1 files changed, 45 insertions, 0 deletions
diff --git a/xpcom/glue/nsXPTCUtils.h b/xpcom/glue/nsXPTCUtils.h
new file mode 100644
index 000000000..8922aca16
--- /dev/null
+++ b/xpcom/glue/nsXPTCUtils.h
@@ -0,0 +1,45 @@
+/* -*- 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 nsXPTCUtils_h__
+#define nsXPTCUtils_h__
+
+#include "xptcall.h"
+#include "mozilla/MemoryReporting.h"
+
+/**
+ * A helper class that initializes an xptcall helper at construction
+ * and releases it at destruction.
+ */
+class nsAutoXPTCStub : protected nsIXPTCProxy
+{
+public:
+  nsISomeInterface* mXPTCStub;
+
+protected:
+  nsAutoXPTCStub() : mXPTCStub(nullptr) {}
+
+  nsresult
+  InitStub(const nsIID& aIID)
+  {
+    return NS_GetXPTCallStub(aIID, this, &mXPTCStub);
+  }
+
+  ~nsAutoXPTCStub()
+  {
+    if (mXPTCStub) {
+      NS_DestroyXPTCallStub(mXPTCStub);
+    }
+  }
+
+  size_t
+  SizeOfExcludingThis(mozilla::MallocSizeOf aMallocSizeOf) const
+  {
+    return mXPTCStub ? NS_SizeOfIncludingThisXPTCallStub(mXPTCStub, aMallocSizeOf) : 0;
+  }
+};
+
+#endif // nsXPTCUtils_h__