Repo created

TMessagesProj/jni/voip/webrtc/api/environment/environment_factory.h

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+/*
+ *  Copyright 2023 The WebRTC Project Authors. All rights reserved.
+ *
+ *  Use of this source code is governed by a BSD-style license
+ *  that can be found in the LICENSE file in the root of the source
+ *  tree. An additional intellectual property rights grant can be found
+ *  in the file PATENTS.  All contributing project authors may
+ *  be found in the AUTHORS file in the root of the source tree.
+ */
+
+#ifndef API_ENVIRONMENT_ENVIRONMENT_FACTORY_H_
+#define API_ENVIRONMENT_ENVIRONMENT_FACTORY_H_
+
+#include <memory>
+#include <utility>
+
+#include "absl/base/nullability.h"
+#include "api/environment/environment.h"
+#include "api/ref_counted_base.h"
+#include "api/scoped_refptr.h"
+#include "rtc_base/system/rtc_export.h"
+
+namespace webrtc {
+
+// These classes are forward declared to reduce amount of headers exposed
+// through api header.
+class Clock;
+class TaskQueueFactory;
+class FieldTrialsView;
+class RtcEventLog;
+
+// Constructs `Environment`.
+// Individual utilities are provided using one of the `Set` functions.
+// `Set` functions do nothing when nullptr value is passed.
+// Creates default implementations for utilities that are not provided.
+//
+// Examples:
+//    Environment default_env = EnvironmentFactory().Create();
+//
+//    EnvironmentFactory factory;
+//    factory.Set(std::make_unique<CustomTaskQueueFactory>());
+//    factory.Set(std::make_unique<CustomFieldTrials>());
+//    Environment custom_env = factory.Create();
+//
+class RTC_EXPORT EnvironmentFactory final {
+ public:
+  EnvironmentFactory() = default;
+  explicit EnvironmentFactory(const Environment& env);
+
+  EnvironmentFactory(const EnvironmentFactory&) = default;
+  EnvironmentFactory(EnvironmentFactory&&) = default;
+  EnvironmentFactory& operator=(const EnvironmentFactory&) = default;
+  EnvironmentFactory& operator=(EnvironmentFactory&&) = default;
+
+  ~EnvironmentFactory() = default;
+
+  void Set(absl::Nullable<std::unique_ptr<const FieldTrialsView>> utility);
+  void Set(absl::Nullable<std::unique_ptr<Clock>> utility);
+  void Set(absl::Nullable<std::unique_ptr<TaskQueueFactory>> utility);
+  void Set(absl::Nullable<std::unique_ptr<RtcEventLog>> utility);
+
+  void Set(absl::Nullable<const FieldTrialsView*> utility);
+  void Set(absl::Nullable<Clock*> utility);
+  void Set(absl::Nullable<TaskQueueFactory*> utility);
+  void Set(absl::Nullable<RtcEventLog*> utility);
+
+  Environment Create() const;
+
+ private:
+  Environment CreateWithDefaults() &&;
+
+  scoped_refptr<const rtc::RefCountedBase> leaf_;
+
+  absl::Nullable<const FieldTrialsView*> field_trials_ = nullptr;
+  absl::Nullable<Clock*> clock_ = nullptr;
+  absl::Nullable<TaskQueueFactory*> task_queue_factory_ = nullptr;
+  absl::Nullable<RtcEventLog*> event_log_ = nullptr;
+};
+
+// Helper for concise way to create an environment.
+// `Environment env = CreateEnvironment(utility1, utility2)` is a shortcut to
+// `EnvironmentFactory factory;
+// factory.Set(utility1);
+// factory.Set(utility2);
+// Environment env = factory.Create();`
+//
+// Examples:
+//    Environment default_env = CreateEnvironment();
+//    Environment custom_env =
+//        CreateEnvironment(std::make_unique<CustomTaskQueueFactory>(),
+//                          std::make_unique<CustomFieldTrials>());
+template <typename... Utilities>
+Environment CreateEnvironment(Utilities&&... utilities);
+
+//------------------------------------------------------------------------------
+// Implementation details follow
+//------------------------------------------------------------------------------
+
+inline void EnvironmentFactory::Set(
+    absl::Nullable<const FieldTrialsView*> utility) {
+  if (utility != nullptr) {
+    field_trials_ = utility;
+  }
+}
+
+inline void EnvironmentFactory::Set(absl::Nullable<Clock*> utility) {
+  if (utility != nullptr) {
+    clock_ = utility;
+  }
+}
+
+inline void EnvironmentFactory::Set(absl::Nullable<TaskQueueFactory*> utility) {
+  if (utility != nullptr) {
+    task_queue_factory_ = utility;
+  }
+}
+
+inline void EnvironmentFactory::Set(absl::Nullable<RtcEventLog*> utility) {
+  if (utility != nullptr) {
+    event_log_ = utility;
+  }
+}
+
+namespace webrtc_create_environment_internal {
+
+inline void Set(EnvironmentFactory& factory) {}
+
+template <typename FirstUtility, typename... Utilities>
+void Set(EnvironmentFactory& factory,
+         FirstUtility&& first,
+         Utilities&&... utilities) {
+  factory.Set(std::forward<FirstUtility>(first));
+  Set(factory, std::forward<Utilities>(utilities)...);
+}
+
+}  // namespace webrtc_create_environment_internal
+
+template <typename... Utilities>
+Environment CreateEnvironment(Utilities&&... utilities) {
+  EnvironmentFactory factory;
+  webrtc_create_environment_internal::Set(
+      factory, std::forward<Utilities>(utilities)...);
+  return factory.Create();
+}
+
+}  // namespace webrtc
+
+#endif  // API_ENVIRONMENT_ENVIRONMENT_FACTORY_H_