components/omnibox/shortcuts_provider.cc

   1 // Copyright (c) 2012 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/shortcuts_provider.h"
   6
   7 #include <algorithm>
   8 #include <cmath>
   9 #include <map>
  10 #include <vector>
  11
  12 #include "base/i18n/break_iterator.h"
  13 #include "base/i18n/case_conversion.h"
  14 #include "base/logging.h"
  15 #include "base/metrics/histogram.h"
  16 #include "base/prefs/pref_service.h"
  17 #include "base/strings/string_number_conversions.h"
  18 #include "base/strings/string_util.h"
  19 #include "base/strings/utf_string_conversions.h"
  20 #include "base/time/time.h"
  21 #include "components/history/core/browser/history_service.h"
  22 #include "components/metrics/proto/omnibox_input_type.pb.h"
  23 #include "components/omnibox/autocomplete_input.h"
  24 #include "components/omnibox/autocomplete_match.h"
  25 #include "components/omnibox/autocomplete_provider_client.h"
  26 #include "components/omnibox/autocomplete_result.h"
  27 #include "components/omnibox/history_provider.h"
  28 #include "components/omnibox/omnibox_field_trial.h"
  29 #include "components/omnibox/url_prefix.h"
  30 #include "components/url_fixer/url_fixer.h"
  31 #include "url/third_party/mozilla/url_parse.h"
  32
  33 namespace {
  34
  35 class DestinationURLEqualsURL {
  36  public:
  37   explicit DestinationURLEqualsURL(const GURL& url) : url_(url) {}
  38   bool operator()(const AutocompleteMatch& match) const {
  39     return match.destination_url == url_;
  40   }
  41
  42  private:
  43   const GURL url_;
  44 };
  45
  46 }  // namespace
  47
  48 const int ShortcutsProvider::kShortcutsProviderDefaultMaxRelevance = 1199;
  49
  50 ShortcutsProvider::ShortcutsProvider(AutocompleteProviderClient* client)
  51     : AutocompleteProvider(AutocompleteProvider::TYPE_SHORTCUTS),
  52       client_(client),
  53       languages_(client_->GetAcceptLanguages()),
  54       initialized_(false) {
  55   scoped_refptr<ShortcutsBackend> backend = client_->GetShortcutsBackend();
  56   if (backend.get()) {
  57     backend->AddObserver(this);
  58     if (backend->initialized())
  59       initialized_ = true;
  60   }
  61 }
  62
  63 void ShortcutsProvider::Start(const AutocompleteInput& input,
  64                               bool minimal_changes) {
  65   matches_.clear();
  66
  67   if (input.from_omnibox_focus() ||
  68       (input.type() == metrics::OmniboxInputType::INVALID) ||
  69       (input.type() == metrics::OmniboxInputType::FORCED_QUERY) ||
  70       input.text().empty() || !initialized_)
  71     return;
  72
  73   base::TimeTicks start_time = base::TimeTicks::Now();
  74   GetMatches(input);
  75   if (input.text().length() < 6) {
  76     base::TimeTicks end_time = base::TimeTicks::Now();
  77     std::string name = "ShortcutsProvider.QueryIndexTime." +
  78                        base::IntToString(input.text().size());
  79     base::HistogramBase* counter = base::Histogram::FactoryGet(
  80         name, 1, 1000, 50, base::Histogram::kUmaTargetedHistogramFlag);
  81     counter->Add(static_cast<int>((end_time - start_time).InMilliseconds()));
  82   }
  83 }
  84
  85 void ShortcutsProvider::DeleteMatch(const AutocompleteMatch& match) {
  86   // Copy the URL since deleting from |matches_| will invalidate |match|.
  87   GURL url(match.destination_url);
  88   DCHECK(url.is_valid());
  89
  90   // When a user deletes a match, he probably means for the URL to disappear out
  91   // of history entirely. So nuke all shortcuts that map to this URL.
  92   scoped_refptr<ShortcutsBackend> backend =
  93       client_->GetShortcutsBackendIfExists();
  94   if (backend.get())  // Can be NULL in Incognito.
