1 files changed, 63 insertions, 0 deletions
diff --git a/xpcom/glue/AppData.h b/xpcom/glue/AppData.h
new file mode 100644
index 0000000000..0134df32ca
--- /dev/null
+++ b/xpcom/glue/AppData.h
@@ -0,0 +1,63 @@
+/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
+/* vim: set ts=8 sts=2 et sw=2 tw=80: */
+/* This Source Code Form is subject to the terms of the Mozilla Public
+ * License, v. 2.0. If a copy of the MPL was not distributed with this
+ * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
+
+#ifndef mozilla_AppData_h
+#define mozilla_AppData_h
+
+#include "nsXREAppData.h"
+#include "nscore.h"
+#include "nsStringGlue.h"
+#include "nsISupportsUtils.h"
+
+namespace mozilla {
+
+// Like nsXREAppData, but releases all strong refs/allocated memory
+// in the destructor.
+class ScopedAppData : public nsXREAppData
+{
+public:
+  ScopedAppData()
+  {
+    Zero();
+    this->size = sizeof(*this);
+  }
+
+  explicit ScopedAppData(const nsXREAppData* aAppData);
+
+  void Zero() { memset(this, 0, sizeof(*this)); }
+
+  ~ScopedAppData();
+};
+
+/**
+ * Given |aStr| is holding a string allocated with NS_Alloc, or null:
+ * replace the value in |aStr| with a new value.
+ *
+ * @param aNewValue Null is permitted. The string is cloned with NS_strdup.
+ */
+void SetAllocatedString(const char*& aStr, const char* aNewValue);
+
+/**
+ * Given "str" is holding a string allocated with NS_Alloc, or null:
+ * replace the value in "str" with a new value.
+ *
+ * @param aNewValue If |aNewValue| is the empty string, |aStr| will be set
+ *                  to null.
+ */
+void SetAllocatedString(const char*& aStr, const nsACString& aNewValue);
+
+template<class T>
+void
+SetStrongPtr(T*& aPtr, T* aNewValue)
+{
+  NS_IF_RELEASE(aPtr);
+  aPtr = aNewValue;
+  NS_IF_ADDREF(aPtr);
+}
+
+} // namespace mozilla
+
+#endif