Session: Minimize direct use of reader when loading sessions

Instead of directly reading things like the project list from the
reader, add a map of "session values" in the session and read these from
the reader once, then use the session to access these values while
loading the details of the session. This is in preparation of separating
the session loading from projectexplorer.

This is similar to Session::(set)Value. We cannot use the same
(set)Value methods directly though, because of differences in the
handling of these values during implict and explicit default session
loading.

Change-Id: I9a4f38a9f958734d20d6e6eb7253f9e44ba1285e
Reviewed-by: Christian Kandeler <christian.kandeler@qt.io>
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>

6 files changed, 93 insertions, 53 deletions

diff --git a/src/plugins/projectexplorer/projectexplorer.cpp b/src/plugins/projectexplorer/projectexplorer.cpp
index 6334dfee58..ca7c40a073 100644
--- a/src/plugins/projectexplorer/projectexplorer.cpp
+++ b/src/plugins/projectexplorer/projectexplorer.cpp
@@ -2400,7 +2400,7 @@ ProjectExplorerPlugin::OpenProjectResult ProjectExplorerPlugin::openProjects(con
                                               Utils::equal(&Project::projectFilePath, filePath));
         if (found) {
             alreadyOpen.append(found);
-            ProjectManager::reportProjectLoadingProgress();
+            SessionManager::sessionLoadingProgress();
             continue;
         }
 
@@ -2429,7 +2429,7 @@ ProjectExplorerPlugin::OpenProjectResult ProjectExplorerPlugin::openProjects(con
                         .arg(mt.name()));
         }
         if (filePaths.size() > 1)
-            ProjectManager::reportProjectLoadingProgress();
+            SessionManager::sessionLoadingProgress();
     }
     dd->updateActions();
 
diff --git a/src/plugins/projectexplorer/projectmanager.cpp b/src/plugins/projectexplorer/projectmanager.cpp
index 09f6ad2cf4..81824c7c7a 100644
--- a/src/plugins/projectexplorer/projectmanager.cpp
+++ b/src/plugins/projectexplorer/projectmanager.cpp
@@ -54,8 +54,8 @@ const char DEFAULT_SESSION[] = "default";
 class ProjectManagerPrivate
 {
 public:
-    void restoreDependencies(const PersistentSettingsReader &reader);
-    void restoreStartupProject(const PersistentSettingsReader &reader);
+    void restoreDependencies();
+    void restoreStartupProject();
     void restoreProjects(const FilePaths &fileList);
     void askUserAboutFailedProjects();
 
@@ -619,11 +619,11 @@ void ProjectManager::removeProjects(const QList<Project *> &remove)
      qDeleteAll(remove);
 }
 
-void ProjectManagerPrivate::restoreDependencies(const PersistentSettingsReader &reader)
+void ProjectManagerPrivate::restoreDependencies()
 {
-    QMap<QString, QVariant> depMap = reader.restoreValue(QLatin1String("ProjectDependencies")).toMap();
-    auto i = depMap.constBegin();
-    while (i != depMap.constEnd()) {
+     QMap<QString, QVariant> depMap = SessionManager::sessionValue("ProjectDependencies").toMap();
+     auto i = depMap.constBegin();
+     while (i != depMap.constEnd()) {
         const QString &key = i.key();
         FilePaths values;
         const QStringList valueList = i.value().toStringList();
@@ -631,7 +631,7 @@ void ProjectManagerPrivate::restoreDependencies(const PersistentSettingsReader &
             values << FilePath::fromString(value);
         m_depMap.insert(FilePath::fromString(key), values);
         ++i;
-    }
+     }
 }
 
 void ProjectManagerPrivate::askUserAboutFailedProjects()
@@ -655,9 +655,10 @@ void ProjectManagerPrivate::askUserAboutFailedProjects()
     }
 }
 
