components/bookmarks/browser/bookmark_index.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/bookmarks/browser/bookmark_index.h"
   6
   7 #include <algorithm>
   8 #include <functional>
   9 #include <iterator>
  10 #include <list>
  11
  12 #include "base/i18n/case_conversion.h"
  13 #include "base/logging.h"
  14 #include "base/strings/utf_offset_string_conversions.h"
  15 #include "components/bookmarks/browser/bookmark_client.h"
  16 #include "components/bookmarks/browser/bookmark_match.h"
  17 #include "components/bookmarks/browser/bookmark_node.h"
  18 #include "components/bookmarks/browser/bookmark_utils.h"
  19 #include "components/query_parser/snippet.h"
  20 #include "third_party/icu/source/common/unicode/normalizer2.h"
  21
  22 namespace bookmarks {
  23
  24 typedef BookmarkClient::NodeTypedCountPair NodeTypedCountPair;
  25 typedef BookmarkClient::NodeTypedCountPairs NodeTypedCountPairs;
  26
  27 namespace {
  28
  29 // Returns a normalized version of the UTF16 string |text|.  If it fails to
  30 // normalize the string, returns |text| itself as a best-effort.
  31 base::string16 Normalize(const base::string16& text) {
  32   UErrorCode status = U_ZERO_ERROR;
  33   const icu::Normalizer2* normalizer2 =
  34       icu::Normalizer2::getInstance(NULL, "nfkc", UNORM2_COMPOSE, status);
  35   icu::UnicodeString unicode_text(
  36       text.data(), static_cast<int32_t>(text.length()));
  37   icu::UnicodeString unicode_normalized_text;
  38   normalizer2->normalize(unicode_text, unicode_normalized_text, status);
  39   if (U_FAILURE(status))
  40     return text;
  41   return base::string16(unicode_normalized_text.getBuffer(),
  42                         unicode_normalized_text.length());
  43 }
  44
  45 // Sort functor for NodeTypedCountPairs. We sort in decreasing order of typed
  46 // count so that the best matches will always be added to the results.
  47 struct NodeTypedCountPairSortFunctor
  48     : std::binary_function<NodeTypedCountPair, NodeTypedCountPair, bool> {
  49   bool operator()(const NodeTypedCountPair& a,
  50                   const NodeTypedCountPair& b) const {
  51     return a.second > b.second;
  52   }
  53 };
  54
  55 // Extract the const Node* stored in a BookmarkClient::NodeTypedCountPair.
  56 struct NodeTypedCountPairExtractNodeFunctor
  57     : std::unary_function<NodeTypedCountPair, const BookmarkNode*> {
  58   const BookmarkNode* operator()(const NodeTypedCountPair& pair) const {
  59     return pair.first;
  60   }
  61 };
  62
  63 }  // namespace
  64
  65 // Used when finding the set of bookmarks that match a query. Each match
  66 // represents a set of terms (as an interator into the Index) matching the
  67 // query as well as the set of nodes that contain those terms in their titles.
  68 struct BookmarkIndex::Match {
  69   // List of terms matching the query.
  70   std::list<Index::const_iterator> terms;
  71
  72   // The set of nodes matching the terms. As an optimization this is empty
  73   // when we match only one term, and is filled in when we get more than one
  74   // term. We can do this as when we have only one matching term we know
  75   // the set of matching nodes is terms.front()->second.
  76   //
  77   // Use nodes_begin() and nodes_end() to get an iterator over the set as
  78   // it handles the necessary switching between nodes and terms.front().
  79   NodeSet nodes;
  80
  81   // Returns an iterator to the beginning of the matching nodes. See
  82   // description of nodes for why this should be used over nodes.begin().
  83   NodeSet::const_iterator nodes_begin() const;
  84
  85   // Returns an iterator to the beginning of the matching nodes. See
  86   // description of nodes for why this should be used over nodes.end().
