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(
 137     const base::string16& input_query,
 138     size_t max_count,
 139     query_parser::MatchingAlgorithm matching_algorithm,
 140     std::vector<BookmarkMatch>* results) {
 141   const base::string16 query = Normalize(input_query);
 142   std::vector<base::string16> terms = ExtractQueryWords(query);
 143   if (terms.empty())
 144     return;
 145
 146   Matches matches;
 147   for (size_t i = 0; i < terms.size(); ++i) {
 148     if (!GetBookmarksMatchingTerm(
 149             terms[i], i == 0, matching_algorithm, &matches)) {
 150       return;
 151     }
 152   }
 153
 154   Nodes sorted_nodes;
 155   SortMatches(matches, &sorted_nodes);
 156
 157   // We use a QueryParser to fill in match positions for us. It's not the most
 158   // efficient way to go about this, but by the time we get here we know what
 159   // matches and so this shouldn't be performance critical.
 160   query_parser::QueryParser parser;
 161   ScopedVector<query_parser::QueryNode> query_nodes;
 162   parser.ParseQueryNodes(query, matching_algorithm, &query_nodes.get());
 163
 164   // The highest typed counts should be at the beginning of the results vector
 165   // so that the best matches will always be included in the results. The loop
 166   // that calculates result relevance in HistoryContentsProvider::ConvertResults
 167   // will run backwards to assure higher relevance will be attributed to the
 168   // best matches.
 169   for (Nodes::const_iterator i = sorted_nodes.begin();
 170        i != sorted_nodes.end() && results->size() < max_count;
 171        ++i)
 172     AddMatchToResults(*i, &parser, query_nodes.get(), results);
 173 }
 174
 175 void BookmarkIndex::SortMatches(const Matches& matches,
 176                                 Nodes* sorted_nodes) const {
 177   NodeSet nodes;
 178   for (Matches::const_iterator i = matches.begin(); i != matches.end(); ++i) {
 179 #if !defined(OS_ANDROID)
 180     nodes.insert(i->nodes_begin(), i->nodes_end());
 181 #else
 182     // Work around a bug in the implementation of std::set::insert in the STL
 183     // used on android (http://crbug.com/367050).
 184     for (NodeSet::const_iterator n = i->nodes_begin(); n != i->nodes_end(); ++n)
 185       nodes.insert(nodes.end(), *n);
 186 #endif
 187   }
 188   sorted_nodes->reserve(sorted_nodes->size() + nodes.size());
 189   if (client_->SupportsTypedCountForNodes()) {
 190     NodeTypedCountPairs node_typed_counts;
 191     client_->GetTypedCountForNodes(nodes, &node_typed_counts);
 192     std::sort(node_typed_counts.begin(),
 193               node_typed_counts.end(),
 194               NodeTypedCountPairSortFunctor());
 195     std::transform(node_typed_counts.begin(),
 196                    node_typed_counts.end(),
 197                    std::back_inserter(*sorted_nodes),
 198                    NodeTypedCountPairExtractNodeFunctor());
 199   } else {
 200     sorted_nodes->insert(sorted_nodes->end(), nodes.begin(), nodes.end());
 201   }
 202 }
 203
 204 void BookmarkIndex::AddMatchToResults(
 205     const BookmarkNode* node,
 206     query_parser::QueryParser* parser,
 207     const query_parser::QueryNodeStarVector& query_nodes,
 208     std::vector<BookmarkMatch>* results) {
 209   // Check that the result matches the query.  The previous search
 210   // was a simple per-word search, while the more complex matching
 211   // of QueryParser may filter it out.  For example, the query
 212   // ["thi"] will match the bookmark titled [Thinking], but since
 213   // ["thi"] is quoted we don't want to do a prefix match.
 214   query_parser::QueryWordVector title_words, url_words;
 215   const base::string16 lower_title =
 216       base::i18n::ToLower(Normalize(node->GetTitle()));
 217   parser->ExtractQueryWords(lower_title, &title_words);
 218   base::OffsetAdjuster::Adjustments adjustments;
 219   parser->ExtractQueryWords(
 220       CleanUpUrlForMatching(node->url(), languages_, &adjustments),
 221       &url_words);
 222   query_parser::Snippet::MatchPositions title_matches, url_matches;
 223   for (size_t i = 0; i < query_nodes.size(); ++i) {
 224     const bool has_title_matches =
 225         query_nodes[i]->HasMatchIn(title_words, &title_matches);
 226     const bool has_url_matches =
 227         query_nodes[i]->HasMatchIn(url_words, &url_matches);
 228     if (!has_title_matches && !has_url_matches)
 229       return;
 230     query_parser::QueryParser::SortAndCoalesceMatchPositions(&title_matches);
 231     query_parser::QueryParser::SortAndCoalesceMatchPositions(&url_matches);
 232   }
 233   BookmarkMatch match;
 234   if (lower_title.length() == node->GetTitle().length()) {
 235     // Only use title matches if the lowercase string is the same length
 236     // as the original string, otherwise the matches are meaningless.
 237     // TODO(mpearson): revise match positions appropriately.
