Load db in memeory and flush db to disk #4 #15

db.go

@@ -5,6 +5,12 @@ import (
 	"log"
 
 	_ "github.com/mattn/go-sqlite3"
+	sqlite3 "github.com/mattn/go-sqlite3"
+)
+
+const (
+	DB_LOCAL_PATH = "bookmarks.db"
+	DB_MEM_PATH   = "file::memory:?cache=shared"
 )
 
 var (
@@ -14,32 +20,30 @@ var (
 const (
 	CREATE_DB_SCHEMA = `CREATE TABLE if not exists bookmarks (
 		id integer PRIMARY KEY,
-		URL text NOT NULL UNIQUE)`
+		URL text NOT NULL UNIQUE,
+		metadata text default '',
+		tags text default '',
+		desc text default '',
+		flags integer default 0
+	)`
 )
 
 // TODO: Use context when making call from request/api
-
 func initInMemoryDb() {
+	//sqlite3conn := []*sqlite3.SQLiteConn{}
 
 	var err error
-	//var tx *sql.Tx
 
-	db, err = sql.Open("sqlite3", "file::memory:?cache=shared")
+	db, err = sql.Open("sqlite3", DB_MEM_PATH)
 	debugPrint("in memory db opened")
 	logPanic(err)
 
 	_, err = db.Exec(CREATE_DB_SCHEMA)
 	logPanic(err)
 
-	//tx, err = db.Begin()
-	//logPanic(err)
-
-	//tx.Exec(CREATE_DB_SCHEMA)
-
-	//tx.Commit()
 }
 
-func initdb() {
+func initDB() {
 	debugPrint("[NotImplemented] initialize local db if not exists or load it")
 	// Check if db exists locally
 
@@ -53,7 +57,7 @@ func initdb() {
 func testInMemoryDb() {
 
 	debugPrint("test in memory")
-	db, err := sql.Open("sqlite3", "file::memory:?cache=shared")
+	db, err := sql.Open("sqlite3", DB_MEM_PATH)
 	defer db.Close()
 	rows, err := db.Query("select URL from bookmarks")
 	defer rows.Close()
@@ -64,3 +68,41 @@ func testInMemoryDb() {
 		log.Println(URL)
 	}
 }
+
+func flushToDisk() {
+	/// Flush in memory sqlite db to disk
+	/// should happen as often as possible to
+	/// avoid losing data
+	debugPrint("Flushing to disk")
+
+	conns := []*sqlite3.SQLiteConn{}
+
+	sql.Register("sqlite_with_backup",
+		&sqlite3.SQLiteDriver{
+			ConnectHook: func(conn *sqlite3.SQLiteConn) error {
+				conns = append(conns, conn)
+
+				return nil
+			},
+		})
+
+	memDb, err := sql.Open("sqlite_with_backup", DB_MEM_PATH)
+	logPanic(err)
+	defer memDb.Close()
+
+	memDb.Ping()
+
+	bkDb, err := sql.Open("sqlite_with_backup", DB_LOCAL_PATH)
+	defer bkDb.Close()
+	logPanic(err)
+	bkDb.Ping()
+
+	bk, err := conns[1].Backup("main", conns[0], "main")
+	logPanic(err)
+
+	_, err = bk.Step(-1)
+	logPanic(err)
+
+	bk.Finish()
+
+}

main.go

@@ -12,8 +12,12 @@ const (
 )
 
 func main() {
-	initdb()
+
+	// Initialize sqlite database available in global `db` variable
+	initDB()
+	flushToDisk()
 	defer db.Close()
+
 	watcher, err := fsnotify.NewWatcher()
 
 	if err != nil {