From 247eef5261265bfb84472c6f0aee85eaf2661957 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Martin=20T=C5=AFma?= <tumic@cbox.cz>
Date: Sat, 28 Apr 2018 19:07:52 +0200
Subject: [PATCH] Added download retries in case of connection timeout

---
 src/map/downloader.cpp | 30 ++++++++++++++++++++----------
 src/map/downloader.h   |  6 ++++--
 2 files changed, 24 insertions(+), 12 deletions(-)

diff --git a/src/map/downloader.cpp b/src/map/downloader.cpp
index 23538baa..45e81c7f 100644
--- a/src/map/downloader.cpp
+++ b/src/map/downloader.cpp
@@ -1,7 +1,6 @@
 #include <QFile>
 #include <QFileInfo>
 #include <QNetworkRequest>
-#include <QNetworkReply>
 #include <QBasicTimer>
 #include "config.h"
 #include "downloader.h"
@@ -26,6 +25,7 @@
 #define ATTR_LEVEL    (QNetworkRequest::Attribute)(QNetworkRequest::User + 2)
 
 #define MAX_REDIRECT_LEVEL 5
+#define RETRIES 3
 
 
 Authorization::Authorization(const QString &username, const QString &password)
@@ -89,10 +89,12 @@ bool Downloader::doDownload(const Download &dl,
 
 	if (!url.isValid() || !(url.scheme() == "http" || url.scheme() == "https")) {
 		qWarning("%s: Invalid URL\n", qPrintable(url.toString()));
+		if (redirect)
+			_errorDownloads.insert(redirect->origin(), RETRIES);
 		return false;
 	}
 
-	if (_errorDownloads.contains(url))
+	if (_errorDownloads.value(url) >= RETRIES)
 		return false;
 	if (_currentDownloads.contains(url) && !redirect)
 		return false;
@@ -141,18 +143,27 @@ bool Downloader::saveToDisk(const QString &filename, QIODevice *data)
 	return true;
 }
 
+void Downloader::insertError(const QUrl &url, QNetworkReply::NetworkError error)
+{
+	if (error == QNetworkReply::OperationCanceledError)
+		_errorDownloads.insert(url, _errorDownloads.value(url) + 1);
+	else
+		_errorDownloads.insert(url, RETRIES);
+}
+
 void Downloader::downloadFinished(QNetworkReply *reply)
 {
 	QUrl url = reply->request().url();
+	QNetworkReply::NetworkError error = reply->error();
 
-	if (reply->error()) {
+	if (error) {
 		QUrl origin = reply->request().attribute(ATTR_ORIGIN).toUrl();
 		if (origin.isEmpty()) {
-			_errorDownloads.insert(url);
+			insertError(url, error);
 			qWarning("Error downloading file: %s: %s\n",
 			  url.toEncoded().constData(), qPrintable(reply->errorString()));
 		} else {
-			_errorDownloads.insert(origin);
+			insertError(origin, error);
 			qWarning("Error downloading file: %s -> %s: %s\n",
 			  origin.toEncoded().constData(), url.toEncoded().constData(),
 			  qPrintable(reply->errorString()));
@@ -167,7 +178,7 @@ void Downloader::downloadFinished(QNetworkReply *reply)
 			int level = reply->request().attribute(ATTR_LEVEL).toInt();
 
 			if (level >= MAX_REDIRECT_LEVEL) {
-				_errorDownloads.insert(origin);
+				_errorDownloads.insert(origin, RETRIES);
 				qWarning("Error downloading file: %s: "
 				  "redirect level limit reached (redirect loop?)\n",
 				  origin.toEncoded().constData());
@@ -182,13 +193,12 @@ void Downloader::downloadFinished(QNetworkReply *reply)
 
 				Redirect redirect(origin.isEmpty() ? url : origin, level + 1);
 				Download dl(redirectUrl, filename);
-				if (!doDownload(dl, reply->request().rawHeader("Authorization"),
-				  &redirect))
-					_errorDownloads.insert(origin.isEmpty() ? url : origin);
+				doDownload(dl, reply->request().rawHeader("Authorization"),
+				  &redirect);
 			}
 		} else {
 			if (!saveToDisk(filename, reply))
-				_errorDownloads.insert(url);
+				_errorDownloads.insert(url, RETRIES);
 		}
 	}
 
diff --git a/src/map/downloader.h b/src/map/downloader.h
index a6b1048e..6dea1d42 100644
--- a/src/map/downloader.h
+++ b/src/map/downloader.h
@@ -2,11 +2,12 @@
 #define DOWNLOADER_H
 
 #include <QNetworkAccessManager>
+#include <QNetworkReply>
 #include <QUrl>
 #include <QList>
 #include <QSet>
+#include <QHash>
 
-class QNetworkReply;
 
 class Download
 {
@@ -59,12 +60,13 @@ private:
 	class Redirect;
 	class ReplyTimeout;
 
+	void insertError(const QUrl &url, QNetworkReply::NetworkError error);
 	bool doDownload(const Download &dl, const QByteArray &authorization,
 	  const Redirect *redirect = 0);
 	bool saveToDisk(const QString &filename, QIODevice *data);
 
 	QSet<QUrl> _currentDownloads;
-	QSet<QUrl> _errorDownloads;
+	QHash<QUrl, int> _errorDownloads;
 
 	static int _timeout;
 	static QNetworkAccessManager *_manager;