src/components/url_matcher/url_matcher.cc

   1 // Copyright 2013 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/url_matcher/url_matcher.h"
   6
   7 #include <algorithm>
   8 #include <iterator>
   9
  10 #include "base/logging.h"
  11 #include "url/gurl.h"
  12 #include "url/url_canon.h"
  13
  14 namespace url_matcher {
  15
  16 // This set of classes implement a mapping of URL Component Patterns, such as
  17 // host_prefix, host_suffix, host_equals, ..., etc., to StringPatterns
  18 // for use in substring comparisons.
  19 //
  20 // The idea of this mapping is to reduce the problem of comparing many
  21 // URL Component Patterns against one URL to the problem of searching many
  22 // substrings in one string:
  23 //
  24 // ----------------------                    -----------------
  25 // | URL Query operator | ----translate----> | StringPattern |
  26 // ----------------------                    -----------------
  27 //                                                   ^
  28 //                                                   |
  29 //                                                compare
  30 //                                                   |
  31 //                                                   v
  32 // ----------------------                    -----------------
  33 // | URL to compare     |                    |               |
  34 // | to all URL Query   | ----translate----> | String        |
  35 // | operators          |                    |               |
  36 // ----------------------                    -----------------
  37 //
  38 // The reason for this problem reduction is that there are efficient algorithms
  39 // for searching many substrings in one string (see Aho-Corasick algorithm).
  40 //
  41 // Additionally, some of the same pieces are reused to implement regular
  42 // expression comparisons. The FilteredRE2 implementation for matching many
  43 // regular expressions against one string uses prefiltering, in which a set
  44 // of substrings (derived from the regexes) are first searched for, to reduce
  45 // the number of regular expressions to test; the prefiltering step also
  46 // uses Aho-Corasick.
  47 //
  48 // Case 1: {host,path,query}_{prefix,suffix,equals} searches.
  49 // ==========================================================
  50 //
  51 // For searches in this class, we normalize URLs as follows:
  52 //
  53 // Step 1:
  54 // Remove scheme, port and segment from URL:
  55 // -> http://www.example.com:8080/index.html?search=foo#first_match becomes
  56 //    www.example.com/index.html?search=foo
  57 //
  58 // We remove the scheme and port number because they can be checked later
  59 // in a secondary filter step. We remove the segment (the #... part) because
  60 // this is not guaranteed to be ASCII-7 encoded.
  61 //
  62 // Step 2:
  63 // Translate URL to String and add the following position markers:
  64 // - BU = Beginning of URL
  65 // - ED = End of Domain
  66 // - EP = End of Path
  67 // - EU = End of URL
  68 // Furthermore, the hostname is canonicalized to start with a ".".
  69 //
  70 // Position markers are represented as characters >127, which are therefore
  71 // guaranteed not to be part of the ASCII-7 encoded URL character set.
  72 //
  73 // -> www.example.com/index.html?search=foo becomes
  74 // BU .www.example.com ED /index.html EP ?search=foo EU
  75 //
  76 // -> www.example.com/index.html becomes
  77 // BU .www.example.com ED /index.html EP EU
  78 //
  79 // Step 3:
  80 // Translate URL Component Patterns as follows:
  81 //
  82 // host_prefix(prefix) = BU add_missing_dot_prefix(prefix)
  83 // -> host_prefix("www.example") = BU .www.example
  84 //
  85 // host_suffix(suffix) = suffix ED
  86 // -> host_suffix("example.com") = example.com ED
  87 // -> host_suffix(".example.com") = .example.com ED
  88 //
  89 // host_equals(domain) = BU add_missing_dot_prefix(domain) ED
  90 // -> host_equals("www.example.com") = BU .www.example.com ED
  91 //
  92 // Similarly for path query parameters ({path, query}_{prefix, suffix, equals}).
  93 //
  94 // With this, we can search the StringPatterns in the normalized URL.
  95 //
  96 //
  97 // Case 2: url_{prefix,suffix,equals,contains} searches.
  98 // =====================================================
  99 //
 100 // Step 1: as above, except that
 101 // - the scheme is not removed
 102 // - the port is not removed if it is specified and does not match the default
 103 //   port for the given scheme.
 104 //
 105 // Step 2:
 106 // Translate URL to String and add the following position markers:
 107 // - BU = Beginning of URL
 108 // - EU = End of URL
 109 //
 110 // -> http://www.example.com:8080/index.html?search=foo#first_match becomes
 111 // BU http://www.example.com:8080/index.html?search=foo EU
 112 // -> http://www.example.com:80/index.html?search=foo#first_match becomes
 113 // BU http://www.example.com/index.html?search=foo EU
 114 //
 115 // url_prefix(prefix) = BU prefix
 116 // -> url_prefix("http://www.example") = BU http://www.example
 117 //
 118 // url_contains(substring) = substring
 119 // -> url_contains("index") = index
 120 //
 121 //
 122 // Case 3: {host,path,query}_contains searches.
 123 // ============================================
 124 //
 125 // These kinds of searches are not supported directly but can be derived
 126 // by a combination of a url_contains() query followed by an explicit test:
 127 //
 128 // host_contains(str) = url_contains(str) followed by test whether str occurs
 129 //   in host component of original URL.
 130 // -> host_contains("example.co") = example.co
 131 //    followed by gurl.host().find("example.co");
 132 //
 133 // [similarly for path_contains and query_contains].
 134 //
 135 //
 136 // Regular expression matching (url_matches searches)
 137 // ==================================================
 138 //
 139 // This class also supports matching regular expressions (RE2 syntax)
 140 // against full URLs, which are transformed as in case 2.
