Histograms - Support histograms for Plugins, GPU

chrome/common/metrics/histogram_sender.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 "chrome/common/metrics/histogram_sender.h"
-
-using base::Histogram;
-using base::StatisticsRecorder;
-
-HistogramSender::HistogramSender() {}
-
-HistogramSender::~HistogramSender() {}
-
-void HistogramSender::TransmitAllHistograms(Histogram::Flags flag_to_set,
-                                            bool send_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 (send_only_uma &&
-        0 == ((*it)->flags() & Histogram::kUmaTargetedHistogramFlag))
-      continue;
-    TransmitHistogram(**it);
-  }
-}
-
-void HistogramSender::TransmitHistogram(const Histogram& histogram) {
-  // Get up-to-date snapshot of sample stats.
-  Histogram::SampleSet snapshot;
-  histogram.SnapshotSample(&snapshot);
-  const std::string& histogram_name = histogram.histogram_name();
-
-  int corruption = histogram.FindCorruption(snapshot);
-
-  // 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) {
-    // The checksum should have caught this, so crash separately if it didn't.
-    CHECK_NE(0, Histogram::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);
-
-  if (corruption) {
-    NOTREACHED();
-    InconsistencyDetected(corruption);
-    // Don't send corrupt data to metrics survices.
-    if (NULL == inconsistencies_.get())
-      inconsistencies_.reset(new ProblemMap);
-    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;
-    UniqueInconsistencyDetected(corruption);
-    return;
-  }
-
-  // Find the already sent stats, or create an empty set.  Remove from our
-  // snapshot anything that we've already sent.
-  LoggedSampleMap::iterator it = logged_samples_.find(histogram_name);
-  Histogram::SampleSet* already_logged;
-  if (logged_samples_.end() == it) {
-    // Add new entry
-    already_logged = &logged_samples_[histogram.histogram_name()];
-    already_logged->Resize(histogram);  // Complete initialization.
-  } else {
-    already_logged = &(it->second);
-    int64 discrepancy(already_logged->TotalCount() -
-                    already_logged->redundant_count());
-    if (discrepancy) {
-      NOTREACHED();  // Already_logged has become corrupt.
-      int problem = static_cast<int>(discrepancy);
-      if (problem != discrepancy)
-        problem = INT_MAX;
-      SnapshotProblemResolved(problem);
-      // With no valid baseline, we'll act like we've sent everything in our
-      // snapshot.
-      already_logged->Subtract(*already_logged);
-      already_logged->Add(snapshot);
-    }
-    // Deduct any stats we've already logged from our snapshot.
-    snapshot.Subtract(*already_logged);
-  }
-
-  // Snapshot now contains only a delta to what we've already_logged.
-  if (snapshot.redundant_count() > 0) {
-    TransmitHistogramDelta(histogram, snapshot);
-    // Add new data into our running total.
-    already_logged->Add(snapshot);
-  }
-}