Launch HQP & HUP score changes.

components/omnibox/browser/omnibox_field_trial.h

 // 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_OMNIBOX_BROWSER_OMNIBOX_FIELD_TRIAL_H_
 #define COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_FIELD_TRIAL_H_
 
 #include <map>
 #include <string>
 #include <vector>
 
 #include "base/basictypes.h"
 #include "base/gtest_prod_util.h"
 #include "components/metrics/proto/omnibox_event.pb.h"
 #include "components/omnibox/browser/autocomplete_match_type.h"
 
 namespace base {
 class TimeDelta;
 }
 
 // The set of parameters customizing the HUP scoring.
 struct HUPScoringParams {
   // A set of parameters describing how to cap a given count score.  First,
   // we apply a half-life based decay of the given count and then find the
-  // maximum relevance score in the corresponding bucket list.
+  // maximum relevance score based on the decay factor or counts specified
+  // in the corresponding bucket list. See comment on |buckets_| for details.
   class ScoreBuckets {
    public:
-    // (decayed_count, max_relevance) pair.
+    // Stores the max relevance at each count/decay factor threshold.
     typedef std::pair<double, int> CountMaxRelevance;
 
     ScoreBuckets();
     ~ScoreBuckets();
 
     // Computes a half-life time decay given the |elapsed_time|.
     double HalfLifeTimeDecay(const base::TimeDelta& elapsed_time) const;
 
     int relevance_cap() const { return relevance_cap_; }
     void set_relevance_cap(int relevance_cap) {
       relevance_cap_ = relevance_cap;
     }
 
     int half_life_days() const { return half_life_days_; }
     void set_half_life_days(int half_life_days) {
       half_life_days_ = half_life_days;
     }
 
+    bool use_decay_factor() const { return use_decay_factor_; }
+    void set_use_decay_factor(bool use_decay_factor) {
+      use_decay_factor_ = use_decay_factor;
+    }
+
     std::vector<CountMaxRelevance>& buckets() { return buckets_; }
     const std::vector<CountMaxRelevance>& buckets() const { return buckets_; }
 
    private:
     // History matches with relevance score greater or equal to |relevance_cap_|
     // are not affected by this experiment.
     // Set to -1, if there is no relevance cap in place and all matches are
     // subject to demotion.
     int relevance_cap_;
 
     // Half life time for a decayed count as measured since the last visit.
     // Set to -1 if not used.
     int half_life_days_;
 
-    // The relevance score caps for given decayed count values.
-    // Each pair (decayed_count, max_score) indicates what the maximum relevance
-    // score is of a decayed count equal or greater than decayed_count.
+    // The relevance score caps at successively decreasing threshold values.
+    // The thresholds are either decayed counts or decay factors, depending on
+    // the value of |use_decay_factor_|.
     //
-    // Consider this example:
+    // Consider this example specifying the decayed counts:
     //   [(1, 1000), (0.5, 500), (0, 100)]
     // If decayed count is 2 (which is >= 1), the corresponding match's maximum
     // relevance will be capped at 1000.  In case of 0.5, the score is capped
     // at 500.  Anything below 0.5 is capped at 100.
     //
     // This list is sorted by the pair's first element in descending order.
     std::vector<CountMaxRelevance> buckets_;
+
+    // True when the bucket thresholds are decay factors rather than counts.
+    bool use_decay_factor_;
   };
 
   HUPScoringParams() : experimental_scoring_enabled(false) {}
 
   bool experimental_scoring_enabled;
 
   ScoreBuckets typed_count_buckets;
 
   // Used only when the typed count is 0.
   ScoreBuckets visited_count_buckets;
@@ skipping 120 matching lines @@
           current_page_classification,
       DemotionMultipliers* demotions_by_type);
 
   // ---------------------------------------------------------
   // For the HistoryURL provider new scoring experiment that is part of the
   // bundled omnibox field trial.
 
   // Initializes the HUP |scoring_params| based on the active HUP scoring
   // experiment.  If there is no such experiment, this function simply sets
   // |scoring_params|->experimental_scoring_enabled to false.
+  static void GetDefaultHUPScoringParams(HUPScoringParams* scoring_params);
   static void GetExperimentalHUPScoringParams(HUPScoringParams* scoring_params);
 
   // For the HQPBookmarkValue experiment that's part of the
   // bundled omnibox field trial.
 
   // Returns the value an untyped visit to a bookmark should receive.
   // Compare this value with the default of 1 for non-bookmarked untyped
   // visits to pages and the default of 20 for typed visits.  Returns
   // 10 if the bookmark value experiment isn't active.
   static int HQPBookmarkValue();
@@ skipping 108 matching lines @@
   static const char kHQPFixFrequencyScoringBugsRule[];
   static const char kHQPNumTitleWordsRule[];
   static const char kHQPAlsoDoHUPLikeScoringRule[];
   static const char kPreventUWYTDefaultForNonURLInputsRule[];
 
   // Parameter names used by the HUP new scoring experiments.
   static const char kHUPNewScoringEnabledParam[];
   static const char kHUPNewScoringTypedCountRelevanceCapParam[];
   static const char kHUPNewScoringTypedCountHalfLifeTimeParam[];
   static const char kHUPNewScoringTypedCountScoreBucketsParam[];
+  static const char kHUPNewScoringTypedCountUseDecayFactorParam[];
   static const char kHUPNewScoringVisitedCountRelevanceCapParam[];
   static const char kHUPNewScoringVisitedCountHalfLifeTimeParam[];
   static const char kHUPNewScoringVisitedCountScoreBucketsParam[];
+  static const char kHUPNewScoringVisitedCountUseDecayFactorParam[];
 
   // Parameter names used by the HQP experimental scoring experiments.
   static const char kHQPExperimentalScoringEnabledParam[];
   static const char kHQPExperimentalScoringBucketsParam[];
   static const char kHQPExperimentalScoringTopicalityThresholdParam[];
 
   // The amount of time to wait before sending a new suggest request after the
   // previous one unless overridden by a field trial parameter.
   // Non-const because some unittests modify this value.
   static int kDefaultMinimumTimeBetweenSuggestQueriesMs;
@@ skipping 17 matching lines @@
   // prioritize different wildcard contexts, see the implementation.  How to
   // interpret the value is left to the caller; this is rule-dependent.
   static std::string GetValueForRuleInContext(
       const std::string& rule,
       metrics::OmniboxEventProto::PageClassification page_classification);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(OmniboxFieldTrial);
 };
 
 #endif  // COMPONENTS_OMNIBOX_BROWSER_OMNIBOX_FIELD_TRIAL_H_