Omnibox - Improve HQP's Also-Do-HUP-Like-Scoring Mode

chrome/browser/autocomplete/scored_history_match.cc

 // Copyright (c) 2012 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.
 
 #include "chrome/browser/autocomplete/scored_history_match.h"
 
 #include <math.h>
 
 #include <algorithm>
 #include <vector>
@@ skipping 35 matching lines @@
 
 // Pre-computed information to speed up calculating topicality scores.
 // |raw_term_score_to_topicality_score| is a simple array mapping how raw terms
 // scores (a weighted sum of the number of hits for the term, weighted by how
 // important the hit is: hostname, path, etc.) to the topicality score we should
 // assign it.  This allows easy lookups of scores without requiring math. This
 // is initialized by InitRawTermScoreToTopicalityScoreArray() called from
 // ScoredHistoryMatch::Init().
 float raw_term_score_to_topicality_score[kMaxRawTermScore];
 
-// The maximum score that can be assigned to non-inlineable matches. This is
-// useful because often we want inlineable matches to come first (even if they
-// don't sometimes score as well as non-inlineable matches) because if a
-// non-inlineable match comes first than all matches will get demoted later in
-// HistoryQuickProvider to non-inlineable scores. Set to -1 to indicate no
-// maximum score.
-int max_assigned_score_for_non_inlineable_matches = -1;
-
 // Whether ScoredHistoryMatch::Init() has been called.
 bool initialized = false;
 
 // Precalculates raw_term_score_to_topicality_score, used in
 // GetTopicalityScore().
 void InitRawTermScoreToTopicalityScoreArray() {
   for (int term_score = 0; term_score < kMaxRawTermScore; ++term_score) {
     float topicality_score;
     if (term_score < 10) {
       // If the term scores less than 10 points (no full-credit hit, or
@@ skipping 205 matching lines @@
     if (!promote_to_inline && IsHostOnly())
       hup_like_score++;
 
     // All the other logic to goes into hup-like-scoring happens in
     // the tie-breaker case of MatchScoreGreater().
 
     // Incorporate hup_like_score into raw_score.
     raw_score = std::max(raw_score, hup_like_score);
   }
 
-  // If this match is not inlineable and there's a cap on the maximum
-  // score that can be given to non-inlineable matches, apply the cap.
-  if (!can_inline && (max_assigned_score_for_non_inlineable_matches != -1)) {
-    raw_score =
-        std::min(raw_score, max_assigned_score_for_non_inlineable_matches);
-  }
-
   // Now that we're done processing this entry, correct the offsets of the
   // matches in |url_matches| so they point to offsets in the original URL
   // spec, not the cleaned-up URL string that we used for matching.
   std::vector<size_t> offsets = OffsetsFromTermMatches(url_matches);
   base::OffsetAdjuster::UnadjustOffsets(adjustments, &offsets);
   url_matches = ReplaceOffsetsInTermMatches(url_matches, offsets);
 }
 
 ScoredHistoryMatch::~ScoredHistoryMatch() {
 }
@@ skipping 79 matching lines @@
   // system; hence CurrentlyOn(UI thread) will fail.)
   using content::BrowserThread;
   DCHECK(!BrowserThread::IsThreadInitialized(BrowserThread::UI) ||
          BrowserThread::CurrentlyOn(BrowserThread::UI));
 
   if (initialized)
     return;
 
   initialized = true;
 
-  // When doing HUP-like scoring, don't allow a non-inlineable match
-  // to beat the score of good inlineable matches.  This is a problem
-  // because if a non-inlineable match ends up with the highest score
-  // from HistoryQuick provider, all HistoryQuick matches get demoted
-  // to non-inlineable scores (scores less than 1200).  Without
-  // HUP-like-scoring, these results would actually come from the HUP
-  // and not be demoted, thus outscoring the demoted HQP results.
-  // When the HQP provides these, we need to clamp the non-inlineable
-  // results to preserve this behavior.
-  if (kAlsoDoHupLikeScoring) {
-    max_assigned_score_for_non_inlineable_matches =
-        HistoryURLProvider::kScoreForBestInlineableResult - 1;
-  }
   bookmark_value_ = OmniboxFieldTrial::HQPBookmarkValue();
   fix_frequency_bugs_ = OmniboxFieldTrial::HQPFixFrequencyScoringBugs();
   allow_tld_matches_ = OmniboxFieldTrial::HQPAllowMatchInTLDValue();
   allow_scheme_matches_ = OmniboxFieldTrial::HQPAllowMatchInSchemeValue();
   num_title_words_to_allow_ = OmniboxFieldTrial::HQPNumTitleWordsToAllow();
 
   InitRawTermScoreToTopicalityScoreArray();
   InitDaysAgoToRecencyScoreArray();
   InitHQPExperimentalParams();
 }
@@ skipping 289 matching lines @@
           base::StringToDouble(it->first, &bucket.first);
       DCHECK(is_valid_intermediate_score);
       bool is_valid_hqp_score = base::StringToInt(it->second, &bucket.second);
       DCHECK(is_valid_hqp_score);
       hqp_buckets->push_back(bucket);
     }
     return true;
   }
   return false;
 }