Move SnapshotSamples to HistogramBase

BUG=139612


Review URL: https://chromiumcodereview.appspot.com/11192077

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@163138 0039d316-1c4b-4281-b951-d872f2087c98

7 files changed, 36 insertions, 22 deletions

diff --git a/base/metrics/histogram.cc b/base/metrics/histogram.cc
index 1c5470e..ec1afdd 100644
--- a/base/metrics/histogram.cc
+++ b/base/metrics/histogram.cc
@@ -17,6 +17,7 @@
 #include "base/compiler_specific.h"
 #include "base/debug/alias.h"
 #include "base/logging.h"
+#include "base/metrics/sample_vector.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/pickle.h"
 #include "base/string_util.h"
@@ -366,10 +367,8 @@ size_t Histogram::bucket_count() const {
   return bucket_count_;
 }
 
-scoped_ptr<SampleVector> Histogram::SnapshotSamples() const {
-  scoped_ptr<SampleVector> samples(new SampleVector(bucket_ranges()));
-  samples->Add(*samples_);
-  return samples.Pass();
+scoped_ptr<HistogramSamples> Histogram::SnapshotSamples() const {
+  return SnapshotSampleVector().PassAs<HistogramSamples>();
 }
 
 bool Histogram::HasConstructionArguments(Sample minimum,
@@ -464,12 +463,18 @@ const string Histogram::GetAsciiBucketRange(size_t i) const {
 //------------------------------------------------------------------------------
 // Private methods
 
+scoped_ptr<SampleVector> Histogram::SnapshotSampleVector() const {
+  scoped_ptr<SampleVector> samples(new SampleVector(bucket_ranges()));
+  samples->Add(*samples_);
+  return samples.Pass();
+}
+
 void Histogram::WriteAsciiImpl(bool graph_it,
                                const string& newline,
                                string* output) const {
   // Get local (stack) copies of all effectively volatile class data so that we
   // are consistent across our output activities.
-  scoped_ptr<SampleVector> snapshot = SnapshotSamples();
+  scoped_ptr<SampleVector> snapshot = SnapshotSampleVector();
   Count sample_count = snapshot->TotalCount();
 
   WriteAsciiHeader(*snapshot, sample_count, output);
@@ -601,7 +606,7 @@ void Histogram::GetParameters(DictionaryValue* params) const {
 }
 
 void Histogram::GetCountAndBucketData(Count* count, ListValue* buckets) const {
-  scoped_ptr<SampleVector> snapshot = SnapshotSamples();
+  scoped_ptr<SampleVector> snapshot = SnapshotSampleVector();
   *count = snapshot->TotalCount();
   size_t index = 0;
   for (size_t i = 0; i < bucket_count(); ++i) {
diff --git a/base/metrics/histogram.h b/base/metrics/histogram.h
index 338498d..f3007a2 100644
--- a/base/metrics/histogram.h
+++ b/base/metrics/histogram.h
@@ -72,7 +72,6 @@
 #include "base/metrics/bucket_ranges.h"
 #include "base/metrics/histogram_base.h"
 #include "base/metrics/histogram_samples.h"
-#include "base/metrics/sample_vector.h"
 #include "base/time.h"
 
 class Pickle;
@@ -481,7 +480,7 @@ class BASE_EXPORT Histogram : public HistogramBase {
 
   // Snapshot the current complete set of sample data.
   // Override with atomic/locked snapshot if needed.
-  virtual scoped_ptr<SampleVector> SnapshotSamples() const;
+  virtual scoped_ptr<HistogramSamples> SnapshotSamples() const OVERRIDE;
 
   virtual bool HasConstructionArguments(Sample minimum,
                                         Sample maximum,
@@ -527,14 +526,17 @@ class BASE_EXPORT Histogram : public HistogramBase {
 
  private:
   // Allow tests to corrupt our innards for testing purposes.
+  FRIEND_TEST_ALL_PREFIXES(HistogramTest, BoundsTest);
+  FRIEND_TEST_ALL_PREFIXES(HistogramTest, BucketPlacementTest);
   FRIEND_TEST_ALL_PREFIXES(HistogramTest, CorruptBucketBounds);
   FRIEND_TEST_ALL_PREFIXES(HistogramTest, CorruptSampleCounts);
-  FRIEND_TEST_ALL_PREFIXES(HistogramTest, Crc32SampleHash);
-  FRIEND_TEST_ALL_PREFIXES(HistogramTest, Crc32TableTest);
 
   friend class StatisticsRecorder;  // To allow it to delete duplicates.
   friend class StatisticsRecorderTest;
 
