components/variations/processed_study.cc

   1 // Copyright 2013 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 "components/variations/processed_study.h"
   6
   7 #include <set>
   8 #include <string>
   9
  10 #include "base/version.h"
  11 #include "components/variations/proto/study.pb.h"
  12
  13 namespace variations {
  14
  15 namespace {
  16
  17 // Validates the sanity of |study| and computes the total probability.
  18 bool ValidateStudyAndComputeTotalProbability(
  19     const Study& study,
  20     base::FieldTrial::Probability* total_probability) {
  21   // At the moment, a missing default_experiment_name makes the study invalid.
  22   if (study.default_experiment_name().empty()) {
  23     DVLOG(1) << study.name() << " has no default experiment defined.";
  24     return false;
  25   }
  26   if (study.filter().has_min_version() &&
  27       !Version::IsValidWildcardString(study.filter().min_version())) {
  28     DVLOG(1) << study.name() << " has invalid min version: "
  29              << study.filter().min_version();
  30     return false;
  31   }
  32   if (study.filter().has_max_version() &&
  33       !Version::IsValidWildcardString(study.filter().max_version())) {
  34     DVLOG(1) << study.name() << " has invalid max version: "
  35              << study.filter().max_version();
  36     return false;
  37   }
  38
  39   const std::string& default_group_name = study.default_experiment_name();
  40   base::FieldTrial::Probability divisor = 0;
  41
  42   bool found_default_group = false;
  43   std::set<std::string> experiment_names;
  44   for (int i = 0; i < study.experiment_size(); ++i) {
  45     if (study.experiment(i).name().empty()) {
  46       DVLOG(1) << study.name() << " is missing experiment " << i << " name";
  47       return false;
  48     }
  49     if (!experiment_names.insert(study.experiment(i).name()).second) {
  50       DVLOG(1) << study.name() << " has a repeated experiment name "
  51                << study.experiment(i).name();
  52       return false;
  53     }
  54
  55     if (!study.experiment(i).has_forcing_flag())
  56       divisor += study.experiment(i).probability_weight();
  57     if (study.experiment(i).name() == default_group_name)
  58       found_default_group = true;
  59   }
  60
  61   if (!found_default_group) {
  62     DVLOG(1) << study.name() << " is missing default experiment in its "
  63              << "experiment list";
  64     // The default group was not found in the list of groups. This study is not
  65     // valid.
  66     return false;
  67   }
  68
  69   *total_probability = divisor;
  70   return true;
  71 }
  72
  73
  74 }  // namespace
  75
  76
  77 ProcessedStudy::ProcessedStudy()
  78     : study_(NULL), total_probability_(0), is_expired_(false) {
  79 }
  80
  81 ProcessedStudy::~ProcessedStudy() {
  82 }
  83
  84 bool ProcessedStudy::Init(const Study* study, bool is_expired) {
  85   base::FieldTrial::Probability total_probability = 0;
  86   if (!ValidateStudyAndComputeTotalProbability(*study, &total_probability))
  87     return false;
  88
  89   study_ = study;
  90   is_expired_ = is_expired;
  91   total_probability_ = total_probability;
  92   return true;
  93 }
  94
  95 int ProcessedStudy::GetExperimentIndexByName(const std::string& name) const {
  96   for (int i = 0; i < study_->experiment_size(); ++i) {
  97     if (study_->experiment(i).name() == name)
  98       return i;
  99   }
 100
 101   return -1;
 102 }
 103
 104 // static
 105 bool ProcessedStudy::ValidateAndAppendStudy(
 106     const Study* study,
 107     bool is_expired,
 108     std::vector<ProcessedStudy>* processed_studies) {
 109   ProcessedStudy processed_study;
 110   if (processed_study.Init(study, is_expired)) {
 111     processed_studies->push_back(processed_study);
 112     return true;
 113   }
 114   return false;
 115 }
 116
 117 }  // namespace variations