 141
 142 namespace {
 143
 144 bool IsRegexCriterion(URLMatcherCondition::Criterion criterion) {
 145   return criterion == URLMatcherCondition::URL_MATCHES;
 146 }
 147
 148 bool IsOriginAndPathRegexCriterion(URLMatcherCondition::Criterion criterion) {
 149   return criterion == URLMatcherCondition::ORIGIN_AND_PATH_MATCHES;
 150 }
 151
 152 }  // namespace
 153
 154 //
 155 // URLMatcherCondition
 156 //
 157
 158 URLMatcherCondition::URLMatcherCondition()
 159     : criterion_(HOST_PREFIX),
 160       string_pattern_(NULL) {}
 161
 162 URLMatcherCondition::~URLMatcherCondition() {}
 163
 164 URLMatcherCondition::URLMatcherCondition(
 165     Criterion criterion,
 166     const StringPattern* string_pattern)
 167     : criterion_(criterion),
 168       string_pattern_(string_pattern) {}
 169
 170 URLMatcherCondition::URLMatcherCondition(const URLMatcherCondition& rhs)
 171     : criterion_(rhs.criterion_),
 172       string_pattern_(rhs.string_pattern_) {}
 173
 174 URLMatcherCondition& URLMatcherCondition::operator=(
 175     const URLMatcherCondition& rhs) {
 176   criterion_ = rhs.criterion_;
 177   string_pattern_ = rhs.string_pattern_;
 178   return *this;
 179 }
 180
 181 bool URLMatcherCondition::operator<(const URLMatcherCondition& rhs) const {
 182   if (criterion_ < rhs.criterion_) return true;
 183   if (criterion_ > rhs.criterion_) return false;
 184   if (string_pattern_ != NULL && rhs.string_pattern_ != NULL)
 185     return *string_pattern_ < *rhs.string_pattern_;
 186   if (string_pattern_ == NULL && rhs.string_pattern_ != NULL) return true;
 187   // Either string_pattern_ != NULL && rhs.string_pattern_ == NULL,
 188   // or both are NULL.
 189   return false;
 190 }
 191
 192 bool URLMatcherCondition::IsFullURLCondition() const {
 193   // For these criteria the SubstringMatcher needs to be executed on the
 194   // GURL that is canonicalized with
 195   // URLMatcherConditionFactory::CanonicalizeURLForFullSearches.
 196   switch (criterion_) {
 197     case HOST_CONTAINS:
 198     case PATH_CONTAINS:
 199     case QUERY_CONTAINS:
 200     case URL_PREFIX:
 201     case URL_SUFFIX:
 202     case URL_CONTAINS:
 203     case URL_EQUALS:
 204       return true;
 205     default:
 206       break;
 207   }
 208   return false;
 209 }
 210
 211 bool URLMatcherCondition::IsRegexCondition() const {
 212   return IsRegexCriterion(criterion_);
 213 }
 214
 215 bool URLMatcherCondition::IsOriginAndPathRegexCondition() const {
 216   return IsOriginAndPathRegexCriterion(criterion_);
 217 }
 218
 219 bool URLMatcherCondition::IsMatch(
 220     const std::set<StringPattern::ID>& matching_patterns,
 221     const GURL& url) const {
 222   DCHECK(string_pattern_);
 223   if (!ContainsKey(matching_patterns, string_pattern_->id()))
 224     return false;
 225   // The criteria HOST_CONTAINS, PATH_CONTAINS, QUERY_CONTAINS are based on
 226   // a substring match on the raw URL. In case of a match, we need to verify
 227   // that the match was found in the correct component of the URL.
 228   switch (criterion_) {
 229     case HOST_CONTAINS:
 230       return url.host().find(string_pattern_->pattern()) !=
 231           std::string::npos;
 232     case PATH_CONTAINS:
 233       return url.path().find(string_pattern_->pattern()) !=
 234           std::string::npos;
 235     case QUERY_CONTAINS:
 236       return url.query().find(string_pattern_->pattern()) !=
 237           std::string::npos;
 238     default:
 239       break;
 240   }
 241   return true;
 242 }
 243
 244 //
 245 // URLMatcherConditionFactory
 246 //
 247
 248 namespace {
 249 // These are symbols that are not contained in 7-bit ASCII used in GURLs.
