components/omnibox/browser/answers_cache.cc

   1 // Copyright 2014 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 #include "components/omnibox/browser/answers_cache.h"
   6
   7 #include "base/i18n/case_conversion.h"
   8 #include "base/strings/string_util.h"
   9
  10 AnswersQueryData::AnswersQueryData() {
  11 }
  12 AnswersQueryData::AnswersQueryData(const base::string16& text,
  13                                    const base::string16& type)
  14     : full_query_text(text), query_type(type) {
  15 }
  16
  17 AnswersCache::AnswersCache(size_t max_entries) : max_entries_(max_entries) {
  18 }
  19
  20 AnswersCache::~AnswersCache() {
  21 }
  22
  23 AnswersQueryData AnswersCache::GetTopAnswerEntry(const base::string16& query) {
  24   base::string16 collapsed_query = base::i18n::ToLower(
  25       base::CollapseWhitespace(query, false));
  26   for (Cache::iterator it = cache_.begin(); it != cache_.end(); ++it) {
  27     // If the query text starts with trimmed input, this is valid prefetch data.
  28     if (base::StartsWith(base::i18n::ToLower(it->full_query_text),
  29                          collapsed_query, base::CompareCase::SENSITIVE)) {
  30       // Move the touched item to the front of the list.
  31       cache_.splice(cache_.begin(), cache_, it);
  32       return cache_.front();
  33     }
  34   }
  35   return AnswersQueryData();
  36 }
  37
  38 void AnswersCache::UpdateRecentAnswers(const base::string16& full_query_text,
  39                                        const base::string16& query_type) {
  40   // If this entry is already part of the cache, just update recency.
  41   for (Cache::iterator it = cache_.begin(); it != cache_.end(); ++it) {
  42     if (full_query_text == it->full_query_text &&
  43         query_type == it->query_type) {
  44       cache_.splice(cache_.begin(), cache_, it);
  45       return;
  46     }
  47   }
  48
  49   // Evict if cache size is exceeded.
  50   if (cache_.size() >= max_entries_)
  51     cache_.pop_back();
  52
  53   cache_.push_front(AnswersQueryData(full_query_text, query_type));
  54 }