Reorganize histograms for persistence.

base/metrics/histogram.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.
 
 // Histogram is an object that aggregates statistics, and can summarize them in
 // various forms, including ASCII graphical, HTML, and numerically (as a
 // vector of numbers corresponding to each of the aggregating buckets).
 // See header file for details and examples.
 
 #include "base/metrics/histogram.h"
 
 #include <math.h>
 
 #include <algorithm>
 #include <string>
 
 #include "base/compiler_specific.h"
 #include "base/debug/alias.h"
 #include "base/logging.h"
 #include "base/metrics/histogram_macros.h"
+#include "base/metrics/metrics_hashes.h"
 #include "base/metrics/sample_vector.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/pickle.h"
 #include "base/strings/string_util.h"
 #include "base/strings/stringprintf.h"
 #include "base/synchronization/lock.h"
 #include "base/values.h"
 
 namespace base {
 
@@ skipping 221 matching lines @@
 
   if (*minimum >= *maximum)
     return false;
   if (*bucket_count < 3)
     return false;
   if (*bucket_count > static_cast<size_t>(*maximum - *minimum + 2))
     return false;
   return true;
 }
 
+uint64_t Histogram::id() const {
+  return samples_->id();
+}
+
 HistogramType Histogram::GetHistogramType() const {
   return HISTOGRAM;
 }
 
 bool Histogram::HasConstructionArguments(Sample expected_minimum,
                                          Sample expected_maximum,
                                          size_t expected_bucket_count) const {
   return ((expected_minimum == declared_min_) &&
           (expected_maximum == declared_max_) &&
           (expected_bucket_count == bucket_count()));
@@ skipping 18 matching lines @@
   samples_->Accumulate(value, count);
 
   FindAndRunCallback(value);
 }
 
 scoped_ptr<HistogramSamples> Histogram::SnapshotSamples() const {
   return SnapshotSampleVector().Pass();
 }
 
 void Histogram::AddSamples(const HistogramSamples& samples) {
+  DCHECK(samples.id() == 0 || samples.id() == samples_->id());
   samples_->Add(samples);
 }
 
 bool Histogram::AddSamplesFromPickle(PickleIterator* iter) {
   return samples_->AddFromPickle(iter);
 }
 
 // The following methods provide a graphical histogram display.
 void Histogram::WriteHTMLGraph(std::string* output) const {
   // TBD(jar) Write a nice HTML bar chart, with divs an mouse-overs etc.
@@ skipping 18 matching lines @@
 
 Histogram::Histogram(const std::string& name,
                      Sample minimum,
                      Sample maximum,
                      const BucketRanges* ranges)
   : HistogramBase(name),
     bucket_ranges_(ranges),
     declared_min_(minimum),
     declared_max_(maximum) {
   if (ranges)
-    samples_.reset(new SampleVector(ranges));
+    samples_.reset(new SampleVector(metrics::HashMetricName(name), ranges));
 }
 
 Histogram::~Histogram() {
 }
 
 bool Histogram::PrintEmptyBucket(size_t index) const {
   return true;
 }
 
 // Use the actual bucket widths (like a linear histogram) until the widths get
@@ skipping 36 matching lines @@
       histogram_name, declared_min, declared_max, bucket_count, flags);
 
   if (!ValidateRangeChecksum(*histogram, range_checksum)) {
     // The serialized histogram might be corrupted.
     return NULL;
   }
   return histogram;
 }
 
 scoped_ptr<SampleVector> Histogram::SnapshotSampleVector() const {
-  scoped_ptr<SampleVector> samples(new SampleVector(bucket_ranges()));
+  scoped_ptr<SampleVector> samples(
+      new SampleVector(metrics::HashMetricName(histogram_name()),
+                       bucket_ranges()));
   samples->Add(*samples_);
   return samples.Pass();
 }
 
 void Histogram::WriteAsciiImpl(bool graph_it,
                                const std::string& newline,
                                std::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 = SnapshotSampleVector();
@@ skipping 486 matching lines @@
 
   BucketRanges* bucket_ranges = new BucketRanges(ranges.size());
   for (size_t i = 0; i < ranges.size(); i++) {
     bucket_ranges->set_range(i, ranges[i]);
   }
   bucket_ranges->ResetChecksum();
   return bucket_ranges;
 }
 
 }  // namespace base