Helium: Adding vector clock

blimp/net/helium/vector_clock_unittest.cc

+// Copyright 2016 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "blimp/net/helium/vector_clock.h"
+
+#include "base/macros.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace blimp {
+namespace {
+
+class VectorClockComparisonTest
+    : public ::testing::TestWithParam<
+          std::tuple<VectorClock, VectorClock, VectorClock::Comparison>> {
+ public:
+  VectorClockComparisonTest() {}
+  ~VectorClockComparisonTest() override {}
+};
+
+TEST_P(VectorClockComparisonTest, CompareTo) {
+  auto param = GetParam();
+  VectorClock v1 = std::get<0>(param);
+  VectorClock v2 = std::get<1>(param);
+  VectorClock::Comparison expected = std::get<2>(param);
+  EXPECT_EQ(expected, v1.CompareTo(v2));
+}
+
+INSTANTIATE_TEST_CASE_P(
+    LessThan,
+    VectorClockComparisonTest,
+    ::testing::Values(std::make_tuple(VectorClock(1, 2),
+                                      VectorClock(1, 3),
+                                      VectorClock::Comparison::LessThan)));
+
+INSTANTIATE_TEST_CASE_P(
+    GreaterThan,
+    VectorClockComparisonTest,
+    ::testing::Values(std::make_tuple(VectorClock(1, 3),
+                                      VectorClock(1, 2),
+                                      VectorClock::Comparison::GreaterThan),
+                      std::make_tuple(VectorClock(2, 2),
+                                      VectorClock(1, 2),
+                                      VectorClock::Comparison::GreaterThan)));
+
+INSTANTIATE_TEST_CASE_P(
+    Conflict,
+    VectorClockComparisonTest,
+    ::testing::Values(std::make_tuple(VectorClock(1, 2),
+                                      VectorClock(0, 1),
+                                      VectorClock::Comparison::Conflict),
+                      std::make_tuple(VectorClock(1, 2),
+                                      VectorClock(0, 3),
+                                      VectorClock::Comparison::Conflict)));
+
+INSTANTIATE_TEST_CASE_P(
+    EqualTo,
+    VectorClockComparisonTest,
+    ::testing::Values(std::make_tuple(VectorClock(1, 1),
+                                      VectorClock(1, 1),
+                                      VectorClock::Comparison::EqualTo),
+                      std::make_tuple(VectorClock(2, 3),
+                                      VectorClock(2, 3),
+                                      VectorClock::Comparison::EqualTo),
+                      std::make_tuple(VectorClock(3, 2),
+                                      VectorClock(3, 2),
+                                      VectorClock::Comparison::EqualTo)));
+
+class VectorClockTest : public testing::Test {
+ public:
+  VectorClockTest() {}
+  ~VectorClockTest() override {}
+
+ protected:
+  void CheckCumulativeMerge(const VectorClock& v1,
+                            const VectorClock& v2,
+                            const VectorClock& expected) {
+    // Compute the merge of v1 and v2
+    VectorClock r1 = v1.MergeWith(v2);
+    EXPECT_EQ(expected.local_revision(), r1.local_revision());
+    EXPECT_EQ(expected.remote_revision(), r1.remote_revision());
+
+    // Compute the merge of v2 and v1
+    VectorClock r2 = v2.MergeWith(v1);
+    EXPECT_EQ(expected.local_revision(), r2.local_revision());
+    EXPECT_EQ(expected.remote_revision(), r2.remote_revision());
+  }
+
+ private:
+  DISALLOW_COPY_AND_ASSIGN(VectorClockTest);
+};
+
+TEST_F(VectorClockTest, IncrementLocal1) {
+  VectorClock v(0, 0);
+  v.IncrementLocal();
+  EXPECT_EQ(1U, v.local_revision());
+  EXPECT_EQ(0U, v.remote_revision());
+}
+
+TEST_F(VectorClockTest, IncrementLocal2) {
+  VectorClock v(4, 5);
+  v.IncrementLocal();
+  EXPECT_EQ(5U, v.local_revision());
+  EXPECT_EQ(5U, v.remote_revision());
+}
+
+TEST_F(VectorClockTest, MergeLocalEqualRemoteSmaller) {
+  VectorClock v1(1, 2);
+  VectorClock v2(1, 4);
+
+  VectorClock expected(1, 4);
+  CheckCumulativeMerge(v1, v2, expected);
+}
+
+TEST_F(VectorClockTest, MergeLocalSmallerRemoteEqual) {
+  VectorClock v1(1, 4);
+  VectorClock v2(2, 4);
+
+  VectorClock expected(2, 4);
+  CheckCumulativeMerge(v1, v2, expected);
+}
+
+TEST_F(VectorClockTest, MergeLocalSmallerRemoteSmaller) {
+  VectorClock v1(1, 2);
+  VectorClock v2(3, 4);
+
+  VectorClock expected(3, 4);
+  CheckCumulativeMerge(v1, v2, expected);
+}
+
+TEST_F(VectorClockTest, MergeLocalSmallerRemoteGreater) {
+  VectorClock v1(1, 4);
+  VectorClock v2(3, 2);
+
+  VectorClock expected(3, 4);
+  CheckCumulativeMerge(v1, v2, expected);
+}
+
+}  // namespace
+}  // namespace blimp