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