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>

9 files changed, 69 insertions, 39 deletions

diff --git a/docs/extensions.md b/docs/extensions.md
index ae5cb5c..709acff 100644
--- a/docs/extensions.md
+++ b/docs/extensions.md
@@ -21,9 +21,8 @@ from PythonExtension import PluginInstance as inst
 inst.extensionDir()
 
 # Returns a list with the names of all Python extensions
-# If loaded only is supplied as True, only extensions that
-# where loaded successfully are returned
-inst.extensionList(loadedOnly = False)
+# Each extension has properties 'name' and 'loaded'
+inst.extensionList()
 
 # Returns the path of the custom location to
 # where missing dependencies should be pip installed
diff --git a/plugins/pythonextensions/bindingheaders/pythonextensions_extension.h b/plugins/pythonextensions/bindingheaders/pythonextensions_extension.h
new file mode 100644
index 0000000..e69de29
--- /dev/null
+++ b/plugins/pythonextensions/bindingheaders/pythonextensions_extension.h
diff --git a/plugins/pythonextensions/pythonextensions.pro b/plugins/pythonextensions/pythonextensions.pro
index c8fe73d..e28b860 100644
--- a/plugins/pythonextensions/pythonextensions.pro
+++ b/plugins/pythonextensions/pythonextensions.pro
@@ -36,6 +36,7 @@ WRAPPED_CLASSES = \
   bindingheaders/pythonextensions.h \
   bindingheaders/pythonextensions_internal.h \
   bindingheaders/pythonextensions_internal_pythonextensionsplugin.h \
+  bindingheaders/pythonextensions_extension.h \
   bindingheaders/core.h \
   bindingheaders/core_actioncontainer.h \
   bindingheaders/core_actionmanager.h \
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
diff --git a/plugins/pythonextensions/pythonextensionsplugin.h b/plugins/pythonextensions/pythonextensionsplugin.h
index 106ee63..1a4bce3 100644
--- a/plugins/pythonextensions/pythonextensionsplugin.h
+++ b/plugins/pythonextensions/pythonextensionsplugin.h
@@ -33,6 +33,13 @@
 #include <QStringList>
 
 namespace PythonExtensions {
+
+class Extension {
+public:
+    QString name;
+    bool loaded;
+};
+
 namespace Internal {
 
 class PythonExtensionsPlugin : public ExtensionSystem::IPlugin
@@ -50,14 +57,16 @@ public:
     ShutdownFlag aboutToShutdown() final;
 
     QDir extensionDir();
-    QStringList extensionList(const bool loadedOnly = false);
+    QVector<Extension> extensionList();
     QString pythonPackagePath();
+
 private:
-    QStringList m_loadedExtensions;
     void initializePythonBindings();
     void initializeOptionalBindings();
     void installRequirements();
     void initializePythonExtensions();
+    QVector<Extension> &extensionListRef();
+    QVector<Extension> m_extensions;
 };
 
 // Util functions
diff --git a/plugins/pythonextensions/pyutil.h b/plugins/pythonextensions/pyutil.h
index 62a1622..23fdb37 100644
--- a/plugins/pythonextensions/pyutil.h
+++ b/plugins/pythonextensions/pyutil.h
@@ -37,7 +37,7 @@ namespace PyUtil {
 // Note: If modifying the bindings, check these types still align
 enum QtCreatorTypes
 {
-    PythonExtensionsPluginType = 33, // SBK_PYTHONEXTENSIONS_INTERNAL_PYTHONEXTENSIONSPLUGIN_IDX
+    PythonExtensionsPluginType = 34, // SBK_PYTHONEXTENSIONS_INTERNAL_PYTHONEXTENSIONSPLUGIN_IDX
 };
 
 enum State
diff --git a/plugins/pythonextensions/typesystem_qtcreator.xml b/plugins/pythonextensions/typesystem_qtcreator.xml
index 736fe44..49dd794 100644
--- a/plugins/pythonextensions/typesystem_qtcreator.xml
+++ b/plugins/pythonextensions/typesystem_qtcreator.xml
@@ -47,6 +47,7 @@
     <load-typesystem name="typesystem_widgets.xml" generate="no"/>
 
     <namespace-type name="PythonExtensions">
+        <value-type name="Extension"/>
         <namespace-type name="Internal">
             <object-type name="PythonExtensionsPlugin"/>
         </namespace-type>
diff --git a/python/extensionmanager/actions.py b/python/extensionmanager/actions.py
index 29d64cc..7f05e77 100644
--- a/python/extensionmanager/actions.py
+++ b/python/extensionmanager/actions.py
@@ -60,8 +60,8 @@ def install(path):
         # Make sure the extension manager does not overwrite
         # extensions that are already installed
         for ext in instance.extensionList():
-            if extName == ext:
-                return "The extension \"{}\" is already installed. Uninstall it before trying again.".format(ext)
+            if extName == ext.name:
+                return "The extension \"{}\" is already installed. Uninstall it before trying again.".format(extName)
         extZip.extractall(instance.extensionDir().absolutePath())
         extZip.close()
     except Exception as e:
diff --git a/python/extensionmanager/list.py b/python/extensionmanager/list.py
index d213c35..32002b1 100644
--- a/python/extensionmanager/list.py
+++ b/python/extensionmanager/list.py
@@ -58,11 +58,11 @@ class ExtensionList(QtWidgets.QListWidget):
         i = 0
         for ext in instance.extensionList():
             item = QtWidgets.QListWidgetItem(self)
-            if not ext in instance.extensionList(True):
-                item.setText(ext + " [did not load]")
+            if not ext.loaded:
+                item.setText(ext.name + " [did not load]")
                 item.setIcon(QtGui.QIcon.fromTheme("dialog-error"))
             else:
-                item.setText(ext)
+                item.setText(ext.name)
                 item.setIcon(QtGui.QIcon.fromTheme("applications-development"))
             if i % 2 == 1:
                 item.setBackground(QtGui.QBrush(QtGui.QColor.fromRgb(240, 240, 240)))