  95     backend->DeleteShortcutsWithURL(url);
  96
  97   matches_.erase(std::remove_if(matches_.begin(), matches_.end(),
  98                                 DestinationURLEqualsURL(url)),
  99                  matches_.end());
 100   // NOTE: |match| is now dead!
 101
 102   // Delete the match from the history DB. This will eventually result in a
 103   // second call to DeleteShortcutsWithURL(), which is harmless.
 104   history::HistoryService* const history_service = client_->GetHistoryService();
 105   DCHECK(history_service);
 106   history_service->DeleteURL(url);
 107 }
 108
 109 ShortcutsProvider::~ShortcutsProvider() {
 110   scoped_refptr<ShortcutsBackend> backend =
 111       client_->GetShortcutsBackendIfExists();
 112   if (backend.get())
 113     backend->RemoveObserver(this);
 114 }
 115
 116 void ShortcutsProvider::OnShortcutsLoaded() {
 117   initialized_ = true;
 118 }
 119
 120 void ShortcutsProvider::GetMatches(const AutocompleteInput& input) {
 121   scoped_refptr<ShortcutsBackend> backend =
 122       client_->GetShortcutsBackendIfExists();
 123   if (!backend.get())
 124     return;
 125   // Get the URLs from the shortcuts database with keys that partially or
 126   // completely match the search term.
 127   base::string16 term_string(base::i18n::ToLower(input.text()));
 128   DCHECK(!term_string.empty());
 129
 130   int max_relevance;
 131   if (!OmniboxFieldTrial::ShortcutsScoringMaxRelevance(
 132           input.current_page_classification(), &max_relevance))
 133     max_relevance = kShortcutsProviderDefaultMaxRelevance;
 134   TemplateURLService* template_url_service = client_->GetTemplateURLService();
 135   const base::string16 fixed_up_input(FixupUserInput(input).second);
 136   for (ShortcutsBackend::ShortcutMap::const_iterator it =
 137            FindFirstMatch(term_string, backend.get());
 138        it != backend->shortcuts_map().end() &&
 139            base::StartsWith(it->first, term_string,
 140                             base::CompareCase::SENSITIVE);
 141        ++it) {
 142     // Don't return shortcuts with zero relevance.
 143     int relevance = CalculateScore(term_string, it->second, max_relevance);
 144     if (relevance) {
 145       matches_.push_back(
 146           ShortcutToACMatch(it->second, relevance, input, fixed_up_input));
 147       matches_.back().ComputeStrippedDestinationURL(
 148           input, client_->GetAcceptLanguages(), template_url_service);
 149     }
 150   }
 151   // Remove duplicates.  This is important because it's common to have multiple
 152   // shortcuts pointing to the same URL, e.g., ma, mai, and mail all pointing
 153   // to mail.google.com, so typing "m" will return them all.  If we then simply
 154   // clamp to kMaxMatches and let the AutocompleteResult take care of
 155   // collapsing the duplicates, we'll effectively only be returning one match,
 156   // instead of several possibilities.
 157   //
 158   // Note that while removing duplicates, we don't populate a match's
 159   // |duplicate_matches| field--duplicates don't need to be preserved in the
 160   // matches because they are only used for deletions, and this provider
 161   // deletes matches based on the URL.
 162   AutocompleteResult::DedupMatchesByDestination(
 163       input.current_page_classification(), false, &matches_);
 164   // Find best matches.
 165   std::partial_sort(
 166       matches_.begin(),
 167       matches_.begin() +
 168           std::min(AutocompleteProvider::kMaxMatches, matches_.size()),
 169       matches_.end(), &AutocompleteMatch::MoreRelevant);
 170   if (matches_.size() > AutocompleteProvider::kMaxMatches) {
 171     matches_.erase(matches_.begin() + AutocompleteProvider::kMaxMatches,
 172                    matches_.end());
 173   }
 174   // Guarantee that all scores are decreasing (but do not assign any scores
 175   // below 1).
