// Copyright (c) 2012 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.
// Test of Histogram class
#include <climits>
#include <algorithm>
#include <vector>
#include "base/logging.h"
#include "base/memory/scoped_ptr.h"
#include "base/metrics/bucket_ranges.h"
#include "base/metrics/histogram.h"
#include "base/metrics/sample_vector.h"
#include "base/metrics/statistics_recorder.h"
#include "base/pickle.h"
#include "base/time/time.h"
#include "testing/gtest/include/gtest/gtest.h"
using std::vector;
namespace base {
class HistogramTest : public testing::Test {
protected:
virtual void SetUp() {
// Each test will have a clean state (no Histogram / BucketRanges
// registered).
InitializeStatisticsRecorder();
}
virtual void TearDown() {
UninitializeStatisticsRecorder();
}
void InitializeStatisticsRecorder() {
statistics_recorder_ = new StatisticsRecorder();
}
void UninitializeStatisticsRecorder() {
delete statistics_recorder_;
statistics_recorder_ = NULL;
}
StatisticsRecorder* statistics_recorder_;
};
// Check for basic syntax and use.
TEST_F(HistogramTest, BasicTest) {
// Try basic construction
HistogramBase* histogram = Histogram::FactoryGet(
"TestHistogram", 1, 1000, 10, HistogramBase::kNoFlags);
EXPECT_TRUE(histogram);
HistogramBase* linear_histogram = LinearHistogram::FactoryGet(
"TestLinearHistogram", 1, 1000, 10, HistogramBase::kNoFlags);
EXPECT_TRUE(linear_histogram);
vector<int> custom_ranges;
custom_ranges.push_back(1);
custom_ranges.push_back(5);
HistogramBase* custom_histogram = CustomHistogram::FactoryGet(
"TestCustomHistogram", custom_ranges, HistogramBase::kNoFlags);
EXPECT_TRUE(custom_histogram);
// Use standard macros (but with fixed samples)
HISTOGRAM_TIMES("Test2Histogram", TimeDelta::FromDays(1));
HISTOGRAM_COUNTS("Test3Histogram", 30);
DHISTOGRAM_TIMES("Test4Histogram", TimeDelta::FromDays(1));
DHISTOGRAM_COUNTS("Test5Histogram", 30);
HISTOGRAM_ENUMERATION("Test6Histogram", 129, 130);
}
// Check that the macro correctly matches histograms by name and records their
// data together.
TEST_F(HistogramTest, NameMatchTest) {
HISTOGRAM_PERCENTAGE("DuplicatedHistogram", 10);
HISTOGRAM_PERCENTAGE("DuplicatedHistogram", 10);
HistogramBase* histogram = LinearHistogram::FactoryGet(
"DuplicatedHistogram", 1, 101, 102, HistogramBase::kNoFlags);
scoped_ptr<HistogramSamples> samples = histogram->SnapshotSamples();
EXPECT_EQ(2, samples->TotalCount());
EXPECT_EQ(2, samples->GetCount(10));
}
TEST_F(HistogramTest, ExponentialRangesTest) {
// Check that we got a nice exponential when there was enough rooom.
BucketRanges ranges(9);
Histogram::InitializeBucketRanges(1, 64, &ranges);
EXPECT_EQ(0, ranges.range(0));
int power_of_2 = 1;
for (int i = 1; i < 8; i++) {
EXPECT_EQ(power_of_2, ranges.range(i));
power_of_2 *= 2;
}
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges.range(8));
// Check the corresponding Histogram will use the correct ranges.
Histogram* histogram = static_cast<Histogram*>(
Histogram::FactoryGet("Histogram", 1, 64, 8, HistogramBase::kNoFlags));
EXPECT_TRUE(ranges.Equals(histogram->bucket_ranges()));
// When bucket count is limited, exponential ranges will partially look like
// linear.
