Refactor of Histogram related code

base/metrics/statistics_recorder_unittest.cc

+// 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.
+
+#include <vector>
+
+#include "base/memory/scoped_ptr.h"
+#include "base/metrics/histogram.h"
+#include "base/metrics/statistics_recorder.h"
+#include "testing/gtest/include/gtest/gtest.h"
+
+namespace base {
+
+class StatisticsRecorderTest : 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;
+  }
+
+  void DeleteHistogram(Histogram* histogram) {
+    delete histogram;
+  }
+
+  StatisticsRecorder* statistics_recorder_;
+};
+
+TEST_F(StatisticsRecorderTest, NotInitialized) {
+  UninitializeStatisticsRecorder();
+
+  ASSERT_FALSE(StatisticsRecorder::IsActive());
+
+  StatisticsRecorder::Histograms registered_histograms;
+  std::vector<const BucketRanges*> registered_ranges;
+
+  // We can still create histograms, but it's not registered.
+  // TODO(kaiwang): Do not depend on Histogram FactoryGet implementation.
+  Histogram* histogram(
+      Histogram::FactoryGet("StatisticsRecorderTest_NotInitialized",
+                            1, 1000, 10, Histogram::kNoFlags));
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(0u, registered_histograms.size());
+
+  // RegisterOrDeleteDuplicateRanges is a no-op.
+  BucketRanges* ranges = new BucketRanges(3);;
+  ranges->ResetChecksum();
+  EXPECT_EQ(ranges,
+            StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges));
+  StatisticsRecorder::GetBucketRanges(&registered_ranges);
+  EXPECT_EQ(0u, registered_ranges.size());
+
+  DeleteHistogram(histogram);
+}
+
+TEST_F(StatisticsRecorderTest, RegisterBucketRanges) {
+  std::vector<const BucketRanges*> registered_ranges;
+
+  BucketRanges* ranges1 = new BucketRanges(3);;
+  ranges1->ResetChecksum();
+  BucketRanges* ranges2 = new BucketRanges(4);;
+  ranges2->ResetChecksum();
+
+  // Register new ranges.
+  EXPECT_EQ(ranges1,
+            StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges1));
+  EXPECT_EQ(ranges2,
+            StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges2));
+  StatisticsRecorder::GetBucketRanges(&registered_ranges);
+  ASSERT_EQ(2u, registered_ranges.size());
+
+  // Register some ranges again.
+  EXPECT_EQ(ranges1,
+            StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges1));
+  registered_ranges.clear();
+  StatisticsRecorder::GetBucketRanges(&registered_ranges);
+  ASSERT_EQ(2u, registered_ranges.size());
+  // Make sure the ranges is still the one we know.
+  ASSERT_EQ(3u, ranges1->size());
+  EXPECT_EQ(0, ranges1->range(0));
+  EXPECT_EQ(0, ranges1->range(1));
+  EXPECT_EQ(0, ranges1->range(2));
+
+  // Register ranges with same values.
+  BucketRanges* ranges3 = new BucketRanges(3);;
+  ranges3->ResetChecksum();
+  EXPECT_EQ(ranges1,  // returning ranges1
+            StatisticsRecorder::RegisterOrDeleteDuplicateRanges(ranges3));
+  registered_ranges.clear();
+  StatisticsRecorder::GetBucketRanges(&registered_ranges);
+  ASSERT_EQ(2u, registered_ranges.size());
+}
+
+TEST_F(StatisticsRecorderTest, RegisterHistogram) {
+  // Create a Histogram that was not registered.
+  // TODO(kaiwang): Do not depend on Histogram FactoryGet implementation.
+  UninitializeStatisticsRecorder();
+  Histogram* histogram = Histogram::FactoryGet(
+      "TestHistogram", 1, 1000, 10, Histogram::kNoFlags);
+
+  // Clean StatisticsRecorder.
+  InitializeStatisticsRecorder();
+  StatisticsRecorder::Histograms registered_histograms;
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(0u, registered_histograms.size());
+
+  // Register the Histogram.
+  EXPECT_EQ(histogram,
+            StatisticsRecorder::RegisterOrDeleteDuplicate(histogram));
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(1u, registered_histograms.size());
+
+  // Register the same Histogram again.
