1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/content/base/src/nsStubMutationObserver.h Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,34 @@
1.4 +/* -*- Mode: C++; tab-width: 2; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
1.5 +/* This Source Code Form is subject to the terms of the Mozilla Public
1.6 + * License, v. 2.0. If a copy of the MPL was not distributed with this
1.7 + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
1.8 +
1.9 +/*
1.10 + * nsStubMutationObserver is an implementation of the nsIMutationObserver
1.11 + * interface (except for the methods on nsISupports) that is intended to be
1.12 + * used as a base class within the content/layout library. All methods do
1.13 + * nothing.
1.14 + */
1.15 +
1.16 +#ifndef nsStubMutationObserver_h_
1.17 +#define nsStubMutationObserver_h_
1.18 +
1.19 +#include "nsIMutationObserver.h"
1.20 +
1.21 +/**
1.22 + * There are two advantages to inheriting from nsStubMutationObserver
1.23 + * rather than directly from nsIMutationObserver:
1.24 + * 1. smaller compiled code size (since there's no need for the code
1.25 + * for the empty virtual function implementations for every
1.26 + * nsIMutationObserver implementation)
1.27 + * 2. the performance of document's loop over observers benefits from
1.28 + * the fact that more of the functions called are the same (which
1.29 + * can reduce instruction cache misses and perhaps improve branch
1.30 + * prediction)
1.31 + */
1.32 +class nsStubMutationObserver : public nsIMutationObserver {
1.33 +public:
1.34 + NS_DECL_NSIMUTATIONOBSERVER
1.35 +};
1.36 +
1.37 +#endif /* !defined(nsStubMutationObserver_h_) */
