SampleSet -> HistogramSamples which can be reused by SparseHistogram

BUG=139612

Review URL: https://chromiumcodereview.appspot.com/10829466

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@158166 0039d316-1c4b-4281-b951-d872f2087c98

4 files changed, 43 insertions, 20 deletions

diff --git a/chrome/common/metrics/metrics_log_base.cc b/chrome/common/metrics/metrics_log_base.cc
index 5b12cfd..938828f 100644
--- a/chrome/common/metrics/metrics_log_base.cc
+++ b/chrome/common/metrics/metrics_log_base.cc
@@ -7,6 +7,8 @@
 #include "base/base64.h"
 #include "base/basictypes.h"
 #include "base/md5.h"
+#include "base/metrics/histogram_base.h"
+#include "base/metrics/histogram_samples.h"
 #include "base/perftimer.h"
 #include "base/string_number_conversions.h"
 #include "base/sys_byteorder.h"
@@ -23,6 +25,9 @@
 #define OPEN_ELEMENT_FOR_SCOPE(name) ScopedElement scoped_element(this, name)
 
 using base::Histogram;
+using base::HistogramBase;
+using base::HistogramSamples;
+using base::SampleCountIterator;
 using base::Time;
 using base::TimeDelta;
 using metrics::HistogramEventProto;
@@ -449,10 +454,9 @@ void MetricsLogBase::EndElement() {
 // the same infrastructure for logging StatsCounters, RatesCounters, etc.
 void MetricsLogBase::RecordHistogramDelta(
     const Histogram& histogram,
-    const Histogram::SampleSet& snapshot) {
+    const HistogramSamples& snapshot) {
   DCHECK(!locked_);
   DCHECK_NE(0, snapshot.TotalCount());
-  DCHECK_EQ(histogram.bucket_count(), snapshot.size());
 
   // We will ignore the MAX_INT/infinite value in the last element of range[].
 
@@ -471,13 +475,17 @@ void MetricsLogBase::RecordHistogramDelta(
   // TODO(jar): Remove sumsquares when protobuffer accepts this as optional.
   WriteInt64Attribute("sumsquares", 0);
 
-  for (size_t i = 0; i < histogram.bucket_count(); i++) {
-    if (snapshot.counts(i)) {
-      OPEN_ELEMENT_FOR_SCOPE("histogrambucket");
-      WriteIntAttribute("min", histogram.ranges(i));
-      WriteIntAttribute("max", histogram.ranges(i + 1));
-      WriteIntAttribute("count", snapshot.counts(i));
-    }
+  for (scoped_ptr<SampleCountIterator> it = snapshot.Iterator();
+       !it->Done();
+       it->Next()) {
+    OPEN_ELEMENT_FOR_SCOPE("histogrambucket");
+    HistogramBase::Sample min;
+    HistogramBase::Sample max;
+    HistogramBase::Count count;
+    it->Get(&min, &max, &count);
+    WriteIntAttribute("min", min);
+    WriteIntAttribute("max", max);
+    WriteIntAttribute("count", count);
   }
 
   // Write the protobuf version.
@@ -485,13 +493,20 @@ void MetricsLogBase::RecordHistogramDelta(
   histogram_proto->set_name_hash(numeric_name_hash);
   histogram_proto->set_sum(snapshot.sum());
 
-  for (size_t i = 0; i < histogram.bucket_count(); ++i) {
-    if (snapshot.counts(i)) {
-      HistogramEventProto::Bucket* bucket = histogram_proto->add_bucket();
-      bucket->set_min(histogram.ranges(i));
-      bucket->set_max(histogram.ranges(i + 1));
-      bucket->set_bucket_index(i);
-      bucket->set_count(snapshot.counts(i));
-    }
+  for (scoped_ptr<SampleCountIterator> it = snapshot.Iterator();
+       !it->Done();
+       it->Next()) {
+    HistogramBase::Sample min;
+    HistogramBase::Sample max;
+    HistogramBase::Count count;
+    it->Get(&min, &max, &count);
+    HistogramEventProto::Bucket* bucket = histogram_proto->add_bucket();
+    bucket->set_min(min);
+    bucket->set_max(max);
+    bucket->set_count(count);
+
+    size_t index;
+    if (it->GetBucketIndex(&index))
+      bucket->set_bucket_index(index);
   }
 }
diff --git a/chrome/common/metrics/metrics_log_base.h b/chrome/common/metrics/metrics_log_base.h
index 0fb43e9..b11f032 100644
--- a/chrome/common/metrics/metrics_log_base.h
+++ b/chrome/common/metrics/metrics_log_base.h
@@ -18,6 +18,10 @@
 
 class GURL;
 
+namespace base {
+class HistogramSamples;
+}  // namespace base
+
 // This class provides base functionality for logging metrics data.
 class MetricsLogBase {
  public:
@@ -72,7 +76,7 @@ class MetricsLogBase {
 
   // Record any changes in a given histogram for transmission.
   void RecordHistogramDelta(const base::Histogram& histogram,
-                            const base::Histogram::SampleSet& snapshot);
+                            const base::HistogramSamples& snapshot);
 
   // Stop writing to this record and generate the encoded representation.
   // None of the Record* methods can be called after this is called.
diff --git a/chrome/common/metrics/metrics_service_base.cc b/chrome/common/metrics/metrics_service_base.cc
index bffe971..84410c4 100644
--- a/chrome/common/metrics/metrics_service_base.cc
+++ b/chrome/common/metrics/metrics_service_base.cc
@@ -37,7 +37,7 @@ void MetricsServiceBase::RecordCurrentHistograms() {
 
 void MetricsServiceBase::RecordDelta(
     const base::Histogram& histogram,
-    const base::Histogram::SampleSet& snapshot) {
+    const base::HistogramSamples& snapshot) {
   log_manager_.current_log()->RecordHistogramDelta(histogram, snapshot);
 }
 
diff --git a/chrome/common/metrics/metrics_service_base.h b/chrome/common/metrics/metrics_service_base.h
index 753cc26..fb72377 100644
--- a/chrome/common/metrics/metrics_service_base.h
+++ b/chrome/common/metrics/metrics_service_base.h
@@ -11,6 +11,10 @@
 #include "base/metrics/histogram_snapshot_manager.h"
 #include "chrome/common/metrics/metrics_log_manager.h"
 
+namespace base {
+class HistogramSamples;
+}  // namespace base
+
 // This class provides base functionality for logging metrics data.
 // TODO(ananta): Factor out more common code from chrome and chrome frame
 // metrics service into this class.
@@ -18,7 +22,7 @@ class MetricsServiceBase : public base::HistogramFlattener {
  public:
   // HistogramFlattener interface (override) methods.
   virtual void RecordDelta(const base::Histogram& histogram,
-                           const base::Histogram::SampleSet& snapshot) OVERRIDE;
+                           const base::HistogramSamples& snapshot) OVERRIDE;
   virtual void InconsistencyDetected(
       base::Histogram::Inconsistencies problem) OVERRIDE;
   virtual void UniqueInconsistencyDetected(