 250 const char kBeginningOfURL[] = {static_cast<char>(-1), 0};
 251 const char kEndOfDomain[] = {static_cast<char>(-2), 0};
 252 const char kEndOfPath[] = {static_cast<char>(-3), 0};
 253 const char kQueryComponentDelimiter[] = {static_cast<char>(-4), 0};
 254 const char kEndOfURL[] = {static_cast<char>(-5), 0};
 255
 256 // The delimiter for query parameters
 257 const char kQuerySeparator = '&';
 258 }  // namespace
 259
 260 URLMatcherConditionFactory::URLMatcherConditionFactory() : id_counter_(0) {}
 261
 262 URLMatcherConditionFactory::~URLMatcherConditionFactory() {
 263   STLDeleteElements(&substring_pattern_singletons_);
 264   STLDeleteElements(&regex_pattern_singletons_);
 265   STLDeleteElements(&origin_and_path_regex_pattern_singletons_);
 266 }
 267
 268 std::string URLMatcherConditionFactory::CanonicalizeURLForComponentSearches(
 269     const GURL& url) const {
 270   return kBeginningOfURL + CanonicalizeHostname(url.host()) + kEndOfDomain +
 271          url.path() + kEndOfPath +
 272          (url.has_query() ? CanonicalizeQuery(url.query(), true, true)
 273                           : std::string()) +
 274          kEndOfURL;
 275 }
 276
 277 URLMatcherCondition URLMatcherConditionFactory::CreateHostPrefixCondition(
 278     const std::string& prefix) {
 279   return CreateCondition(URLMatcherCondition::HOST_PREFIX,
 280       kBeginningOfURL + CanonicalizeHostname(prefix));
 281 }
 282
 283 URLMatcherCondition URLMatcherConditionFactory::CreateHostSuffixCondition(
 284     const std::string& suffix) {
 285   return CreateCondition(URLMatcherCondition::HOST_SUFFIX,
 286       suffix + kEndOfDomain);
 287 }
 288
 289 URLMatcherCondition URLMatcherConditionFactory::CreateHostContainsCondition(
 290     const std::string& str) {
 291   return CreateCondition(URLMatcherCondition::HOST_CONTAINS, str);
 292 }
 293
 294 URLMatcherCondition URLMatcherConditionFactory::CreateHostEqualsCondition(
 295     const std::string& str) {
 296   return CreateCondition(URLMatcherCondition::HOST_EQUALS,
 297       kBeginningOfURL + CanonicalizeHostname(str) + kEndOfDomain);
 298 }
 299
 300 URLMatcherCondition URLMatcherConditionFactory::CreatePathPrefixCondition(
 301     const std::string& prefix) {
 302   return CreateCondition(URLMatcherCondition::PATH_PREFIX,
 303       kEndOfDomain + prefix);
 304 }
 305
 306 URLMatcherCondition URLMatcherConditionFactory::CreatePathSuffixCondition(
 307     const std::string& suffix) {
 308   return CreateCondition(URLMatcherCondition::PATH_SUFFIX, suffix + kEndOfPath);
 309 }
 310
 311 URLMatcherCondition URLMatcherConditionFactory::CreatePathContainsCondition(
 312     const std::string& str) {
 313   return CreateCondition(URLMatcherCondition::PATH_CONTAINS, str);
 314 }
 315
 316 URLMatcherCondition URLMatcherConditionFactory::CreatePathEqualsCondition(
 317     const std::string& str) {
 318   return CreateCondition(URLMatcherCondition::PATH_EQUALS,
 319       kEndOfDomain + str + kEndOfPath);
 320 }
 321
 322 URLMatcherCondition URLMatcherConditionFactory::CreateQueryPrefixCondition(
 323     const std::string& prefix) {
 324   std::string pattern;
 325   if (!prefix.empty() && prefix[0] == '?')
 326     pattern = kEndOfPath + CanonicalizeQuery(prefix.substr(1), true, false);
 327   else
 328     pattern = kEndOfPath + CanonicalizeQuery(prefix, true, false);
 329
 330   return CreateCondition(URLMatcherCondition::QUERY_PREFIX, pattern);
 331 }
 332
 333 URLMatcherCondition URLMatcherConditionFactory::CreateQuerySuffixCondition(
 334     const std::string& suffix) {
 335   if (!suffix.empty() && suffix[0] == '?') {
 336     return CreateQueryEqualsCondition(suffix);
 337   } else {
 338     return CreateCondition(URLMatcherCondition::QUERY_SUFFIX,
 339                            CanonicalizeQuery(suffix, false, true) + kEndOfURL);
 340   }
 341 }
 342
 343 URLMatcherCondition URLMatcherConditionFactory::CreateQueryContainsCondition(
 344     const std::string& str) {
 345   if (!str.empty() && str[0] == '?')
 346     return CreateQueryPrefixCondition(str);
 347   else
 348     return CreateCondition(URLMatcherCondition::QUERY_CONTAINS, str);
 349 }
 350
 351 URLMatcherCondition URLMatcherConditionFactory::CreateQueryEqualsCondition(
 352     const std::string& str) {
 353   std::string pattern;
 354   if (!str.empty() && str[0] == '?')
 355     pattern =
 356         kEndOfPath + CanonicalizeQuery(str.substr(1), true, true) + kEndOfURL;
 357   else
 358     pattern = kEndOfPath + CanonicalizeQuery(str, true, true) + kEndOfURL;
 359
 360   return CreateCondition(URLMatcherCondition::QUERY_EQUALS, pattern);
 361 }
 362
 363 URLMatcherCondition
 364     URLMatcherConditionFactory::CreateHostSuffixPathPrefixCondition(
 365     const std::string& host_suffix,
 366     const std::string& path_prefix) {
 367   return CreateCondition(URLMatcherCondition::HOST_SUFFIX_PATH_PREFIX,
 368       host_suffix + kEndOfDomain + path_prefix);
 369 }
 370
 371 URLMatcherCondition
 372 URLMatcherConditionFactory::CreateHostEqualsPathPrefixCondition(
 373     const std::string& host,
 374     const std::string& path_prefix) {
 375   return CreateCondition(URLMatcherCondition::HOST_EQUALS_PATH_PREFIX,
 376       kBeginningOfURL + CanonicalizeHostname(host) + kEndOfDomain +
 377       path_prefix);
 378 }
 379
 380 std::string URLMatcherConditionFactory::CanonicalizeURLForFullSearches(
 381     const GURL& url) const {
 382   GURL::Replacements replacements;
 383   replacements.ClearPassword();
 384   replacements.ClearUsername();
 385   replacements.ClearRef();
 386   // Clear port if it is implicit from scheme.
