toolkit/components/bitsdownload/Bits.cpp

   1 /* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- */
   2 /* vim: set ts=8 sts=2 et sw=2 tw=80: */
   3 /* This Source Code Form is subject to the terms of the Mozilla Public
   4  * License, v. 2.0. If a copy of the MPL was not distributed with this
   5  * file, You can obtain one at http://mozilla.org/MPL/2.0/. */
   6 #include "mozilla/ClearOnShutdown.h"
   7 #include "mozilla/StaticPtr.h"
   8 #include "nsCOMPtr.h"
   9 #include "Bits.h"
  10
  11 // This anonymous namespace prevents outside C++ code from improperly accessing
  12 // these implementation details.
  13 namespace {
  14 extern "C" {
  15 // Implemented in Rust.
  16 void new_bits_service(nsIBits** result);
  17 }
  18
  19 static mozilla::StaticRefPtr<nsIBits> sBitsService;
  20 }  // namespace
  21
  22 already_AddRefed<nsIBits> GetBitsService() {
  23   nsCOMPtr<nsIBits> bitsService;
  24
  25   if (sBitsService) {
  26     bitsService = sBitsService;
  27   } else {
  28     new_bits_service(getter_AddRefs(bitsService));
  29     sBitsService = bitsService;
  30     mozilla::ClearOnShutdown(&sBitsService);
  31   }
  32
  33   return bitsService.forget();
  34 }