Reduce queries to python version

Instead of doing at least 2 queries for python infos, now requires only
1 query (in ideal condition), and the result is cached.

src/base/search/searchdownloadhandler.cpp

@@ -48,7 +48,7 @@ SearchDownloadHandler::SearchDownloadHandler(const QString &siteUrl, const QStri
         url
     };
     // Launch search
-    m_downloadProcess->start(Utils::ForeignApps::Python::pythonExecutable(), params, QIODevice::ReadOnly);
+    m_downloadProcess->start(Utils::ForeignApps::pythonInfo().executableName, params, QIODevice::ReadOnly);
 }
 
 void SearchDownloadHandler::downloadProcessFinished(int exitcode)

src/base/search/searchhandler.cpp

@@ -70,7 +70,7 @@ SearchHandler::SearchHandler(const QString &pattern, const QString &category, co
     };
 
     // Launch search
-    m_searchProcess->setProgram(Utils::ForeignApps::Python::pythonExecutable());
+    m_searchProcess->setProgram(Utils::ForeignApps::pythonInfo().executableName);
     m_searchProcess->setArguments(params + m_pattern.split(" "));
 
 #if (QT_VERSION >= QT_VERSION_CHECK(5, 6, 0))

src/base/search/searchpluginmanager.cpp

@@ -64,7 +64,7 @@ namespace
 QPointer<SearchPluginManager> SearchPluginManager::m_instance = nullptr;
 
 SearchPluginManager::SearchPluginManager()
-    : m_updateUrl(QString("http://searchplugins.qbittorrent.org/%1/engines/").arg(Utils::ForeignApps::Python::pythonVersion() >= 3 ? "nova3" : "nova"))
+    : m_updateUrl(QString("http://searchplugins.qbittorrent.org/%1/engines/").arg(Utils::ForeignApps::pythonInfo().version.majorNumber() >= 3 ? "nova3" : "nova"))
 {
     Q_ASSERT(!m_instance); // only one instance is allowed
     m_instance = this;
@@ -323,7 +323,7 @@ QString SearchPluginManager::pluginsLocation()
 QString SearchPluginManager::engineLocation()
 {
     QString folder = "nova";
-    if (Utils::ForeignApps::Python::pythonVersion() >= 3)
+    if (Utils::ForeignApps::pythonInfo().version.majorNumber() >= 3)
         folder = "nova3";
     const QString location = Utils::Fs::expandPathAbs(specialFolderLocation(SpecialFolder::Data) + folder);
     QDir locationDir(location);
@@ -371,7 +371,7 @@ void SearchPluginManager::updateNova()
 
     // create nova directory if necessary
     QDir searchDir(engineLocation());
-    QString novaFolder = Utils::ForeignApps::Python::pythonVersion() >= 3 ? "searchengine/nova3" : "searchengine/nova";
+    QString novaFolder = Utils::ForeignApps::pythonInfo().version.majorNumber() >= 3 ? "searchengine/nova3" : "searchengine/nova";
     QFile packageFile(searchDir.absoluteFilePath("__init__.py"));
     packageFile.open(QIODevice::WriteOnly | QIODevice::Text);
     packageFile.close();
@@ -437,7 +437,7 @@ void SearchPluginManager::update()
     QStringList params;
     params << Utils::Fs::toNativePath(engineLocation() + "/nova2.py");
     params << "--capabilities";
-    nova.start(Utils::ForeignApps::Python::pythonExecutable(), params, QIODevice::ReadOnly);
+    nova.start(Utils::ForeignApps::pythonInfo().executableName, params, QIODevice::ReadOnly);
     nova.waitForStarted();
     nova.waitForFinished();
 

src/base/utils/foreignapps.cpp

@@ -35,99 +35,66 @@
 
 #include "base/logger.h"
 
-/**
- * Detects the python version.
- */
-int Utils::ForeignApps::Python::pythonVersion()
+using namespace Utils::ForeignApps;
+
+namespace
 {
-    static int version = -1;
-    if (version < 0) {
-        QString versionComplete = pythonVersionComplete().trimmed();
-        QStringList splitted = versionComplete.split('.');
-        if (splitted.size() > 1) {
-            int highVer = splitted.at(0).toInt();
-            if ((highVer == 2) || (highVer == 3))
-                version = highVer;
+    bool testPythonInstallation(const QString &exeName, PythonInfo &info)
+    {
+        QProcess proc;
+        proc.start(exeName, {"--version"}, QIODevice::ReadOnly);
+        if (proc.waitForFinished() && (proc.exitCode() == QProcess::NormalExit)) {
+            QByteArray procOutput = proc.readAllStandardOutput();
+            if (procOutput.isEmpty())
+                procOutput = proc.readAllStandardError();
+            procOutput = procOutput.simplified();
+
+            // Software 'Anaconda' installs its own python interpreter
+            // and `python --version` returns a string like this:
+            // "Python 3.4.3 :: Anaconda 2.3.0 (64-bit)"
+            const QList<QByteArray> outputSplit = procOutput.split(' ');
+            if (outputSplit.size() <= 1)
+                return false;
+
+            try {
+                info = {exeName, outputSplit[1]};
+            }
+            catch (const std::runtime_error &err) {
+                return false;
+            }
+
+            LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Python detected, version: %1").arg(info.version), Log::INFO);
+            return true;
         }
+
+        return false;
     }
-    return version;
 }
 
