sender_unittest.cc | Explore in Territory

// Copyright 2020 The Chromium Authors
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#include "cast/streaming/public/sender.h"

#include <stdint.h>

#include <algorithm>
#include <array>
#include <chrono>
#include <limits>
#include <map>
#include <set>
#include <utility>
#include <vector>

#include "cast/streaming/impl/compound_rtcp_builder.h"
#include "cast/streaming/impl/frame_collector.h"
#include "cast/streaming/impl/frame_crypto.h"
#include "cast/streaming/impl/packet_util.h"
#include "cast/streaming/public/constants.h"
#include "cast/streaming/public/encoded_frame.h"
#include "cast/streaming/public/frame_id.h"
#include "cast/streaming/impl/rtcp_session.h"
#include "cast/streaming/impl/rtp_defines.h"
#include "cast/streaming/impl/rtp_packet_parser.h"
#include "cast/streaming/sender_packet_router.h"
#include "cast/streaming/impl/sender_report_parser.h"
#include "cast/streaming/impl/session_config.h"
#include "cast/streaming/ssrc.h"
#include "cast/streaming/testing/mock_environment.h"
#include "cast/streaming/testing/simple_socket_subscriber.h"
#include "gmock/gmock.h"
#include "gtest/gtest.h"
#include "platform/base/span.h"
#include "platform/test/byte_view_test_util.h"
#include "platform/test/fake_clock.h"
#include "platform/test/fake_task_runner.h"
#include "util/alarm.h"
#include "util/chrono_helpers.h"
#include "util/std_util.h"
#include "util/yet_another_bit_vector.h"

_;
AtLeast;
Invoke;
InvokeWithoutArgs;
Mock;
NiceMock;
Return;
Sequence;
StrictMock;

namespace openscreen::cast {
namespace {

// Sender configuration.
constexpr Ssrc kSenderSsrc = …;
constexpr Ssrc kReceiverSsrc = …;
constexpr int kRtpTimebase = …;
constexpr milliseconds kTargetPlayoutDelay{ … };
constexpr auto kAesKey = …;
constexpr auto kCastIvMask = …;
constexpr RtpPayloadType kRtpPayloadType = …;

// The number of RTP ticks advanced per frame, for 100 FPS media.
constexpr int kRtpTicksPerFrame = …;

// The number of milliseconds advanced per frame, for 100 FPS media.
constexpr milliseconds kFrameDuration{ … };
static_assert …;

// An Encoded frame that also holds onto its own copy of data.
struct EncodedFrameWithBuffer : public EncodedFrame { … };

// SenderPacketRouter configuration for these tests.
constexpr int kNumPacketsPerBurst = …;
constexpr milliseconds kBurstInterval{ … };

// An arbitrary value, subtracted from "now," to specify the reference_time on
// frames that are about to be enqueued. This simulates that capture+encode
// happened in the past, before Sender::EnqueueFrame() is called.
constexpr milliseconds kCaptureDelay{ … };

// In some tests, the computed time values could be off a little bit due to
// imprecision in certain wire-format timestamp types. The following macro
// behaves just like Gtest's EXPECT_NEAR(), but works with all the time types
// too.
#define EXPECT_NEARLY_EQUAL(duration_a, duration_b, epsilon) …

void OverrideRtpTimestamp(int frame_count, EncodedFrame* frame, int fps) { … }

// Simulates UDP/IPv6 traffic in one direction (from Sender→Receiver, or
// Receiver→Sender), with a settable amount of delay.
class SimulatedNetworkPipe { … };

// Processes packets from the Sender under test, allowing unit tests to set
// expectations for parsed RTP or RTCP packets, to confirm proper behavior of
// the Sender.
class MockReceiver : public Environment::PacketConsumer { … };

class MockObserver : public Sender::Observer { … };

class SenderTest : public testing::Test { … };

// Tests that the Sender can send EncodedFrames over an ideal network (i.e., low
// latency, no loss), and does so without having to transmit the same packet
// twice.
TEST_F(SenderTest, SendsFramesEfficiently) { … }

// Tests that the Sender properly updates the checkpoint frame ID while
// it is cancelling frames. See https://crbug.com/1433584 for an example crash
// where the checkpoint frame ID is invalid.
TEST_F(SenderTest, WaitsUntilEndOfReportToUpdateObservers) { … }

// Tests that the Sender correctly computes the current in-flight media
// duration, a backlog signal for clients.
TEST_F(SenderTest, ComputesInFlightMediaDuration) { … }

// Tests that the Sender computes the maximum in-flight media duration based on
// its analysis of current network conditions. By implication, this demonstrates
// that the Sender is also measuring the network round-trip time.
TEST_F(SenderTest, RespondsToNetworkLatencyChanges) { … }

// Tests that the Sender rejects frames if too large a span of FrameIds would be
// in-flight at once.
TEST_F(SenderTest, RejectsEnqueuingBeforeProtocolDesignLimit) { … }

TEST_F(SenderTest, CanCancelAllInFlightFrames) { … }

// Tests that the Sender rejects frames if too-long a media duration is
// in-flight. This is the Sender's primary flow control mechanism.
TEST_F(SenderTest, RejectsEnqueuingIfTooLongMediaDurationIsInFlight) { … }

// Tests that the Sender propagates the Receiver's picture loss indicator to the
// Observer::OnPictureLost(), and via calls to NeedsKeyFrame(); but only when
// producing a key frame is absolutely necessary.
TEST_F(SenderTest, ManagesReceiverPictureLossWorkflow) { … }

// Tests that the Receiver should get a Sender Report just before the first RTP
// packet, and at regular intervals thereafter. The Sender Report contains the
// lip-sync information necessary for play-out timing.
TEST_F(SenderTest, ProvidesSenderReports) { … }

TEST_F(SenderTest, ReferenceTimesCanBeNonMonotonic) { … }

// Tests that the Sender provides Kickstart packets whenever the Receiver may
// not know about new frames.
TEST_F(SenderTest, ProvidesKickstartPacketsIfReceiverDoesNotACK) { … }

// Tests that the Sender only retransmits packets specifically NACK'ed by the
// Receiver.
TEST_F(SenderTest, ResendsIndividuallyNackedPackets) { … }

// Tests that the Sender retransmits an entire frame if the Receiver requests it
// (i.e., a full frame NACK), but does not retransmit any packets for frames
// (before or after) that have been acknowledged.
TEST_F(SenderTest, ResendsMissingFrames) { … }

}  // namespace
}  // namespace openscreen::cast
chromium/third_party/openscreen/src/cast/streaming/impl/sender_unittest.cc
