1 // Copyright (c) 2012 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 "chrome/browser/performance_monitor/metric.h" 6 7 #include "base/basictypes.h" 8 #include "base/logging.h" 9 #include "base/strings/string_number_conversions.h" 10 #include "base/time/time.h" 11 #include "chrome/browser/performance_monitor/constants.h" 12 13 namespace performance_monitor { 14 15 namespace { 16 17 // For certain metrics (for instance, bytes read), it is possible that there is 18 // no maximum value which we can safely assume. 19 const double kNoMaximum = -1.0; 20 21 // These constants are designed to keep metrics reasonable. However, due to the 22 // variety of system configurations which can run chrome, these values may not 23 // catch *all* erroneous values. For instance, on a one-CPU machine, any CPU 24 // usage > 100 is erroneous, but on a 16-CPU machine, it's perfectly normal. 25 // These are "best-guesses" in order to weed out obviously-false values. A 26 // metric is valid if it is greater than or equal to the minimum and less than 27 // the maximum, i.e. if it falls in the range [min, max). 28 const double kMinUndefined = 0.0; 29 const double kMaxUndefined = 0.0; // No undefined metric is valid. 30 const double kMinCpuUsage = 0.0; 31 const double kMaxCpuUsage = 100000.0; // 100% on a 1000-CPU machine. 32 const double kMinPrivateMemoryUsage = 0.0; 33 const double kMaxPrivateMemoryUsage = kBytesPerTerabyte; 34 const double kMinSharedMemoryUsage = 0.0; 35 const double kMaxSharedMemoryUsage = kBytesPerTerabyte; 36 const double kMinStartupTime = 0.0; 37 const double kMaxStartupTime = base::Time::kMicrosecondsPerMinute * 15.0; 38 const double kMinTestStartupTime = 0.0; 39 const double kMaxTestStartupTime = base::Time::kMicrosecondsPerMinute * 15.0; 40 const double kMinSessionRestoreTime = 0.0; 41 const double kMaxSessionRestoreTime = base::Time::kMicrosecondsPerMinute * 15.0; 42 const double kMinPageLoadTime = 0.0; 43 const double kMaxPageLoadTime = base::Time::kMicrosecondsPerMinute * 15.0; 44 const double kMinNetworkBytesRead = 0.0; 45 const double kMaxNetworkBytesRead = kNoMaximum; 46 47 struct MetricBound { 48 double min; 49 double max; 50 }; 51 52 const MetricBound kMetricBounds[] = { 53 { kMinUndefined, kMaxUndefined }, 54 { kMinCpuUsage, kMaxCpuUsage }, 55 { kMinPrivateMemoryUsage, kMaxPrivateMemoryUsage }, 56 { kMinSharedMemoryUsage, kMaxSharedMemoryUsage }, 57 { kMinStartupTime, kMaxStartupTime }, 58 { kMinTestStartupTime, kMaxTestStartupTime }, 59 { kMinSessionRestoreTime, kMaxSessionRestoreTime }, 60 { kMinPageLoadTime, kMaxPageLoadTime }, 61 { kMinNetworkBytesRead, kMaxNetworkBytesRead }, 62 }; 63 64 COMPILE_ASSERT(ARRAYSIZE_UNSAFE(kMetricBounds) == METRIC_NUMBER_OF_METRICS, 65 metric_bounds_size_doesnt_match_metric_count); 66 67 } // namespace 68 69 Metric::Metric() : type(METRIC_UNDEFINED), value(0.0) { 70 } 71 72 Metric::Metric(MetricType metric_type, 73 const base::Time& metric_time, 74 const double metric_value) 75 : type(metric_type), time(metric_time), value(metric_value) { 76 } 77 78 Metric::Metric(MetricType metric_type, 79 const std::string& metric_time, 80 const std::string& metric_value) : type(metric_type) { 81 int64 conversion = 0; 82 base::StringToInt64(metric_time, &conversion); 83 time = base::Time::FromInternalValue(conversion); 84 CHECK(base::StringToDouble(metric_value, &value)); 85 } 86 87 Metric::~Metric() { 88 } 89 90 bool Metric::IsValid() const { 91 return type < METRIC_NUMBER_OF_METRICS && 92 (value < kMetricBounds[type].max || 93 kMetricBounds[type].max == kNoMaximum) && 94 value >= kMetricBounds[type].min; 95 } 96 97 std::string Metric::ValueAsString() const { 98 return base::DoubleToString(value); 99 } 100 101 } // namespace performance_monitor 102