 176   for (ACMatches::iterator it = matches_.begin(); it != matches_.end(); ++it) {
 177     max_relevance = std::min(max_relevance, it->relevance);
 178     it->relevance = max_relevance;
 179     if (max_relevance > 1)
 180       --max_relevance;
 181   }
 182 }
 183
 184 AutocompleteMatch ShortcutsProvider::ShortcutToACMatch(
 185     const ShortcutsDatabase::Shortcut& shortcut,
 186     int relevance,
 187     const AutocompleteInput& input,
 188     const base::string16& fixed_up_input_text) {
 189   DCHECK(!input.text().empty());
 190   AutocompleteMatch match;
 191   match.provider = this;
 192   match.relevance = relevance;
 193   match.deletable = true;
 194   match.fill_into_edit = shortcut.match_core.fill_into_edit;
 195   match.destination_url = shortcut.match_core.destination_url;
 196   DCHECK(match.destination_url.is_valid());
 197   match.contents = shortcut.match_core.contents;
 198   match.contents_class = AutocompleteMatch::ClassificationsFromString(
 199       shortcut.match_core.contents_class);
 200   match.description = shortcut.match_core.description;
 201   match.description_class = AutocompleteMatch::ClassificationsFromString(
 202       shortcut.match_core.description_class);
 203   match.transition = ui::PageTransitionFromInt(shortcut.match_core.transition);
 204   match.type = static_cast<AutocompleteMatch::Type>(shortcut.match_core.type);
 205   match.keyword = shortcut.match_core.keyword;
 206   match.RecordAdditionalInfo("number of hits", shortcut.number_of_hits);
 207   match.RecordAdditionalInfo("last access time", shortcut.last_access_time);
 208   match.RecordAdditionalInfo("original input text",
 209                              base::UTF16ToUTF8(shortcut.text));
 210
 211   // Set |inline_autocompletion| and |allowed_to_be_default_match| if possible.
 212   // If the match is a search query this is easy: simply check whether the
 213   // user text is a prefix of the query.  If the match is a navigation, we
 214   // assume the fill_into_edit looks something like a URL, so we use
 215   // URLPrefix::GetInlineAutocompleteOffset() to try and strip off any prefixes
 216   // that the user might not think would change the meaning, but would
 217   // otherwise prevent inline autocompletion.  This allows, for example, the
 218   // input of "foo.c" to autocomplete to "foo.com" for a fill_into_edit of
 219   // "http://foo.com".
 220   if (AutocompleteMatch::IsSearchType(match.type)) {
 221     if (base::StartsWith(base::i18n::ToLower(match.fill_into_edit),
 222                          base::i18n::ToLower(input.text()),
 223                          base::CompareCase::SENSITIVE)) {
 224       match.inline_autocompletion =
 225           match.fill_into_edit.substr(input.text().length());
 226       match.allowed_to_be_default_match =
 227           !input.prevent_inline_autocomplete() ||
 228           match.inline_autocompletion.empty();
 229     }
 230   } else {
 231     const size_t inline_autocomplete_offset =
 232         URLPrefix::GetInlineAutocompleteOffset(
 233             input.text(), fixed_up_input_text, true, match.fill_into_edit);
 234     if (inline_autocomplete_offset != base::string16::npos) {
 235       match.inline_autocompletion =
 236           match.fill_into_edit.substr(inline_autocomplete_offset);
 237       match.allowed_to_be_default_match =
 238           !HistoryProvider::PreventInlineAutocomplete(input) ||
 239           match.inline_autocompletion.empty();
 240     }
 241   }
 242   match.EnsureUWYTIsAllowedToBeDefault(input,
 243                                        client_->GetAcceptLanguages(),
 244                                        client_->GetTemplateURLService());
 245
 246   // Try to mark pieces of the contents and description as matches if they
 247   // appear in |input.text()|.
