// Copyright 2014 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. #ifndef COMPONENTS_VARIATIONS_VARIATIONS_SEED_SIMULATOR_H_ #define COMPONENTS_VARIATIONS_VARIATIONS_SEED_SIMULATOR_H_ #include #include #include "base/compiler_specific.h" #include "base/component_export.h" #include "base/metrics/field_trial.h" #include "base/version.h" #include "components/variations/proto/study.pb.h" #include "components/variations/proto/variations_seed.pb.h" namespace variations { class ProcessedStudy; struct ClientFilterableState; class VariationsSeed; // VariationsSeedSimulator simulates the result of creating a set of studies // and detecting which studies would result in group changes. class COMPONENT_EXPORT(VARIATIONS) VariationsSeedSimulator { public: // The result of variations seed simulation, counting the number of experiment // group changes of each type that are expected to occur on a restart with the // seed. struct COMPONENT_EXPORT(VARIATIONS) Result { Result(); ~Result(); // The number of expected group changes that do not fall into any special // category. This is a lower bound due to session randomized studies. int normal_group_change_count; // The number of expected group changes that fall in the category of killed // experiments that should trigger the "best effort" restart mechanism. int kill_best_effort_group_change_count; // The number of expected group changes that fall in the category of killed // experiments that should trigger the "critical" restart mechanism. int kill_critical_group_change_count; }; // Creates the simulator with the given default and low entropy providers. The // |low_entropy_provider| will be used for studies that should only use a low // entropy source. This is defined by // VariationsSeedProcessor::ShouldStudyUseLowEntropy, in // variations_seed_processor.h. VariationsSeedSimulator( const base::FieldTrial::EntropyProvider& default_entropy_provider, const base::FieldTrial::EntropyProvider& low_entropy_provider); VariationsSeedSimulator(const VariationsSeedSimulator&) = delete; VariationsSeedSimulator& operator=(const VariationsSeedSimulator&) = delete; virtual ~VariationsSeedSimulator(); // Computes differences between the current process' field trial state and // the result of evaluating |seed| with the given parameters. Returns the // results of the simulation as a set of expected group change counts of each // type. Result SimulateSeedStudies(const VariationsSeed& seed, const ClientFilterableState& client_state); private: friend class VariationsSeedSimulatorTest; enum ChangeType { NO_CHANGE, CHANGED, CHANGED_KILL_BEST_EFFORT, CHANGED_KILL_CRITICAL, }; // Computes differences between the current process' field trial state and // the result of evaluating the |processed_studies| list. It is expected that // |processed_studies| have already been filtered and only contain studies // that apply to the configuration being simulated. Returns the results of the // simulation as a set of expected group change counts of each type. Result ComputeDifferences( const std::vector& processed_studies); // Maps proto enum |type| to a ChangeType. ChangeType ConvertExperimentTypeToChangeType(Study_Experiment_Type type); // For the given |processed_study| with PERMANENT consistency, simulates group // assignment and returns a corresponding ChangeType if the result differs // from that study's group in the current process. ChangeType PermanentStudyGroupChanged(const ProcessedStudy& processed_study, const std::string& selected_group); // For the given |processed_study| with SESSION consistency, determines if // there are enough changes in the study config that restarting will result // in a guaranteed different group assignment (or different params) and // returns the corresponding ChangeType. ChangeType SessionStudyGroupChanged(const ProcessedStudy& filtered_study, const std::string& selected_group); const base::FieldTrial::EntropyProvider& default_entropy_provider_; const base::FieldTrial::EntropyProvider& low_entropy_provider_; }; } // namespace variations #endif // COMPONENTS_VARIATIONS_VARIATIONS_SEED_SIMULATOR_H_