Componentize ScoredHistoryMatch

components/history/core/browser/scored_history_match.h

Index: components/history/core/browser/scored_history_match.h
diff --git a/chrome/browser/history/scored_history_match.h b/components/history/core/browser/scored_history_match.h
similarity index 19%
rename from chrome/browser/history/scored_history_match.h
rename to components/history/core/browser/scored_history_match.h
index 15a37e7bd73673dc4efe2ca93a5e29a06d3e8d59..bfc9a2e74ed2b33356fb78657d99b371f8856072 100644
--- a/chrome/browser/history/scored_history_match.h
+++ b/components/history/core/browser/scored_history_match.h
@@ -2,60 +2,67 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
-#ifndef CHROME_BROWSER_HISTORY_SCORED_HISTORY_MATCH_H_
-#define CHROME_BROWSER_HISTORY_SCORED_HISTORY_MATCH_H_
+#ifndef COMPONENTS_HISTORY_CORE_BROWSER_SCORED_HISTORY_MATCH_H_
+#define COMPONENTS_HISTORY_CORE_BROWSER_SCORED_HISTORY_MATCH_H_
 
-#include <map>
-#include <set>
+#include <string>
 #include <vector>
 
 #include "base/strings/string16.h"
+#include "base/time/time.h"
 #include "components/history/core/browser/history_match.h"
 #include "components/history/core/browser/history_types.h"
 #include "components/history/core/browser/in_memory_url_index_types.h"
-#include "testing/gtest/include/gtest/gtest_prod.h"
 
 namespace history {
 
-class HistoryClient;
-class ScoredHistoryMatchTest;
-
 // An HistoryMatch that has a score as well as metrics defining where in the
 // history item's URL and/or page title matches have occurred.
-class ScoredHistoryMatch : public history::HistoryMatch {
- public:
-  // The maximum number of recent visits to examine in GetFrequency().
-  // Public so url_index_private_data.cc knows how many visits it is
-  // expected to deliver (at minimum) to this class.
-  static const size_t kMaxVisitsToScore;
-
-  ScoredHistoryMatch();  // Required by STL.
-
-  // Creates a new match with a raw score calculated for the history item
-  // given in |row| with recent visits as indicated in |visits|.  First
-  // determines if the row qualifies by seeing if all of the terms in
-  // |terms_vector| occur in |row|.  If so, calculates a raw score.  This raw
-  // score is in part determined by whether the matches occur at word
-  // boundaries, the locations of which are stored in |word_starts|.  For some
-  // terms, it's appropriate to look for the word boundary within the term.
-  // For instance, the term ".net" should look for a word boundary at the "n".
-  // These offsets (".net" should have an offset of 1) come from
-  // |terms_to_word_starts_offsets|.  |history_client| is used to determine
-  // if the match's URL is referenced by any bookmarks, which can also affect
-  // the raw score.  The raw score allows the matches to be ordered and can be
-  // used to influence the final score calculated by the client of this index.
-  // If the row does not qualify the raw score will be 0.  |languages| is used
-  // to help parse/format the URL before looking for the terms.
-  ScoredHistoryMatch(const URLRow& row,
-                     const VisitInfoVector& visits,
-                     const std::string& languages,
-                     const base::string16& lower_string,
-                     const String16Vector& terms_vector,
-                     const WordStarts& terms_to_word_starts_offsets,
-                     const RowWordStarts& word_starts,
-                     const base::Time now,
-                     HistoryClient* history_client);
-  ~ScoredHistoryMatch();
+struct ScoredHistoryMatch : public HistoryMatch {
+  // Builder allows the embedder to control how matches are scored (we cannot

[Mark P, 2015/02/07 07:00:13]

nit: Builder -> The Builder inner class
or something, the current phrasing makes it hard to parse at first.