 248   const base::string16 term_string = base::i18n::ToLower(input.text());
 249   WordMap terms_map(CreateWordMapForString(term_string));
 250   if (!terms_map.empty()) {
 251     match.contents_class = ClassifyAllMatchesInString(
 252         term_string, terms_map, match.contents, match.contents_class);
 253     match.description_class = ClassifyAllMatchesInString(
 254         term_string, terms_map, match.description, match.description_class);
 255   }
 256   return match;
 257 }
 258
 259 // static
 260 ShortcutsProvider::WordMap ShortcutsProvider::CreateWordMapForString(
 261     const base::string16& text) {
 262   // First, convert |text| to a vector of the unique words in it.
 263   WordMap word_map;
 264   base::i18n::BreakIterator word_iter(text,
 265                                       base::i18n::BreakIterator::BREAK_WORD);
 266   if (!word_iter.Init())
 267     return word_map;
 268   std::vector<base::string16> words;
 269   while (word_iter.Advance()) {
 270     if (word_iter.IsWord())
 271       words.push_back(word_iter.GetString());
 272   }
 273   if (words.empty())
 274     return word_map;
 275   std::sort(words.begin(), words.end());
 276   words.erase(std::unique(words.begin(), words.end()), words.end());
 277
 278   // Now create a map from (first character) to (words beginning with that
 279   // character).  We insert in reverse lexicographical order and rely on the
 280   // multimap preserving insertion order for values with the same key.  (This
 281   // is mandated in C++11, and part of that decision was based on a survey of
 282   // existing implementations that found that it was already true everywhere.)
 283   std::reverse(words.begin(), words.end());
 284   for (std::vector<base::string16>::const_iterator i(words.begin());
 285        i != words.end(); ++i)
 286     word_map.insert(std::make_pair((*i)[0], *i));
 287   return word_map;
 288 }
 289
 290 // static
 291 ACMatchClassifications ShortcutsProvider::ClassifyAllMatchesInString(
 292     const base::string16& find_text,
 293     const WordMap& find_words,
 294     const base::string16& text,
 295     const ACMatchClassifications& original_class) {
 296   DCHECK(!find_text.empty());
 297   DCHECK(!find_words.empty());
 298
 299   // The code below assumes |text| is nonempty and therefore the resulting
 300   // classification vector should always be nonempty as well.  Returning early
 301   // if |text| is empty assures we'll return the (correct) empty vector rather
 302   // than a vector with a single (0, NONE) match.
 303   if (text.empty())
 304     return original_class;
 305
 306   // First check whether |text| begins with |find_text| and mark that whole
 307   // section as a match if so.
 308   base::string16 text_lowercase(base::i18n::ToLower(text));
 309   ACMatchClassifications match_class;
 310   size_t last_position = 0;
 311   if (base::StartsWith(text_lowercase, find_text,
 312                        base::CompareCase::SENSITIVE)) {
 313     match_class.push_back(
 314         ACMatchClassification(0, ACMatchClassification::MATCH));
 315     last_position = find_text.length();
 316     // If |text_lowercase| is actually equal to |find_text|, we don't need to
 317     // (and in fact shouldn't) put a trailing NONE classification after the end
 318     // of the string.
 319     if (last_position < text_lowercase.length()) {
 320       match_class.push_back(
 321           ACMatchClassification(last_position, ACMatchClassification::NONE));
 322     }
 323   } else {
 324     // |match_class| should start at position 0.  If the first matching word is
 325     // found at position 0, this will be popped from the vector further down.
 326     match_class.push_back(
 327         ACMatchClassification(0, ACMatchClassification::NONE));
 328   }
 329
 330   // Now, starting with |last_position|, check each character in
 331   // |text_lowercase| to see if we have words starting with that character in
 332   // |find_words|.  If so, check each of them to see if they match the portion
 333   // of |text_lowercase| beginning with |last_position|.  Accept the first
 334   // matching word found (which should be the longest possible match at this
 335   // location, given the construction of |find_words|) and add a MATCH region to
 336   // |match_class|, moving |last_position| to be after the matching word.  If we
 337   // found no matching words, move to the next character and repeat.