  87   NodeSet::const_iterator nodes_end() const;
  88 };
  89
  90 BookmarkIndex::NodeSet::const_iterator
  91     BookmarkIndex::Match::nodes_begin() const {
  92   return nodes.empty() ? terms.front()->second.begin() : nodes.begin();
  93 }
  94
  95 BookmarkIndex::NodeSet::const_iterator BookmarkIndex::Match::nodes_end() const {
  96   return nodes.empty() ? terms.front()->second.end() : nodes.end();
  97 }
  98
  99 BookmarkIndex::BookmarkIndex(BookmarkClient* client,
 100                              const std::string& languages)
 101     : client_(client),
 102       languages_(languages) {
 103   DCHECK(client_);
 104 }
 105
 106 BookmarkIndex::~BookmarkIndex() {
 107 }
 108
 109 void BookmarkIndex::Add(const BookmarkNode* node) {
 110   if (!node->is_url())
 111     return;
 112   std::vector<base::string16> terms =
 113       ExtractQueryWords(Normalize(node->GetTitle()));
 114   for (size_t i = 0; i < terms.size(); ++i)
 115     RegisterNode(terms[i], node);
 116   terms =
 117       ExtractQueryWords(CleanUpUrlForMatching(node->url(), languages_, NULL));
 118   for (size_t i = 0; i < terms.size(); ++i)
 119     RegisterNode(terms[i], node);
 120 }
 121
 122 void BookmarkIndex::Remove(const BookmarkNode* node) {
 123   if (!node->is_url())
 124     return;
 125
 126   std::vector<base::string16> terms =
 127       ExtractQueryWords(Normalize(node->GetTitle()));
 128   for (size_t i = 0; i < terms.size(); ++i)
 129     UnregisterNode(terms[i], node);
 130   terms =
 131       ExtractQueryWords(CleanUpUrlForMatching(node->url(), languages_, NULL));
 132   for (size_t i = 0; i < terms.size(); ++i)
 133     UnregisterNode(terms[i], node);
 134 }
 135
 136 void BookmarkIndex::GetBookmarksMatching(const base::string16& input_query,
 137                                          size_t max_count,
 138                                          std::vector<BookmarkMatch>* results) {
 139   const base::string16 query = Normalize(input_query);
 140   std::vector<base::string16> terms = ExtractQueryWords(query);
 141   if (terms.empty())
 142     return;
 143
 144   Matches matches;
 145   for (size_t i = 0; i < terms.size(); ++i) {
 146     if (!GetBookmarksMatchingTerm(terms[i], i == 0, &matches))
 147       return;
 148   }
 149
 150   Nodes sorted_nodes;
 151   SortMatches(matches, &sorted_nodes);
 152
 153   // We use a QueryParser to fill in match positions for us. It's not the most
 154   // efficient way to go about this, but by the time we get here we know what
 155   // matches and so this shouldn't be performance critical.
 156   query_parser::QueryParser parser;
 157   ScopedVector<query_parser::QueryNode> query_nodes;
 158   parser.ParseQueryNodes(query, &query_nodes.get());
 159
 160   // The highest typed counts should be at the beginning of the results vector
 161   // so that the best matches will always be included in the results. The loop
 162   // that calculates result relevance in HistoryContentsProvider::ConvertResults
 163   // will run backwards to assure higher relevance will be attributed to the
 164   // best matches.
 165   for (Nodes::const_iterator i = sorted_nodes.begin();
 166        i != sorted_nodes.end() && results->size() < max_count;
 167        ++i)
 168     AddMatchToResults(*i, &parser, query_nodes.get(), results);
 169 }
 170
 171 void BookmarkIndex::SortMatches(const Matches& matches,
 172                                 Nodes* sorted_nodes) const {
 173   NodeSet nodes;
 174   for (Matches::const_iterator i = matches.begin(); i != matches.end(); ++i) {
 175 #if !defined(OS_ANDROID)
 176     nodes.insert(i->nodes_begin(), i->nodes_end());
 177 #else
 178     // Work around a bug in the implementation of std::set::insert in the STL
 179     // used on android (http://crbug.com/367050).