+  // Implementation of SnapshotSamples function.
+  scoped_ptr<SampleVector> SnapshotSampleVector() const;
+
   //----------------------------------------------------------------------------
   // Helpers for emitting Ascii graphic.  Each method appends data to output.
 
diff --git a/base/metrics/histogram_base.h b/base/metrics/histogram_base.h
index 44cc239..211606a 100644
--- a/base/metrics/histogram_base.h
+++ b/base/metrics/histogram_base.h
@@ -9,12 +9,15 @@
 
 #include "base/base_export.h"
 #include "base/basictypes.h"
+#include "base/memory/scoped_ptr.h"
 
 namespace base {
 
 class DictionaryValue;
 class ListValue;
 
+class HistogramSamples;
+
 class BASE_EXPORT HistogramBase {
  public:
   typedef int Sample;  // Used for samples.
@@ -50,6 +53,8 @@ class BASE_EXPORT HistogramBase {
 
   virtual void Add(Sample value) = 0;
 
+  virtual scoped_ptr<HistogramSamples> SnapshotSamples() const = 0;
+
   // The following methods provide graphical histogram displays.
   virtual void WriteHTMLGraph(std::string* output) const = 0;
   virtual void WriteAscii(std::string* output) const = 0;
diff --git a/base/metrics/histogram_unittest.cc b/base/metrics/histogram_unittest.cc
index f016487..99f75a5 100644
--- a/base/metrics/histogram_unittest.cc
+++ b/base/metrics/histogram_unittest.cc
@@ -208,7 +208,7 @@ TEST(HistogramTest, BoundsTest) {
   histogram->Add(10000);
 
   // Verify they landed in the underflow, and overflow buckets.
-  scoped_ptr<SampleVector> samples = histogram->SnapshotSamples();
+  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();
@@ -232,7 +232,7 @@ TEST(HistogramTest, BoundsTest) {
 
   // Verify they landed in the underflow, and overflow buckets.
   scoped_ptr<SampleVector> custom_samples =
-      test_custom_histogram->SnapshotSamples();
+      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();
@@ -255,7 +255,7 @@ TEST(HistogramTest, BucketPlacementTest) {
   }
 
   // Check to see that the bucket counts reflect our additions.
-  scoped_ptr<SampleVector> samples = histogram->SnapshotSamples();
+  scoped_ptr<SampleVector> samples = histogram->SnapshotSampleVector();
   for (int i = 0; i < 8; i++)
     EXPECT_EQ(i + 1, samples->GetCountAtIndex(i));
 }
@@ -268,7 +268,7 @@ TEST(HistogramTest, CorruptSampleCounts) {
   histogram->Add(20);
   histogram->Add(40);
 
-  scoped_ptr<SampleVector> snapshot = histogram->SnapshotSamples();
+  scoped_ptr<SampleVector> snapshot = histogram->SnapshotSampleVector();
   EXPECT_EQ(Histogram::NO_INCONSISTENCIES,
             histogram->FindCorruption(*snapshot));
   EXPECT_EQ(2, snapshot->redundant_count());
@@ -291,7 +291,7 @@ TEST(HistogramTest, CorruptBucketBounds) {
   Histogram* histogram(Histogram::FactoryGet(
       "Histogram", 1, 64, 8, Histogram::kNoFlags));  // As per header file.
 
