Prefetch cache pt1 - MRU

chrome/browser/autocomplete/search_provider.cc

 // Copyright 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/search_provider.h"
 
 #include <algorithm>
 #include <cmath>
 
 #include "base/base64.h"
@@ skipping 118 matching lines @@
 // static
 int SearchProvider::kMinimumTimeBetweenSuggestQueriesMs = 100;
 
 SearchProvider::SearchProvider(AutocompleteProviderListener* listener,
                                TemplateURLService* template_url_service,
                                Profile* profile)
     : BaseSearchProvider(template_url_service, profile,
                          AutocompleteProvider::TYPE_SEARCH),
       listener_(listener),
       suggest_results_pending_(0),
-      providers_(template_url_service) {
+      providers_(template_url_service),
+      answers_cache_(1) {
 }
 
 // static
 std::string SearchProvider::GetSuggestMetadata(const AutocompleteMatch& match) {
   return match.GetAdditionalInfo(kSuggestMetadataKey);
 }
 
 void SearchProvider::ResetSession() {
   field_trial_triggered_in_session_ = false;
 }
@@ skipping 512 matching lines @@
 
   // Bail if the suggestion URL is invalid with the given replacements.
   TemplateURLRef::SearchTermsArgs search_term_args(input.text());
   search_term_args.input_type = input.type();
   search_term_args.cursor_position = input.cursor_position();
   search_term_args.page_classification = input.current_page_classification();
   if (OmniboxFieldTrial::EnableAnswersInSuggest()) {
     search_term_args.session_token = GetSessionToken();
     if (!prefetch_data_.full_query_text.empty()) {
       search_term_args.prefetch_query =
-          base::UTF16ToUTF8(last_answer_seen_.full_query_text);
+          base::UTF16ToUTF8(prefetch_data_.full_query_text);
       search_term_args.prefetch_query_type =
-          base::UTF16ToUTF8(last_answer_seen_.query_type);
+          base::UTF16ToUTF8(prefetch_data_.query_type);
     }
   }
   GURL suggest_url(template_url->suggestions_url_ref().ReplaceSearchTerms(
       search_term_args,
       providers_.template_url_service()->search_terms_data()));
   if (!suggest_url.is_valid())
     return NULL;
   // Send the current page URL if user setting and URL requirements are met and
   // the user is in the field trial.
   if (CanSendURL(current_page_url_, suggest_url, template_url,
@@ skipping 564 matching lines @@
   // only be in the second slot if AutocompleteController ranked a local search
   // history or a verbatim item higher than the answer.
   AutocompleteResult::const_iterator match = result.begin();
   if (match->answer_contents.empty() && result.size() > 1)
     ++match;
   if (match->answer_contents.empty() || match->answer_type.empty() ||
       match->fill_into_edit.empty())
     return;
 
   // Valid answer encountered, cache it for further queries.
-  last_answer_seen_.full_query_text = match->fill_into_edit;
-  last_answer_seen_.query_type = match->answer_type;
+  answers_cache_.UpdateRecentAnswers(match->fill_into_edit, match->answer_type);
 }
 
 void SearchProvider::DoAnswersQuery(const AutocompleteInput& input) {
-  // If the query text starts with trimmed input, this is valid prefetch data.
-  prefetch_data_ = StartsWith(last_answer_seen_.full_query_text,
-                              base::CollapseWhitespace(input.text(), false),
-                              false) ?
-      last_answer_seen_ : AnswersQueryData();
+  prefetch_data_ = answers_cache_.GetTopAnswerEntry(input.text());
 }