 387   if (url.has_port()) {
 388     const std::string& port = url.scheme();
 389     if (url::DefaultPortForScheme(port.c_str(), port.size()) ==
 390         url.EffectiveIntPort()) {
 391       replacements.ClearPort();
 392     }
 393   }
 394   return kBeginningOfURL + url.ReplaceComponents(replacements).spec() +
 395       kEndOfURL;
 396 }
 397
 398 static std::string CanonicalizeURLForRegexSearchesHelper(
 399     const GURL& url,
 400     bool clear_query) {
 401   GURL::Replacements replacements;
 402   replacements.ClearPassword();
 403   replacements.ClearUsername();
 404   replacements.ClearRef();
 405   if (clear_query)
 406     replacements.ClearQuery();
 407   // Clear port if it is implicit from scheme.
 408   if (url.has_port()) {
 409     const std::string& port = url.scheme();
 410     if (url::DefaultPortForScheme(port.c_str(), port.size()) ==
 411         url.EffectiveIntPort()) {
 412       replacements.ClearPort();
 413     }
 414   }
 415   return url.ReplaceComponents(replacements).spec();
 416 }
 417
 418 std::string URLMatcherConditionFactory::CanonicalizeURLForRegexSearches(
 419     const GURL& url) const {
 420   return CanonicalizeURLForRegexSearchesHelper(url, false);
 421 }
 422
 423 std::string
 424 URLMatcherConditionFactory::CanonicalizeURLForOriginAndPathRegexSearches(
 425     const GURL& url) const {
 426   return CanonicalizeURLForRegexSearchesHelper(url, true);
 427 }
 428
 429 URLMatcherCondition URLMatcherConditionFactory::CreateURLPrefixCondition(
 430     const std::string& prefix) {
 431   return CreateCondition(URLMatcherCondition::URL_PREFIX,
 432       kBeginningOfURL + prefix);
 433 }
 434
 435 URLMatcherCondition URLMatcherConditionFactory::CreateURLSuffixCondition(
 436     const std::string& suffix) {
 437   return CreateCondition(URLMatcherCondition::URL_SUFFIX, suffix + kEndOfURL);
 438 }
 439
 440 URLMatcherCondition URLMatcherConditionFactory::CreateURLContainsCondition(
 441     const std::string& str) {
 442   return CreateCondition(URLMatcherCondition::URL_CONTAINS, str);
 443 }
 444
 445 URLMatcherCondition URLMatcherConditionFactory::CreateURLEqualsCondition(
 446     const std::string& str) {
 447   return CreateCondition(URLMatcherCondition::URL_EQUALS,
 448       kBeginningOfURL + str + kEndOfURL);
 449 }
 450
 451 URLMatcherCondition URLMatcherConditionFactory::CreateURLMatchesCondition(
 452     const std::string& regex) {
 453   return CreateCondition(URLMatcherCondition::URL_MATCHES, regex);
 454 }
 455
 456 URLMatcherCondition
 457 URLMatcherConditionFactory::CreateOriginAndPathMatchesCondition(
 458     const std::string& regex) {
 459   return CreateCondition(URLMatcherCondition::ORIGIN_AND_PATH_MATCHES, regex);
 460 }
 461
 462 void URLMatcherConditionFactory::ForgetUnusedPatterns(
 463       const std::set<StringPattern::ID>& used_patterns) {
 464   PatternSingletons::iterator i = substring_pattern_singletons_.begin();
 465   while (i != substring_pattern_singletons_.end()) {
 466     if (ContainsKey(used_patterns, (*i)->id())) {
 467       ++i;
 468     } else {
 469       delete *i;
 470       substring_pattern_singletons_.erase(i++);
 471     }
 472   }
 473   i = regex_pattern_singletons_.begin();
 474   while (i != regex_pattern_singletons_.end()) {
 475     if (ContainsKey(used_patterns, (*i)->id())) {
 476       ++i;
 477     } else {
 478       delete *i;
 479       regex_pattern_singletons_.erase(i++);
 480     }
 481   }
 482   i = origin_and_path_regex_pattern_singletons_.begin();
 483   while (i != origin_and_path_regex_pattern_singletons_.end()) {
 484     if (ContainsKey(used_patterns, (*i)->id())) {
 485       ++i;
 486     } else {
 487       delete *i;
 488       origin_and_path_regex_pattern_singletons_.erase(i++);
 489     }
 490   }
 491 }
 492
 493 bool URLMatcherConditionFactory::IsEmpty() const {
 494   return substring_pattern_singletons_.empty() &&
 495       regex_pattern_singletons_.empty() &&
 496       origin_and_path_regex_pattern_singletons_.empty();
 497 }
 498
 499 URLMatcherCondition URLMatcherConditionFactory::CreateCondition(
 500     URLMatcherCondition::Criterion criterion,
 501     const std::string& pattern) {
 502   StringPattern search_pattern(pattern, 0);
 503   PatternSingletons* pattern_singletons = NULL;
 504   if (IsRegexCriterion(criterion))
 505     pattern_singletons = &regex_pattern_singletons_;
 506   else if (IsOriginAndPathRegexCriterion(criterion))
 507     pattern_singletons = &origin_and_path_regex_pattern_singletons_;
 508   else
 509     pattern_singletons = &substring_pattern_singletons_;
 510
 511   PatternSingletons::const_iterator iter =
 512       pattern_singletons->find(&search_pattern);
 513
 514   if (iter != pattern_singletons->end()) {
 515     return URLMatcherCondition(criterion, *iter);
 516   } else {
 517     StringPattern* new_pattern =
 518         new StringPattern(pattern, id_counter_++);
 519     pattern_singletons->insert(new_pattern);
 520     return URLMatcherCondition(criterion, new_pattern);
 521   }
 522 }
 523
 524 std::string URLMatcherConditionFactory::CanonicalizeHostname(
 525     const std::string& hostname) const {
 526   if (!hostname.empty() && hostname[0] == '.')