+  // use a base::Callback<> as base::Bind() is limited to 6 parameters).
+  class Builder {
+   public:
+    Builder() {}
+    virtual ~Builder() {}
+
+    // Creates a new match with a raw score calculated for the history item
+    // given in |row| with recent visits as indicated in |visits|.  First
+    // determines if the row qualifies by seeing if all of the terms in
+    // |terms_vector| occur in |row|.  If so, calculates a raw score.  This raw
+    // score is in part determined by whether the matches occur at word
+    // boundaries, the locations of which are stored in |word_starts|.  For some
+    // terms, it's appropriate to look for the word boundary within the term.
+    // For instance, the term ".net" should look for a word boundary at the "n".
+    // These offsets (".net" should have an offset of 1) come from
+    // |terms_to_word_starts_offsets|.  |history_client| is used to determine
+    // if the match's URL is referenced by any bookmarks, which can also affect
+    // the raw score.  The raw score allows the matches to be ordered and can be
+    // used to influence the final score calculated by the client of this index.
+    // If the row does not qualify the raw score will be 0.  |languages| is used
+    // to help parse/format the URL before looking for the terms.
+    virtual ScoredHistoryMatch Build(
+        const URLRow& row,
+        const VisitInfoVector& visits,
+        const std::string& languages,
+        const base::string16& lower_string,
+        const String16Vector& terms_vector,
+        const WordStarts& terms_to_word_starts_offsets,
+        const RowWordStarts& word_starts,
+        const base::Time now) const = 0;
+  };
+
+  // Required for STL, we don't use this directly.
+  ScoredHistoryMatch();
+
+  ScoredHistoryMatch(const URLRow& url_info,

[Mark P, 2015/02/07 07:00:14]

Please comment this.  The meaning of some of the variables you're introduced is
not obvious.
Perhaps it should be as simple as x, y, and z are passed to the HistoryMatch()
superclass constructor; a, b, and c are used to initialize local variables.

[sdefresne, 2015/02/09 10:01:14]

Done.

+                     size_t input_location,
+                     bool match_in_scheme,
+                     bool innermost_match,
+                     int raw_score,
+                     const TermMatches& url_matches,
+                     const TermMatches& title_matches,
+                     bool can_inline);
 
   // Compares two matches by score.  Functor supporting URLIndexPrivateData's
   // HistoryItemsForTerms function.  Looks at particular fields within
@@ -63,84 +70,14 @@ class ScoredHistoryMatch : public history::HistoryMatch {
   static bool MatchScoreGreater(const ScoredHistoryMatch& m1,
                                 const ScoredHistoryMatch& m2);
 
-  // Accessors:
-  int raw_score() const { return raw_score_; }
-  const TermMatches& url_matches() const { return url_matches_; }
-  const TermMatches& title_matches() const { return title_matches_; }
-  bool can_inline() const { return can_inline_; }
-
-  // Returns |term_matches| after removing all matches that are not at a
-  // word break that are in the range [|start_pos|, |end_pos|).
-  // start_pos == string::npos is treated as start_pos = length of string.
-  // (In other words, no matches will be filtered.)
-  // end_pos == string::npos is treated as end_pos = length of string.
-  static TermMatches FilterTermMatchesByWordStarts(
-      const TermMatches& term_matches,
-      const WordStarts& terms_to_word_starts_offsets,
-      const WordStarts& word_starts,
-      size_t start_pos,
-      size_t end_pos);
-
- private:
-  friend class ScoredHistoryMatchTest;
-  FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringBookmarks);
-  FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringDiscountFrecency);
-  FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringScheme);
-  FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringTLD);
-
-  // The number of days of recency scores to precompute.
-  static const int kDaysToPrecomputeRecencyScoresFor;
-
-  // The number of raw term score buckets use; raw term scores
-  // greater this are capped at the score of the largest bucket.
-  static const int kMaxRawTermScore;
-
-  // Return a topicality score based on how many matches appear in the
-  // url and the page's title and where they are (e.g., at word
-  // boundaries).  Revises |url_matches_| and |title_matches_| in the
-  // process so they only reflect matches used for scoring.  (For
-  // instance, some mid-word matches are not given credit in scoring.)
-  float GetTopicalityScore(const int num_terms,
-                           const base::string16& cleaned_up_url,
-                           const WordStarts& terms_to_word_starts_offsets,
-                           const RowWordStarts& word_starts);
-
-  // Precalculates raw_term_score_to_topicality_score_, used in
-  // GetTopicalityScore().
-  static void FillInTermScoreToTopicalityScoreArray();
-
-  // Returns a recency score based on |last_visit_days_ago|, which is
-  // how many days ago the page was last visited.
-  static float GetRecencyScore(int last_visit_days_ago);
-
-  // Pre-calculates days_ago_to_recency_numerator_, used in
-  // GetRecencyScore().
-  static void FillInDaysAgoToRecencyScoreArray();
-
-  // Examines the first kMaxVisitsToScore and return a score (higher is
-  // better) based the rate of visits, whether the page is bookmarked, and
-  // how often those visits are typed navigations (i.e., explicitly
-  // invoked by the user).  |now| is passed in to avoid unnecessarily
-  // recomputing it frequently.
-  static float GetFrequency(const base::Time& now,
-                            const bool bookmarked,
-                            const VisitInfoVector& visits);
-
-  // Combines the two component scores into a final score that's
-  // an appropriate value to use as a relevancy score.
-  static float GetFinalRelevancyScore(
-      float topicality_score,
-      float frequency_score);
-
-  // Sets |also_do_hup_like_scoring_|,
-  // |max_assigned_score_for_non_inlineable_matches_|, |bookmark_value_|,
-  // |allow_tld_matches_|, and |allow_scheme_matches_| based on the field
-  // trial state.
-  static void Init();
+  // The maximum number of recent visits to examine in GetFrequency().
+  // Public so url_index_private_data.cc knows how many visits it is
+  // expected to deliver (at minimum) to this class.
+  static const size_t kMaxVisitsToScore;
 
