Improving histogram test cases
Getting rid of the use or rand() in SpikyValues test cases to
make the test deterministic.
Improving accuracy for the histogram percentiles by selecting
more restricted lower and upper bound for a percentile.
Change-Id: If38750945e1980e8f637e836de02bee6f608e945
diff --git a/src/base/histogram-inl.h b/src/base/histogram-inl.h
index e9e52b6..3ffb9a0 100644
--- a/src/base/histogram-inl.h
+++ b/src/base/histogram-inl.h
@@ -145,7 +145,7 @@
template <class Value>
inline void Histogram<Value>::PrintBins(std::ostream &os) {
DCHECK_GT(sample_size_, 0ull);
- DCHECK(new_values_added_);
+ DCHECK(!new_values_added_);
size_t bin_idx = 0;
while (bin_idx < cumulative_freq_.size()) {
if (bin_idx > 0 &&
@@ -206,20 +206,30 @@
BuildCDF();
new_values_added_ = false;
}
-;
template <class Value>
inline double Histogram<Value>::Percentile(double per) const {
DCHECK_GT(cumulative_perc_.size(), 0ull);
- size_t idx;
+ size_t idx, upper_idx = 0, lower_idx = 0;
for (idx = 0; idx < cumulative_perc_.size(); idx++) {
- if (per <= cumulative_perc_[idx + 1])
+
+ if (per <= cumulative_perc_[idx]) {
+ upper_idx = idx;
break;
+ }
+
+ if (per >= cumulative_perc_[idx] &&
+ cumulative_perc_[idx] != cumulative_perc_[idx - 1] && idx != 0) {
+ lower_idx = idx;
+ }
}
- double lower_value = static_cast<double>(ranges_[idx]);
- double upper_value = static_cast<double>(ranges_[idx + 1]);
- double lower_perc = cumulative_perc_[idx];
- double upper_perc = cumulative_perc_[idx + 1];
+
+ double upper_value = static_cast<double>(ranges_[upper_idx]);
+ double lower_value = static_cast<double>(ranges_[lower_idx]);
+
+ double lower_perc = cumulative_perc_[lower_idx];
+ double upper_perc = cumulative_perc_[upper_idx];
+
if (per == lower_perc) {
return lower_value;
}
@@ -227,12 +237,12 @@
return upper_value;
}
DCHECK_GT(upper_perc, lower_perc);
+
double value = lower_value + (upper_value - lower_value) *
(per - lower_perc) / (upper_perc - lower_perc);
-
return value;
}
-} // namespace art
+} // namespace art
#endif // SRC_BASE_HISTOGRAM_INL_H_
diff --git a/src/base/histogram_test.cc b/src/base/histogram_test.cc
index 2adb41b..28812fd 100644
--- a/src/base/histogram_test.cc
+++ b/src/base/histogram_test.cc
@@ -31,7 +31,6 @@
mean = hist->Mean();
EXPECT_EQ(mean, 20.5);
}
-;
TEST(Histtest, VarianceTest) {
@@ -46,7 +45,6 @@
EXPECT_EQ(variance, 64.25);
delete hist;
}
-;
TEST(Histtest, Percentile) {
@@ -59,7 +57,9 @@
hist->AddValue(50);
hist->AddValue(60);
hist->AddValue(70);
+
hist->AddValue(98);
+
hist->AddValue(110);
hist->AddValue(121);
hist->AddValue(132);
@@ -69,12 +69,10 @@
hist->CreateHistogram();
PerValue = hist->Percentile(0.50);
- EXPECT_GE(PerValue, 70);
- EXPECT_LE(PerValue, 110);
+ EXPECT_EQ(static_cast<int>(PerValue * 10), 875);
delete hist;
}
-;
TEST(Histtest, UpdateRange) {
@@ -108,7 +106,7 @@
std::string text;
std::stringstream stream;
std::string expected =
- "UpdateRange:\t0.99% C.I. 15.262us-214.475us Avg: 126.380us Max: 212us\n";
+ "UpdateRange:\t0.99% C.I. 1.050us-214.475us Avg: 126.380us Max: 212us\n";
hist->PrintConfidenceIntervals(stream, 0.99);
EXPECT_EQ(expected, stream.str());
@@ -154,7 +152,7 @@
std::string text;
std::stringstream stream;
std::string expected =
- "Reset:\t0.99% C.I. 15.262us-214.475us Avg: 126.380us Max: 212us\n";
+ "Reset:\t0.99% C.I. 1.050us-214.475us Avg: 126.380us Max: 212us\n";
hist->PrintConfidenceIntervals(stream, 0.99);
EXPECT_EQ(expected, stream.str());
@@ -195,10 +193,9 @@
hist->CreateHistogram();
PerValue = hist->Percentile(0.50);
- std::string text;
std::stringstream stream;
std::string expected =
- "MultipleCreateHist:\t0.99% C.I. 15.262us-214.475us Avg: 126.380us Max: 212us\n";
+ "MultipleCreateHist:\t0.99% C.I. 1.050us-214.475us Avg: 126.380us Max: 212us\n";
hist->PrintConfidenceIntervals(stream, 0.99);
EXPECT_EQ(expected, stream.str());
@@ -207,46 +204,41 @@
delete hist;
}
-;
TEST(Histtest, SingleValue) {
Histogram<uint64_t> *hist = new Histogram<uint64_t>("SingleValue");
- double PerValue_10;
- double PerValue_90;
hist->AddValue(1);
hist->CreateHistogram();
- PerValue_10 = hist->Percentile(0.1);
- PerValue_90 = hist->Percentile(0.9);
- EXPECT_GT(PerValue_10, 0);
- EXPECT_LT(PerValue_90, 5);
+ std::stringstream stream;
+ std::string expected =
+ "SingleValue:\t0.99% C.I. 0.025us-4.975us Avg: 1us Max: 1us\n";
+ hist->PrintConfidenceIntervals(stream, 0.99);
+ EXPECT_EQ(stream.str(), expected);
delete hist;
}
-;
TEST(Histtest, SpikyValues) {
Histogram<uint64_t> *hist = new Histogram<uint64_t>("SpikyValues");
- double PerValue_005;
- double PerValue_995;
- for (size_t Idx = 0; Idx < 300; Idx++) {
- hist->AddValue(rand() % 200);
+ for (uint64_t idx = 0ull; idx < 30ull; idx++) {
+ for (uint64_t idx_inner = 0ull; idx_inner < 5ull; idx_inner++) {
+ hist->AddValue(idx * idx_inner);
+ }
}
hist->AddValue(10000);
hist->CreateHistogram();
- PerValue_005 = hist->Percentile(0.005);
- PerValue_995 = hist->Percentile(0.995);
- EXPECT_EQ(1.075, PerValue_005);
- EXPECT_EQ(199747, static_cast<int>(PerValue_995 * 1000));
+ std::stringstream stream;
+ std::string expected =
+ "SpikyValues:\t0.99% C.I. 0.089us-2541.825us Avg: 95.033us Max: 10000us\n";
+ hist->PrintConfidenceIntervals(stream, 0.99);
+ EXPECT_EQ(stream.str(), expected);
+
delete hist;
}
-;
-
-
-