-void ProjectManagerPrivate::restoreStartupProject(const PersistentSettingsReader &reader)
+void ProjectManagerPrivate::restoreStartupProject()
 {
-    const FilePath startupProject = FilePath::fromSettings(reader.restoreValue("StartupProject"));
+    const FilePath startupProject = FilePath::fromSettings(
+        SessionManager::sessionValue("StartupProject"));
     if (!startupProject.isEmpty()) {
         for (Project *pro : std::as_const(m_projects)) {
             if (pro->projectFilePath() == startupProject) {
@@ -732,7 +733,6 @@ bool ProjectManager::loadSession(const QString &session, bool initial)
     if (!loadImplicitDefault && !SessionManager::sessions().contains(session))
         return false;
 
-    FilePaths fileList;
     // Try loading the file
     FilePath fileName = SessionManager::sessionNameToFileName(loadImplicitDefault ? DEFAULT_SESSION : session);
     PersistentSettingsReader reader;
@@ -749,8 +749,6 @@ bool ProjectManager::loadSession(const QString &session, bool initial)
             emit SessionManager::instance()->sessionLoaded(DEFAULT_SESSION);
             return true;
         }
-
-        fileList = FileUtils::toFilePathList(reader.restoreValue("ProjectList").toStringList());
     } else if (loadImplicitDefault) {
         return true;
     }
@@ -771,20 +769,11 @@ bool ProjectManager::loadSession(const QString &session, bool initial)
         return false;
     }
 
-    // find a list of projects to close later
-    const QList<Project *> projectsToRemove = Utils::filtered(projects(), [&fileList](Project *p) {
-        return !fileList.contains(p->projectFilePath());
-    });
-    const QList<Project *> openProjects = projects();
-    const FilePaths projectPathsToLoad = Utils::filtered(fileList, [&openProjects](const FilePath &path) {
-        return !Utils::contains(openProjects, [&path](Project *p) {
-            return p->projectFilePath() == path;
-        });
-    });
     d->m_failedProjects.clear();
     d->m_depMap.clear();
     if (!switchFromImplicitToExplicitDefault)
         sb_d->m_values.clear();
+    sb_d->m_sessionValues.clear();
     d->m_casadeSetActive = false;
 
     sb_d->m_sessionName = session;
@@ -798,37 +787,52 @@ bool ProjectManager::loadSession(const QString &session, bool initial)
         ProgressManager::addTask(sb_d->m_future.future(), Tr::tr("Loading Session"),
            "ProjectExplorer.SessionFile.Load");
 
-        sb_d->m_future.setProgressRange(0, 1);
+        sb_d->m_future.setProgressRange(0, 1 /*initialization*/ + 1 /*editors*/);
         sb_d->m_future.setProgressValue(0);
 
         if (!switchFromImplicitToExplicitDefault)
             sb_d->restoreValues(reader);
-        emit SessionManager::instance()->aboutToLoadSession(session);
+        sb_d->restoreSessionValues(reader);
 
         // retrieve all values before the following code could change them again
         Id modeId = Id::fromSetting(SessionManager::value(QLatin1String("ActiveMode")));
         if (!modeId.isValid())
             modeId = Id(Core::Constants::MODE_EDIT);
 
-        QColor c = QColor(reader.restoreValue(QLatin1String("Color")).toString());
+        QColor c = QColor(SessionManager::sessionValue("Color").toString());
         if (c.isValid())
             StyleHelper::setBaseColor(c);
 
-        sb_d->m_future.setProgressRange(0, projectPathsToLoad.count() + 1/*initialization above*/ + 1/*editors*/);
-        sb_d->m_future.setProgressValue(1);
-        QCoreApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
+        SessionManager::sessionLoadingProgress();
 
-        d->restoreProjects(projectPathsToLoad);
-        sb_d->sessionLoadingProgress();
-        d->restoreDependencies(reader);
-        d->restoreStartupProject(reader);
+        sb_d->restoreEditors();
 
