Implemented the GetSources() in native code.

webrtc/modules/rtp_rtcp/source/rtp_receiver_unittest.cc

+/*
+ *  Copyright (c) 2017 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.
+ */
+
+#include <memory>
+
+#include "webrtc/common_types.h"
+#include "webrtc/modules/rtp_rtcp/include/rtp_header_parser.h"
+#include "webrtc/modules/rtp_rtcp/include/rtp_payload_registry.h"
+#include "webrtc/modules/rtp_rtcp/include/rtp_receiver.h"
+#include "webrtc/modules/rtp_rtcp/include/rtp_rtcp_defines.h"
+#include "webrtc/test/gtest.h"
+
+namespace webrtc {
+
+const uint32_t kTestRate = 64000u;
+const uint8_t kTestPayload[] = {'t', 'e', 's', 't'};
+const uint8_t kPcmuPayloadType = 96;
+const int64_t kGetSourcesTimeoutMs = 10000;
+const int kMaxSourceListsSize = 100;
+
+class RtpReceiverTest : public ::testing::Test {
+ protected:
+  RtpReceiverTest() : fake_clock(123456) {}
+  ~RtpReceiverTest() {}
+
+  void SetUp() override {

[Taylor Brandstetter, 2017/04/05 04:27:55]

nit: This code can just go in the constructor.

[Zhi Huang, 2017/04/06 03:09:50]

Done.

+    rtp_payload_registry_.reset(new RTPPayloadRegistry());
+
+    rtp_receiver_.reset(RtpReceiver::CreateAudioReceiver(
+        &fake_clock, nullptr, nullptr, rtp_payload_registry_.get()));
+
+    CodecInst voice_codec = {};
+    voice_codec.pltype = kPcmuPayloadType;
+    voice_codec.plfreq = 8000;
+    voice_codec.rate = kTestRate;
+    memcpy(voice_codec.plname, "PCMU", 5);
+    rtp_receiver_->RegisterReceivePayload(voice_codec);
+  }
+
+  std::unique_ptr<RTPPayloadRegistry> rtp_payload_registry_;

[danilchap, 2017/04/05 16:24:21]

nit: doesn't need to wrap it in unique_ptr

[Zhi Huang, 2017/04/06 03:09:50]

Done.

+  std::unique_ptr<RtpReceiver> rtp_receiver_;
+  SimulatedClock fake_clock;

[danilchap, 2017/04/05 16:24:22]

put fake_clock before rtp_receiver_ to be sure it is destroyed after.
(also, it will allow to initialize rtp_receiver_ in the initialization list of
the constructor.)

[Zhi Huang, 2017/04/06 03:09:50]

Done.

+};
+
+TEST_F(RtpReceiverTest, GetSources) {
+  int64_t timestamp = fake_clock.TimeInMilliseconds();
+  RTPHeader header;
+  header.payloadType = kPcmuPayloadType;
+  header.ssrc = 1;
+  header.timestamp = timestamp;
+  header.numCSRCs = 2;
+  header.arrOfCSRCs[0] = 111;
+  header.arrOfCSRCs[1] = 222;
+  PayloadUnion payload_specific = {AudioPayload()};
+  bool in_order = false;
+
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  auto sources = rtp_receiver_->GetSources();
+  // One SSRC source and two CSRC sources.
+  ASSERT_EQ(3u, sources.size());
+  EXPECT_EQ(1u, sources[0].source_id());

[Taylor Brandstetter, 2017/04/05 04:27:55]

nit: We aren't guaranteeing anything about the order, so the test should
probably be written in an order-agnostic way. For example, using a "find by
source ID" helper function.

[Zhi Huang, 2017/04/06 03:09:50]

Maybe should use FindSourceByIdAndType since two sources can have same id but
different type.
Done.

