base/metrics/stats_counters.cc

   1 // Copyright (c) 2010 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "base/metrics/stats_counters.h"
   6
   7 namespace base {
   8
   9 StatsCounter::StatsCounter(const std::string& name)
  10     : counter_id_(-1) {
  11   // We prepend the name with 'c:' to indicate that it is a counter.
  12   name_ = "c:";
  13   name_.append(name);
  14 }
  15
  16 StatsCounter::~StatsCounter() {
  17 }
  18
  19 void StatsCounter::Set(int value) {
  20   int* loc = GetPtr();
  21   if (loc)
  22     *loc = value;
  23 }
  24
  25 void StatsCounter::Add(int value) {
  26   int* loc = GetPtr();
  27   if (loc)
  28     (*loc) += value;
  29 }
  30
  31 StatsCounter::StatsCounter()
  32     : counter_id_(-1) {
  33 }
  34
  35 int* StatsCounter::GetPtr() {
  36   StatsTable* table = StatsTable::current();
  37   if (!table)
  38     return NULL;
  39
  40   // If counter_id_ is -1, then we haven't looked it up yet.
  41   if (counter_id_ == -1) {
  42     counter_id_ = table->FindCounter(name_);
  43     if (table->GetSlot() == 0) {
  44       if (!table->RegisterThread("")) {
  45         // There is no room for this thread.  This thread
  46         // cannot use counters.
  47         counter_id_ = 0;
  48         return NULL;
  49       }
  50     }
  51   }
  52
  53   // If counter_id_ is > 0, then we have a valid counter.
  54   if (counter_id_ > 0)
  55     return table->GetLocation(counter_id_, table->GetSlot());
  56
  57   // counter_id_ was zero, which means the table is full.
  58   return NULL;
  59 }
  60
  61
  62 StatsCounterTimer::StatsCounterTimer(const std::string& name) {
  63   // we prepend the name with 't:' to indicate that it is a timer.
  64   name_ = "t:";
  65   name_.append(name);
  66 }
  67
  68 StatsCounterTimer::~StatsCounterTimer() {
  69 }
  70
  71 void StatsCounterTimer::Start() {
  72   if (!Enabled())
  73     return;
  74   start_time_ = TimeTicks::Now();
  75   stop_time_ = TimeTicks();
  76 }
  77
  78 // Stop the timer and record the results.
  79 void StatsCounterTimer::Stop() {
  80   if (!Enabled() || !Running())
  81     return;
  82   stop_time_ = TimeTicks::Now();
  83   Record();
  84 }
  85
  86 // Returns true if the timer is running.
  87 bool StatsCounterTimer::Running() {
  88   return Enabled() && !start_time_.is_null() && stop_time_.is_null();
  89 }
  90
  91 // Accept a TimeDelta to increment.
  92 void StatsCounterTimer::AddTime(TimeDelta time) {
  93   Add(static_cast<int>(time.InMilliseconds()));
  94 }
  95
  96 void StatsCounterTimer::Record() {
  97   AddTime(stop_time_ - start_time_);
  98 }
  99
 100
 101 StatsRate::StatsRate(const std::string& name)
 102     : StatsCounterTimer(name),
 103       counter_(name),
 104       largest_add_(std::string(" ").append(name).append("MAX")) {
 105 }
 106
 107 StatsRate::~StatsRate() {
 108 }
 109
 110 void StatsRate::Add(int value) {
 111   counter_.Increment();
 112   StatsCounterTimer::Add(value);
 113   if (value > largest_add_.value())
 114     largest_add_.Set(value);
 115 }
 116
 117 }  // namespace base