| /* |
| * 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_SIMULATED_NETWORK_H_ |
| #define API_TEST_SIMULATED_NETWORK_H_ |
| |
| #include <stddef.h> |
| #include <stdint.h> |
| |
| #include <functional> |
| #include <vector> |
| |
| #include "absl/functional/any_invocable.h" |
| #include "absl/types/optional.h" |
| #include "api/units/data_rate.h" |
| |
| namespace webrtc { |
| |
| struct PacketInFlightInfo { |
| PacketInFlightInfo(size_t size, int64_t send_time_us, uint64_t packet_id) |
| : size(size), send_time_us(send_time_us), packet_id(packet_id) {} |
| |
| size_t size; |
| int64_t send_time_us; |
| // Unique identifier for the packet in relation to other packets in flight. |
| uint64_t packet_id; |
| }; |
| |
| struct PacketDeliveryInfo { |
| static constexpr int kNotReceived = -1; |
| PacketDeliveryInfo(PacketInFlightInfo source, int64_t receive_time_us) |
| : receive_time_us(receive_time_us), packet_id(source.packet_id) {} |
| |
| bool operator==(const PacketDeliveryInfo& other) const { |
| return receive_time_us == other.receive_time_us && |
| packet_id == other.packet_id; |
| } |
| |
| int64_t receive_time_us; |
| uint64_t packet_id; |
| }; |
| |
| // BuiltInNetworkBehaviorConfig is a built-in network behavior configuration |
| // for built-in network behavior that will be used by WebRTC if no custom |
| // NetworkBehaviorInterface is provided. |
| struct BuiltInNetworkBehaviorConfig { |
| // Queue length in number of packets. |
| size_t queue_length_packets = 0; |
| // Delay in addition to capacity induced delay. |
| int queue_delay_ms = 0; |
| // Standard deviation of the extra delay. |
| int delay_standard_deviation_ms = 0; |
| // Link capacity in kbps. 0 is treated as infinite capacity. |
| // Deprecated, please use link_capacity instead. |
| // TODO(bugs.webrtc.org/14525): Remove once all usage has migrated. |
| int link_capacity_kbps = 0; |
| DataRate link_capacity = DataRate::Infinity(); |
| // Random packet loss, range 0 to 100. |
| double loss_percent = 0.; |
| // If packets are allowed to be reordered. |
| bool allow_reordering = false; |
| // The average length of a burst of lost packets. |
| int avg_burst_loss_length = -1; |
| // Additional bytes to add to packet size. |
| int packet_overhead = 0; |
| }; |
| |
| // Interface that represents a Network behaviour. |
| // |
| // It is clients of this interface responsibility to enqueue and dequeue |
| // packets (based on the estimated delivery time expressed by |
| // NextDeliveryTimeUs). |
| // |
| // To enqueue packets, call EnqueuePacket: |
| // EXPECT_TRUE(network.EnqueuePacket( |
| // PacketInFlightInfo(/*size=*/1, /*send_time_us=*/0, /*packet_id=*/1))); |
| // |
| // To know when to call DequeueDeliverablePackets to pull packets out of the |
| // network, call NextDeliveryTimeUs and schedule a task to invoke |
| // DequeueDeliverablePackets (if not already scheduled). |
| // |
| // DequeueDeliverablePackets will return a vector of delivered packets, but this |
| // vector can be empty in case of extra delay. In such case, make sure to invoke |
| // NextDeliveryTimeUs and schedule a task to call DequeueDeliverablePackets for |
| // the next estimated delivery of packets. |
| // |
| // std::vector<PacketDeliveryInfo> delivered_packets = |
| // network.DequeueDeliverablePackets(/*receive_time_us=*/1000000); |
| class NetworkBehaviorInterface { |
| public: |
| // Enqueues a packet in the network and returns true if the action was |
| // successful, false otherwise (for example, because the network capacity has |
| // been saturated). If the return value is false, the packet should be |
| // considered as dropped and it will not be returned by future calls |
| // to DequeueDeliverablePackets. |
| // Packets enqueued will exit the network when DequeueDeliverablePackets is |
| // called and enough time has passed (see NextDeliveryTimeUs). |
| virtual bool EnqueuePacket(PacketInFlightInfo packet_info) = 0; |
| // Retrieves all packets that should be delivered by the given receive time. |
| // Not all the packets in the returned std::vector are actually delivered. |
| // In order to know the state of each packet it is necessary to check the |
| // `receive_time_us` field of each packet. If that is set to |
| // PacketDeliveryInfo::kNotReceived then the packet is considered lost in the |
| // network. |
| virtual std::vector<PacketDeliveryInfo> DequeueDeliverablePackets( |
| int64_t receive_time_us) = 0; |
| // Returns time in microseconds when caller should call |
| // DequeueDeliverablePackets to get the next set of delivered packets. It is |
| // possible that no packet will be delivered by that time (e.g. in case of |
| // random extra delay), in such case this method should be called again to get |
| // the updated estimated delivery time. |
| virtual absl::optional<int64_t> NextDeliveryTimeUs() const = 0; |
| // Registers a callback that should be triggered by an implementation if the |
| // next NextDeliveryTimeUs() has changed between a call to NextDeliveryTimeUs |
| // and DequeueDeliverablePackets. |
| // The intended usage is to invoke NextDeliveryTimeUs and reschedule the |
| // DequeueDeliverablePackets call when network parameters (such as link |
| // capacity) changes. |
| virtual void RegisterDeliveryTimeChangedCallback( |
| absl::AnyInvocable<void()> callback) {} |
| virtual ~NetworkBehaviorInterface() = default; |
| }; |
| |
| // Class simulating a network link. This is a simple and naive solution just |
| // faking capacity and adding an extra transport delay in addition to the |
| // capacity introduced delay. |
| class SimulatedNetworkInterface : public NetworkBehaviorInterface { |
| public: |
| // Sets a new configuration. |
| virtual void SetConfig(const BuiltInNetworkBehaviorConfig& config) = 0; |
| virtual void UpdateConfig( |
| std::function<void(BuiltInNetworkBehaviorConfig*)> config_modifier) = 0; |
| // Pauses the network until `until_us`. This affects both delivery (calling |
| // DequeueDeliverablePackets before `until_us` results in an empty std::vector |
| // of packets) and capacity (the network is paused, so packets are not |
| // flowing and they will restart flowing at `until_us`). |
| virtual void PauseTransmissionUntil(int64_t until_us) = 0; |
| }; |
| |
| } // namespace webrtc |
| |
| #endif // API_TEST_SIMULATED_NETWORK_H_ |