+  EXPECT_EQ(timestamp, sources[0].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[0].source_type());
+  EXPECT_EQ(222u, sources[1].source_id());
+  EXPECT_EQ(timestamp, sources[1].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_CSRC_SOURCE, sources[1].source_type());
+  EXPECT_EQ(111u, sources[2].source_id());
+  EXPECT_EQ(timestamp, sources[2].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_CSRC_SOURCE, sources[2].source_type());
+
+  // Advance the fake clock and the method is expected to return the
+  // contributing source object with same |source| and updated |timestamp()|.
+  fake_clock.AdvanceTimeMilliseconds(1);
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  sources = rtp_receiver_->GetSources();
+  ASSERT_EQ(3u, sources.size());
+  EXPECT_EQ(1u, sources[0].source_id());
+  EXPECT_EQ(timestamp + 1, sources[0].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[0].source_type());
+  EXPECT_EQ(222u, sources[1].source_id());
+  EXPECT_EQ(timestamp + 1, sources[1].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_CSRC_SOURCE, sources[1].source_type());
+  EXPECT_EQ(111u, sources[2].source_id());
+  EXPECT_EQ(timestamp + 1, sources[2].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_CSRC_SOURCE, sources[2].source_type());
+
+  // Simulate the time out.
+  fake_clock.AdvanceTimeMilliseconds(kGetSourcesTimeoutMs + 1);

[Taylor Brandstetter, 2017/04/05 04:27:55]

To make the test even more thorough, could advance the time to
kGetSourcesTimeoutMs - 1 and verify that they still are returned.

[Zhi Huang, 2017/04/06 03:09:50]

Done.

+  sources = rtp_receiver_->GetSources();
+  // All the sources should be out of date.
+  ASSERT_EQ(0u, sources.size());
+}
+
+// Test the case that the SSRC is changed.
+TEST_F(RtpReceiverTest, GetSourcesChangeSSRC) {
+  int64_t prev_time = -1;
+  int64_t cur_time = fake_clock.TimeInMilliseconds();
+  RTPHeader header;
+  header.payloadType = kPcmuPayloadType;
+  header.ssrc = 1;
+  header.timestamp = cur_time;
+  PayloadUnion payload_specific = {AudioPayload()};
+  bool in_order = false;
+
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  auto sources = rtp_receiver_->GetSources();
+  ASSERT_EQ(1u, sources.size());
+  EXPECT_EQ(1u, sources[0].source_id());
+  EXPECT_EQ(cur_time, sources[0].timestamp());
+
+  // The SSRC is changed and the old SSRC is expected to be returned.
+  fake_clock.AdvanceTimeMilliseconds(100);
+  prev_time = cur_time;
+  cur_time = fake_clock.TimeInMilliseconds();
+  header.ssrc = 2;
+  header.timestamp = cur_time;
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  sources = rtp_receiver_->GetSources();
+  ASSERT_EQ(2u, sources.size());
+  EXPECT_EQ(2u, sources[0].source_id());
+  EXPECT_EQ(cur_time, sources[0].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[0].source_type());
+  EXPECT_EQ(1u, sources[1].source_id());
+  EXPECT_EQ(prev_time, sources[1].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[1].source_type());
+
+  // The SSRC is changed again and happen to be changed back to 1. No
+  // duplication is expected.
+  fake_clock.AdvanceTimeMilliseconds(100);
+  header.ssrc = 1;
+  header.timestamp = cur_time;
+  prev_time = cur_time;
+  cur_time = fake_clock.TimeInMilliseconds();
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  sources = rtp_receiver_->GetSources();
+  ASSERT_EQ(2u, sources.size());
+  EXPECT_EQ(1u, sources[0].source_id());
+  EXPECT_EQ(cur_time, sources[0].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[0].source_type());
+  EXPECT_EQ(2u, sources[1].source_id());
+  EXPECT_EQ(prev_time, sources[1].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[1].source_type());
+
+  // Old SSRC source timeout.
+  fake_clock.AdvanceTimeMilliseconds(kGetSourcesTimeoutMs);
+  cur_time = fake_clock.TimeInMilliseconds();
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  sources = rtp_receiver_->GetSources();
+  ASSERT_EQ(1u, sources.size());
+  EXPECT_EQ(1u, sources[0].source_id());
+  EXPECT_EQ(cur_time, sources[0].timestamp());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[0].source_type());
+}
+
+// Test that the out of date objects will be removed when the source lists are
+// too large.
+TEST_F(RtpReceiverTest, GetSourcesMaxListSize) {

