Move StatisticsRecorder out of histogram.cc/h for further refactoring.

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/debug/leak_annotations.h"
 #include "base/logging.h"
 #include "base/pickle.h"
 #include "base/stringprintf.h"
+#include "base/metrics/statistics_recorder.h"
 #include "base/synchronization/lock.h"
 
 namespace base {
 
 // Static table of checksums for all possible 8 bit bytes.
 const uint32 Histogram::kCrcTable[256] = {0x0, 0x77073096L, 0xee0e612cL,
 0x990951baL, 0x76dc419L, 0x706af48fL, 0xe963a535L, 0x9e6495a3L, 0xedb8832L,
 0x79dcb8a4L, 0xe0d5e91eL, 0x97d2d988L, 0x9b64c2bL, 0x7eb17cbdL, 0xe7b82d07L,
 0x90bf1d91L, 0x1db71064L, 0x6ab020f2L, 0xf3b97148L, 0x84be41deL, 0x1adad47dL,
 0x6ddde4ebL, 0xf4d4b551L, 0x83d385c7L, 0x136c9856L, 0x646ba8c0L, 0xfd62f97aL,
@@ skipping 36 matching lines @@
 0x24b4a3a6L, 0xbad03605L, 0xcdd70693L, 0x54de5729L, 0x23d967bfL, 0xb3667a2eL,
 0xc4614ab8L, 0x5d681b02L, 0x2a6f2b94L, 0xb40bbe37L, 0xc30c8ea1L, 0x5a05df1bL,
 0x2d02ef8dL,
 };
 
 typedef Histogram::Count Count;
 
 // static
 const size_t Histogram::kBucketCount_MAX = 16384u;
 
-// Collect the number of histograms created.
-static uint32 number_of_histograms_ = 0;
-// Collect the number of vectors saved because of caching ranges.
-static uint32 number_of_vectors_saved_ = 0;
-// Collect the number of ranges_ elements saved because of caching ranges.
-static size_t saved_ranges_size_ = 0;
-
 Histogram* Histogram::FactoryGet(const std::string& name,
                                  Sample minimum,
                                  Sample maximum,
                                  size_t bucket_count,
                                  Flags flags) {
   Histogram* histogram(NULL);
 
   // Defensive code.
   if (minimum < 1)
     minimum = 1;
@@ skipping 936 matching lines @@
   DCHECK_LE(custom_ranges.size(), bucket_count());
   for (size_t index = 0; index < custom_ranges.size(); ++index)
     SetBucketRange(index, custom_ranges[index]);
   ResetRangeChecksum();
 }
 
 double CustomHistogram::GetBucketSize(Count current, size_t i) const {
   return 1;
 }
 