   // An interim score taking into consideration location and completeness
   // of the match.
-  int raw_score_;
+  int raw_score;
 
   // Both these TermMatches contain the set of matches that are considered
   // important.  At this time, that means they exclude mid-word matches
@@ -148,61 +85,17 @@ class ScoredHistoryMatch : public history::HistoryMatch {
   // construction of ScoredHistoryMatch, they may contain all matches, but
   // unimportant matches are eliminated by GetTopicalityScore(), called
   // during construction.)
+
   // Term matches within the URL.
-  TermMatches url_matches_;
+  TermMatches url_matches;
   // Term matches within the page title.
-  TermMatches title_matches_;
+  TermMatches title_matches;
 
   // True if this is a candidate for in-line autocompletion.
-  bool can_inline_;
-
-  // Pre-computed information to speed up calculating recency scores.
-  // |days_ago_to_recency_score_| is a simple array mapping how long
-  // ago a page was visited (in days) to the recency score we should
-  // assign it.  This allows easy lookups of scores without requiring
-  // math.  This is initialized upon first use of GetRecencyScore(),
-  // which calls FillInDaysAgoToRecencyScoreArray(),
-  static float* days_ago_to_recency_score_;
-
-  // 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 upon first use of GetTopicalityScore(),
-  // which calls FillInTermScoreToTopicalityScoreArray().
-  static float* raw_term_score_to_topicality_score_;
-
-  // Used so we initialize static variables only once (on first use).
-  static bool initialized_;
-
-  // Untyped visits to bookmarked pages score this, compared to 1 for
-  // untyped visits to non-bookmarked pages and 20 for typed visits.
-  static int bookmark_value_;
-
-  // If true, we allow input terms to match in the TLD (e.g., .com).
-  static bool allow_tld_matches_;
-
-  // If true, we allow input terms to match in the scheme (e.g., http://).
-  static bool allow_scheme_matches_;
-
-  // If true, assign raw scores to be max(whatever it normally would be,
-  // a score that's similar to the score HistoryURL provider would assign).
-  // This variable is set in the constructor by examining the field trial
-  // state.
-  static bool also_do_hup_like_scoring_;
-
-  // 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.
-  static int max_assigned_score_for_non_inlineable_matches_;
+  bool can_inline;
 };
 typedef std::vector<ScoredHistoryMatch> ScoredHistoryMatches;
 
 }  // namespace history
 
-#endif  // CHROME_BROWSER_HISTORY_SCORED_HISTORY_MATCH_H_
+#endif  // COMPONENTS_HISTORY_CORE_BROWSER_SCORED_HISTORY_MATCH_H_