-        removeProjects(projectsToRemove); // only remove old projects now that the startup project is set!
+        // let other code restore the session
+        emit SessionManager::instance()->aboutToLoadSession(session);
+
+        // find a list of projects to close later
+        const FilePaths fileList = FileUtils::toFilePathList(
+            SessionManager::sessionValue("ProjectList").toStringList());
+        const QList<Project *> projectsToRemove
+            = Utils::filtered(projects(), [&fileList](Project *p) {
+                  return !fileList.contains(p->projectFilePath());
+              });
+        const QList<Project *> openProjects = projects();
+        const FilePaths projectPathsToLoad
+            = Utils::filtered(fileList, [&openProjects](const FilePath &path) {
+                  return !Utils::contains(openProjects, [&path](Project *p) {
+                      return p->projectFilePath() == path;
+                  });
+              });
+
+        SessionManager::addSessionLoadingSteps(projectPathsToLoad.count());
 
-        sb_d->restoreEditors(reader);
+        d->restoreProjects(projectPathsToLoad);
+        SessionManager::sessionLoadingProgress();
+        d->restoreDependencies();
+        d->restoreStartupProject();
 
-        sb_d->m_future.reportFinished();
-        sb_d->m_future = QFutureInterface<void>();
+        removeProjects(projectsToRemove); // only remove old projects now that the startup project is set!
 
         // Fall back to Project mode if the startup project is unconfigured and
         // use the mode saved in the session otherwise
@@ -843,9 +847,12 @@ bool ProjectManager::loadSession(const QString &session, bool initial)
         ModeManager::setFocusToCurrentMode();
     }
 
-    d->m_casadeSetActive = reader.restoreValue(QLatin1String("CascadeSetActive"), false).toBool();
+    d->m_casadeSetActive = SessionManager::sessionValue("CascadeSetActive", false).toBool();
     sb_d->m_lastActiveTimes.insert(session, QDateTime::currentDateTime());
 
+    sb_d->m_future.reportFinished();
+    sb_d->m_future = QFutureInterface<void>();
+
     emit SessionManager::instance()->sessionLoaded(session);
 
     // Starts a event loop, better do that at the very end
@@ -854,11 +861,6 @@ bool ProjectManager::loadSession(const QString &session, bool initial)
     return true;
 }
 
-void ProjectManager::reportProjectLoadingProgress()
-{
-    sb_d->sessionLoadingProgress();
-}
-
 FilePaths ProjectManager::projectsForSessionName(const QString &session)
 {
     const FilePath fileName = SessionManager::sessionNameToFileName(session);
diff --git a/src/plugins/projectexplorer/projectmanager.h b/src/plugins/projectexplorer/projectmanager.h
index ad3e402992..1aa58d6aa5 100644
--- a/src/plugins/projectexplorer/projectmanager.h
+++ b/src/plugins/projectexplorer/projectmanager.h
@@ -82,8 +82,6 @@ public:
 
     static Utils::FilePaths projectsForSessionName(const QString &session);
 
-    static void reportProjectLoadingProgress();
-
     static bool loadSession(const QString &session, bool initial = false);
 
 signals:
diff --git a/src/plugins/projectexplorer/session.cpp b/src/plugins/projectexplorer/session.cpp
index f158814776..a259e5336e 100644
--- a/src/plugins/projectexplorer/session.cpp
+++ b/src/plugins/projectexplorer/session.cpp
@@ -141,6 +141,17 @@ QVariant SessionManager::value(const QString &name)
     return (it == sb_d->m_values.constEnd()) ? QVariant() : *it;
 }
 
+void SessionManager::setSessionValue(const QString &name, const QVariant &value)
+{
+    sb_d->m_sessionValues.insert(name, value);
+}
+
+QVariant SessionManager::sessionValue(const QString &name, const QVariant &defaultValue)
+{
+    auto it = sb_d->m_sessionValues.constFind(name);
+    return (it == sb_d->m_sessionValues.constEnd()) ? defaultValue : *it;
+}
+
 QString SessionManager::activeSession()
 {
     return sb_d->m_sessionName;
@@ -382,12 +393,24 @@ void SessionManagerPrivate::restoreValues(const PersistentSettingsReader &reader
     }
 }
 
