tor-browser

The Tor Browser
git clone https://git.dasho.dev/tor-browser.git
Log | Files | Refs | README | LICENSE

environment_factory.h (4774B)

      1 /*
      2 *  Copyright 2023 The WebRTC Project Authors. All rights reserved.
      3 *
      4 *  Use of this source code is governed by a BSD-style license
      5 *  that can be found in the LICENSE file in the root of the source
      6 *  tree. An additional intellectual property rights grant can be found
      7 *  in the file PATENTS.  All contributing project authors may
      8 *  be found in the AUTHORS file in the root of the source tree.
      9 */
     10 
     11 #ifndef API_ENVIRONMENT_ENVIRONMENT_FACTORY_H_
     12 #define API_ENVIRONMENT_ENVIRONMENT_FACTORY_H_
     13 
     14 #include <memory>
     15 #include <utility>
     16 
     17 #include "absl/base/nullability.h"
     18 #include "api/environment/environment.h"
     19 #include "api/field_trials_view.h"
     20 #include "api/ref_counted_base.h"
     21 #include "api/rtc_event_log/rtc_event_log.h"
     22 #include "api/scoped_refptr.h"
     23 #include "api/task_queue/task_queue_factory.h"
     24 #include "rtc_base/system/rtc_export.h"
     25 #include "system_wrappers/include/clock.h"
     26 
     27 namespace webrtc {
     28 // Constructs `Environment`.
     29 // Individual utilities are provided using one of the `Set` functions.
     30 // `Set` functions do nothing when nullptr value is passed.
     31 // Creates default implementations for utilities that are not provided.
     32 //
     33 // Examples:
     34 //    Environment default_env = EnvironmentFactory().Create();
     35 //
     36 //    EnvironmentFactory factory;
     37 //    factory.Set(std::make_unique<CustomTaskQueueFactory>());
     38 //    factory.Set(std::make_unique<CustomFieldTrials>());
     39 //    Environment custom_env = factory.Create();
     40 //
     41 class RTC_EXPORT EnvironmentFactory final {
     42 public:
     43  EnvironmentFactory() = default;
     44  explicit EnvironmentFactory(const Environment& env);
     45 
     46  EnvironmentFactory(const EnvironmentFactory&) = default;
     47  EnvironmentFactory(EnvironmentFactory&&) = default;
     48  EnvironmentFactory& operator=(const EnvironmentFactory&) = default;
     49  EnvironmentFactory& operator=(EnvironmentFactory&&) = default;
     50 
     51  ~EnvironmentFactory() = default;
     52 
     53  void Set(absl_nullable std::unique_ptr<const FieldTrialsView> utility);
     54  void Set(absl_nullable std::unique_ptr<Clock> utility);
     55  void Set(absl_nullable std::unique_ptr<TaskQueueFactory> utility);
     56  void Set(absl_nullable std::unique_ptr<RtcEventLog> utility);
     57 
     58  void Set(const FieldTrialsView* absl_nullable utility);
     59  void Set(Clock* absl_nullable utility);
     60  void Set(TaskQueueFactory* absl_nullable utility);
     61  void Set(RtcEventLog* absl_nullable utility);
     62 
     63  Environment Create() const;
     64 
     65 private:
     66  Environment CreateWithDefaults() &&;
     67 
     68  scoped_refptr<const RefCountedBase> leaf_;
     69 
     70  const FieldTrialsView* absl_nullable field_trials_ = nullptr;
     71  Clock* absl_nullable clock_ = nullptr;
     72  TaskQueueFactory* absl_nullable task_queue_factory_ = nullptr;
     73  RtcEventLog* absl_nullable event_log_ = nullptr;
     74 };
     75 
     76 // Helper for concise way to create an environment.
     77 // `Environment env = CreateEnvironment(utility1, utility2)` is a shortcut to
     78 // `EnvironmentFactory factory;
     79 // factory.Set(utility1);
     80 // factory.Set(utility2);
     81 // Environment env = factory.Create();`
     82 //
     83 // Examples:
     84 //    Environment default_env = CreateEnvironment();
     85 //    Environment custom_env =
     86 //        CreateEnvironment(std::make_unique<CustomTaskQueueFactory>(),
     87 //                          std::make_unique<CustomFieldTrials>());
     88 template <typename... Utilities>
     89 Environment CreateEnvironment(Utilities&&... utilities);
     90 
     91 //------------------------------------------------------------------------------
     92 // Implementation details follow
     93 //------------------------------------------------------------------------------
     94 
     95 inline void EnvironmentFactory::Set(
     96    const FieldTrialsView* absl_nullable utility) {
     97  if (utility != nullptr) {
     98    field_trials_ = utility;
     99  }
    100 }
    101 
    102 inline void EnvironmentFactory::Set(Clock* absl_nullable utility) {
    103  if (utility != nullptr) {
    104    clock_ = utility;
    105  }
    106 }
    107 
    108 inline void EnvironmentFactory::Set(TaskQueueFactory* absl_nullable utility) {
    109  if (utility != nullptr) {
    110    task_queue_factory_ = utility;
    111  }
    112 }
    113 
    114 inline void EnvironmentFactory::Set(RtcEventLog* absl_nullable utility) {
    115  if (utility != nullptr) {
    116    event_log_ = utility;
    117  }
    118 }
    119 
    120 namespace webrtc_create_environment_internal {
    121 
    122 inline void Set(EnvironmentFactory& /* factory */) {}
    123 
    124 template <typename FirstUtility, typename... Utilities>
    125 void Set(EnvironmentFactory& factory,
    126         FirstUtility&& first,
    127         Utilities&&... utilities) {
    128  factory.Set(std::forward<FirstUtility>(first));
    129  Set(factory, std::forward<Utilities>(utilities)...);
    130 }
    131 
    132 }  // namespace webrtc_create_environment_internal
    133 
    134 template <typename... Utilities>
    135 Environment CreateEnvironment(Utilities&&... utilities) {
    136  EnvironmentFactory factory;
    137  webrtc_create_environment_internal::Set(
    138      factory, std::forward<Utilities>(utilities)...);
    139  return factory.Create();
    140 }
    141 
    142 }  // namespace webrtc
    143 
    144 #endif  // API_ENVIRONMENT_ENVIRONMENT_FACTORY_H_