Add option to align file to piece boundary when creating new torrent

Alignment is achieved by adding dummy pad files between files which is
handled by libtorrent.
Closes #10460.

src/base/bittorrent/torrentcreatorthread.cpp

@@ -54,7 +54,7 @@ namespace
 #else
     using LTCreateFlags = lt::create_flags_t;
     using LTPieceIndex = lt::piece_index_t;
-#endif    
+#endif
 
     // do not include files and folders whose
     // name starts with a .
@@ -138,8 +138,8 @@ void TorrentCreatorThread::run()
 
         if (isInterruptionRequested()) return;
 
-        lt::create_torrent newTorrent(fs, m_params.pieceSize, -1
-                                        , (m_params.isAlignmentOptimized ? lt::create_torrent::optimize_alignment : LTCreateFlags {}));
+        lt::create_torrent newTorrent(fs, m_params.pieceSize, m_params.paddedFileSizeLimit
+            , (m_params.isAlignmentOptimized ? lt::create_torrent::optimize_alignment : LTCreateFlags {}));
 
         // Add url seeds
         for (QString seed : asConst(m_params.urlSeeds)) {
@@ -205,7 +205,7 @@ void TorrentCreatorThread::run()
     }
 }
 
-int TorrentCreatorThread::calculateTotalPieces(const QString &inputPath, const int pieceSize, const bool isAlignmentOptimized)
+int TorrentCreatorThread::calculateTotalPieces(const QString &inputPath, const int pieceSize, const bool isAlignmentOptimized, const int paddedFileSizeLimit)
 {
     if (inputPath.isEmpty())
         return 0;
@@ -213,6 +213,6 @@ int TorrentCreatorThread::calculateTotalPieces(const QString &inputPath, const i
     lt::file_storage fs;
     lt::add_files(fs, Utils::Fs::toNativePath(inputPath).toStdString(), fileFilter);
 
-    return lt::create_torrent(fs, pieceSize, -1
-                                , (isAlignmentOptimized ? lt::create_torrent::optimize_alignment : LTCreateFlags {})).num_pieces();
+    return lt::create_torrent(fs, pieceSize, paddedFileSizeLimit
+        , (isAlignmentOptimized ? lt::create_torrent::optimize_alignment : LTCreateFlags {})).num_pieces();
 }

src/base/bittorrent/torrentcreatorthread.h

@@ -39,6 +39,7 @@ namespace BitTorrent
         bool isPrivate;
         bool isAlignmentOptimized;
         int pieceSize;
+        int paddedFileSizeLimit;
         QString inputPath;
         QString savePath;
         QString comment;
@@ -57,7 +58,8 @@ namespace BitTorrent
 
         void create(const TorrentCreatorParams &params);
 
-        static int calculateTotalPieces(const QString &inputPath, int pieceSize, bool isAlignmentOptimized);
+        static int calculateTotalPieces(const QString &inputPath
+            , const int pieceSize, const bool isAlignmentOptimized, int paddedFileSizeLimit);
 
     protected:
         void run() override;

src/gui/torrentcreatordialog.cpp

@@ -55,6 +55,7 @@ TorrentCreatorDialog::TorrentCreatorDialog(QWidget *parent, const QString &defau
     , m_storeStartSeeding(SETTINGS_KEY("StartSeeding"))
     , m_storeIgnoreRatio(SETTINGS_KEY("IgnoreRatio"))
     , m_storeOptimizeAlignment(SETTINGS_KEY("OptimizeAlignment"), true)
+    , m_paddedFileSizeLimit(SETTINGS_KEY("PaddedFileSizeLimit"), -1)
     , m_storeLastAddPath(SETTINGS_KEY("LastAddPath"), QDir::homePath())
     , m_storeTrackerList(SETTINGS_KEY("TrackerList"))
     , m_storeWebSeedList(SETTINGS_KEY("WebSeedList"))
@@ -117,6 +118,12 @@ int TorrentCreatorDialog::getPieceSize() const
     return pieceSizes[m_ui->comboPieceSize->currentIndex()] * 1024;
 }
 
