostVisited() error
 	GetDownloadedBooks() (books []Book, err error)
-	UpdateDownloadedBooks() error
 	GetTags() ([]string, error)
-	UpdateTags() error
-	GetVisits(visitType VisitType) ([]Visits, error)
-	UpdateHourVisits() error
-	UpdateDayVisits() error
-	UpdateMonthVisits() error
-	UpdateHourDownloads() error
-	UpdateDayDownloads() error
-	UpdateMonthDownloads() error
 }
 
+const (
+	tagsDisplay = 50
+)
+
 type pgDB struct {
-	sql *pg.DB
+	sql  *pg.DB
+	tags []string
 }
 
 // Options for the database
@@ -57,7 +52,11 @@ func Init(options Options) (DB, error) {
 		Database: options.Name,
 	})
 	// TODO: create db
-	return &pgDB{sql}, nil
+
+	db := pgDB{sql, []string{}}
+	go db.tagUpdater()
+
+	return &db, nil
 }
 
 // Close the database connection