[Taylor Brandstetter, 2017/04/05 04:27:55]

This test would succeed even if the out-of-date objects weren't removed, because
they'd be filtered when GetSources is called. I understand this test is meant to
exercise the "remove old objects" code, but there isn't really a way to test
that in a black box fashion.

[Zhi Huang, 2017/04/06 03:09:50]

Agreed. Thanks for catching this.
I plan to expose the source list from the RtpReceiverImpl and downcast the
RtpReceiver to get the list directly. Does it make sense to you? I think it
might be acceptable to have downcasting in the test.

+  int64_t timestamp = fake_clock.TimeInMilliseconds();
+  bool in_order = false;
+  RTPHeader header;
+  header.payloadType = kPcmuPayloadType;
+  header.timestamp = timestamp;
+  PayloadUnion payload_specific = {AudioPayload()};
+  header.numCSRCs = 1;
+
+  for (size_t i = 0; i < kMaxSourceListsSize; ++i) {
+    header.ssrc = i;
+    header.arrOfCSRCs[0] = (i + 1);
+    EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                                 payload_specific, in_order));
+  }
+  auto sources = rtp_receiver_->GetSources();
+  // Expect |kMaxSourceListsSize| SSRC sources and |kMaxSourceListsSize| CSRC
+  // sources.
+  ASSERT_TRUE(sources.size() == 2 * kMaxSourceListsSize);
+  for (size_t i = 0; i < kMaxSourceListsSize; ++i) {
+    // The SSRC source IDs are expected to be 99, 98, 97 ... 0
+    EXPECT_EQ(kMaxSourceListsSize - i - 1, sources[i].source_id());
+    EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[i].source_type());
+    EXPECT_EQ(timestamp, sources[i].timestamp());
+
+    // The CSRC source IDs are expected to be 100, 99, 98 ... 1
+    EXPECT_EQ(kMaxSourceListsSize - i,
+              sources[i + kMaxSourceListsSize].source_id());
+    EXPECT_EQ(RtpSourceType::RTP_CSRC_SOURCE,
+              sources[i + kMaxSourceListsSize].source_type());
+    EXPECT_EQ(timestamp, sources[i + kMaxSourceListsSize].timestamp());
+  }
+
+  // Timeout. All the existing objects are out of date and are expected to be
+  // removed.
+  fake_clock.AdvanceTimeMilliseconds(kGetSourcesTimeoutMs + 1);
+  header.ssrc = 111;
+  header.arrOfCSRCs[0] = 222;
+  EXPECT_TRUE(rtp_receiver_->IncomingRtpPacket(header, kTestPayload, 4,
+                                               payload_specific, in_order));
+  sources = rtp_receiver_->GetSources();
+  ASSERT_EQ(2u, sources.size());
+  EXPECT_EQ(111u, sources[0].source_id());
+  EXPECT_EQ(RtpSourceType::RTP_SSRC_SOURCE, sources[0].source_type());
+  EXPECT_EQ(fake_clock.TimeInMilliseconds(), sources[0].timestamp());
+
+  EXPECT_EQ(222u, sources[1].source_id());
+  EXPECT_EQ(RtpSourceType::RTP_CSRC_SOURCE, sources[1].source_type());
+  EXPECT_EQ(fake_clock.TimeInMilliseconds(), sources[1].timestamp());
+}
+
+}  // namespace webrtc