 338   while (last_position < text_lowercase.length()) {
 339     std::pair<WordMap::const_iterator, WordMap::const_iterator> range(
 340         find_words.equal_range(text_lowercase[last_position]));
 341     size_t next_character = last_position + 1;
 342     for (WordMap::const_iterator i(range.first); i != range.second; ++i) {
 343       const base::string16& word = i->second;
 344       size_t word_end = last_position + word.length();
 345       if ((word_end <= text_lowercase.length()) &&
 346           !text_lowercase.compare(last_position, word.length(), word)) {
 347         // Collapse adjacent ranges into one.
 348         if (match_class.back().offset == last_position)
 349           match_class.pop_back();
 350
 351         AutocompleteMatch::AddLastClassificationIfNecessary(
 352             &match_class, last_position, ACMatchClassification::MATCH);
 353         if (word_end < text_lowercase.length()) {
 354           match_class.push_back(
 355               ACMatchClassification(word_end, ACMatchClassification::NONE));
 356         }
 357         last_position = word_end;
 358         break;
 359       }
 360     }
 361     last_position = std::max(last_position, next_character);
 362   }
 363
 364   return AutocompleteMatch::MergeClassifications(original_class, match_class);
 365 }
 366
 367 ShortcutsBackend::ShortcutMap::const_iterator ShortcutsProvider::FindFirstMatch(
 368     const base::string16& keyword,
 369     ShortcutsBackend* backend) {
 370   DCHECK(backend);
 371   ShortcutsBackend::ShortcutMap::const_iterator it =
 372       backend->shortcuts_map().lower_bound(keyword);
 373   // Lower bound not necessarily matches the keyword, check for item pointed by
 374   // the lower bound iterator to at least start with keyword.
 375   return ((it == backend->shortcuts_map().end()) ||
 376           base::StartsWith(it->first, keyword, base::CompareCase::SENSITIVE))
 377              ? it
 378              : backend->shortcuts_map().end();
 379 }
 380
 381 int ShortcutsProvider::CalculateScore(
 382     const base::string16& terms,
 383     const ShortcutsDatabase::Shortcut& shortcut,
 384     int max_relevance) {
 385   DCHECK(!terms.empty());
 386   DCHECK_LE(terms.length(), shortcut.text.length());
 387
 388   // The initial score is based on how much of the shortcut the user has typed.
 389   // Using the square root of the typed fraction boosts the base score rapidly
 390   // as characters are typed, compared with simply using the typed fraction
 391   // directly. This makes sense since the first characters typed are much more
 392   // important for determining how likely it is a user wants a particular
 393   // shortcut than are the remaining continued characters.
 394   double base_score = max_relevance * sqrt(static_cast<double>(terms.length()) /
 395                                            shortcut.text.length());
 396
 397   // Then we decay this by half each week.
 398   const double kLn2 = 0.6931471805599453;
 399   base::TimeDelta time_passed = base::Time::Now() - shortcut.last_access_time;
 400   // Clamp to 0 in case time jumps backwards (e.g. due to DST).
 401   double decay_exponent =
 402       std::max(0.0, kLn2 * static_cast<double>(time_passed.InMicroseconds()) /
 403                         base::Time::kMicrosecondsPerWeek);
 404
 405   // We modulate the decay factor based on how many times the shortcut has been
 406   // used. Newly created shortcuts decay at full speed; otherwise, decaying by
 407   // half takes |n| times as much time, where n increases by
 408   // (1.0 / each 5 additional hits), up to a maximum of 5x as long.
 409   const double kMaxDecaySpeedDivisor = 5.0;
 410   const double kNumUsesPerDecaySpeedDivisorIncrement = 5.0;
 411   double decay_divisor = std::min(
 412       kMaxDecaySpeedDivisor,
 413       (shortcut.number_of_hits + kNumUsesPerDecaySpeedDivisorIncrement - 1) /
 414           kNumUsesPerDecaySpeedDivisorIncrement);
 415
 416   return static_cast<int>((base_score / exp(decay_exponent / decay_divisor)) +
 417                           0.5);
 418 }