From 37d1696e16a23700443dea33eed0294d54f2532c Mon Sep 17 00:00:00 2001
From: wmayer <wmayer@users.sourceforge.net>
Date: Fri, 17 May 2013 13:29:11 +0200
Subject: [PATCH] 0000175: Auto save function (first step)

---
 src/Gui/Application.cpp | 79 +++++++++++++++++++++++++++++++++++++++++
 src/Gui/Application.h   |  1 +
 src/Gui/MainWindow.cpp  |  2 ++
 3 files changed, 82 insertions(+)

diff --git a/src/Gui/Application.cpp b/src/Gui/Application.cpp
index 0ae0513cf..915de9b8d 100644
--- a/src/Gui/Application.cpp
+++ b/src/Gui/Application.cpp
@@ -41,8 +41,11 @@
 # include <QGLFramebufferObject>
 #endif
 # include <QSessionManager>
+# include <QTextStream>
 #endif
 
+#include <boost/interprocess/sync/file_lock.hpp>
+
 
 // FreeCAD Base header
 #include <Base/Console.h>
@@ -1748,9 +1751,24 @@ void Application::runApplication(void)
     Base::Console().Log("Init: Entering event loop\n");
 
     try {
+        std::stringstream s;
+        s << Base::FileInfo::getTempPath() << App::GetApplication().getExecutableName()
+          << "_" << QCoreApplication::applicationPid() << ".lock";
+        // open a lock file with the PID
+        Base::FileInfo fi(s.str());
+        Base::ofstream lock(fi);
+        boost::interprocess::file_lock flock(s.str().c_str());
+        flock.lock();
+
         int ret = mainApp.exec();
         if (ret == systemExit)
             throw Base::SystemExitException();
+
+        // close the lock file, in case of a crash we can see the existing lock file
+        // on the next restart and try to repair the documents, if needed.
+        flock.unlock();
+        lock.close();
+        fi.deleteFile();
     }
     catch (const Base::SystemExitException&) {
         Base::Console().Message("System exit\n");
@@ -1765,3 +1783,64 @@ void Application::runApplication(void)
 
     Base::Console().Log("Finish: Event loop left\n");
 }
+
+void Application::checkForPreviousCrashes()
+{
+    QDir tmp = QDir::temp();
+    tmp.setNameFilters(QStringList() << QString::fromAscii("*.lock"));
+    tmp.setFilter(QDir::Files);
+
+    QList<QFileInfo> restoreDocFiles;
+    QString exeName = QString::fromAscii(App::GetApplication().getExecutableName());
+    QList<QFileInfo> locks = tmp.entryInfoList();
+    for (QList<QFileInfo>::iterator it = locks.begin(); it != locks.end(); ++it) {
+        QString bn = it->baseName();
+        if (bn.startsWith(exeName)) {
+            QString fn = it->absoluteFilePath();
+            boost::interprocess::file_lock flock((const char*)fn.toLocal8Bit());
+            if (flock.try_lock()) {
+                // OK, this file is a leftover from a previous crash
+                QString crashed_pid = bn.mid(exeName.length()+1);
+                // search for transient directories with this PID
+                QString filter;
+                QTextStream str(&filter);
+                str << exeName << "_Doc_*_" << crashed_pid;
+                tmp.setNameFilters(QStringList() << filter);
+                tmp.setFilter(QDir::Dirs);
+                QList<QFileInfo> dirs = tmp.entryInfoList();
+                if (dirs.isEmpty()) {
+                    // delete the lock file immediately if not transient directories are related
+                    tmp.remove(fn);
+                }
+                else {
+                    int countDeletedDocs = 0;
+                    for (QList<QFileInfo>::iterator it = dirs.begin(); it != dirs.end(); ++it) {
+                        QDir doc_dir(it->absoluteFilePath());
+                        doc_dir.setFilter(QDir::NoDotAndDotDot|QDir::AllEntries);
+                        uint entries = doc_dir.entryList().count();
+                        if (entries == 0) {
+                            // in this case we can delete the transient directory because
+                            // we cannot do anything
+                            if (tmp.rmdir(it->filePath()))
+                                countDeletedDocs++;
+                        }
+                        else {
+                            // store the transient directory in case it's not empty
+                            restoreDocFiles << *it;
+                        }
+                    }
+
+                    // all directories corresponding to the lock file have been deleted
+                    // so delete the lock file, too
+                    if (countDeletedDocs == dirs.size()) {
+                        tmp.remove(fn);
+                    }
+                }
+            }
+        }
+    }
+
+    if (!restoreDocFiles.isEmpty()) {
+        //TODO:
+    }
+}
diff --git a/src/Gui/Application.h b/src/Gui/Application.h
index 1901c3694..42e739254 100644
--- a/src/Gui/Application.h
+++ b/src/Gui/Application.h
@@ -157,6 +157,7 @@ public:
 
     /// true when the application shuting down
     bool isClosing(void);
+    void checkForPreviousCrashes();
 
     /** @name workbench handling */
     //@{
diff --git a/src/Gui/MainWindow.cpp b/src/Gui/MainWindow.cpp
index 6c91f19ed..e9b621430 100644
--- a/src/Gui/MainWindow.cpp
+++ b/src/Gui/MainWindow.cpp
@@ -1174,6 +1174,8 @@ void MainWindow::delayedStartup()
     if (hGrp->GetBool("CreateNewDoc", false)) {
         App::GetApplication().newDocument();
     }
+
+    Application::Instance->checkForPreviousCrashes();
 }
 
 void MainWindow::appendRecentFile(const QString& filename)