BucketRanges ranges2(16);
Histogram::InitializeBucketRanges(1, 32, &ranges2);
EXPECT_EQ(0, ranges2.range(0));
EXPECT_EQ(1, ranges2.range(1));
EXPECT_EQ(2, ranges2.range(2));
EXPECT_EQ(3, ranges2.range(3));
EXPECT_EQ(4, ranges2.range(4));
EXPECT_EQ(5, ranges2.range(5));
EXPECT_EQ(6, ranges2.range(6));
EXPECT_EQ(7, ranges2.range(7));
EXPECT_EQ(9, ranges2.range(8));
EXPECT_EQ(11, ranges2.range(9));
EXPECT_EQ(14, ranges2.range(10));
EXPECT_EQ(17, ranges2.range(11));
EXPECT_EQ(21, ranges2.range(12));
EXPECT_EQ(26, ranges2.range(13));
EXPECT_EQ(32, ranges2.range(14));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges2.range(15));
// Check the corresponding Histogram will use the correct ranges.
Histogram* histogram2 = static_cast<Histogram*>(
Histogram::FactoryGet("Histogram2", 1, 32, 15, HistogramBase::kNoFlags));
EXPECT_TRUE(ranges2.Equals(histogram2->bucket_ranges()));
}
TEST_F(HistogramTest, LinearRangesTest) {
BucketRanges ranges(9);
LinearHistogram::InitializeBucketRanges(1, 7, &ranges);
// Gets a nice linear set of bucket ranges.
for (int i = 0; i < 8; i++)
EXPECT_EQ(i, ranges.range(i));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges.range(8));
// The correspoding LinearHistogram should use the correct ranges.
Histogram* histogram = static_cast<Histogram*>(
LinearHistogram::FactoryGet("Linear", 1, 7, 8, HistogramBase::kNoFlags));
EXPECT_TRUE(ranges.Equals(histogram->bucket_ranges()));
// Linear ranges are not divisible.
BucketRanges ranges2(6);
LinearHistogram::InitializeBucketRanges(1, 6, &ranges2);
EXPECT_EQ(0, ranges2.range(0));
EXPECT_EQ(1, ranges2.range(1));
EXPECT_EQ(3, ranges2.range(2));
EXPECT_EQ(4, ranges2.range(3));
EXPECT_EQ(6, ranges2.range(4));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges2.range(5));
// The correspoding LinearHistogram should use the correct ranges.
Histogram* histogram2 = static_cast<Histogram*>(
LinearHistogram::FactoryGet("Linear2", 1, 6, 5, HistogramBase::kNoFlags));
EXPECT_TRUE(ranges2.Equals(histogram2->bucket_ranges()));
}
TEST_F(HistogramTest, ArrayToCustomRangesTest) {
const HistogramBase::Sample ranges[3] = {5, 10, 20};
vector<HistogramBase::Sample> ranges_vec =
CustomHistogram::ArrayToCustomRanges(ranges, 3);
ASSERT_EQ(6u, ranges_vec.size());
EXPECT_EQ(5, ranges_vec[0]);
EXPECT_EQ(6, ranges_vec[1]);
EXPECT_EQ(10, ranges_vec[2]);
EXPECT_EQ(11, ranges_vec[3]);
EXPECT_EQ(20, ranges_vec[4]);
EXPECT_EQ(21, ranges_vec[5]);
}
TEST_F(HistogramTest, CustomHistogramTest) {
// A well prepared custom ranges.
vector<HistogramBase::Sample> custom_ranges;
custom_ranges.push_back(1);
custom_ranges.push_back(2);
Histogram* histogram = static_cast<Histogram*>(
CustomHistogram::FactoryGet("TestCustomHistogram1", custom_ranges,
HistogramBase::kNoFlags));
const BucketRanges* ranges = histogram->bucket_ranges();
ASSERT_EQ(4u, ranges->size());
EXPECT_EQ(0, ranges->range(0)); // Auto added.
EXPECT_EQ(1, ranges->range(1));
EXPECT_EQ(2, ranges->range(2));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges->range(3)); // Auto added.