 527     return hostname;
 528   else
 529     return "." + hostname;
 530 }
 531
 532 // This function prepares the query string by replacing query separator with a
 533 // magic value (|kQueryComponentDelimiter|). When the boolean
 534 // |prepend_beginning_of_query_component| is true the function prepends the
 535 // query with the same magic. This is done to locate the start of a key value
 536 // pair in the query string. The parameter |query| is passed by value
 537 // intentionally, since it is locally modified.
 538 std::string URLMatcherConditionFactory::CanonicalizeQuery(
 539     std::string query,
 540     bool prepend_beginning_of_query_component,
 541     bool append_end_of_query_component) const {
 542   for (std::string::iterator it = query.begin(); it != query.end(); ++it) {
 543     if (*it == kQuerySeparator)
 544       *it = kQueryComponentDelimiter[0];
 545   }
 546   if (prepend_beginning_of_query_component)
 547     query = kQueryComponentDelimiter + query;
 548   if (append_end_of_query_component)
 549     query += kQueryComponentDelimiter;
 550   return query;
 551 }
 552
 553 bool URLMatcherConditionFactory::StringPatternPointerCompare::operator()(
 554     StringPattern* lhs,
 555     StringPattern* rhs) const {
 556   if (lhs == NULL && rhs != NULL) return true;
 557   if (lhs != NULL && rhs != NULL)
 558     return lhs->pattern() < rhs->pattern();
 559   // Either both are NULL or only rhs is NULL.
 560   return false;
 561 }
 562
 563 //
 564 // URLQueryElementMatcherCondition
 565 //
 566
 567 URLQueryElementMatcherCondition::URLQueryElementMatcherCondition(
 568     const std::string& key,
 569     const std::string& value,
 570     QueryValueMatchType query_value_match_type,
 571     QueryElementType query_element_type,
 572     Type match_type,
 573     URLMatcherConditionFactory* factory) {
 574   match_type_ = match_type;
 575
 576   if (query_element_type == ELEMENT_TYPE_KEY_VALUE) {
 577     key_ = kQueryComponentDelimiter + key + "=";
 578     value_ = value;
 579   } else {
 580     key_ = kQueryComponentDelimiter + key;
 581     value_ = std::string();
 582   }
 583
 584   if (query_value_match_type == QUERY_VALUE_MATCH_EXACT)
 585     value_ += kQueryComponentDelimiter;
 586
 587   // If |value_| is empty no need to find the |key_| and verify if the value
 588   // matches. Simply checking the presence of key is sufficient, which is done
 589   // by MATCH_ANY
 590   if (value_.empty())
 591     match_type_ = MATCH_ANY;
 592
 593   URLMatcherCondition condition;
 594   // If |match_type_| is MATCH_ANY, then we could simply look for the
 595   // combination of |key_| + |value_|, which can be efficiently done by
 596   // SubstringMatcher
 597   if (match_type_ == MATCH_ANY)
 598     condition = factory->CreateQueryContainsCondition(key_ + value_);
 599   else
 600     condition = factory->CreateQueryContainsCondition(key_);
 601   string_pattern_ = condition.string_pattern();
 602
 603   key_length_ = key_.length();
 604   value_length_ = value_.length();
 605 }
 606
 607 URLQueryElementMatcherCondition::~URLQueryElementMatcherCondition() {}
 608
 609 bool URLQueryElementMatcherCondition::operator<(
 610     const URLQueryElementMatcherCondition& rhs) const {
 611   if (match_type_ != rhs.match_type_)
 612     return match_type_ < rhs.match_type_;
 613   if (string_pattern_ != NULL && rhs.string_pattern_ != NULL)
 614     return *string_pattern_ < *rhs.string_pattern_;
 615   if (string_pattern_ == NULL && rhs.string_pattern_ != NULL)
 616     return true;
 617   // Either string_pattern_ != NULL && rhs.string_pattern_ == NULL,
 618   // or both are NULL.
 619   return false;
 620 }
 621
 622 bool URLQueryElementMatcherCondition::IsMatch(
 623     const std::string& url_for_component_searches) const {
 624   switch (match_type_) {
 625     case MATCH_ANY: {
 626       // For MATCH_ANY, no additional verification step is needed. We can trust
 627       // the SubstringMatcher to do the verification.
