Componentize ScoredHistoryMatch

components/history/core/browser/scored_history_match.h

Index: components/history/core/browser/scored_history_match.h
diff --git a/components/history/core/browser/scored_history_match.h b/components/history/core/browser/scored_history_match.h
new file mode 100644
index 0000000000000000000000000000000000000000..bfc9a2e74ed2b33356fb78657d99b371f8856072
--- /dev/null
+++ b/components/history/core/browser/scored_history_match.h
@@ -0,0 +1,101 @@
+// 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.
+
+#ifndef COMPONENTS_HISTORY_CORE_BROWSER_SCORED_HISTORY_MATCH_H_
+#define COMPONENTS_HISTORY_CORE_BROWSER_SCORED_HISTORY_MATCH_H_
+
+#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"
+
+namespace history {
+
+// 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.
+struct ScoredHistoryMatch : public HistoryMatch {
+  // Builder allows the embedder to control how matches are scored (we cannot
+  // use a base::Callback<> as base::Bind() is limited to 6 parameters).
+  class Builder {

[Mark P, 2015/02/04 19:54:04]

Having a ScoredHistoryMatchBuilder and a ScoredHistoryMatch::Builder be two
different things that both exist is confusing.  Can you come up with a better
naming system?

+   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,
+                     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
+  // with url_info to make tie-breaking a bit smarter.
+  static bool MatchScoreGreater(const ScoredHistoryMatch& m1,
+                                const ScoredHistoryMatch& m2);
+
+  // 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;
+
+  // Both these TermMatches contain the set of matches that are considered
+  // important.  At this time, that means they exclude mid-word matches
+  // except in the hostname of the URL.  (Technically, during early
+  // 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;
+  // Term matches within the page title.
+  TermMatches title_matches;
+
+  // True if this is a candidate for in-line autocompletion.
+  bool can_inline;
+};
+typedef std::vector<ScoredHistoryMatch> ScoredHistoryMatches;
+
+}  // namespace history
+
+#endif  // COMPONENTS_HISTORY_CORE_BROWSER_SCORED_HISTORY_MATCH_H_