content/common/inter_process_time_ticks_converter_unittest.cc

   1 // Copyright (c) 2011 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "content/common/inter_process_time_ticks_converter.h"
   6
   7 #include "base/time.h"
   8 #include "testing/gtest/include/gtest/gtest.h"
   9
  10 using base::TimeTicks;
  11
  12 namespace content {
  13
  14 namespace {
  15
  16 struct TestParams {
  17   int64 local_lower_bound;
  18   int64 remote_lower_bound;
  19   int64 remote_upper_bound;
  20   int64 local_upper_bound;
  21   int64 test_time;
  22   int64 test_delta;
  23 };
  24
  25 struct TestResults {
  26   int64 result_time;
  27   int32 result_delta;
  28 };
  29
  30 TestResults RunTest(const TestParams& params) {
  31   TimeTicks local_lower_bound = TimeTicks::FromInternalValue(
  32       params.local_lower_bound);
  33   TimeTicks local_upper_bound = TimeTicks::FromInternalValue(
  34       params.local_upper_bound);
  35   TimeTicks remote_lower_bound = TimeTicks::FromInternalValue(
  36       params.remote_lower_bound);
  37   TimeTicks remote_upper_bound = TimeTicks::FromInternalValue(
  38       params.remote_upper_bound);
  39   TimeTicks test_time = TimeTicks::FromInternalValue(params.test_time);
  40
  41   InterProcessTimeTicksConverter converter(
  42       LocalTimeTicks::FromTimeTicks(local_lower_bound),
  43       LocalTimeTicks::FromTimeTicks(local_upper_bound),
  44       RemoteTimeTicks::FromTimeTicks(remote_lower_bound),
  45       RemoteTimeTicks::FromTimeTicks(remote_upper_bound));
  46
  47   TestResults results;
  48   results.result_time = converter.ToLocalTimeTicks(
  49       RemoteTimeTicks::FromTimeTicks(
  50           test_time)).ToTimeTicks().ToInternalValue();
  51   results.result_delta = converter.ToLocalTimeDelta(
  52       RemoteTimeDelta::FromRawDelta(params.test_delta)).ToInt32();
  53   return results;
  54 }
  55
  56 TEST(InterProcessTimeTicksConverterTest, NullTime) {
  57   // Null / zero times should remain null.
  58   TestParams p;
  59   p.local_lower_bound = 1;
  60   p.remote_lower_bound = 2;
  61   p.remote_upper_bound = 5;
  62   p.local_upper_bound = 6;
  63   p.test_time = 0;
  64   p.test_delta = 0;
  65   TestResults results = RunTest(p);
  66   EXPECT_EQ(0, results.result_time);
  67   EXPECT_EQ(0, results.result_delta);
  68 }
  69
  70 TEST(InterProcessTimeTicksConverterTest, NoSkew) {
  71   // All times are monotonic and centered, so no adjustment should occur.
  72   TestParams p;
  73   p.local_lower_bound = 1;
  74   p.remote_lower_bound = 2;
  75   p.remote_upper_bound = 5;
  76   p.local_upper_bound = 6;
  77   p.test_time = 3;
  78   p.test_delta = 1;
  79   TestResults results = RunTest(p);
  80   EXPECT_EQ(3, results.result_time);
  81   EXPECT_EQ(1, results.result_delta);
  82 }
  83
  84 TEST(InterProcessTimeTicksConverterTest, OffsetMidpoints) {
  85   // All times are monotonic, but not centered. Adjust the |remote_*| times so
  86   // they are centered within the |local_*| times.
  87   TestParams p;
  88   p.local_lower_bound = 1;
  89   p.remote_lower_bound = 3;
  90   p.remote_upper_bound = 6;
  91   p.local_upper_bound = 6;
  92   p.test_time = 4;
  93   p.test_delta = 1;
  94   TestResults results = RunTest(p);
  95   EXPECT_EQ(3, results.result_time);
  96   EXPECT_EQ(1, results.result_delta);
  97 }
  98
  99 TEST(InterProcessTimeTicksConverterTest, DoubleEndedSkew) {
 100   // |remote_lower_bound| occurs before |local_lower_bound| and
 101   // |remote_upper_bound| occurs after |local_upper_bound|. We must adjust both
 102   // bounds and scale down the delta. |test_time| is on the midpoint, so it
 103   // doesn't change. The ratio of local time to network time is 1:2, so we scale
 104   // |test_delta| to half.
 105   TestParams p;
 106   p.local_lower_bound = 3;
 107   p.remote_lower_bound = 1;
 108   p.remote_upper_bound = 9;
 109   p.local_upper_bound = 7;
 110   p.test_time = 5;
 111   p.test_delta = 2;
 112   TestResults results = RunTest(p);
 113   EXPECT_EQ(5, results.result_time);
 114   EXPECT_EQ(1, results.result_delta);
 115 }
 116
 117 TEST(InterProcessTimeTicksConverterTest, FrontEndSkew) {
 118   // |remote_upper_bound| is coherent, but |remote_lower_bound| is not. So we
 119   // adjust the lower bound and move |test_time| out. The scale factor is 2:3,
 120   // but since we use integers, the numbers truncate from 3.33 to 3 and 1.33
 121   // to 1.