 180     for (NodeSet::const_iterator n = i->nodes_begin(); n != i->nodes_end(); ++n)
 181       nodes.insert(nodes.end(), *n);
 182 #endif
 183   }
 184   sorted_nodes->reserve(sorted_nodes->size() + nodes.size());
 185   if (client_->SupportsTypedCountForNodes()) {
 186     NodeTypedCountPairs node_typed_counts;
 187     client_->GetTypedCountForNodes(nodes, &node_typed_counts);
 188     std::sort(node_typed_counts.begin(),
 189               node_typed_counts.end(),
 190               NodeTypedCountPairSortFunctor());
 191     std::transform(node_typed_counts.begin(),
 192                    node_typed_counts.end(),
 193                    std::back_inserter(*sorted_nodes),
 194                    NodeTypedCountPairExtractNodeFunctor());
 195   } else {
 196     sorted_nodes->insert(sorted_nodes->end(), nodes.begin(), nodes.end());
 197   }
 198 }
 199
 200 void BookmarkIndex::AddMatchToResults(
 201     const BookmarkNode* node,
 202     query_parser::QueryParser* parser,
 203     const query_parser::QueryNodeStarVector& query_nodes,
 204     std::vector<BookmarkMatch>* results) {
 205   // Check that the result matches the query.  The previous search
 206   // was a simple per-word search, while the more complex matching
 207   // of QueryParser may filter it out.  For example, the query
 208   // ["thi"] will match the bookmark titled [Thinking], but since
 209   // ["thi"] is quoted we don't want to do a prefix match.
 210   query_parser::QueryWordVector title_words, url_words;
 211   const base::string16 lower_title =
 212       base::i18n::ToLower(Normalize(node->GetTitle()));
 213   parser->ExtractQueryWords(lower_title, &title_words);
 214   base::OffsetAdjuster::Adjustments adjustments;
 215   parser->ExtractQueryWords(
 216       CleanUpUrlForMatching(node->url(), languages_, &adjustments),
 217       &url_words);
 218   query_parser::Snippet::MatchPositions title_matches, url_matches;
 219   for (size_t i = 0; i < query_nodes.size(); ++i) {
 220     const bool has_title_matches =
 221         query_nodes[i]->HasMatchIn(title_words, &title_matches);
 222     const bool has_url_matches =
 223         query_nodes[i]->HasMatchIn(url_words, &url_matches);
 224     if (!has_title_matches && !has_url_matches)
 225       return;
 226     query_parser::QueryParser::SortAndCoalesceMatchPositions(&title_matches);
 227     query_parser::QueryParser::SortAndCoalesceMatchPositions(&url_matches);
 228   }
 229   BookmarkMatch match;
 230   if (lower_title.length() == node->GetTitle().length()) {
 231     // Only use title matches if the lowercase string is the same length
 232     // as the original string, otherwise the matches are meaningless.
 233     // TODO(mpearson): revise match positions appropriately.
 234     match.title_match_positions.swap(title_matches);
 235   }
 236   // Now that we're done processing this entry, correct the offsets of the
 237   // matches in |url_matches| so they point to offsets in the original URL
 238   // spec, not the cleaned-up URL string that we used for matching.
 239   std::vector<size_t> offsets =
 240       BookmarkMatch::OffsetsFromMatchPositions(url_matches);
 241   base::OffsetAdjuster::UnadjustOffsets(adjustments, &offsets);
 242   url_matches =
 243       BookmarkMatch::ReplaceOffsetsInMatchPositions(url_matches, offsets);
 244   match.url_match_positions.swap(url_matches);
 245   match.node = node;
 246   results->push_back(match);
 247 }
 248
 249 bool BookmarkIndex::GetBookmarksMatchingTerm(const base::string16& term,
 250                                                       bool first_term,
 251                                                       Matches* matches) {
 252   Index::const_iterator i = index_.lower_bound(term);
 253   if (i == index_.end())
 254     return false;
 255
 256   if (!query_parser::QueryParser::IsWordLongEnoughForPrefixSearch(term)) {
 257     // Term is too short for prefix match, compare using exact match.
