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1 // Copyright (c) 2012 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 #ifndef CHROME_BROWSER_HISTORY_SCORED_HISTORY_MATCH_H_ | |
6 #define CHROME_BROWSER_HISTORY_SCORED_HISTORY_MATCH_H_ | |
7 | |
8 #include <map> | |
9 #include <set> | |
10 #include <vector> | |
11 | |
12 #include "base/strings/string16.h" | |
13 #include "components/history/core/browser/history_match.h" | |
14 #include "components/history/core/browser/history_types.h" | |
15 #include "components/history/core/browser/in_memory_url_index_types.h" | |
16 #include "testing/gtest/include/gtest/gtest_prod.h" | |
17 | |
18 namespace history { | |
19 | |
20 class HistoryClient; | |
21 class ScoredHistoryMatchTest; | |
22 | |
23 // An HistoryMatch that has a score as well as metrics defining where in the | |
24 // history item's URL and/or page title matches have occurred. | |
25 class ScoredHistoryMatch : public history::HistoryMatch { | |
26 public: | |
27 // The maximum number of recent visits to examine in GetFrequency(). | |
28 // Public so url_index_private_data.cc knows how many visits it is | |
29 // expected to deliver (at minimum) to this class. | |
30 static const size_t kMaxVisitsToScore; | |
31 | |
32 ScoredHistoryMatch(); // Required by STL. | |
33 | |
34 // Creates a new match with a raw score calculated for the history item | |
35 // given in |row| with recent visits as indicated in |visits|. First | |
36 // determines if the row qualifies by seeing if all of the terms in | |
37 // |terms_vector| occur in |row|. If so, calculates a raw score. This raw | |
38 // score is in part determined by whether the matches occur at word | |
39 // boundaries, the locations of which are stored in |word_starts|. For some | |
40 // terms, it's appropriate to look for the word boundary within the term. | |
41 // For instance, the term ".net" should look for a word boundary at the "n". | |
42 // These offsets (".net" should have an offset of 1) come from | |
43 // |terms_to_word_starts_offsets|. |history_client| is used to determine | |
44 // if the match's URL is referenced by any bookmarks, which can also affect | |
45 // the raw score. The raw score allows the matches to be ordered and can be | |
46 // used to influence the final score calculated by the client of this index. | |
47 // If the row does not qualify the raw score will be 0. |languages| is used | |
48 // to help parse/format the URL before looking for the terms. | |
49 ScoredHistoryMatch(const URLRow& row, | |
50 const VisitInfoVector& visits, | |
51 const std::string& languages, | |
52 const base::string16& lower_string, | |
53 const String16Vector& terms_vector, | |
54 const WordStarts& terms_to_word_starts_offsets, | |
55 const RowWordStarts& word_starts, | |
56 const base::Time now, | |
57 HistoryClient* history_client); | |
58 ~ScoredHistoryMatch(); | |
59 | |
60 // Compares two matches by score. Functor supporting URLIndexPrivateData's | |
61 // HistoryItemsForTerms function. Looks at particular fields within | |
62 // with url_info to make tie-breaking a bit smarter. | |
63 static bool MatchScoreGreater(const ScoredHistoryMatch& m1, | |
64 const ScoredHistoryMatch& m2); | |
65 | |
66 // Accessors: | |
67 int raw_score() const { return raw_score_; } | |
68 const TermMatches& url_matches() const { return url_matches_; } | |
69 const TermMatches& title_matches() const { return title_matches_; } | |
70 bool can_inline() const { return can_inline_; } | |
71 | |
72 // Returns |term_matches| after removing all matches that are not at a | |
73 // word break that are in the range [|start_pos|, |end_pos|). | |
74 // start_pos == string::npos is treated as start_pos = length of string. | |
75 // (In other words, no matches will be filtered.) | |
76 // end_pos == string::npos is treated as end_pos = length of string. | |
77 static TermMatches FilterTermMatchesByWordStarts( | |
78 const TermMatches& term_matches, | |
79 const WordStarts& terms_to_word_starts_offsets, | |
80 const WordStarts& word_starts, | |
81 size_t start_pos, | |
82 size_t end_pos); | |
83 | |
84 private: | |
85 friend class ScoredHistoryMatchTest; | |
86 FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringBookmarks); | |
87 FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringDiscountFrecency); | |
88 FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringScheme); | |
89 FRIEND_TEST_ALL_PREFIXES(ScoredHistoryMatchTest, ScoringTLD); | |
90 | |
91 // The number of days of recency scores to precompute. | |
92 static const int kDaysToPrecomputeRecencyScoresFor; | |
93 | |
94 // The number of raw term score buckets use; raw term scores | |
95 // greater this are capped at the score of the largest bucket. | |
96 static const int kMaxRawTermScore; | |
97 | |
98 // Return a topicality score based on how many matches appear in the | |
99 // url and the page's title and where they are (e.g., at word | |
100 // boundaries). Revises |url_matches_| and |title_matches_| in the | |
101 // process so they only reflect matches used for scoring. (For | |
102 // instance, some mid-word matches are not given credit in scoring.) | |
103 float GetTopicalityScore(const int num_terms, | |
104 const base::string16& cleaned_up_url, | |