-/**
- * Detects the python executable by calling "python --version".
- */
-QString Utils::ForeignApps::Python::pythonExecutable()
+bool Utils::ForeignApps::PythonInfo::isValid() const
+{
+    return (!executableName.isEmpty() && version.isValid());
+}
+
+PythonInfo Utils::ForeignApps::pythonInfo()
 {
-    static QString executable;
-    if (executable.isEmpty()) {
-        QProcess pythonProc;
+    static PythonInfo pyInfo;
+    if (!pyInfo.isValid()) {
 #if defined(Q_OS_UNIX)
-        /*
-         * On Unix-Like Systems python2 and python3 should always exist
-         * http://legacy.python.org/dev/peps/pep-0394/
-         */
-        pythonProc.start("python3", {"--version"}, QIODevice::ReadOnly);
-        if (pythonProc.waitForFinished() && (pythonProc.exitCode() == 0)) {
-            executable = "python3";
-            return executable;
-        }
-        pythonProc.start("python2", {"--version"}, QIODevice::ReadOnly);
-        if (pythonProc.waitForFinished() && (pythonProc.exitCode() == 0)) {
-            executable = "python2";
-            return executable;
-        }
+        // On Unix-Like Systems python2 and python3 should always exist
+        // https://legacy.python.org/dev/peps/pep-0394/
+        if (testPythonInstallation("python3", pyInfo))
+            return pyInfo;
+        if (testPythonInstallation("python2", pyInfo))
+            return pyInfo;
 #endif
         // Look for "python" in Windows and in UNIX if "python2" and "python3" are
         // not detected.
-        pythonProc.start("python", {"--version"}, QIODevice::ReadOnly);
-        if (pythonProc.waitForFinished() && (pythonProc.exitCode() == 0))
-            executable = "python";
-        else
-            Logger::instance()->addMessage(QCoreApplication::translate("misc", "Python not detected"), Log::INFO);
-    }
-    return executable;
-}
-
-/**
- * Returns the complete python version
- * eg 2.7.9
- * Make sure to have setup python first
- */
-QString Utils::ForeignApps::Python::pythonVersionComplete()
-{
-    static QString version;
-    if (version.isEmpty()) {
-        if (pythonExecutable().isEmpty())
-            return version;
-        QProcess pythonProc;
-        pythonProc.start(pythonExecutable(), {"--version"}, QIODevice::ReadOnly);
-        if (pythonProc.waitForFinished() && (pythonProc.exitCode() == 0)) {
-            QByteArray output = pythonProc.readAllStandardOutput();
-            if (output.isEmpty())
-                output = pythonProc.readAllStandardError();
+        if (testPythonInstallation("python", pyInfo))
+            return pyInfo;
 
-            // Software 'Anaconda' installs its own python interpreter
-            // and `python --version` returns a string like this:
-            // `Python 3.4.3 :: Anaconda 2.3.0 (64-bit)`
-            const QList<QByteArray> outSplit = output.split(' ');
-            if (outSplit.size() > 1) {
-                version = outSplit.at(1).trimmed();
-                Logger::instance()->addMessage(QCoreApplication::translate("misc", "Python version: %1").arg(version), Log::INFO);
-            }
-
-            // If python doesn't report a 3-piece version e.g. 3.6.1
-            // then fill the missing pieces with zero
-            const QStringList verSplit = version.split('.', QString::SkipEmptyParts);
-            if (verSplit.size() < 3) {
-                for (int i = verSplit.size(); i < 3; ++i) {
-                    if (version.endsWith('.'))
-                        version.append('0');
-                    else
-                        version.append(".0");
-                }
-                Logger::instance()->addMessage(QCoreApplication::translate("misc", "Normalized Python version: %1").arg(version), Log::INFO);
-            }
-        }
+        LogMsg(QCoreApplication::translate("Utils::ForeignApps", "Python not detected"), Log::INFO);
     }
-    return version;
+
+    return pyInfo;
 }

src/base/utils/foreignapps.h

@@ -31,15 +31,22 @@
 
 #include <QString>
 
+#include "base/utils/version.h"
+
 namespace Utils
 {
     namespace ForeignApps
     {
-        namespace Python
+        struct PythonInfo
         {
-            int pythonVersion();
-            QString pythonExecutable();
-            QString pythonVersionComplete();
-        }
+            using Version = Utils::Version<quint8, 3, 1>;
+
+            bool isValid() const;
+
+            QString executableName;
+            Version version;
+        };
+
+        PythonInfo pythonInfo();
     }
 }

src/base/utils/version.h

@@ -58,7 +58,7 @@ namespace Utils
 
         template <typename ... Other>
         constexpr Version(Other ... components)
-            : m_components {{components ...}}
+            : m_components {{static_cast<T>(components) ...}}
         {
         }
 