 122   TestParams p;
 123   p.local_lower_bound = 3;
 124   p.remote_lower_bound = 1;
 125   p.remote_upper_bound = 7;
 126   p.local_upper_bound = 7;
 127   p.test_time = 3;
 128   p.test_delta = 2;
 129   TestResults results = RunTest(p);
 130   EXPECT_EQ(4, results.result_time);
 131   EXPECT_EQ(1, results.result_delta);
 132 }
 133
 134 TEST(InterProcessTimeTicksConverterTest, BackEndSkew) {
 135   // Like the previous test, but |remote_lower_bound| is coherent and
 136   // |remote_upper_bound| is skewed.
 137   TestParams p;
 138   p.local_lower_bound = 1;
 139   p.remote_lower_bound = 1;
 140   p.remote_upper_bound = 7;
 141   p.local_upper_bound = 5;
 142   p.test_time = 3;
 143   p.test_delta = 2;
 144   TestResults results = RunTest(p);
 145   EXPECT_EQ(2, results.result_time);
 146   EXPECT_EQ(1, results.result_delta);
 147 }
 148
 149 TEST(InterProcessTimeTicksConverterTest, Instantaneous) {
 150   // The bounds are all okay, but the |remote_lower_bound| and
 151   // |remote_upper_bound| have the same value. No adjustments should be made and
 152   // no divide-by-zero errors should occur.
 153   TestParams p;
 154   p.local_lower_bound = 1;
 155   p.remote_lower_bound = 2;
 156   p.remote_upper_bound = 2;
 157   p.local_upper_bound = 3;
 158   p.test_time = 2;
 159   p.test_delta = 0;
 160   TestResults results = RunTest(p);
 161   EXPECT_EQ(2, results.result_time);
 162   EXPECT_EQ(0, results.result_delta);
 163 }
 164
 165 TEST(InterProcessTimeTicksConverterTest, OffsetInstantaneous) {
 166   // The bounds are all okay, but the |remote_lower_bound| and
 167   // |remote_upper_bound| have the same value and are offset from the midpoint
 168   // of |local_lower_bound| and |local_upper_bound|. An offset should be applied
 169   // to make the midpoints line up.
 170   TestParams p;
 171   p.local_lower_bound = 1;
 172   p.remote_lower_bound = 3;
 173   p.remote_upper_bound = 3;
 174   p.local_upper_bound = 3;
 175   p.test_time = 3;
 176   p.test_delta = 0;
 177   TestResults results = RunTest(p);
 178   EXPECT_EQ(2, results.result_time);
 179   EXPECT_EQ(0, results.result_delta);
 180 }
 181
 182 TEST(InterProcessTimeTicksConverterTest, DisjointInstantaneous) {
 183   // |local_lower_bound| and |local_upper_bound| are the same. No matter what
 184   // the other values are, they must fit within [local_lower_bound,
 185   // local_upper_bound].  So, all of the values should be adjusted so they are
 186   // exactly that value.
 187   TestParams p;
 188   p.local_lower_bound = 1;
 189   p.remote_lower_bound = 2;
 190   p.remote_upper_bound = 2;
 191   p.local_upper_bound = 1;
 192   p.test_time = 2;
 193   p.test_delta = 0;
 194   TestResults results = RunTest(p);
 195   EXPECT_EQ(1, results.result_time);
 196   EXPECT_EQ(0, results.result_delta);
 197 }
 198
 199 TEST(InterProcessTimeTicksConverterTest, RoundingNearEdges) {
 200   // Verify that rounding never causes a value to appear outside the given
 201   // |local_*| range.
 202   const int kMaxRange = 101;
 203   for (int i = 1; i < kMaxRange; ++i) {
 204     for (int j = 1; j < kMaxRange; ++j) {
 205       TestParams p;
 206       p.local_lower_bound = 1;
 207       p.remote_lower_bound = 1;
 208       p.remote_upper_bound = j;
 209       p.local_upper_bound = i;
 210
 211       p.test_time = 1;
 212       p.test_delta = 0;
 213       TestResults results = RunTest(p);
 214       EXPECT_LE(1, results.result_time);
 215       EXPECT_EQ(0, results.result_delta);
 216
 217       p.test_time = j;
 218       p.test_delta = j - 1;
 219       results = RunTest(p);
 220       EXPECT_GE(i, results.result_time);
 221       EXPECT_GE(i - 1, results.result_delta);
 222     }
 223   }
 224 }
 225
 226 TEST(InterProcessTimeTicksConverterTest, DisjointRanges) {
 227   TestParams p;
 228   p.local_lower_bound = 10;
 229   p.remote_lower_bound = 30;
 230   p.remote_upper_bound = 41;
 231   p.local_upper_bound = 20;
 232   p.test_time = 41;
 233   p.test_delta = 0;
 234   TestResults results = RunTest(p);
 235   EXPECT_EQ(20, results.result_time);
 236   EXPECT_EQ(0, results.result_delta);
 237 }
 238
 239 }  // anonymous namespace
 240
 241 }  // namespace content