Save partial downloads on disk, not on RAM

src/Downloader.cpp

@@ -39,6 +39,9 @@
 
 #include "Downloader.h"
 
+static const QString PARTIAL_DOWN (".part");
+static const QDir DOWNLOAD_DIR (QDir::homePath() + "/Downloads/");
+
 Downloader::Downloader (QWidget* parent) : QWidget (parent) {
     m_ui = new Ui::Downloader;
     m_ui->setupUi (this);
@@ -47,7 +50,8 @@ Downloader::Downloader (QWidget* parent) : QWidget (parent) {
     m_manager = new QNetworkAccessManager();
 
     /* Initialize internal values */
-    m_filePath = "";
+    m_url = "";
+    m_fileName = "";
     m_startTime = 0;
     m_useCustomProcedures = false;
 
@@ -82,6 +86,17 @@ bool Downloader::useCustomInstallProcedures() const {
     return m_useCustomProcedures;
 }
 
+/**
+ * Changes the URL, which is used to indentify the downloader dialog
+ * with an \c Updater instance
+ *
+ * \note the \a url parameter is not the download URL, it is the URL of
+ *       the AppCast file
+ */
+void Downloader::setUrlId (const QString& url) {
+    m_url = url;
+}
+
 /**
  * Begins downloading the file at the given \a url
  */
@@ -96,25 +111,42 @@ void Downloader::startDownload (const QUrl& url) {
     m_startTime = QDateTime::currentDateTime().toTime_t();
     m_reply = m_manager->get (QNetworkRequest (url));
 
+    /* Ensure that downloads directory exists */
+    if (!DOWNLOAD_DIR.exists())
+        DOWNLOAD_DIR.mkpath (".");
+
+    /* Remove old downloads */
+    QFile::remove (DOWNLOAD_DIR.filePath (m_fileName));
+    QFile::remove (DOWNLOAD_DIR.filePath (m_fileName + PARTIAL_DOWN));
+
     /* Update UI when download progress changes or download finishes */
     connect (m_reply, SIGNAL (downloadProgress (qint64, qint64)),
              this,      SLOT (updateProgress   (qint64, qint64)));
     connect (m_reply, SIGNAL (redirected       (QUrl)),
              this,      SLOT (startDownload    (QUrl)));
-    connect (m_reply, SIGNAL (finished()),
-             this,      SLOT (onDownloadFinished()));
 
     showNormal();
 }
 
+/**
+ * Changes the name of the downloaded file
+ */
+void Downloader::setFileName (const QString& file) {
+    m_fileName = file;
+
+    if (m_fileName.isEmpty())
+        m_fileName = "QSU_Update.bin";
+}
+
 /**
  * Opens the downloaded file.
  * \note If the downloaded file is not found, then the function will alert the
  *       user about the error.
  */
 void Downloader::openDownload() {
-    if (!m_filePath.isEmpty())
-        QDesktopServices::openUrl (QUrl::fromLocalFile (m_filePath));
+    if (!m_fileName.isEmpty())
+        QDesktopServices::openUrl (QUrl::fromLocalFile (DOWNLOAD_DIR.filePath (
+                                       m_fileName)));
 
     else {
         QMessageBox::critical (this,
@@ -136,6 +168,13 @@ void Downloader::installUpdate() {
     if (useCustomInstallProcedures())
         return;
 
+    /* Update labels */
+    m_ui->stopButton->setText    (tr ("Close"));
+    m_ui->downloadLabel->setText (tr ("Download complete!"));
+    m_ui->timeLabel->setText     (tr ("The installer will open separately")
+                                  + "...");
+
+    /* Ask the user to install the download */
     QMessageBox box;
     box.setIcon (QMessageBox::Question);
     box.setDefaultButton   (QMessageBox::Ok);
@@ -146,11 +185,13 @@ void Downloader::installUpdate() {
                      "quit the application.")
                  + "</h3>");
 
+    /* User wants to install the download */
     if (box.exec() == QMessageBox::Ok) {
         if (!useCustomInstallProcedures())
             openDownload();
     }
 
+    /* Wait */
     else {
         m_ui->openButton->setEnabled (true);
         m_ui->openButton->setVisible (true);
@@ -182,24 +223,9 @@ void Downloader::cancelDownload() {
 }
 