+  EXPECT_EQ(histogram,
+            StatisticsRecorder::RegisterOrDeleteDuplicate(histogram));
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(1u, registered_histograms.size());
+}
+
+TEST_F(StatisticsRecorderTest, FindHistogram) {
+  Histogram* histogram1 = Histogram::FactoryGet(
+      "TestHistogram1", 1, 1000, 10, Histogram::kNoFlags);
+  Histogram* histogram2 = Histogram::FactoryGet(
+      "TestHistogram2", 1, 1000, 10, Histogram::kNoFlags);
+
+  EXPECT_EQ(histogram1, StatisticsRecorder::FindHistogram("TestHistogram1"));
+  EXPECT_EQ(histogram2, StatisticsRecorder::FindHistogram("TestHistogram2"));
+  EXPECT_TRUE(StatisticsRecorder::FindHistogram("TestHistogram") == NULL);
+}
+
+TEST_F(StatisticsRecorderTest, GetSnapshot) {
+  Histogram::FactoryGet("TestHistogram1", 1, 1000, 10, Histogram::kNoFlags);
+  Histogram::FactoryGet("TestHistogram2", 1, 1000, 10, Histogram::kNoFlags);
+  Histogram::FactoryGet("TestHistogram3", 1, 1000, 10, Histogram::kNoFlags);
+
+  StatisticsRecorder::Histograms snapshot;
+  StatisticsRecorder::GetSnapshot("Test", &snapshot);
+  EXPECT_EQ(3u, snapshot.size());
+
+  snapshot.clear();
+  StatisticsRecorder::GetSnapshot("1", &snapshot);
+  EXPECT_EQ(1u, snapshot.size());
+
+  snapshot.clear();
+  StatisticsRecorder::GetSnapshot("hello", &snapshot);
+  EXPECT_EQ(0u, snapshot.size());
+}
+
+TEST_F(StatisticsRecorderTest, RegisterHistogramWithFactoryGet) {
+  StatisticsRecorder::Histograms registered_histograms;
+
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  ASSERT_EQ(0u, registered_histograms.size());
+
+  // Create a Histogram.
+  Histogram* histogram = Histogram::FactoryGet(
+      "TestHistogram", 1, 1000, 10, Histogram::kNoFlags);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(1u, registered_histograms.size());
+
+  // Get an existing histogram.
+  Histogram* histogram2 = Histogram::FactoryGet(
+      "TestHistogram", 1, 1000, 10, Histogram::kNoFlags);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(1u, registered_histograms.size());
+  EXPECT_EQ(histogram, histogram2);
+
+  // Create a LinearHistogram.
+  histogram = LinearHistogram::FactoryGet(
+      "TestLinearHistogram", 1, 1000, 10, Histogram::kNoFlags);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(2u, registered_histograms.size());
+
+  // Create a BooleanHistogram.
+  histogram = BooleanHistogram::FactoryGet(
+      "TestBooleanHistogram", Histogram::kNoFlags);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(3u, registered_histograms.size());
+
+  // Create a CustomHistogram.
+  std::vector<int> custom_ranges;
+  custom_ranges.push_back(1);
+  custom_ranges.push_back(5);
+  histogram = CustomHistogram::FactoryGet(
+      "TestCustomHistogram", custom_ranges, Histogram::kNoFlags);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(4u, registered_histograms.size());
+}
+
+TEST_F(StatisticsRecorderTest, RegisterHistogramWithMacros) {
+  StatisticsRecorder::Histograms registered_histograms;
+
+  Histogram* histogram = Histogram::FactoryGet(
+      "TestHistogramCounts", 1, 1000000, 50, Histogram::kNoFlags);
+
+  // The histogram we got from macro is the same as from FactoryGet.
+  HISTOGRAM_COUNTS("TestHistogramCounts", 30);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  ASSERT_EQ(1u, registered_histograms.size());
+  EXPECT_EQ(histogram, registered_histograms[0]);
+
+  HISTOGRAM_TIMES("TestHistogramTimes", TimeDelta::FromDays(1));
+  HISTOGRAM_ENUMERATION("TestHistogramEnumeration", 20, 200);
+
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+  EXPECT_EQ(3u, registered_histograms.size());
+
+  // Debugging only macros.
+  DHISTOGRAM_TIMES("TestHistogramDebugTimes", TimeDelta::FromDays(1));
+  DHISTOGRAM_COUNTS("TestHistogramDebugCounts", 30);
+  registered_histograms.clear();
+  StatisticsRecorder::GetHistograms(&registered_histograms);
+#ifndef NDEBUG
+  EXPECT_EQ(5u, registered_histograms.size());
+#else
+  EXPECT_EQ(3u, registered_histograms.size());
+#endif
+}
+
+TEST_F(StatisticsRecorderTest, BucketRangesSharing) {
+  Histogram* histogram1(Histogram::FactoryGet(
+      "Histogram", 1, 64, 8, Histogram::kNoFlags));
+  Histogram* histogram2(Histogram::FactoryGet(
+      "Histogram2", 1, 64, 8, Histogram::kNoFlags));
+  Histogram* histogram3(Histogram::FactoryGet(
+      "Histogram3", 1, 64, 16, Histogram::kNoFlags));
+
+  const BucketRanges* bucket_ranges1 = histogram1->bucket_ranges();
+  const BucketRanges* bucket_ranges2 = histogram2->bucket_ranges();
+  const BucketRanges* bucket_ranges3 = histogram3->bucket_ranges();
+  EXPECT_EQ(bucket_ranges1, bucket_ranges2);
+  EXPECT_FALSE(bucket_ranges1->Equals(bucket_ranges3));
+}
+
+}  // namespace base