Index: components/omnibox/browser/match_compare.h |
diff --git a/components/omnibox/browser/match_compare.h b/components/omnibox/browser/match_compare.h |
new file mode 100644 |
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+++ b/components/omnibox/browser/match_compare.h |
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+// Copyright 2016 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_MATCH_COMPARE_H_ |
+#define COMPONENTS_OMNIBOX_BROWSER_MATCH_COMPARE_H_ |
+ |
+#include "components/omnibox/browser/omnibox_field_trial.h" |
+ |
+// This class implements a special version of AutocompleteMatch::MoreRelevant |
+// that allows matches of particular types to be demoted in AutocompleteResult. |
+template <class Match> |
+class CompareWithDemoteByType { |
+ public: |
+ CompareWithDemoteByType( |
+ metrics::OmniboxEventProto::PageClassification page_classification) { |
+ OmniboxFieldTrial::GetDemotionsByType(page_classification, &demotions_); |
+ } |
+ |
+ // Returns the relevance score of |match| demoted appropriately by |
+ // |demotions_by_type_|. |
+ int GetDemotedRelevance(const Match& match) const { |
+ OmniboxFieldTrial::DemotionMultipliers::const_iterator demotion_it = |
+ demotions_.find(match.type); |
+ return (demotion_it == demotions_.end()) |
+ ? match.relevance |
+ : (match.relevance * demotion_it->second); |
+ } |
+ |
+ // Comparison function. |
+ bool operator()(const Match& elem1, const Match& elem2) { |
+ // Compute demoted relevance scores for each match. |
+ const int demoted_relevance1 = GetDemotedRelevance(elem1); |
+ const int demoted_relevance2 = GetDemotedRelevance(elem2); |
+ // For equal-relevance matches, we sort alphabetically, so that providers |
+ // who return multiple elements at the same priority get a "stable" sort |
+ // across multiple updates. |
+ return (demoted_relevance1 == demoted_relevance2) |
+ ? (elem1.contents < elem2.contents) |
+ : (demoted_relevance1 > demoted_relevance2); |
+ } |
+ |
+ private: |
+ OmniboxFieldTrial::DemotionMultipliers demotions_; |
+}; |
+ |
+template <class Match> |
+class DestinationSort { |
+ public: |
+ DestinationSort( |
+ metrics::OmniboxEventProto::PageClassification page_classification) |
+ : demote_by_type_(page_classification) {} |
+ bool operator()(const Match& elem1, const Match& elem2) { |
+ // Sort identical destination_urls together. |
+ // Place the most relevant matches first, so that when we call |
+ // std::unique(), these are the ones that get preserved. |
+ return (elem1.stripped_destination_url == elem2.stripped_destination_url) |
+ ? demote_by_type_(elem1, elem2) |
+ : (elem1.stripped_destination_url < |
+ elem2.stripped_destination_url); |
+ } |
+ |
+ private: |
+ CompareWithDemoteByType<Match> demote_by_type_; |
+}; |
+ |
+#endif // COMPONENTS_OMNIBOX_BROWSER_MATCH_COMPARE_H_ |