 238     match.title_match_positions.swap(title_matches);
 239   }
 240   // Now that we're done processing this entry, correct the offsets of the
 241   // matches in |url_matches| so they point to offsets in the original URL
 242   // spec, not the cleaned-up URL string that we used for matching.
 243   std::vector<size_t> offsets =
 244       BookmarkMatch::OffsetsFromMatchPositions(url_matches);
 245   base::OffsetAdjuster::UnadjustOffsets(adjustments, &offsets);
 246   url_matches =
 247       BookmarkMatch::ReplaceOffsetsInMatchPositions(url_matches, offsets);
 248   match.url_match_positions.swap(url_matches);
 249   match.node = node;
 250   results->push_back(match);
 251 }
 252
 253 bool BookmarkIndex::GetBookmarksMatchingTerm(
 254     const base::string16& term,
 255     bool first_term,
 256     query_parser::MatchingAlgorithm matching_algorithm,
 257     Matches* matches) {
 258   Index::const_iterator i = index_.lower_bound(term);
 259   if (i == index_.end())
 260     return false;
 261
 262   if (!query_parser::QueryParser::IsWordLongEnoughForPrefixSearch(
 263       term, matching_algorithm)) {
 264     // Term is too short for prefix match, compare using exact match.
 265     if (i->first != term)
 266       return false;  // No bookmarks with this term.
 267
 268     if (first_term) {
 269       Match match;
 270       match.terms.push_back(i);
 271       matches->push_back(match);
 272       return true;
 273     }
 274     CombineMatchesInPlace(i, matches);
 275   } else if (first_term) {
 276     // This is the first term and we're doing a prefix match. Loop through
 277     // index adding all entries that start with term to matches.
 278     while (i != index_.end() &&
 279            i->first.size() >= term.size() &&
 280            term.compare(0, term.size(), i->first, 0, term.size()) == 0) {
 281       Match match;
 282       match.terms.push_back(i);
 283       matches->push_back(match);
 284       ++i;
 285     }
 286   } else {
 287     // Prefix match and not the first term. Loop through index combining
 288     // current matches in matches with term, placing result in result.
 289     Matches result;
 290     while (i != index_.end() &&
 291            i->first.size() >= term.size() &&
 292            term.compare(0, term.size(), i->first, 0, term.size()) == 0) {
 293       CombineMatches(i, *matches, &result);
 294       ++i;
 295     }
 296     matches->swap(result);
 297   }
 298   return !matches->empty();
 299 }
 300
 301 void BookmarkIndex::CombineMatchesInPlace(const Index::const_iterator& index_i,
 302                                           Matches* matches) {
 303   for (size_t i = 0; i < matches->size(); ) {
 304     Match* match = &((*matches)[i]);
 305     NodeSet intersection;
 306     std::set_intersection(match->nodes_begin(), match->nodes_end(),
 307                           index_i->second.begin(), index_i->second.end(),
 308                           std::inserter(intersection, intersection.begin()));
 309     if (intersection.empty()) {
 310       matches->erase(matches->begin() + i);
 311     } else {
 312       match->terms.push_back(index_i);
 313       match->nodes.swap(intersection);
 314       ++i;
 315     }
 316   }
 317 }
 318
 319 void BookmarkIndex::CombineMatches(const Index::const_iterator& index_i,
 320                                    const Matches& current_matches,
 321                                    Matches* result) {
 322   for (size_t i = 0; i < current_matches.size(); ++i) {
 323     const Match& match = current_matches[i];
 324     NodeSet intersection;
 325     std::set_intersection(match.nodes_begin(), match.nodes_end(),
 326                           index_i->second.begin(), index_i->second.end(),
 327                           std::inserter(intersection, intersection.begin()));
 328     if (!intersection.empty()) {
 329       result->push_back(Match());
 330       Match& combined_match = result->back();
 331       combined_match.terms = match.terms;
 332       combined_match.terms.push_back(index_i);
 333       combined_match.nodes.swap(intersection);
 334     }
 335   }
 336 }
 337
 338 std::vector<base::string16> BookmarkIndex::ExtractQueryWords(
 339     const base::string16& query) {
 340   std::vector<base::string16> terms;
 341   if (query.empty())
 342     return std::vector<base::string16>();
 343   query_parser::QueryParser parser;
 344   parser.ParseQueryWords(base::i18n::ToLower(query),
 345                          query_parser::MatchingAlgorithm::DEFAULT,
 346                          &terms);
 347   return terms;
 348 }
 349
 350 void BookmarkIndex::RegisterNode(const base::string16& term,
 351                                  const BookmarkNode* node) {
 352   index_[term].insert(node);
 353 }
 354
 355 void BookmarkIndex::UnregisterNode(const base::string16& term,
 356                                    const BookmarkNode* node) {
 357   Index::iterator i = index_.find(term);
 358   if (i == index_.end()) {
 359     // We can get here if the node has the same term more than once. For
 360     // example, a bookmark with the title 'foo foo' would end up here.
 361     return;
 362   }
 363   i->second.erase(node);
 364   if (i->second.empty())
 365     index_.erase(i);
 366 }
 367
 368 }  // namespace bookmarks