RTCStats and RTCStatsReport added (webrtc/stats)

webrtc/stats/rtcstats_unittest.cc

+/*
+ *  Copyright 2016 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 "webrtc/api/rtcstats.h"
+#include "webrtc/api/rtcstatsreport.h"
+
+#include "webrtc/base/checks.h"
+#include "webrtc/base/gunit.h"
+#include "webrtc/base/logging.h"
+
+namespace webrtc {
+
+class RTCTestStats : public RTCStats {
+ public:
+  static const char* const kType;
+
+  RTCTestStats(const std::string& id, double timestamp)
+      : RTCStats(id, timestamp),
+        m_int32("mInt32"),
+        m_uint32("mUint32"),
+        m_int64("mInt64"),
+        m_uint64("mUint64"),
+        m_double("mDouble"),
+        m_static_string("mStaticString"),
+        m_string("mString"),
+        m_sequence_int32("mSequenceInt32"),
+        m_sequence_uint32("mSequenceUint32"),
+        m_sequence_int64("mSequenceInt64"),
+        m_sequence_uint64("mSequenceUint64"),
+        m_sequence_double("mSequenceDouble"),
+        m_sequence_static_string("mSequenceStaticString"),
+        m_sequence_string("mSequenceString") {
+  }
+  std::unique_ptr<RTCStats> copy() const override {
+    return std::unique_ptr<RTCStats>(new RTCTestStats(*this));
+  }
+
+  const char* const* type() const override { return &kType; }
+  const char* type_name() const override { return kType; }

[hta - Chromium, 2016/08/15 15:14:57]

Is there any chance that these could be different? If not, can we declare them
in the base class template? (less chance of later errors)

There might be C++ reasons why that wouldn't work.

[hbos, 2016/08/15 22:46:43]

It is possible to have default implementations, but because it is a static class
variable the implementation needs to know of the subclass type (T::kType, not
RTCStats::kType). I added:

template<typename T>
class RTCStatsSubclass : public RTCStats { ... };

Where T is the deriving class:

class RTCFooStats : public RTCStatsSubclass<RTCFooStats> { ... };

I think only with template can I define the boilerplate methods copy(), type()
and type_name(). I updated the code like that and added comments. For subclasses
of subclasses though you have to override again.

The only alternative I can think of is using macros...

+  std::vector<const RTCStatsMemberInterface*> Members() const override {
+    const RTCStatsMemberInterface* members[] = {
+      &m_int32,
+      &m_uint32,
+      &m_int64,
+      &m_uint64,
+      &m_double,
+      &m_static_string,
+      &m_string,
+      &m_sequence_int32,
+      &m_sequence_uint32,
+      &m_sequence_int64,
+      &m_sequence_uint64,
+      &m_sequence_double,
+      &m_sequence_static_string,
+      &m_sequence_string
+    };
+    return MembersVector(members, sizeof(members) / sizeof(members[0]));
+  }
+
+  RTCStatsMember<int32_t> m_int32;
+  RTCStatsMember<uint32_t> m_uint32;
+  RTCStatsMember<int64_t> m_int64;
+  RTCStatsMember<uint64_t> m_uint64;
+  RTCStatsMember<double> m_double;
+  RTCStatsMember<const char*> m_static_string;
+  RTCStatsMember<std::string> m_string;
+
+  RTCStatsMember<std::vector<int32_t>> m_sequence_int32;
+  RTCStatsMember<std::vector<uint32_t>> m_sequence_uint32;
+  RTCStatsMember<std::vector<int64_t>> m_sequence_int64;
+  RTCStatsMember<std::vector<uint64_t>> m_sequence_uint64;
+  RTCStatsMember<std::vector<double>> m_sequence_double;
+  RTCStatsMember<std::vector<const char*>> m_sequence_static_string;
+  RTCStatsMember<std::vector<std::string>> m_sequence_string;
+};
+
+const char* const RTCTestStats::kType = "test";
+
+class RTCTestStats2 : public RTCStats {
+ public:
+  static const char* const kType;
+
+  RTCTestStats2(const std::string& id, double timestamp)
+      : RTCStats(id, timestamp) {
+  }
+  std::unique_ptr<RTCStats> copy() const override {
+    return std::unique_ptr<RTCStats>(new RTCTestStats2(*this));
+  }
+
+  const char* const* type() const override { return &kType; }
+  const char* type_name() const override { return kType; }
+  std::vector<const RTCStatsMemberInterface*> Members() const override {
+    return std::vector<const RTCStatsMemberInterface*>();
+  }
+};
+
+const char* const RTCTestStats2::kType = "test2";
+
+class RTCTestStats3 : public RTCStats {
+ public:
+  static const char* const kType;
+
+  RTCTestStats3(const std::string& id, double timestamp)
+      : RTCStats(id, timestamp) {
+  }
+  std::unique_ptr<RTCStats> copy() const override {
+    return std::unique_ptr<RTCStats>(new RTCTestStats3(*this));
+  }
+
+  const char* const* type() const override { return &kType; }
+  const char* type_name() const override { return kType; }
+  std::vector<const RTCStatsMemberInterface*> Members() const override {
+    return std::vector<const RTCStatsMemberInterface*>();
+  }
+};

[hta - Chromium, 2016/08/15 15:14:57]

For completeness, derive a class from RTCTestStats3 and see that it works as
expected.

[hbos, 2016/08/15 22:46:43]

Done.