 /**
- * Writes the downloaded data to a temp. directory and updates the UI controls.
- * \note If the function detects that the downloaded data is an HTML file
- *       (e.g. a redirection notice from the server), the function will add the
- *       *.html extension to the downloaded file. This ensures that the download
- *       will be resumed when the OS opens a web-browser with the redirection
- *       notice.
+ * Writes the downloaded data to the disk
  */
-void Downloader::onDownloadFinished() {
-    m_ui->stopButton->setText    (tr ("Close"));
-    m_ui->downloadLabel->setText (tr ("Download complete!"));
-    m_ui->timeLabel->setText     (tr ("The installer will open separately")
-                                  + "...");
-
-    QByteArray data = m_reply->readAll();
-
-    if (!data.isEmpty()) {
-        QString name = m_reply->url().toString().split ("/").last();
-
+void Downloader::saveFile (qint64 received, qint64 total) {
     /* Check if we need to redirect */
     QUrl url = m_reply->attribute (
                    QNetworkRequest::RedirectionTargetAttribute).toUrl();
@@ -209,21 +235,28 @@ void Downloader::onDownloadFinished() {
     }
 
     /* Save downloaded data to disk */
-        QFile file (QDir::tempPath() + "/" + name);
-        if (file.open (QIODevice::WriteOnly)) {
-            file.write (data);
+    QFile file (DOWNLOAD_DIR.filePath (m_fileName + PARTIAL_DOWN));
+    if (file.open (QIODevice::WriteOnly | QIODevice::Append)) {
+        file.write (m_reply->readAll());
         file.close();
-
-            m_filePath = file.fileName();
-            emit downloadFinished (m_reply->url().toString(), m_filePath);
     }
 
     /* Open downloaded update */
+    if (received >= total && total > 0) {
+        /* Rename file */
+        QFile::rename (DOWNLOAD_DIR.filePath (m_fileName + PARTIAL_DOWN),
+                       DOWNLOAD_DIR.filePath (m_fileName));
+
+        /* Notify application */
+        emit downloadFinished (m_url, DOWNLOAD_DIR.filePath (m_fileName));
+
+        /* Install the update */
         m_reply->close();
         installUpdate();
     }
 }
 
+
 /**
  * Calculates the appropiate size units (bytes, KB or MB) for the received
  * data and the total download size. Then, this function proceeds to update the
@@ -268,6 +301,7 @@ void Downloader::updateProgress (qint64 received, qint64 total) {
 
         calculateSizes (received, total);
         calculateTimeRemaining (received, total);
+        saveFile (received, total);
     }
 
     else {

src/Downloader.h

@@ -56,14 +56,16 @@ class Downloader : public QWidget {
     bool useCustomInstallProcedures() const;
 
   public slots:
+    void setUrlId (const QString& url);
     void startDownload (const QUrl& url);
+    void setFileName (const QString& file);
     void setUseCustomInstallProcedures (const bool custom);
 
   private slots:
     void openDownload();
     void installUpdate();
     void cancelDownload();
-    void onDownloadFinished();
+    void saveFile (qint64 received, qint64 total);
     void calculateSizes (qint64 received, qint64 total);
     void updateProgress (qint64 received, qint64 total);
     void calculateTimeRemaining (qint64 received, qint64 total);
@@ -72,8 +74,9 @@ class Downloader : public QWidget {
     qreal round (const qreal& input);
 
   private:
+    QString m_url;
     uint m_startTime;
-    QString m_filePath;
+    QString m_fileName;
     Ui::Downloader* m_ui;
     QNetworkReply* m_reply;
     bool m_useCustomProcedures;

src/Updater.cpp

@@ -362,8 +362,11 @@ void Updater::setUpdateAvailable (const bool available) {
             if (!openUrl().isEmpty())
                 QDesktopServices::openUrl (QUrl (openUrl()));
 
-            else if (downloaderEnabled())
+            else if (downloaderEnabled()) {
+                m_downloader->setUrlId (url());
+                m_downloader->setFileName (downloadUrl().split ("/").last());
                 m_downloader->startDownload (QUrl (downloadUrl()));
+            }
 
             else
                 QDesktopServices::openUrl (QUrl (downloadUrl()));