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