// A unordered custom ranges.
custom_ranges.clear();
custom_ranges.push_back(2);
custom_ranges.push_back(1);
histogram = static_cast<Histogram*>(
CustomHistogram::FactoryGet("TestCustomHistogram2", custom_ranges,
HistogramBase::kNoFlags));
ranges = histogram->bucket_ranges();
ASSERT_EQ(4u, ranges->size());
EXPECT_EQ(0, ranges->range(0));
EXPECT_EQ(1, ranges->range(1));
EXPECT_EQ(2, ranges->range(2));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges->range(3));
// A custom ranges with duplicated values.
custom_ranges.clear();
custom_ranges.push_back(4);
custom_ranges.push_back(1);
custom_ranges.push_back(4);
histogram = static_cast<Histogram*>(
CustomHistogram::FactoryGet("TestCustomHistogram3", custom_ranges,
HistogramBase::kNoFlags));
ranges = histogram->bucket_ranges();
ASSERT_EQ(4u, ranges->size());
EXPECT_EQ(0, ranges->range(0));
EXPECT_EQ(1, ranges->range(1));
EXPECT_EQ(4, ranges->range(2));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges->range(3));
}
TEST_F(HistogramTest, CustomHistogramWithOnly2Buckets) {
// This test exploits the fact that the CustomHistogram can have 2 buckets,
// while the base class Histogram is *supposed* to have at least 3 buckets.
// We should probably change the restriction on the base class (or not inherit
// the base class!).
vector<HistogramBase::Sample> custom_ranges;
custom_ranges.push_back(4);
Histogram* histogram = static_cast<Histogram*>(
CustomHistogram::FactoryGet("2BucketsCustomHistogram", custom_ranges,
HistogramBase::kNoFlags));
const BucketRanges* ranges = histogram->bucket_ranges();
ASSERT_EQ(3u, ranges->size());
EXPECT_EQ(0, ranges->range(0));
EXPECT_EQ(4, ranges->range(1));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges->range(2));
}
// Make sure histogram handles out-of-bounds data gracefully.
TEST_F(HistogramTest, BoundsTest) {
const size_t kBucketCount = 50;
Histogram* histogram = static_cast<Histogram*>(
Histogram::FactoryGet("Bounded", 10, 100, kBucketCount,
HistogramBase::kNoFlags));
// Put two samples "out of bounds" above and below.
histogram->Add(5);
histogram->Add(-50);
histogram->Add(100);
histogram->Add(10000);
// Verify they landed in the underflow, and overflow buckets.
scoped_ptr<SampleVector> samples = histogram->SnapshotSampleVector();
EXPECT_EQ(2, samples->GetCountAtIndex(0));
EXPECT_EQ(0, samples->GetCountAtIndex(1));
size_t array_size = histogram->bucket_count();
EXPECT_EQ(kBucketCount, array_size);
EXPECT_EQ(0, samples->GetCountAtIndex(array_size - 2));
EXPECT_EQ(2, samples->GetCountAtIndex(array_size - 1));
vector<int> custom_ranges;
custom_ranges.push_back(10);
custom_ranges.push_back(50);
custom_ranges.push_back(100);
Histogram* test_custom_histogram = static_cast<Histogram*>(
CustomHistogram::FactoryGet("TestCustomRangeBoundedHistogram",
custom_ranges, HistogramBase::kNoFlags));
// Put two samples "out of bounds" above and below.
test_custom_histogram->Add(5);
test_custom_histogram->Add(-50);
test_custom_histogram->Add(100);
test_custom_histogram->Add(1000);
test_custom_histogram->Add(INT_MAX);
// Verify they landed in the underflow, and overflow buckets.
scoped_ptr<SampleVector> custom_samples =
test_custom_histogram->SnapshotSampleVector();
EXPECT_EQ(2, custom_samples->GetCountAtIndex(0));
EXPECT_EQ(0, custom_samples->GetCountAtIndex(1));
size_t bucket_count = test_custom_histogram->bucket_count();
EXPECT_EQ(0, custom_samples->GetCountAtIndex(bucket_count - 2));
EXPECT_EQ(3, custom_samples->GetCountAtIndex(bucket_count - 1));
}
// Check to be sure samples land as expected is "correct" buckets.
