Avoid scanning extension directory over and over again

And get rid of separate management of a list of loaded extensions.
Instead save the name and state of an extension in a separate class.
It will probably get more information about the extension, like its
location. The extension manager UI now can also iterate over that list
once.

Change-Id: I4872e55d621837a7d476e69b919f06aeb491ff03
Reviewed-by: Eike Ziller <eike.ziller@qt.io>

1 files changed, 48 insertions, 28 deletions

diff --git a/plugins/pythonextensions/pythonextensionsplugin.cpp b/plugins/pythonextensions/pythonextensionsplugin.cpp
index 3136bbc..b3730b4 100644
--- a/plugins/pythonextensions/pythonextensionsplugin.cpp
+++ b/plugins/pythonextensions/pythonextensionsplugin.cpp
@@ -39,6 +39,8 @@
 #include <extensionsystem/pluginmanager.h>
 #include <extensionsystem/pluginspec.h>
 
+#include <utils/algorithm.h>
+
 #include <QDir>
 #include <QIODevice>
 #include <QFile>
@@ -131,19 +133,32 @@ QDir PythonExtensionsPlugin::extensionDir()
     return extension_dir;
 }
 
-QStringList PythonExtensionsPlugin::extensionList(const bool loadedOnly)
+static QVector<Extension> getExtensionList(const QDir &directory)
 {
-    if (loadedOnly)
-        return m_loadedExtensions;
+    if (!directory.exists())
+        return {};
+
+    QStringList entries = directory.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
+    entries.removeAll("site-packages");
+    entries.removeAll("__pycache__");
+    return Utils::transform<QVector>(entries, [](const QString &entry) {
+        return Extension({entry, false});
+    });
+}
 
-    QDir extension_dir = extensionDir();
-    if (!extension_dir.exists())
-        return QStringList();
+QVector<Extension> PythonExtensionsPlugin::extensionList()
+{
+    return extensionListRef();
+}
 
-    QStringList extension_list = extension_dir.entryList(QDir::AllDirs | QDir::NoDotAndDotDot);
-    extension_list.removeAll("site-packages");
-    extension_list.removeAll("__pycache__");
-    return extension_list;
+QVector<Extension> &PythonExtensionsPlugin::extensionListRef()
+{
+    static bool initialized = false;
+    if (!initialized) {
+        m_extensions = getExtensionList(extensionDir());
+        initialized = true;
+    }
+    return m_extensions;
 }
 
 QString PythonExtensionsPlugin::pythonPackagePath()
@@ -207,16 +222,18 @@ void PythonExtensionsPlugin::installRequirements()
     if (!extension_dir.exists())
         return;
 
-    QStringList extension_list = extensionList();
-    for (const QString &extension : extension_list) {
-        QString extension_requirements(extension_dir.absolutePath() + "/" + extension + "/requirements.txt");
-        if (QFileInfo::exists(extension_requirements) && !QFileInfo::exists(extension_requirements + ".installed")) {
-            if (!PyUtil::pipInstallRequirements(
-                extension_requirements.toStdString(),
-                pythonPackagePath().toStdString()
-            )) {
-                qWarning() << "Failed to install requirements for extension" << extension;
-                Core::MessageManager::write(Constants::MESSAGE_MANAGER_PREFIX + tr("Failed to install requirements for extension ") + extension);
+    QVector<Extension> extension_list = extensionListRef();
+    for (const Extension &extension : extension_list) {
+        QString extension_requirements(extension_dir.absolutePath() + "/" + extension.name
+                                       + "/requirements.txt");
+        if (QFileInfo::exists(extension_requirements)
+                && !QFileInfo::exists(extension_requirements + ".installed")) {
+            if (!PyUtil::pipInstallRequirements(extension_requirements.toStdString(),
+                                                pythonPackagePath().toStdString())) {
+                qWarning() << "Failed to install requirements for extension" << extension.name;
+                Core::MessageManager::write(Constants::MESSAGE_MANAGER_PREFIX
+                                            + tr("Failed to install requirements for extension ")
+                                            + extension.name);
             }
         }
     }
@@ -234,22 +251,25 @@ void PythonExtensionsPlugin::initializePythonExtensions()
 
     qDebug() << "Found Python extension directory at location" << extension_dir.absolutePath();
 
-    QStringList extension_list = extensionList();
+    QVector<Extension> &extension_list = extensionListRef();
 
     qDebug() << "Number of Python extensions found:" << extension_list.size();
 
+    int loadedCount = 0;
     // Run the extension initialization code
-    for (const QString &extension : extension_list) {
-        qDebug() << "Trying to initialize extension" << extension;
-        if (!PyUtil::runScript("import " + extension.toStdString())) {
-            qWarning() << "Failed to initialize extension" << extension;
-            Core::MessageManager::write(Constants::MESSAGE_MANAGER_PREFIX + tr("Failed to initialize extension ") + extension);
+    for (Extension &extension : extension_list) {
+        qDebug() << "Trying to initialize extension" << extension.name;
+        if (PyUtil::runScript("import " + extension.name.toStdString())) {
+            extension.loaded = true;
+            ++loadedCount;
         } else {
-            m_loadedExtensions << extension;
+            qWarning() << "Failed to initialize extension" << extension.name;
+            Core::MessageManager::write(Constants::MESSAGE_MANAGER_PREFIX
+                                        + tr("Failed to initialize extension ") + extension.name);
         }
     }
 
-    qDebug() << "Number of Python extensions loaded:" << m_loadedExtensions.size();
+    qDebug() << "Number of Python extensions loaded:" << loadedCount;
 }
 
 } // namespace Internal