 258     if (i->first != term)
 259       return false;  // No bookmarks with this term.
 260
 261     if (first_term) {
 262       Match match;
 263       match.terms.push_back(i);
 264       matches->push_back(match);
 265       return true;
 266     }
 267     CombineMatchesInPlace(i, matches);
 268   } else if (first_term) {
 269     // This is the first term and we're doing a prefix match. Loop through
 270     // index adding all entries that start with term to matches.
 271     while (i != index_.end() &&
 272            i->first.size() >= term.size() &&
 273            term.compare(0, term.size(), i->first, 0, term.size()) == 0) {
 274       Match match;
 275       match.terms.push_back(i);
 276       matches->push_back(match);
 277       ++i;
 278     }
 279   } else {
 280     // Prefix match and not the first term. Loop through index combining
 281     // current matches in matches with term, placing result in result.
 282     Matches result;
 283     while (i != index_.end() &&
 284            i->first.size() >= term.size() &&
 285            term.compare(0, term.size(), i->first, 0, term.size()) == 0) {
 286       CombineMatches(i, *matches, &result);
 287       ++i;
 288     }
 289     matches->swap(result);
 290   }
 291   return !matches->empty();
 292 }
 293
 294 void BookmarkIndex::CombineMatchesInPlace(const Index::const_iterator& index_i,
 295                                           Matches* matches) {
 296   for (size_t i = 0; i < matches->size(); ) {
 297     Match* match = &((*matches)[i]);
 298     NodeSet intersection;
 299     std::set_intersection(match->nodes_begin(), match->nodes_end(),
 300                           index_i->second.begin(), index_i->second.end(),
 301                           std::inserter(intersection, intersection.begin()));
 302     if (intersection.empty()) {
 303       matches->erase(matches->begin() + i);
 304     } else {
 305       match->terms.push_back(index_i);
 306       match->nodes.swap(intersection);
 307       ++i;
 308     }
 309   }
 310 }
 311
 312 void BookmarkIndex::CombineMatches(const Index::const_iterator& index_i,
 313                                    const Matches& current_matches,
 314                                    Matches* result) {
 315   for (size_t i = 0; i < current_matches.size(); ++i) {
 316     const Match& match = current_matches[i];
 317     NodeSet intersection;
 318     std::set_intersection(match.nodes_begin(), match.nodes_end(),
 319                           index_i->second.begin(), index_i->second.end(),
 320                           std::inserter(intersection, intersection.begin()));
 321     if (!intersection.empty()) {
 322       result->push_back(Match());
 323       Match& combined_match = result->back();
 324       combined_match.terms = match.terms;
 325       combined_match.terms.push_back(index_i);
 326       combined_match.nodes.swap(intersection);
 327     }
 328   }
 329 }
 330
 331 std::vector<base::string16> BookmarkIndex::ExtractQueryWords(
 332     const base::string16& query) {
 333   std::vector<base::string16> terms;
 334   if (query.empty())
 335     return std::vector<base::string16>();
 336   query_parser::QueryParser parser;
 337   parser.ParseQueryWords(base::i18n::ToLower(query), &terms);
 338   return terms;
 339 }
 340
 341 void BookmarkIndex::RegisterNode(const base::string16& term,
 342                                  const BookmarkNode* node) {
 343   index_[term].insert(node);
 344 }
 345
 346 void BookmarkIndex::UnregisterNode(const base::string16& term,
 347                                    const BookmarkNode* node) {
 348   Index::iterator i = index_.find(term);
 349   if (i == index_.end()) {
 350     // We can get here if the node has the same term more than once. For
 351     // example, a bookmark with the title 'foo foo' would end up here.
 352     return;
 353   }
 354   i->second.erase(node);
 355   if (i->second.empty())
 356     index_.erase(i);
 357 }
 358
 359 }  // namespace bookmarks