+
+const char* const RTCTestStats3::kType = "test3";
+
+class RTCStatsTest : public testing::Test {
+};
+
+TEST_F(RTCStatsTest, TestRTCStatsAndMembers) {
+  RTCTestStats stats("testId", 42.0);
+  EXPECT_EQ(stats.id(), "testId");
+  EXPECT_EQ(stats.timestamp(), 42.0);
+  std::vector<const RTCStatsMemberInterface*> members = stats.Members();
+  EXPECT_EQ(members.size(), static_cast<size_t>(14));
+  for (const RTCStatsMemberInterface* member : members) {
+    EXPECT_FALSE(member->has_value());
+  }
+  stats.m_int32 = 123;
+  stats.m_uint32 = 123;
+  stats.m_int64 = 123;
+  stats.m_uint64 = 123;
+  stats.m_double = 123.0;
+  stats.m_static_string = "123";
+  stats.m_string = std::string("123");
+  stats.m_sequence_int32 = std::vector<int32_t>();
+  stats.m_sequence_uint32 = std::vector<uint32_t>();
+  stats.m_sequence_int64 = std::vector<int64_t>();
+  stats.m_sequence_uint64 = std::vector<uint64_t>();
+  stats.m_sequence_double = std::vector<double>();
+  stats.m_sequence_static_string = std::vector<const char*>();

[hta - Chromium, 2016/08/15 15:14:57]

Might be nice to thrown in a test that stats.m_sequence_string doesn't have a
value yet (catches the case of some are instantiated, some aren't).

[hbos, 2016/08/15 22:46:43]

The for loop above has already tested all members' |has_value|. An empty
sequence counts as a value, was that a confusion? I'll rename it to
|is_defined|.

+  stats.m_sequence_string = std::vector<std::string>();
+  for (const RTCStatsMemberInterface* member : members) {
+    EXPECT_TRUE(member->has_value());
+  }
+  EXPECT_EQ(*stats.m_int32, static_cast<int32_t>(123));
+  EXPECT_EQ(*stats.m_uint32, static_cast<uint32_t>(123));
+  EXPECT_EQ(*stats.m_int64, static_cast<int64_t>(123));
+  EXPECT_EQ(*stats.m_uint64, static_cast<uint64_t>(123));
+  EXPECT_EQ(*stats.m_double, 123.0);
+  EXPECT_EQ(*stats.m_static_string, "123");
+  EXPECT_EQ(*stats.m_string, std::string("123"));
+  EXPECT_EQ(*stats.m_sequence_int32, std::vector<int32_t>());
+  EXPECT_EQ(*stats.m_sequence_uint32, std::vector<uint32_t>());
+  EXPECT_EQ(*stats.m_sequence_int64, std::vector<int64_t>());
+  EXPECT_EQ(*stats.m_sequence_uint64, std::vector<uint64_t>());
+  EXPECT_EQ(*stats.m_sequence_double, std::vector<double>());
+  EXPECT_EQ(*stats.m_sequence_static_string, std::vector<const char*>());
+  EXPECT_EQ(*stats.m_sequence_string, std::vector<std::string>());

[hta - Chromium, 2016/08/15 15:14:57]

Throw in a case where you give a value to a sequence member too. I don't think
you need more than one, but you should have one.

[hbos, 2016/08/15 22:46:43]

Done.

+}
+
+TEST_F(RTCStatsTest, TestRTCStatsReport) {
+  rtc::scoped_refptr<RTCStatsReport> report = RTCStatsReport::Create();
+  EXPECT_EQ(report->size(), static_cast<size_t>(0));
+  report->AddStats(std::unique_ptr<RTCStats>(new RTCTestStats("a0", 1.0)));
+  report->AddStats(std::unique_ptr<RTCStats>(new RTCTestStats("a1", 2.0)));
+  report->AddStats(std::unique_ptr<RTCStats>(new RTCTestStats2("b0", 4.0)));
+  report->AddStats(std::unique_ptr<RTCStats>(new RTCTestStats2("b1", 8.0)));
+  report->AddStats(std::unique_ptr<RTCStats>(new RTCTestStats("a2", 16.0)));
+  report->AddStats(std::unique_ptr<RTCStats>(new RTCTestStats2("b2", 32.0)));
+  EXPECT_EQ(report->size(), static_cast<size_t>(6));
+
+  EXPECT_EQ((*report)["missing"], nullptr);
+  EXPECT_EQ((*report)["a0"]->id(), "a0");
+  EXPECT_EQ((*report)["b2"]->id(), "b2");
+
+  std::vector<const RTCTestStats*> a = report->GetStatsOfType<RTCTestStats>();
+  EXPECT_EQ(a.size(), static_cast<size_t>(3));
+  uint32_t mask = 0;
+  for (const RTCTestStats* stats : a)
+    mask |= static_cast<uint32_t>(stats->timestamp());
+  EXPECT_EQ(mask, static_cast<uint32_t>(1 | 2 | 16));
+
+  std::vector<const RTCTestStats2*> b = report->GetStatsOfType<RTCTestStats2>();
+  EXPECT_EQ(b.size(), static_cast<size_t>(3));
+  mask = 0;
+  for (const RTCTestStats2* stats : b)
+    mask |= static_cast<uint32_t>(stats->timestamp());
+  EXPECT_EQ(mask, static_cast<uint32_t>(4 | 8 | 32));
+
+  EXPECT_EQ(report->GetStatsOfType<RTCTestStats3>().size(),
+            static_cast<size_t>(0));
+}
+
+}  // namespace webrtc