105 const WordStarts& terms_to_word_starts_offsets, | |
106 const RowWordStarts& word_starts); | |
107 | |
108 // Precalculates raw_term_score_to_topicality_score_, used in | |
109 // GetTopicalityScore(). | |
110 static void FillInTermScoreToTopicalityScoreArray(); | |
111 | |
112 // Returns a recency score based on |last_visit_days_ago|, which is | |
113 // how many days ago the page was last visited. | |
114 static float GetRecencyScore(int last_visit_days_ago); | |
115 | |
116 // Pre-calculates days_ago_to_recency_numerator_, used in | |
117 // GetRecencyScore(). | |
118 static void FillInDaysAgoToRecencyScoreArray(); | |
119 | |
120 // Examines the first kMaxVisitsToScore and return a score (higher is | |
121 // better) based the rate of visits, whether the page is bookmarked, and | |
122 // how often those visits are typed navigations (i.e., explicitly | |
123 // invoked by the user). |now| is passed in to avoid unnecessarily | |
124 // recomputing it frequently. | |
125 static float GetFrequency(const base::Time& now, | |
126 const bool bookmarked, | |
127 const VisitInfoVector& visits); | |
128 | |
129 // Combines the two component scores into a final score that's | |
130 // an appropriate value to use as a relevancy score. | |
131 static float GetFinalRelevancyScore( | |
132 float topicality_score, | |
133 float frequency_score); | |
134 | |
135 // Sets |also_do_hup_like_scoring_|, | |
136 // |max_assigned_score_for_non_inlineable_matches_|, |bookmark_value_|, | |
137 // |allow_tld_matches_|, and |allow_scheme_matches_| based on the field | |
138 // trial state. | |
139 static void Init(); | |
140 | |
141 // An interim score taking into consideration location and completeness | |
142 // of the match. | |
143 int raw_score_; | |
144 | |
145 // Both these TermMatches contain the set of matches that are considered | |
146 // important. At this time, that means they exclude mid-word matches | |
147 // except in the hostname of the URL. (Technically, during early | |
148 // construction of ScoredHistoryMatch, they may contain all matches, but | |
149 // unimportant matches are eliminated by GetTopicalityScore(), called | |
150 // during construction.) | |
151 // Term matches within the URL. | |
152 TermMatches url_matches_; | |
153 // Term matches within the page title. | |
154 TermMatches title_matches_; | |
155 | |
156 // True if this is a candidate for in-line autocompletion. | |
157 bool can_inline_; | |
158 | |
159 // Pre-computed information to speed up calculating recency scores. | |
160 // |days_ago_to_recency_score_| is a simple array mapping how long | |
161 // ago a page was visited (in days) to the recency score we should | |
162 // assign it. This allows easy lookups of scores without requiring | |
163 // math. This is initialized upon first use of GetRecencyScore(), | |
164 // which calls FillInDaysAgoToRecencyScoreArray(), | |
165 static float* days_ago_to_recency_score_; | |
166 | |
167 // Pre-computed information to speed up calculating topicality | |
168 // scores. |raw_term_score_to_topicality_score_| is a simple array | |
169 // mapping how raw terms scores (a weighted sum of the number of | |
170 // hits for the term, weighted by how important the hit is: | |
171 // hostname, path, etc.) to the topicality score we should assign | |
172 // it. This allows easy lookups of scores without requiring math. | |
173 // This is initialized upon first use of GetTopicalityScore(), | |
174 // which calls FillInTermScoreToTopicalityScoreArray(). | |
175 static float* raw_term_score_to_topicality_score_; | |
176 | |
177 // Used so we initialize static variables only once (on first use). | |
178 static bool initialized_; | |
179 | |
180 // Untyped visits to bookmarked pages score this, compared to 1 for | |
181 // untyped visits to non-bookmarked pages and 20 for typed visits. | |
182 static int bookmark_value_; | |
183 | |
184 // If true, we allow input terms to match in the TLD (e.g., .com). | |
185 static bool allow_tld_matches_; | |
186 | |
187 // If true, we allow input terms to match in the scheme (e.g., http://). | |
188 static bool allow_scheme_matches_; | |
189 | |
190 // If true, assign raw scores to be max(whatever it normally would be, | |
191 // a score that's similar to the score HistoryURL provider would assign). | |
192 // This variable is set in the constructor by examining the field trial | |
193 // state. | |
194 static bool also_do_hup_like_scoring_; | |
195 | |
196 // The maximum score that can be assigned to non-inlineable matches. | |
197 // This is useful because often we want inlineable matches to come | |
198 // first (even if they don't sometimes score as well as non-inlineable | |
199 // matches) because if a non-inlineable match comes first than all matches | |
200 // will get demoted later in HistoryQuickProvider to non-inlineable scores. | |
201 // Set to -1 to indicate no maximum score. | |
202 static int max_assigned_score_for_non_inlineable_matches_; | |
203 }; | |
204 typedef std::vector<ScoredHistoryMatch> ScoredHistoryMatches; | |
205 | |
206 } // namespace history | |
207 | |
208 #endif // CHROME_BROWSER_HISTORY_SCORED_HISTORY_MATCH_H_ | |
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