TEST_F(HistogramTest, BucketPlacementTest) {
Histogram* histogram = static_cast<Histogram*>(
Histogram::FactoryGet("Histogram", 1, 64, 8, HistogramBase::kNoFlags));
// Add i+1 samples to the i'th bucket.
histogram->Add(0);
int power_of_2 = 1;
for (int i = 1; i < 8; i++) {
for (int j = 0; j <= i; j++)
histogram->Add(power_of_2);
power_of_2 *= 2;
}
// Check to see that the bucket counts reflect our additions.
scoped_ptr<SampleVector> samples = histogram->SnapshotSampleVector();
for (int i = 0; i < 8; i++)
EXPECT_EQ(i + 1, samples->GetCountAtIndex(i));
}
TEST_F(HistogramTest, CorruptSampleCounts) {
Histogram* histogram = static_cast<Histogram*>(
Histogram::FactoryGet("Histogram", 1, 64, 8, HistogramBase::kNoFlags));
// Add some samples.
histogram->Add(20);
histogram->Add(40);
scoped_ptr<SampleVector> snapshot = histogram->SnapshotSampleVector();
EXPECT_EQ(HistogramBase::NO_INCONSISTENCIES,
histogram->FindCorruption(*snapshot));
EXPECT_EQ(2, snapshot->redundant_count());
EXPECT_EQ(2, snapshot->TotalCount());
snapshot->counts_[3] += 100; // Sample count won't match redundant count.
EXPECT_EQ(HistogramBase::COUNT_LOW_ERROR,
histogram->FindCorruption(*snapshot));
snapshot->counts_[2] -= 200;
EXPECT_EQ(HistogramBase::COUNT_HIGH_ERROR,
histogram->FindCorruption(*snapshot));
// But we can't spot a corruption if it is compensated for.
snapshot->counts_[1] += 100;
EXPECT_EQ(HistogramBase::NO_INCONSISTENCIES,
histogram->FindCorruption(*snapshot));
}
TEST_F(HistogramTest, CorruptBucketBounds) {
Histogram* histogram = static_cast<Histogram*>(
Histogram::FactoryGet("Histogram", 1, 64, 8, HistogramBase::kNoFlags));
scoped_ptr<SampleVector> snapshot = histogram->SnapshotSampleVector();
EXPECT_EQ(HistogramBase::NO_INCONSISTENCIES,
histogram->FindCorruption(*snapshot));
BucketRanges* bucket_ranges =
const_cast<BucketRanges*>(histogram->bucket_ranges());
HistogramBase::Sample tmp = bucket_ranges->range(1);
bucket_ranges->set_range(1, bucket_ranges->range(2));
bucket_ranges->set_range(2, tmp);
EXPECT_EQ(
HistogramBase::BUCKET_ORDER_ERROR | HistogramBase::RANGE_CHECKSUM_ERROR,
histogram->FindCorruption(*snapshot));
bucket_ranges->set_range(2, bucket_ranges->range(1));
bucket_ranges->set_range(1, tmp);
EXPECT_EQ(0, histogram->FindCorruption(*snapshot));
// Show that two simple changes don't offset each other
bucket_ranges->set_range(3, bucket_ranges->range(3) + 1);
EXPECT_EQ(HistogramBase::RANGE_CHECKSUM_ERROR,
histogram->FindCorruption(*snapshot));
bucket_ranges->set_range(4, bucket_ranges->range(4) - 1);
EXPECT_EQ(HistogramBase::RANGE_CHECKSUM_ERROR,
histogram->FindCorruption(*snapshot));
// Repair histogram so that destructor won't DCHECK().
bucket_ranges->set_range(3, bucket_ranges->range(3) - 1);
bucket_ranges->set_range(4, bucket_ranges->range(4) + 1);
}
TEST_F(HistogramTest, HistogramSerializeInfo) {
Histogram* histogram = static_cast<Histogram*>(
Histogram::FactoryGet("Histogram", 1, 64, 8,
HistogramBase::kIPCSerializationSourceFlag));
Pickle pickle;
histogram->SerializeInfo(&pickle);
PickleIterator iter(pickle);
int type;
EXPECT_TRUE(iter.ReadInt(&type));
EXPECT_EQ(HISTOGRAM, type);
std::string name;
EXPECT_TRUE(iter.ReadString(&name));
EXPECT_EQ("Histogram", name);
int flag;
EXPECT_TRUE(iter.ReadInt(&flag));
EXPECT_EQ(HistogramBase::kIPCSerializationSourceFlag, flag);
int min;
EXPECT_TRUE(iter.ReadInt(&min));
EXPECT_EQ(1, min);
int max;
EXPECT_TRUE(iter.ReadInt(&max));
EXPECT_EQ(64, max);
int64 bucket_count;
EXPECT_TRUE(iter.ReadInt64(&bucket_count));
EXPECT_EQ(8, bucket_count);
uint32 checksum;
EXPECT_TRUE(iter.ReadUInt32(&checksum));
EXPECT_EQ(histogram->bucket_ranges()->checksum(), checksum);
// No more data in the pickle.