 628       return true;
 629     }
 630     case MATCH_ALL: {
 631       size_t start = 0;
 632       int found = 0;
 633       size_t offset;
 634       while ((offset = url_for_component_searches.find(key_, start)) !=
 635              std::string::npos) {
 636         if (url_for_component_searches.compare(
 637                 offset + key_length_, value_length_, value_) != 0) {
 638           return false;
 639         } else {
 640           ++found;
 641         }
 642         start = offset + key_length_ + value_length_ - 1;
 643       }
 644       return !!found;
 645     }
 646     case MATCH_FIRST: {
 647       size_t offset = url_for_component_searches.find(key_);
 648       return url_for_component_searches.compare(
 649                  offset + key_length_, value_length_, value_) == 0;
 650     }
 651     case MATCH_LAST: {
 652       size_t offset = url_for_component_searches.rfind(key_);
 653       return url_for_component_searches.compare(
 654                  offset + key_length_, value_length_, value_) == 0;
 655     }
 656   }
 657   NOTREACHED();
 658   return false;
 659 }
 660
 661 //
 662 // URLMatcherSchemeFilter
 663 //
 664
 665 URLMatcherSchemeFilter::URLMatcherSchemeFilter(const std::string& filter)
 666     : filters_(1) {
 667   filters_.push_back(filter);
 668 }
 669
 670 URLMatcherSchemeFilter::URLMatcherSchemeFilter(
 671     const std::vector<std::string>& filters)
 672     : filters_(filters) {}
 673
 674 URLMatcherSchemeFilter::~URLMatcherSchemeFilter() {}
 675
 676 bool URLMatcherSchemeFilter::IsMatch(const GURL& url) const {
 677   return std::find(filters_.begin(), filters_.end(), url.scheme()) !=
 678       filters_.end();
 679 }
 680
 681 //
 682 // URLMatcherPortFilter
 683 //
 684
 685 URLMatcherPortFilter::URLMatcherPortFilter(
 686     const std::vector<URLMatcherPortFilter::Range>& ranges)
 687     : ranges_(ranges) {}
 688
 689 URLMatcherPortFilter::~URLMatcherPortFilter() {}
 690
 691 bool URLMatcherPortFilter::IsMatch(const GURL& url) const {
 692   int port = url.EffectiveIntPort();
 693   for (std::vector<Range>::const_iterator i = ranges_.begin();
 694        i != ranges_.end(); ++i) {
 695     if (i->first <= port && port <= i->second)
 696       return true;
 697   }
 698   return false;
 699 }
 700
 701 // static
 702 URLMatcherPortFilter::Range URLMatcherPortFilter::CreateRange(int from,
 703                                                               int to) {
 704   return Range(from, to);
 705 }
 706
 707 // static
 708 URLMatcherPortFilter::Range URLMatcherPortFilter::CreateRange(int port) {
 709   return Range(port, port);
 710 }
 711
 712 //
 713 // URLMatcherConditionSet
 714 //
 715
 716 URLMatcherConditionSet::~URLMatcherConditionSet() {}
 717
 718 URLMatcherConditionSet::URLMatcherConditionSet(
 719     ID id,
 720     const Conditions& conditions)
 721     : id_(id),
 722       conditions_(conditions) {}
 723
 724 URLMatcherConditionSet::URLMatcherConditionSet(
 725     ID id,
 726     const Conditions& conditions,
 727     scoped_ptr<URLMatcherSchemeFilter> scheme_filter,
 728     scoped_ptr<URLMatcherPortFilter> port_filter)
 729     : id_(id),
 730       conditions_(conditions),
 731       scheme_filter_(scheme_filter.Pass()),
 732       port_filter_(port_filter.Pass()) {}
 733
 734 URLMatcherConditionSet::URLMatcherConditionSet(
 735     ID id,
 736     const Conditions& conditions,
 737     const QueryConditions& query_conditions,
 738     scoped_ptr<URLMatcherSchemeFilter> scheme_filter,
 739     scoped_ptr<URLMatcherPortFilter> port_filter)
 740     : id_(id),
 741       conditions_(conditions),
 742       query_conditions_(query_conditions),
 743       scheme_filter_(scheme_filter.Pass()),
 744       port_filter_(port_filter.Pass()) {}
 745
 746 bool URLMatcherConditionSet::IsMatch(
 747     const std::set<StringPattern::ID>& matching_patterns,
 748     const GURL& url) const {
 749   return IsMatch(matching_patterns, url, std::string());
 750 }
 751
 752 bool URLMatcherConditionSet::IsMatch(
 753     const std::set<StringPattern::ID>& matching_patterns,
 754     const GURL& url,
 755     const std::string& url_for_component_searches) const {
 756   for (Conditions::const_iterator i = conditions_.begin();
 757        i != conditions_.end(); ++i) {
 758     if (!i->IsMatch(matching_patterns, url))
 759       return false;
 760   }
 761   if (scheme_filter_.get() && !scheme_filter_->IsMatch(url))
 762     return false;
 763   if (port_filter_.get() && !port_filter_->IsMatch(url))
 764     return false;
 765   if (query_conditions_.empty())
 766     return true;
 767   // The loop is duplicated below for performance reasons. If not all query
 768   // elements are found, no need to verify match that is expected to take more
 769   // cycles.
 770   for (QueryConditions::const_iterator i = query_conditions_.begin();
 771        i != query_conditions_.end();
 772        ++i) {
 773     if (!ContainsKey(matching_patterns, i->string_pattern()->id()))
 774       return false;
 775   }
 776   for (QueryConditions::const_iterator i = query_conditions_.begin();
 777        i != query_conditions_.end();
 778        ++i) {
 779     if (!i->IsMatch(url_for_component_searches))
 780       return false;
 781   }
 782   return true;
 783 }
 784
 785 //
 786 // URLMatcher
 787 //
 788
 789 URLMatcher::URLMatcher() {}
 790
 791 URLMatcher::~URLMatcher() {}
 792
 793 void URLMatcher::AddConditionSets(
 794     const URLMatcherConditionSet::Vector& condition_sets) {
 795   for (URLMatcherConditionSet::Vector::const_iterator i =
 796        condition_sets.begin(); i != condition_sets.end(); ++i) {
 797     DCHECK(url_matcher_condition_sets_.find((*i)->id()) ==
 798         url_matcher_condition_sets_.end());
 799     url_matcher_condition_sets_[(*i)->id()] = *i;
 800   }
 801   UpdateInternalDatastructures();
 802 }
 803
 804 void URLMatcher::RemoveConditionSets(
 805     const std::vector<URLMatcherConditionSet::ID>& condition_set_ids) {
 806   for (std::vector<URLMatcherConditionSet::ID>::const_iterator i =
 807        condition_set_ids.begin(); i != condition_set_ids.end(); ++i) {
 808     DCHECK(url_matcher_condition_sets_.find(*i) !=
 809         url_matcher_condition_sets_.end());
 810     url_matcher_condition_sets_.erase(*i);
 811   }
 812   UpdateInternalDatastructures();
 813 }
 814
 815 void URLMatcher::ClearUnusedConditionSets() {
 816   UpdateConditionFactory();
 817 }
 818
 819 std::set<URLMatcherConditionSet::ID> URLMatcher::MatchURL(
 820     const GURL& url) const {
 821   // Find all IDs of StringPatterns that match |url|.
