App: Added flag to disable App's persistent data

If the application does not need persistent data (persist.pack in runtime folder), it can now be disabled when the app's subsystems are initialized.
skyjake · Mar 8, 2014 · f19b3ef · f19b3ef
1 parent 5f20611
commit f19b3ef
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Showing 2 changed files with 23 additions and 13 deletions.
diff --git a/doomsday/libdeng2/include/de/core/app.h b/doomsday/libdeng2/include/de/core/app.h
@@ -61,11 +61,15 @@ class DENG2_PUBLIC App : DENG2_OBSERVES(Clock, TimeChange)
 {
 public:
     enum SubsystemInitFlag {
-        DefaultSubsystems   = 0x0,
-        DisablePlugins      = 0x1
+        DefaultSubsystems     = 0x0,
+        DisablePlugins        = 0x1,
+        DisablePersistentData = 0x2
     };
     Q_DECLARE_FLAGS(SubsystemInitFlags, SubsystemInitFlag)
 
+    /// Throws if attempting to access persistent data when it has been disabled at init.
+    DENG2_ERROR(PersistentDataNotAvailable);
+
     /**
      * Notified when application startup has been fully completed.
      */

diff --git a/doomsday/libdeng2/src/core/app.cpp b/doomsday/libdeng2/src/core/app.cpp
@@ -438,9 +438,12 @@ NativePath App::nativeHomePath()
 
 Archive &App::persistentData()
 {
-    DENG2_ASSERT(DENG2_APP->d->persistentData != 0);
-
-    return *DENG2_APP->d->persistentData;
+    Archive *persist = DENG2_APP->d->persistentData;
+    if(!persist)
+    {
+        throw PersistentDataNotAvailable("App::persistentData", "Persistent data is disabled");
+    }
+    return *persist;
 }
 
 NativePath App::currentWorkPath()
@@ -485,17 +488,20 @@ void App::initSubsystems(SubsystemInitFlags flags)
 
     d->initFileSystem(allowPlugins);
 
-    if(!homeFolder().has("persist.pack") || commandLine().has("-reset"))
+    if(!flags.testFlag(DisablePersistentData))
     {
-        // Recreate the persistent state data package.
-        ZipArchive arch;
-        arch.add("Info", String(QString("# Package for %1's persistent state.\n").arg(d->appName)).toUtf8());
-        Writer(homeFolder().replaceFile("persist.pack")) << arch;
+        if(!homeFolder().has("persist.pack") || commandLine().has("-reset"))
+        {
+            // Recreate the persistent state data package.
+            ZipArchive arch;
+            arch.add("Info", String(QString("# Package for %1's persistent state.\n").arg(d->appName)).toUtf8());
+            Writer(homeFolder().replaceFile("persist.pack")) << arch;
 
-        homeFolder().populate(Folder::PopulateOnlyThisFolder);
-    }            
+            homeFolder().populate(Folder::PopulateOnlyThisFolder);
+        }
 
-    d->persistentData = &homeFolder().locate<PackageFolder>("persist.pack").archive();
+        d->persistentData = &homeFolder().locate<PackageFolder>("persist.pack").archive();
+    }
 
     // The configuration.
     d->config = new Config(d->configPath);