-//------------------------------------------------------------------------------
-// The next section handles global (central) support for all histograms, as well
-// as startup/teardown of this service.
-//------------------------------------------------------------------------------
-
-// This singleton instance should be started during the single threaded portion
-// of main(), and hence it is not thread safe.  It initializes globals to
-// provide support for all future calls.
-StatisticsRecorder::StatisticsRecorder() {
-  DCHECK(!histograms_);
-  if (lock_ == NULL) {
-    // This will leak on purpose. It's the only way to make sure we won't race
-    // against the static uninitialization of the module while one of our
-    // static methods relying on the lock get called at an inappropriate time
-    // during the termination phase. Since it's a static data member, we will
-    // leak one per process, which would be similar to the instance allocated
-    // during static initialization and released only on  process termination.
-    lock_ = new base::Lock;
-  }
-  base::AutoLock auto_lock(*lock_);
-  histograms_ = new HistogramMap;
-  ranges_ = new RangesMap;
-}
-
-StatisticsRecorder::~StatisticsRecorder() {
-  DCHECK(histograms_ && lock_);
-
-  if (dump_on_exit_) {
-    std::string output;
-    WriteGraph("", &output);
-    DLOG(INFO) << output;
-  }
-  // Clean up.
-  HistogramMap* histograms = NULL;
-  {
-    base::AutoLock auto_lock(*lock_);
-    histograms = histograms_;
-    histograms_ = NULL;
-  }
-  RangesMap* ranges = NULL;
-  {
-    base::AutoLock auto_lock(*lock_);
-    ranges = ranges_;
-    ranges_ = NULL;
-  }
-  // We are going to leak the histograms and the ranges.
-  delete histograms;
-  delete ranges;
-  // We don't delete lock_ on purpose to avoid having to properly protect
-  // against it going away after we checked for NULL in the static methods.
-}
-
-// static
-bool StatisticsRecorder::IsActive() {
-  if (lock_ == NULL)
-    return false;
-  base::AutoLock auto_lock(*lock_);
-  return NULL != histograms_;
-}
-
-Histogram* StatisticsRecorder::RegisterOrDeleteDuplicate(Histogram* histogram) {
-  // As per crbug.com/79322 the histograms are intentionally leaked, so we need
-  // to annotate them. Because ANNOTATE_LEAKING_OBJECT_PTR may be used only once
-  // for an object, the duplicates should not be annotated.
-  // Callers are responsible for not calling RegisterOrDeleteDuplicate(ptr)
-  // twice if (lock_ == NULL) || (!histograms_).
-  DCHECK(histogram->HasValidRangeChecksum());
-  if (lock_ == NULL) {
-    ANNOTATE_LEAKING_OBJECT_PTR(histogram);  // see crbug.com/79322
-    return histogram;
-  }
-  base::AutoLock auto_lock(*lock_);
-  if (!histograms_) {
-    ANNOTATE_LEAKING_OBJECT_PTR(histogram);  // see crbug.com/79322
-    return histogram;
-  }
-  const std::string name = histogram->histogram_name();
-  HistogramMap::iterator it = histograms_->find(name);
-  // Avoid overwriting a previous registration.
-  if (histograms_->end() == it) {
-    (*histograms_)[name] = histogram;
-    ANNOTATE_LEAKING_OBJECT_PTR(histogram);  // see crbug.com/79322
-    RegisterOrDeleteDuplicateRanges(histogram);
-    ++number_of_histograms_;
-  } else {
-    delete histogram;  // We already have one by this name.
-    histogram = it->second;
-  }
-  return histogram;
-}
-
-// static
-void StatisticsRecorder::RegisterOrDeleteDuplicateRanges(Histogram* histogram) {
-  DCHECK(histogram);
-  CachedRanges* histogram_ranges = histogram->cached_ranges();
-  DCHECK(histogram_ranges);
-  uint32 checksum = histogram->range_checksum();
-  histogram_ranges->SetRangeChecksum(checksum);
-
-  RangesMap::iterator ranges_it = ranges_->find(checksum);
-  if (ranges_->end() == ranges_it) {
-    // Register the new CachedRanges.
-    std::list<CachedRanges*>* checksum_matching_list(
-        new std::list<CachedRanges*>());
-    checksum_matching_list->push_front(histogram_ranges);
-    (*ranges_)[checksum] = checksum_matching_list;
-    return;
-  }
-
-  // Use the registered CachedRanges if the registered CachedRanges has same
-  // ranges_ as |histogram|'s CachedRanges.
-  std::list<CachedRanges*>* checksum_matching_list = ranges_it->second;
-  std::list<CachedRanges*>::iterator checksum_matching_list_it;
-  for (checksum_matching_list_it = checksum_matching_list->begin();
-       checksum_matching_list_it != checksum_matching_list->end();
-       ++checksum_matching_list_it) {
-    CachedRanges* existing_histogram_ranges = *checksum_matching_list_it;
-    DCHECK(existing_histogram_ranges);
-    if (existing_histogram_ranges->Equals(histogram_ranges)) {
-      histogram->set_cached_ranges(existing_histogram_ranges);
-      ++number_of_vectors_saved_;
-      saved_ranges_size_ += histogram_ranges->size();
-      delete histogram_ranges;
-      return;
-    }
-  }
-
-  // We haven't found a CachedRanges which has the same ranges. Register the
-  // new CachedRanges.
-  DCHECK(checksum_matching_list_it == checksum_matching_list->end());
