Connect SparseHistogram with the rest of stats system

base/metrics/histogram_snapshot_manager.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 "base/metrics/histogram_snapshot_manager.h"
 
 #include "base/memory/scoped_ptr.h"
 #include "base/metrics/histogram_flattener.h"
 #include "base/metrics/histogram_samples.h"
 #include "base/metrics/statistics_recorder.h"
 #include "base/stl_util.h"
 
 using std::map;
 using std::string;
 
 namespace base {
 
 HistogramSnapshotManager::HistogramSnapshotManager(
     HistogramFlattener* histogram_flattener)
     : histogram_flattener_(histogram_flattener) {
   DCHECK(histogram_flattener_);
 }
 
 HistogramSnapshotManager::~HistogramSnapshotManager() {
   STLDeleteValues(&logged_samples_);
 }
 
-void HistogramSnapshotManager::PrepareDeltas(Histogram::Flags flag_to_set,
+void HistogramSnapshotManager::PrepareDeltas(HistogramBase::Flags flag_to_set,
                                              bool record_only_uma) {
   StatisticsRecorder::Histograms histograms;
   StatisticsRecorder::GetHistograms(&histograms);
   for (StatisticsRecorder::Histograms::const_iterator it = histograms.begin();
        histograms.end() != it;
        ++it) {
     (*it)->SetFlags(flag_to_set);
     if (record_only_uma &&
         0 == ((*it)->flags() & Histogram::kUmaTargetedHistogramFlag))
       continue;
     PrepareDelta(**it);
   }
 }
 
-void HistogramSnapshotManager::PrepareDelta(const Histogram& histogram) {
+void HistogramSnapshotManager::PrepareDelta(const HistogramBase& histogram) {
   DCHECK(histogram_flattener_);
 
   // Get up-to-date snapshot of sample stats.
   scoped_ptr<HistogramSamples> snapshot(histogram.SnapshotSamples());
   const std::string& histogram_name = histogram.histogram_name();
 
   int corruption = histogram.FindCorruption(*snapshot);

[Ilya Sherman, 2013/02/21 05:36:06]

int32?

[kaiwang, 2013/02/27 04:39:42]

Done.

 
   // Crash if we detect that our histograms have been overwritten.  This may be
   // a fair distance from the memory smasher, but we hope to correlate these
   // crashes with other events, such as plugins, or usage patterns, etc.
-  if (Histogram::BUCKET_ORDER_ERROR & corruption) {
+  if (BUCKET_ORDER_ERROR & corruption) {
     // The checksum should have caught this, so crash separately if it didn't.
-    CHECK_NE(0, Histogram::RANGE_CHECKSUM_ERROR & corruption);
+    CHECK_NE(0, RANGE_CHECKSUM_ERROR & corruption);
     CHECK(false);  // Crash for the bucket order corruption.
   }
   // Checksum corruption might not have caused order corruption.
-  CHECK_EQ(0, Histogram::RANGE_CHECKSUM_ERROR & corruption);
+  CHECK_EQ(0, RANGE_CHECKSUM_ERROR & corruption);
 
   // Note, at this point corruption can only be COUNT_HIGH_ERROR or
   // COUNT_LOW_ERROR and they never arise together, so we don't need to extract
   // bits from corruption.
   if (corruption) {
     DLOG(ERROR) << "Histogram: " << histogram_name
                 << " has data corruption: " << corruption;
     histogram_flattener_->InconsistencyDetected(
-        static_cast<Histogram::Inconsistencies>(corruption));
+        static_cast<HistogramInconsistency>(corruption));

[Ilya Sherman, 2013/02/21 05:36:06]

Seems like if you're willing to cast here, you might as well just have the
return type for HistogramBase::FindCorruption be HistogramInconsistency.

[kaiwang, 2013/02/27 04:39:42]

the value FindCorruption returns can be a combination of HistogramInconsistency.
As the comment above mentioned, in this case, only one type of inconsistency can
happen, hence it's directly casted.

     // Don't record corrupt data to metrics services.
     int old_corruption = inconsistencies_[histogram_name];
     if (old_corruption == (corruption | old_corruption))
       return;  // We've already seen this corruption for this histogram.
     inconsistencies_[histogram_name] |= corruption;
     histogram_flattener_->UniqueInconsistencyDetected(
-        static_cast<Histogram::Inconsistencies>(corruption));
+        static_cast<HistogramInconsistency>(corruption));
     return;
   }
 
   HistogramSamples* to_log;
   map<string, HistogramSamples*>::iterator it =
       logged_samples_.find(histogram_name);
   if (it == logged_samples_.end()) {
     to_log = snapshot.release();
 
     // This histogram has not been logged before, add a new entry.
@@ skipping 20 matching lines @@
 
   histogram_flattener_->InconsistencyDetectedInLoggedCount(discrepancy);
   if (discrepancy > Histogram::kCommonRaceBasedCountMismatch) {
     // Fix logged_samples.
     logged_samples->Subtract(*logged_samples);
     logged_samples->Add(new_snapshot);
   }
 }
 
 }  // namespace base