From 3e601ea2cbdd44cecae77e659263c4afdf41363a Mon Sep 17 00:00:00 2001
From: Alexey Skobkin <skobkin-ru@ya.ru>
Date: Sat, 19 Oct 2019 04:07:24 +0300
Subject: [PATCH] Fixing stupid memory leak caused by excessive pointer
 dereference.

---
 magnetico-migrator.go | 10 ++++------
 old/sqlite.go         | 11 ++++++-----
 2 files changed, 10 insertions(+), 11 deletions(-)

diff --git a/magnetico-migrator.go b/magnetico-migrator.go
index 3e164a5..424983a 100644
--- a/magnetico-migrator.go
+++ b/magnetico-migrator.go
@@ -11,13 +11,12 @@ import (
 	"go.uber.org/zap"
 	"gopkg.in/alecthomas/kingpin.v2"
 	"net/url"
-	"time"
 )
 
 var (
 	goDatabaseUrl = kingpin.Flag("go-database", "magneticod Go version database URL.").Short('g').String()
 	pyDatabaseUrl = kingpin.Flag("py-database", "Python version database URL.").Short('p').Required().String()
-	chunkSize     = kingpin.Flag("chunk-size", "How many torrents to retrieve from old DB at once").Short('c').Default("50").Uint64()
+	chunkSize     = kingpin.Flag("chunk-size", "How many torrents to retrieve from old DB at once").Short('c').Default("200").Uint64()
 
 	progress pb.ProgressBar
 )
@@ -46,16 +45,15 @@ func main() {
 	}
 	defer pyDatabase.Close()
 
-	torrentsTotal, err := old.GetNumberOfTorrents(*pyDatabase)
+	torrentsTotal, err := old.GetNumberOfTorrents(pyDatabase)
 	if err != nil {
 		zap.L().Panic("Couldn't count torrents", zap.Error(err))
 	}
 
 	progress = *pb.Full.New(int(torrentsTotal))
-	progress.SetRefreshRate(time.Second)
 	progress.Start()
 
-	err = mergeDatabases(*pyDatabase, goDatabase)
+	err = mergeDatabases(pyDatabase, goDatabase)
 	if err != nil {
 		logger.Error("Error while processing data", zap.Error(err))
 	}
@@ -63,7 +61,7 @@ func main() {
 	progress.Finish()
 }
 
-func mergeDatabases(pyDb sql.DB, goDb persistence.Database) error {
+func mergeDatabases(pyDb *sql.DB, goDb persistence.Database) error {
 	maxId, err := old.GetLastTorrentId(pyDb)
 	if err != nil {
 		zap.L().Fatal("Error while getting last torrent ID from old database")
diff --git a/old/sqlite.go b/old/sqlite.go
index eecb420..df81ef6 100644
--- a/old/sqlite.go
+++ b/old/sqlite.go
@@ -16,10 +16,11 @@ type TorrentData struct {
 
 func OpenSqliteDb(url_ url.URL) (*sql.DB, error) {
 	url_.Scheme = ""
+
 	return sql.Open("sqlite3", url_.String())
 }
 
-func GetNumberOfTorrents(db sql.DB) (uint, error) {
+func GetNumberOfTorrents(db *sql.DB) (uint, error) {
 	rows, err := db.Query("SELECT COUNT(id) FROM torrents;")
 	if err != nil {
 		return 0, err
@@ -43,7 +44,7 @@ func GetNumberOfTorrents(db sql.DB) (uint, error) {
 	}
 }
 
-func GetLastTorrentId(db sql.DB) (uint64, error) {
+func GetLastTorrentId(db *sql.DB) (uint64, error) {
 	rows, err := db.Query("SELECT MAX(id) FROM torrents;")
 	if err != nil {
 		return 0, err
@@ -67,8 +68,8 @@ func GetLastTorrentId(db sql.DB) (uint64, error) {
 	}
 }
 
-func GetTorrentsChunk(db sql.DB, fromId uint64, size uint64) ([]TorrentData, error) {
-	chunk := make([]TorrentData, 0)
+func GetTorrentsChunk(db *sql.DB, fromId uint64, size uint64) ([]TorrentData, error) {
+	chunk := make([]TorrentData, 0, size)
 
 	// Selecting torrents
 	tRows, err := db.Query(`
@@ -106,7 +107,7 @@ func GetTorrentsChunk(db sql.DB, fromId uint64, size uint64) ([]TorrentData, err
 	return chunk, nil
 }
 
-func GetFilesForTorrent(pyDb sql.DB, torrent persistence.TorrentMetadata) ([]persistence.File, error) {
+func GetFilesForTorrent(pyDb *sql.DB, torrent persistence.TorrentMetadata) ([]persistence.File, error) {
 	files := make([]persistence.File, 0)
 
 	// Selecting files for torrent