+int TorrentCreatorDialog::getPaddedFileSizeLimit() const
+{
+    const int value = m_ui->spinPaddedFileSizeLimit->value();
+    return ((value >= 0) ? (value * 1024) : -1);
+}
+
 void TorrentCreatorDialog::dropEvent(QDropEvent *event)
 {
     event->acceptProposedAction();
@@ -164,14 +171,19 @@ void TorrentCreatorDialog::onCreateButtonClicked()
 
     const QStringList trackers = m_ui->trackersList->toPlainText().trimmed()
         .replace(QRegularExpression("\n\n[\n]+"), "\n\n").split('\n');
-    const QStringList urlSeeds = m_ui->URLSeedsList->toPlainText().split('\n', QString::SkipEmptyParts);
-    const QString comment = m_ui->txtComment->toPlainText();
-    const QString source = m_ui->lineEditSource->text();
+    const BitTorrent::TorrentCreatorParams params {
+        m_ui->checkPrivate->isChecked()
+        , m_ui->checkOptimizeAlignment->isChecked()
+        , getPieceSize(), getPaddedFileSizeLimit()
+        , input, destination
+        , m_ui->txtComment->toPlainText()
+        , m_ui->lineEditSource->text()
+        , trackers
+        , m_ui->URLSeedsList->toPlainText().split('\n', QString::SkipEmptyParts)
+    };
 
     // run the creator thread
-    m_creatorThread->create({ m_ui->checkPrivate->isChecked()
-        , m_ui->checkOptimizeAlignment->isChecked(), getPieceSize()
-        , input, destination, comment, source, trackers, urlSeeds });
+    m_creatorThread->create(params);
 }
 
 void TorrentCreatorDialog::handleCreationFailure(const QString &msg)
@@ -216,11 +228,12 @@ void TorrentCreatorDialog::updatePiecesCount()
     const QString path = m_ui->textInputPath->text().trimmed();
     const bool isAlignmentOptimized = m_ui->checkOptimizeAlignment->isChecked();
 
-    const int count = BitTorrent::TorrentCreatorThread::calculateTotalPieces(path, getPieceSize(), isAlignmentOptimized);
+    const int count = BitTorrent::TorrentCreatorThread::calculateTotalPieces(path
+        , getPieceSize(), isAlignmentOptimized, getPaddedFileSizeLimit());
     m_ui->labelTotalPieces->setText(QString::number(count));
 }
 
-void TorrentCreatorDialog::setInteractionEnabled(bool enabled)
+void TorrentCreatorDialog::setInteractionEnabled(const bool enabled) const
 {
     m_ui->textInputPath->setEnabled(enabled);
     m_ui->addFileButton->setEnabled(enabled);
@@ -229,10 +242,13 @@ void TorrentCreatorDialog::setInteractionEnabled(bool enabled)
     m_ui->URLSeedsList->setEnabled(enabled);
     m_ui->txtComment->setEnabled(enabled);
     m_ui->comboPieceSize->setEnabled(enabled);
+    m_ui->buttonCalcTotalPieces->setEnabled(enabled);
     m_ui->checkPrivate->setEnabled(enabled);
     m_ui->checkStartSeeding->setEnabled(enabled);
     m_ui->buttonBox->button(QDialogButtonBox::Ok)->setEnabled(enabled);
     m_ui->checkIgnoreShareLimits->setEnabled(enabled && m_ui->checkStartSeeding->isChecked());
+    m_ui->checkOptimizeAlignment->setEnabled(enabled);
+    m_ui->spinPaddedFileSizeLimit->setEnabled(enabled);
 }
 
 void TorrentCreatorDialog::saveSettings()
@@ -244,6 +260,7 @@ void TorrentCreatorDialog::saveSettings()
     m_storeStartSeeding = m_ui->checkStartSeeding->isChecked();
     m_storeIgnoreRatio = m_ui->checkIgnoreShareLimits->isChecked();
     m_storeOptimizeAlignment = m_ui->checkOptimizeAlignment->isChecked();
+    m_paddedFileSizeLimit = m_ui->spinPaddedFileSizeLimit->value();
 