EXPECT_FALSE(iter.SkipBytes(1));
}
TEST_F(HistogramTest, CustomHistogramSerializeInfo) {
vector<int> custom_ranges;
custom_ranges.push_back(10);
custom_ranges.push_back(100);
HistogramBase* custom_histogram = CustomHistogram::FactoryGet(
"TestCustomRangeBoundedHistogram",
custom_ranges,
HistogramBase::kNoFlags);
Pickle pickle;
custom_histogram->SerializeInfo(&pickle);
// Validate the pickle.
PickleIterator iter(pickle);
int i;
std::string s;
int64 bucket_count;
uint32 ui32;
EXPECT_TRUE(iter.ReadInt(&i) && iter.ReadString(&s) && iter.ReadInt(&i) &&
iter.ReadInt(&i) && iter.ReadInt(&i) &&
iter.ReadInt64(&bucket_count) && iter.ReadUInt32(&ui32));
EXPECT_EQ(3, bucket_count);
int range;
EXPECT_TRUE(iter.ReadInt(&range));
EXPECT_EQ(10, range);
EXPECT_TRUE(iter.ReadInt(&range));
EXPECT_EQ(100, range);
// No more data in the pickle.
EXPECT_FALSE(iter.SkipBytes(1));
}
#if GTEST_HAS_DEATH_TEST
// For Histogram, LinearHistogram and CustomHistogram, the minimum for a
// declared range is 1, while the maximum is (HistogramBase::kSampleType_MAX -
// 1). But we accept ranges exceeding those limits, and silently clamped to
// those limits. This is for backwards compatibility.
TEST(HistogramDeathTest, BadRangesTest) {
HistogramBase* histogram = Histogram::FactoryGet(
"BadRanges", 0, HistogramBase::kSampleType_MAX, 8,
HistogramBase::kNoFlags);
EXPECT_TRUE(
histogram->HasConstructionArguments(
1, HistogramBase::kSampleType_MAX - 1, 8));
HistogramBase* linear_histogram = LinearHistogram::FactoryGet(
"BadRangesLinear", 0, HistogramBase::kSampleType_MAX, 8,
HistogramBase::kNoFlags);
EXPECT_TRUE(
linear_histogram->HasConstructionArguments(
1, HistogramBase::kSampleType_MAX - 1, 8));
vector<int> custom_ranges;
custom_ranges.push_back(0);
custom_ranges.push_back(5);
Histogram* custom_histogram = static_cast<Histogram*>(
CustomHistogram::FactoryGet(
"BadRangesCustom", custom_ranges, HistogramBase::kNoFlags));
const BucketRanges* ranges = custom_histogram->bucket_ranges();
ASSERT_EQ(3u, ranges->size());
EXPECT_EQ(0, ranges->range(0));
EXPECT_EQ(5, ranges->range(1));
EXPECT_EQ(HistogramBase::kSampleType_MAX, ranges->range(2));
// CustomHistogram does not accepts kSampleType_MAX as range.
custom_ranges.push_back(HistogramBase::kSampleType_MAX);
EXPECT_DEATH(CustomHistogram::FactoryGet("BadRangesCustom2", custom_ranges,
HistogramBase::kNoFlags),
"");
// CustomHistogram needs at least 1 valid range.
custom_ranges.clear();
custom_ranges.push_back(0);
EXPECT_DEATH(CustomHistogram::FactoryGet("BadRangesCustom3", custom_ranges,
HistogramBase::kNoFlags),
"");
}
#endif
} // namespace base