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