-  checksum_matching_list->push_front(histogram_ranges);
-}
-
-// static
-void StatisticsRecorder::CollectHistogramStats(const std::string& suffix) {
-  static int uma_upload_attempt = 0;
-  ++uma_upload_attempt;
-  if (uma_upload_attempt == 1) {
-    UMA_HISTOGRAM_COUNTS_10000(
-        "Histogram.SharedRange.Count.FirstUpload." + suffix,
-        number_of_histograms_);
-    UMA_HISTOGRAM_COUNTS_10000(
-        "Histogram.SharedRange.RangesSaved.FirstUpload." + suffix,
-        number_of_vectors_saved_);
-    UMA_HISTOGRAM_COUNTS(
-        "Histogram.SharedRange.ElementsSaved.FirstUpload." + suffix,
-        static_cast<int>(saved_ranges_size_));
-    number_of_histograms_ = 0;
-    number_of_vectors_saved_ = 0;
-    saved_ranges_size_ = 0;
-    return;
-  }
-  if (uma_upload_attempt == 2) {
-    UMA_HISTOGRAM_COUNTS_10000(
-        "Histogram.SharedRange.Count.SecondUpload." + suffix,
-        number_of_histograms_);
-    UMA_HISTOGRAM_COUNTS_10000(
-        "Histogram.SharedRange.RangesSaved.SecondUpload." + suffix,
-        number_of_vectors_saved_);
-    UMA_HISTOGRAM_COUNTS(
-        "Histogram.SharedRange.ElementsSaved.SecondUpload." + suffix,
-        static_cast<int>(saved_ranges_size_));
-    number_of_histograms_ = 0;
-    number_of_vectors_saved_ = 0;
-    saved_ranges_size_ = 0;
-    return;
-  }
-  UMA_HISTOGRAM_COUNTS_10000(
-      "Histogram.SharedRange.Count.RestOfUploads." + suffix,
-      number_of_histograms_);
-  UMA_HISTOGRAM_COUNTS_10000(
-      "Histogram.SharedRange.RangesSaved.RestOfUploads." + suffix,
-      number_of_vectors_saved_);
-  UMA_HISTOGRAM_COUNTS(
-      "Histogram.SharedRange.ElementsSaved.RestOfUploads." + suffix,
-      static_cast<int>(saved_ranges_size_));
-}
-
-// static
-void StatisticsRecorder::WriteHTMLGraph(const std::string& query,
-                                        std::string* output) {
-  if (!IsActive())
-    return;
-
-  Histograms snapshot;
-  GetSnapshot(query, &snapshot);
-  for (Histograms::iterator it = snapshot.begin();
-       it != snapshot.end();
-       ++it) {
-    (*it)->WriteHTMLGraph(output);
-    output->append("<br><hr><br>");
-  }
-}
-
-// static
-void StatisticsRecorder::WriteGraph(const std::string& query,
-                                    std::string* output) {
-  if (!IsActive())
-    return;
-  if (query.length())
-    StringAppendF(output, "Collections of histograms for %s\n", query.c_str());
-  else
-    output->append("Collections of all histograms\n");
-
-  Histograms snapshot;
-  GetSnapshot(query, &snapshot);
-  for (Histograms::iterator it = snapshot.begin();
-       it != snapshot.end();
-       ++it) {
-    (*it)->WriteAscii(true, "\n", output);
-    output->append("\n");
-  }
-}
-
-// static
-void StatisticsRecorder::GetHistograms(Histograms* output) {
-  if (lock_ == NULL)
-    return;
-  base::AutoLock auto_lock(*lock_);
-  if (!histograms_)
-    return;
-  for (HistogramMap::iterator it = histograms_->begin();
-       histograms_->end() != it;
-       ++it) {
-    DCHECK_EQ(it->first, it->second->histogram_name());
-    output->push_back(it->second);
-  }
-}
-
-bool StatisticsRecorder::FindHistogram(const std::string& name,
-                                       Histogram** histogram) {
-  if (lock_ == NULL)
-    return false;
-  base::AutoLock auto_lock(*lock_);
-  if (!histograms_)
-    return false;
-  HistogramMap::iterator it = histograms_->find(name);
-  if (histograms_->end() == it)
-    return false;
-  *histogram = it->second;
-  return true;
-}
-
-// private static
-void StatisticsRecorder::GetSnapshot(const std::string& query,
-                                     Histograms* snapshot) {
-  if (lock_ == NULL)
-    return;
-  base::AutoLock auto_lock(*lock_);
-  if (!histograms_)
-    return;
-  for (HistogramMap::iterator it = histograms_->begin();
-       histograms_->end() != it;
-       ++it) {
-    if (it->first.find(query) != std::string::npos)
-      snapshot->push_back(it->second);
-  }
-}
-
 CachedRanges::CachedRanges(size_t bucket_count, int initial_value)
     : ranges_(bucket_count, initial_value),
       range_checksum_(0) {
 }
 
 CachedRanges::~CachedRanges() {
 }
 
 void CachedRanges::SetBucketRange(size_t i, Histogram::Sample value) {
   DCHECK_LT(i, ranges_.size());
   DCHECK_GE(value, 0);
   ranges_[i] = value;
 }
 
 bool CachedRanges::Equals(CachedRanges* other) const {
   if (range_checksum_ != other->range_checksum_)
     return false;
   if (ranges_.size() != other->ranges_.size())
     return false;
   for (size_t index = 0; index < ranges_.size(); ++index) {
     if (ranges_[index] != other->ranges_[index])
       return false;
   }
   return true;
 }
 
-// static
-StatisticsRecorder::HistogramMap* StatisticsRecorder::histograms_ = NULL;
-// static
-StatisticsRecorder::RangesMap* StatisticsRecorder::ranges_ = NULL;
-// static
-base::Lock* StatisticsRecorder::lock_ = NULL;
-// static
-bool StatisticsRecorder::dump_on_exit_ = false;
 }  // namespace base