text: /*
   *  Copyright (c) 2018 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_TEST_NETEQ_SIMULATOR_H_
  #define API_TEST_NETEQ_SIMULATOR_H_
  
  #include <stdint.h>
  
  #include <map>
  #include <vector>
  
  namespace webrtc {
  namespace test {
  
  class NetEqSimulator {
   public:
    virtual ~NetEqSimulator() = default;
  
    enum class Action { kNormal, kExpand, kAccelerate, kPreemptiveExpand };
  
    // The results of one simulation step.
    struct SimulationStepResult {
      SimulationStepResult();
      SimulationStepResult(const SimulationStepResult& other);
      ~SimulationStepResult();
  
      bool is_simulation_finished = false;
      // The amount of audio produced (in ms) with the actions in this time step.
      std::map<Action, int> action_times_ms;
      // The amount of wall clock time (in ms) that elapsed since the previous
      // event. This is not necessarily equal to the sum of the values in
      // action_times_ms.
      int64_t simulation_step_ms = 0;
    };
  
    struct NetEqState {
      NetEqState();
      NetEqState(const NetEqState& other);
      ~NetEqState();
      // The sum of the packet buffer and sync buffer delay.
      int current_delay_ms = 0;
      // An indicator that packet loss occurred since the last GetAudio event.
      bool packet_loss_occurred = false;
      // An indicator that the packet buffer has been flushed since the last
      // GetAudio event.
      bool packet_buffer_flushed = false;
      // Indicates if the next needed packet is available in the buffer.
      bool next_packet_available = false;
      // The inter-arrival times in ms of the packets that have arrived since the
      // last GetAudio event.
      std::vector<int> packet_iat_ms;
      // The current packet size in ms.
      int packet_size_ms = 0;
    };
  
    // Runs the simulation until we hit the next GetAudio event. If the simulation
    // is finished, is_simulation_finished will be set to true in the returned
    // SimulationStepResult.
    virtual SimulationStepResult RunToNextGetAudio() = 0;
  
    // Set the next action to be taken by NetEq. This will override any action
    // that NetEq would normally decide to take.
    virtual void SetNextAction(Action next_operation) = 0;
  
    // Get the current state of NetEq.
    virtual NetEqState GetNetEqState() = 0;
  };
  
  }  // namespace test
  }  // namespace webrtc
  
  #endif  // API_TEST_NETEQ_SIMULATOR_H_
  