 822   // See URLMatcherConditionFactory for the canonicalization of URLs and the
 823   // distinction between full url searches and url component searches.
 824   std::set<StringPattern::ID> matches;
 825   std::string url_for_component_searches;
 826
 827   if (!full_url_matcher_.IsEmpty()) {
 828     full_url_matcher_.Match(
 829         condition_factory_.CanonicalizeURLForFullSearches(url), &matches);
 830   }
 831   if (!url_component_matcher_.IsEmpty()) {
 832     url_for_component_searches =
 833         condition_factory_.CanonicalizeURLForComponentSearches(url);
 834     url_component_matcher_.Match(url_for_component_searches, &matches);
 835   }
 836   if (!regex_set_matcher_.IsEmpty()) {
 837     regex_set_matcher_.Match(
 838         condition_factory_.CanonicalizeURLForRegexSearches(url), &matches);
 839   }
 840   if (!origin_and_path_regex_set_matcher_.IsEmpty()) {
 841     origin_and_path_regex_set_matcher_.Match(
 842         condition_factory_.CanonicalizeURLForOriginAndPathRegexSearches(url),
 843         &matches);
 844   }
 845
 846   // Calculate all URLMatcherConditionSets for which all URLMatcherConditions
 847   // were fulfilled.
 848   std::set<URLMatcherConditionSet::ID> result;
 849   for (std::set<StringPattern::ID>::const_iterator i = matches.begin();
 850        i != matches.end(); ++i) {
 851     // For each URLMatcherConditionSet there is exactly one condition
 852     // registered in substring_match_triggers_. This means that the following
 853     // logic tests each URLMatcherConditionSet exactly once if it can be
 854     // completely fulfilled.
 855     StringPatternTriggers::const_iterator triggered_condition_sets_iter =
 856         substring_match_triggers_.find(*i);
 857     if (triggered_condition_sets_iter == substring_match_triggers_.end())
 858       continue;  // Not all substring matches are triggers for a condition set.
 859     const std::set<URLMatcherConditionSet::ID>& condition_sets =
 860         triggered_condition_sets_iter->second;
 861     for (std::set<URLMatcherConditionSet::ID>::const_iterator j =
 862          condition_sets.begin(); j != condition_sets.end(); ++j) {
 863       URLMatcherConditionSets::const_iterator condition_set_iter =
 864           url_matcher_condition_sets_.find(*j);
 865       DCHECK(condition_set_iter != url_matcher_condition_sets_.end());
 866       if (condition_set_iter->second->IsMatch(
 867               matches, url, url_for_component_searches))
 868         result.insert(*j);
 869     }
 870   }
 871
 872   return result;
 873 }
 874
 875 bool URLMatcher::IsEmpty() const {
 876   return condition_factory_.IsEmpty() &&
 877       url_matcher_condition_sets_.empty() &&
 878       substring_match_triggers_.empty() &&
 879       full_url_matcher_.IsEmpty() &&
 880       url_component_matcher_.IsEmpty() &&
 881       regex_set_matcher_.IsEmpty() &&
 882       origin_and_path_regex_set_matcher_.IsEmpty() &&
 883       registered_full_url_patterns_.empty() &&
 884       registered_url_component_patterns_.empty();
 885 }
 886
 887 void URLMatcher::UpdateSubstringSetMatcher(bool full_url_conditions) {
 888   // The purpose of |full_url_conditions| is just that we need to execute
 889   // the same logic once for Full URL searches and once for URL Component
 890   // searches (see URLMatcherConditionFactory).
 891
 892   // Determine which patterns need to be registered when this function
 893   // terminates.
 894   std::set<const StringPattern*> new_patterns;
 895   for (URLMatcherConditionSets::const_iterator condition_set_iter =
 896       url_matcher_condition_sets_.begin();
 897       condition_set_iter != url_matcher_condition_sets_.end();
 898       ++condition_set_iter) {
 899     const URLMatcherConditionSet::Conditions& conditions =
 900         condition_set_iter->second->conditions();
 901     for (URLMatcherConditionSet::Conditions::const_iterator condition_iter =
 902          conditions.begin(); condition_iter != conditions.end();
 903          ++condition_iter) {
 904       // If we are called to process Full URL searches, ignore others, and
 905       // vice versa. (Regex conditions are updated in UpdateRegexSetMatcher.)