-void SessionManagerPrivate::restoreEditors(const PersistentSettingsReader &reader)
+void SessionManagerPrivate::restoreSessionValues(const PersistentSettingsReader &reader)
 {
-    const QVariant editorsettings = reader.restoreValue(QLatin1String("EditorSettings"));
+    const QVariantMap values = reader.restoreValues();
+    // restore toplevel items that are not restored by restoreValues
+    const auto end = values.constEnd();
+    for (auto it = values.constBegin(); it != end; ++it) {
+        if (it.key() == "valueKeys" || it.key().startsWith("value-"))
+            continue;
+        m_sessionValues.insert(it.key(), it.value());
+    }
+}
+
+void SessionManagerPrivate::restoreEditors()
+{
+    const QVariant editorsettings = m_sessionValues.value("EditorSettings");
     if (editorsettings.isValid()) {
         EditorManager::restoreState(QByteArray::fromBase64(editorsettings.toByteArray()));
-        sessionLoadingProgress();
+        SessionManager::sessionLoadingProgress();
     }
 }
 
@@ -412,10 +435,15 @@ void SessionManager::markSessionFileDirty()
     sb_d->m_virginSession = false;
 }
 
-void SessionManagerPrivate::sessionLoadingProgress()
+void SessionManager::sessionLoadingProgress()
 {
-    m_future.setProgressValue(m_future.progressValue() + 1);
+    sb_d->m_future.setProgressValue(sb_d->m_future.progressValue() + 1);
     QCoreApplication::processEvents(QEventLoop::ExcludeUserInputEvents);
 }
 
+void SessionManager::addSessionLoadingSteps(int steps)
+{
+    sb_d->m_future.setProgressRange(0, sb_d->m_future.progressMaximum() + steps);
+}
+
 } // namespace ProjectExplorer
diff --git a/src/plugins/projectexplorer/session.h b/src/plugins/projectexplorer/session.h
index 21f571b1f3..9af82d066c 100644
--- a/src/plugins/projectexplorer/session.h
+++ b/src/plugins/projectexplorer/session.h
@@ -47,15 +47,26 @@ public:
     static bool isDefaultSession(const QString &session);
 
     // Let other plugins store persistent values within the session file
+    // These are settings that are also saved and loaded at startup, and are taken over
+    // to the default session when switching from implicit to explicit default session
     static void setValue(const QString &name, const QVariant &value);
     static QVariant value(const QString &name);
 
+    // These are settings that are specific to a session and are not loaded
+    // at startup and also not taken over to the default session when switching from implicit
+    static void setSessionValue(const QString &name, const QVariant &value);
+    static QVariant sessionValue(const QString &name, const QVariant &defaultValue = {});
+
     static bool loadingSession();
     static void markSessionFileDirty();
 
+    static void sessionLoadingProgress();
+    static void addSessionLoadingSteps(int steps);
 signals:
     void startupSessionRestored();
     void aboutToUnloadSession(QString sessionName);
+    // Sent during session loading, after the values of the session are available via value() and
+    // sessionValue. Use to restore values from the new session
     void aboutToLoadSession(QString sessionName);
     void sessionLoaded(QString sessionName);
     void aboutToSaveSession();
diff --git a/src/plugins/projectexplorer/session_p.h b/src/plugins/projectexplorer/session_p.h
index 471c78c06e..40f691ab2d 100644
--- a/src/plugins/projectexplorer/session_p.h
+++ b/src/plugins/projectexplorer/session_p.h
@@ -15,8 +15,8 @@ public:
     void restoreStartupSession();
 
     void restoreValues(const PersistentSettingsReader &reader);
-    void restoreEditors(const PersistentSettingsReader &reader);
-    void sessionLoadingProgress();
+    void restoreSessionValues(const PersistentSettingsReader &reader);
+    void restoreEditors();
 
     bool isStartupSessionRestored();
     void saveSettings();
@@ -38,6 +38,7 @@ public:
     QHash<QString, QDateTime> m_lastActiveTimes;
 
     QMap<QString, QVariant> m_values;
+    QMap<QString, QVariant> m_sessionValues;
     QFutureInterface<void> m_future;
     PersistentSettingsWriter *m_writer = nullptr;
 };