-  scoped_ptr<SampleVector> snapshot = histogram->SnapshotSamples();
+  scoped_ptr<SampleVector> snapshot = histogram->SnapshotSampleVector();
   EXPECT_EQ(Histogram::NO_INCONSISTENCIES,
             histogram->FindCorruption(*snapshot));
 
diff --git a/base/metrics/sparse_histogram.cc b/base/metrics/sparse_histogram.cc
index 236a19e..bb9061c 100644
--- a/base/metrics/sparse_histogram.cc
+++ b/base/metrics/sparse_histogram.cc
@@ -4,6 +4,7 @@
 
 #include "base/metrics/sparse_histogram.h"
 
+#include "base/metrics/sample_map.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/synchronization/lock.h"
 
@@ -31,7 +32,7 @@ void SparseHistogram::Add(Sample value) {
   redundant_count_ += 1;
 }
 
-scoped_ptr<SampleMap> SparseHistogram::SnapshotSamples() const {
+scoped_ptr<HistogramSamples> SparseHistogram::SnapshotSamples() const {
   scoped_ptr<SampleMap> snapshot(new SampleMap());
 
   base::AutoLock auto_lock(lock_);
@@ -41,7 +42,7 @@ scoped_ptr<SampleMap> SparseHistogram::SnapshotSamples() const {
     snapshot->Accumulate(it->first, it->second);
   }
   snapshot->ResetRedundantCount(redundant_count_);
-  return snapshot.Pass();
+  return snapshot.PassAs<HistogramSamples>();
 }
 
 void SparseHistogram::WriteHTMLGraph(string* output) const {
diff --git a/base/metrics/sparse_histogram.h b/base/metrics/sparse_histogram.h
index 3c39b13..d209fd8 100644
--- a/base/metrics/sparse_histogram.h
+++ b/base/metrics/sparse_histogram.h
@@ -13,11 +13,12 @@
 #include "base/compiler_specific.h"
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_base.h"
-#include "base/metrics/sample_map.h"
 #include "base/synchronization/lock.h"
 
 namespace base {
 
+class HistogramSamples;
+
 class BASE_EXPORT_PRIVATE SparseHistogram : public HistogramBase {
  public:
   // If there's one with same name, return the existing one. If not, create a
@@ -31,7 +32,7 @@ class BASE_EXPORT_PRIVATE SparseHistogram : public HistogramBase {
   virtual void WriteHTMLGraph(std::string* output) const OVERRIDE;
   virtual void WriteAscii(std::string* output) const OVERRIDE;
 
-  virtual scoped_ptr<SampleMap> SnapshotSamples() const;
+  virtual scoped_ptr<HistogramSamples> SnapshotSamples() const OVERRIDE;
 
  private:
   // Clients should always use FactoryGet to create SparseHistogram.
diff --git a/base/metrics/sparse_histogram_unittest.cc b/base/metrics/sparse_histogram_unittest.cc
index 2fe614f..b4eb8fd 100644
--- a/base/metrics/sparse_histogram_unittest.cc
+++ b/base/metrics/sparse_histogram_unittest.cc
@@ -20,18 +20,18 @@ class SparseHistogramTest : public testing::Test {
 
 TEST_F(SparseHistogramTest, BasicTest) {
   scoped_ptr<SparseHistogram> histogram(NewSparseHistogram("Sparse1"));
-  scoped_ptr<SampleMap> snapshot(histogram->SnapshotSamples());
+  scoped_ptr<HistogramSamples> snapshot(histogram->SnapshotSamples());
   EXPECT_EQ(0, snapshot->TotalCount());
   EXPECT_EQ(0, snapshot->sum());
 
   histogram->Add(100);
-  scoped_ptr<SampleMap> snapshot1(histogram->SnapshotSamples());
+  scoped_ptr<HistogramSamples> snapshot1(histogram->SnapshotSamples());
   EXPECT_EQ(1, snapshot1->TotalCount());
   EXPECT_EQ(1, snapshot1->GetCount(100));
 
   histogram->Add(100);
   histogram->Add(101);
-  scoped_ptr<SampleMap> snapshot2(histogram->SnapshotSamples());
+  scoped_ptr<HistogramSamples> snapshot2(histogram->SnapshotSamples());
   EXPECT_EQ(3, snapshot2->TotalCount());
   EXPECT_EQ(2, snapshot2->GetCount(100));
   EXPECT_EQ(1, snapshot2->GetCount(101));