     m_storeTrackerList = m_ui->trackersList->toPlainText();
     m_storeWebSeedList = m_ui->URLSeedsList->toPlainText();
@@ -261,8 +278,9 @@ void TorrentCreatorDialog::loadSettings()
     m_ui->checkPrivate->setChecked(m_storePrivateTorrent);
     m_ui->checkStartSeeding->setChecked(m_storeStartSeeding);
     m_ui->checkIgnoreShareLimits->setChecked(m_storeIgnoreRatio);
-    m_ui->checkOptimizeAlignment->setChecked(m_storeOptimizeAlignment);
     m_ui->checkIgnoreShareLimits->setEnabled(m_ui->checkStartSeeding->isChecked());
+    m_ui->checkOptimizeAlignment->setChecked(m_storeOptimizeAlignment);
+    m_ui->spinPaddedFileSizeLimit->setValue(m_paddedFileSizeLimit);
 
     m_ui->trackersList->setPlainText(m_storeTrackerList);
     m_ui->URLSeedsList->setPlainText(m_storeWebSeedList);

src/gui/torrentcreatordialog.h

@@ -68,8 +68,10 @@ private:
 
     void saveSettings();
     void loadSettings();
+    void setInteractionEnabled(bool enabled) const;
+
     int getPieceSize() const;
-    void setInteractionEnabled(bool enabled);
+    int getPaddedFileSizeLimit() const;
 
     Ui::TorrentCreatorDialog *m_ui;
     BitTorrent::TorrentCreatorThread *m_creatorThread;
@@ -81,6 +83,7 @@ private:
     CachedSettingValue<bool> m_storeStartSeeding;
     CachedSettingValue<bool> m_storeIgnoreRatio;
     CachedSettingValue<bool> m_storeOptimizeAlignment;
+    CachedSettingValue<int> m_paddedFileSizeLimit;
     CachedSettingValue<QString> m_storeLastAddPath;
     CachedSettingValue<QString> m_storeTrackerList;
     CachedSettingValue<QString> m_storeWebSeedList;

src/gui/torrentcreatordialog.ui

@@ -7,7 +7,7 @@
     <x>0</x>
     <y>0</y>
     <width>592</width>
-    <height>658</height>
+    <height>731</height>
    </rect>
   </property>
   <property name="acceptDrops">
@@ -225,13 +225,58 @@
        </widget>
       </item>
       <item>
-       <widget class="QCheckBox" name="checkOptimizeAlignment">
-        <property name="text">
+       <widget class="QGroupBox" name="checkOptimizeAlignment">
+        <property name="title">
          <string>Optimize alignment</string>
         </property>
-        <property name="checked">
+        <property name="checkable">
          <bool>true</bool>
         </property>
+        <layout class="QVBoxLayout" name="verticalLayout_4">
+         <item>
+          <layout class="QHBoxLayout" name="horizontalLayout_4">
+           <item>
+            <widget class="QLabel" name="lblPaddedFileSizeLimit">
+             <property name="text">
+              <string>Align to piece boundary for files larger than:</string>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <widget class="QSpinBox" name="spinPaddedFileSizeLimit">
+             <property name="specialValueText">
+              <string>Disabled</string>
+             </property>
+             <property name="suffix">
+              <string> KiB</string>
+             </property>
+             <property name="minimum">
+              <number>-1</number>
+             </property>
+             <property name="maximum">
+              <number>2147483647</number>
+             </property>
+             <property name="value">
+              <number>-1</number>
+             </property>
+            </widget>
+           </item>
+           <item>
+            <spacer name="horizontalSpacer">
+             <property name="orientation">
+              <enum>Qt::Horizontal</enum>
+             </property>
+             <property name="sizeHint" stdset="0">
+              <size>
+               <width>40</width>
+               <height>20</height>
+              </size>
+             </property>
+            </spacer>
+           </item>
+          </layout>
+         </item>
+        </layout>
        </widget>
       </item>
      </layout>