@@ -129,6 +129,11 @@ namespace Utils
             return res;
         }
 
+        constexpr bool isValid() const
+        {
+            return (*this != ThisType {});
+        }
+
         constexpr bool operator==(const ThisType &other) const
         {
             return (m_components == other.m_components);

src/gui/mainwindow.cpp

@@ -1743,45 +1743,42 @@ void MainWindow::on_actionRSSReader_triggered()
 void MainWindow::on_actionSearchWidget_triggered()
 {
     if (!m_hasPython && m_ui->actionSearchWidget->isChecked()) {
-        int pythonVersion = Utils::ForeignApps::Python::pythonVersion();
+        int majorVersion = Utils::ForeignApps::pythonInfo().version.majorNumber();
 
         // Check if python is already in PATH
-        if (pythonVersion > 0)
+        if (majorVersion > 0) {
             // Prevent translators from messing with PATH
             Logger::instance()->addMessage(tr("Python found in %1: %2", "Python found in PATH: /usr/local/bin:/usr/bin:/etc/bin")
                 .arg("PATH", qgetenv("PATH").constData()), Log::INFO);
+        }
 #ifdef Q_OS_WIN
-        else if (addPythonPathToEnv())
-            pythonVersion = Utils::ForeignApps::Python::pythonVersion();
+        else if (addPythonPathToEnv()) {
+            majorVersion = Utils::ForeignApps::pythonInfo().version.majorNumber();
+        }
 #endif
+        else {
+            QMessageBox::information(this, tr("Undetermined Python version"), tr("Couldn't determine your Python version. Search engine disabled."));
+            m_ui->actionSearchWidget->setChecked(false);
+            Preferences::instance()->setSearchEnabled(false);
+            return;
+        }
 
         bool res = false;
 
-        if ((pythonVersion == 2) || (pythonVersion == 3)) {
+        if ((majorVersion == 2) || (majorVersion == 3)) {
             // Check Python minimum requirement: 2.7.9 / 3.3.0
-            QString version = Utils::ForeignApps::Python::pythonVersionComplete();
-            QStringList splitted = version.split('.');
-            if (splitted.size() > 2) {
-                int middleVer = splitted.at(1).toInt();
-                int lowerVer = splitted.at(2).toInt();
-                if (((pythonVersion == 2) && (middleVer < 7))
-                    || ((pythonVersion == 2) && (middleVer == 7) && (lowerVer < 9))
-                    || ((pythonVersion == 3) && (middleVer < 3))) {
-                    QMessageBox::information(this, tr("Old Python Interpreter"), tr("Your Python version (%1) is outdated. Please upgrade to latest version for search engines to work.\nMinimum requirement: 2.7.9 / 3.3.0.").arg(version));
-                    m_ui->actionSearchWidget->setChecked(false);
-                    Preferences::instance()->setSearchEnabled(false);
-                    return;
-                }
-                else {
-                    res = true;
-                }
-            }
-            else {
-                QMessageBox::information(this, tr("Undetermined Python version"), tr("Couldn't determine your Python version (%1). Search engine disabled.").arg(version));
+            using Version = Utils::ForeignApps::PythonInfo::Version;
+            const Version pyVersion = Utils::ForeignApps::pythonInfo().version;
+
+            if (((majorVersion == 2) && (pyVersion < Version {2, 7, 9}))
+                || ((majorVersion == 3) && (pyVersion < Version {3, 3, 0}))) {
+                QMessageBox::information(this, tr("Old Python Interpreter"), tr("Your Python version (%1) is outdated. Please upgrade to latest version for search engines to work.\nMinimum requirement: 2.7.9 / 3.3.0.").arg(pyVersion));
                 m_ui->actionSearchWidget->setChecked(false);
                 Preferences::instance()->setSearchEnabled(false);
                 return;
             }
+
+            res = true;
         }
 
         if (res) {
@@ -2086,7 +2083,7 @@ void MainWindow::pythonDownloadSuccess(const QString &url, const QString &filePa
     m_hasPython = addPythonPathToEnv();
     if (m_hasPython) {
         // Make it print the version to Log
-        Utils::ForeignApps::Python::pythonVersion();
+        Utils::ForeignApps::pythonInfo();
         m_ui->actionSearchWidget->setChecked(true);
         displaySearchTab(true);
     }

src/gui/search/searchwidget.cpp

@@ -285,7 +285,7 @@ void SearchWidget::giveFocusToSearchInput()
 // Function called when we click on search button
 void SearchWidget::on_searchButton_clicked()
 {
-    if (Utils::ForeignApps::Python::pythonVersion() < 0) {
+    if (Utils::ForeignApps::pythonInfo().version.majorNumber() <= 0) {
         m_mainWindow->showNotificationBaloon(tr("Search Engine"), tr("Please install Python to use the Search Engine."));
         return;
     }