From 014b42cbb3af403d51991dd9a2e64c1af779ca0f Mon Sep 17 00:00:00 2001
From: "A. Svensson" <lmasvensson@gmail.com>
Date: Thu, 21 Apr 2016 14:54:02 +0200
Subject: [PATCH] Handle errors better in updater/scraper/poller.

---
 src/poller.go  |  7 +++---
 src/scraper.go | 58 ++++++++++++++++++++++++++++++++------------------
 src/updater.go | 18 ++++++++++------
 3 files changed, 51 insertions(+), 32 deletions(-)

diff --git a/src/poller.go b/src/poller.go
index 702603c..3891c8c 100644
--- a/src/poller.go
+++ b/src/poller.go
@@ -57,8 +57,7 @@ func poll_players(host string, timeout int) (int, error) {
 	return int(players), nil
 }
 
-// TODO: return errors!
-func PollServers(servers []ServerConfig, timeout int) []*RawServerData {
+func PollServers(servers []ServerConfig, timeout int) ([]*RawServerData, error) {
 	var wg sync.WaitGroup
 	var tmp []*RawServerData
 	for _, s := range servers {
@@ -66,7 +65,7 @@ func PollServers(servers []ServerConfig, timeout int) []*RawServerData {
 		go func(s ServerConfig) {
 			defer wg.Done()
 			players, err := poll_players(s.GameUrl, timeout)
-			if err != nil {
+			if log_error(err) {
 				return
 			}
 			gameurl := fmt.Sprintf("byond://%s", s.GameUrl)
@@ -74,5 +73,5 @@ func PollServers(servers []ServerConfig, timeout int) []*RawServerData {
 		}(s)
 	}
 	wg.Wait()
-	return tmp
+	return tmp, nil
 }
diff --git a/src/scraper.go b/src/scraper.go
index 00af45b..4acdf7c 100644
--- a/src/scraper.go
+++ b/src/scraper.go
@@ -19,48 +19,62 @@ var (
 	RE_PLAYERS = regexp.MustCompile(`Logged in: (\d+) player`)
 )
 
-// TODO: return errors!
-func ScrapePage() []*RawServerData {
-	data := download_data()
-	return parse_data(data)
+func ScrapePage() ([]*RawServerData, error) {
+	data, err := download_data()
+	if err != nil {
+		return nil, err
+	}
+
+	tmp, err := parse_data(data)
+	if err != nil {
+		return nil, err
+	}
+	return tmp, nil
 }
 
-func download_data() *goquery.Document {
+func download_data() (*goquery.Document, error) {
 	var r io.Reader
 	if IsDebugging() {
 		fmt.Println("Scraper data source: ./dump.html")
 		f, err := os.Open("./tmp/dump.html")
-		log_error(err)
+		if err != nil {
+			return nil, err
+		}
 		defer f.Close()
 		r = charmap.Windows1252.NewDecoder().Reader(f)
 	} else {
 		client := &http.Client{
 			Timeout: time.Duration(1) * time.Minute,
 		}
-		resp, e := client.Get("http://www.byond.com/games/exadv1/spacestation13")
-		log_error(e)
+		resp, err := client.Get("http://www.byond.com/games/exadv1/spacestation13")
+		if err != nil {
+			return nil, err
+		}
 		defer resp.Body.Close()
 		// Yep, Byond serve's it's pages with Windows-1252 encoding...
 		r = charmap.Windows1252.NewDecoder().Reader(resp.Body)
-
 	}
-	doc, e := goquery.NewDocumentFromReader(r)
-	log_error(e)
-	return doc
+	doc, err := goquery.NewDocumentFromReader(r)
+	if err != nil {
+		return nil, err
+	}
+	return doc, nil
 }
 
-func parse_data(data *goquery.Document) []*RawServerData {
+func parse_data(data *goquery.Document) ([]*RawServerData, error) {
 	var servers []*RawServerData
 	data.Find(".live_game_entry").Each(func(i int, s *goquery.Selection) {
-		tmp := parse_server_data(s)
-		if tmp != nil {
-			servers = append(servers, tmp)
+		tmp, err := parse_server_data(s)
+		if !log_error(err) {
+			if tmp != nil {
+				servers = append(servers, tmp)
+			}
 		}
 	})
-	return servers
+	return servers, nil
 }
 
-func parse_server_data(raw *goquery.Selection) *RawServerData {
+func parse_server_data(raw *goquery.Selection) (*RawServerData, error) {
 	s := raw.Find(".live_game_status")
 
 	t := s.Find("b").First()
@@ -72,7 +86,7 @@ func parse_server_data(raw *goquery.Selection) *RawServerData {
 	title = strings.Replace(title, "\n", "", -1)
 	if len(title) < 1 {
 		// Yes, someone has made a public server without a server name at least once
-		return nil
+		return nil, fmt.Errorf("Empty name for server")
 	}
 
 	game_url := s.Find("span.smaller").Find("nobr").Text()
@@ -90,9 +104,11 @@ func parse_server_data(raw *goquery.Selection) *RawServerData {
 	// than 2 there's multiple matches, which is fishy...
 	if len(ret) == 2 {
 		p, err := strconv.ParseInt(ret[1], 10, 0)
-		log_error(err)
+		if err != nil {
+			return nil, err
+		}
 		players = int(p)
 	}
 
-	return &RawServerData{title, game_url, site_url, players, Now()}
+	return &RawServerData{title, game_url, site_url, players, Now()}, nil
 }
diff --git a/src/updater.go b/src/updater.go
index 906f2cc..28add56 100644
--- a/src/updater.go
+++ b/src/updater.go
@@ -23,22 +23,26 @@ func (i *Instance) UpdateServers() {
 	tx := i.DB.NewTransaction()
 
 	config, err := LoadConfig(SERVERS_CONFIG)
-	if err != nil {
-		fmt.Printf("Unable to load servers to poll: %s\n", err) // TODO
-	} else {
+	if !log_error(err) {
 		if i.Debug {
 			fmt.Println("\nPolling servers...")
 		}
-		for _, s := range PollServers(config.PollServers, config.Timeout) {
-			i.update_server(tx, s)
+		polled, err := PollServers(config.PollServers, config.Timeout)
+		if !log_error(err) {
+			for _, s := range polled {
+				i.update_server(tx, s)
+			}
 		}
 	}
 
 	if i.Debug {
 		fmt.Println("\nScraping servers...")
 	}
-	for _, s := range ScrapePage() {
-		i.update_server(tx, s)
+	scraped, err := ScrapePage()
+	if !log_error(err) {
+		for _, s := range scraped {
+			i.update_server(tx, s)
+		}
 	}
 
 	if i.Debug {