 906       if (!condition_iter->IsRegexCondition() &&
 907           !condition_iter->IsOriginAndPathRegexCondition() &&
 908           full_url_conditions == condition_iter->IsFullURLCondition())
 909         new_patterns.insert(condition_iter->string_pattern());
 910     }
 911
 912     if (full_url_conditions)
 913       continue;
 914
 915     const URLMatcherConditionSet::QueryConditions& query_conditions =
 916         condition_set_iter->second->query_conditions();
 917     for (URLMatcherConditionSet::QueryConditions::const_iterator
 918              query_condition_iter = query_conditions.begin();
 919          query_condition_iter != query_conditions.end();
 920          ++query_condition_iter) {
 921       new_patterns.insert(query_condition_iter->string_pattern());
 922     }
 923   }
 924
 925   // This is the set of patterns that were registered before this function
 926   // is called.
 927   std::set<const StringPattern*>& registered_patterns =
 928       full_url_conditions ? registered_full_url_patterns_
 929                           : registered_url_component_patterns_;
 930
 931   // Add all patterns that are in new_patterns but not in registered_patterns.
 932   std::vector<const StringPattern*> patterns_to_register =
 933       base::STLSetDifference<std::vector<const StringPattern*> >(
 934           new_patterns, registered_patterns);
 935
 936   // Remove all patterns that are in registered_patterns but not in
 937   // new_patterns.
 938   std::vector<const StringPattern*> patterns_to_unregister =
 939       base::STLSetDifference<std::vector<const StringPattern*> >(
 940            registered_patterns, new_patterns);
 941
 942   // Update the SubstringSetMatcher.
 943   SubstringSetMatcher& url_matcher =
 944       full_url_conditions ? full_url_matcher_ : url_component_matcher_;
 945   url_matcher.RegisterAndUnregisterPatterns(patterns_to_register,
 946                                             patterns_to_unregister);
 947
 948   // Update the set of registered_patterns for the next time this function
 949   // is being called.
 950   registered_patterns.swap(new_patterns);
 951 }
 952
 953 void URLMatcher::UpdateRegexSetMatcher() {
 954   std::vector<const StringPattern*> new_patterns;
 955   std::vector<const StringPattern*> new_origin_and_path_patterns;
 956
 957   for (URLMatcherConditionSets::const_iterator condition_set_iter =
 958       url_matcher_condition_sets_.begin();
 959       condition_set_iter != url_matcher_condition_sets_.end();
 960       ++condition_set_iter) {
 961     const URLMatcherConditionSet::Conditions& conditions =
 962         condition_set_iter->second->conditions();
 963     for (URLMatcherConditionSet::Conditions::const_iterator condition_iter =
 964          conditions.begin(); condition_iter != conditions.end();
 965          ++condition_iter) {
 966       if (condition_iter->IsRegexCondition()) {
 967         new_patterns.push_back(condition_iter->string_pattern());
 968       } else if (condition_iter->IsOriginAndPathRegexCondition()) {
 969         new_origin_and_path_patterns.push_back(
 970             condition_iter->string_pattern());
 971       }
 972     }
 973   }
 974
 975   // Start over from scratch. We can't really do better than this, since the
 976   // FilteredRE2 backend doesn't support incremental updates.
 977   regex_set_matcher_.ClearPatterns();
 978   regex_set_matcher_.AddPatterns(new_patterns);
 979   origin_and_path_regex_set_matcher_.ClearPatterns();
 980   origin_and_path_regex_set_matcher_.AddPatterns(new_origin_and_path_patterns);
 981 }
 982
 983 void URLMatcher::UpdateTriggers() {
 984   // Count substring pattern frequencies.
 985   std::map<StringPattern::ID, size_t> substring_pattern_frequencies;
 986   for (URLMatcherConditionSets::const_iterator condition_set_iter =
 987       url_matcher_condition_sets_.begin();
 988       condition_set_iter != url_matcher_condition_sets_.end();
 989       ++condition_set_iter) {
 990     const URLMatcherConditionSet::Conditions& conditions =
 991         condition_set_iter->second->conditions();
 992     for (URLMatcherConditionSet::Conditions::const_iterator condition_iter =
 993          conditions.begin(); condition_iter != conditions.end();
 994          ++condition_iter) {
 995       const StringPattern* pattern = condition_iter->string_pattern();
 996       substring_pattern_frequencies[pattern->id()]++;
 997     }
 998
 999     const URLMatcherConditionSet::QueryConditions& query_conditions =
1000         condition_set_iter->second->query_conditions();
1001     for (URLMatcherConditionSet::QueryConditions::const_iterator
1002              query_condition_iter = query_conditions.begin();
1003          query_condition_iter != query_conditions.end();
1004          ++query_condition_iter) {
1005       const StringPattern* pattern = query_condition_iter->string_pattern();
1006       substring_pattern_frequencies[pattern->id()]++;
1007     }
1008   }
1009
1010   // Update trigger conditions: Determine for each URLMatcherConditionSet which
1011   // URLMatcherCondition contains a StringPattern that occurs least
1012   // frequently in this URLMatcher. We assume that this condition is very
1013   // specific and occurs rarely in URLs. If a match occurs for this
1014   // URLMatcherCondition, we want to test all other URLMatcherCondition in the
1015   // respective URLMatcherConditionSet as well to see whether the entire
1016   // URLMatcherConditionSet is considered matching.
1017   substring_match_triggers_.clear();
1018   for (URLMatcherConditionSets::const_iterator condition_set_iter =
1019       url_matcher_condition_sets_.begin();
1020       condition_set_iter != url_matcher_condition_sets_.end();
1021       ++condition_set_iter) {
1022     const URLMatcherConditionSet::Conditions& conditions =
1023         condition_set_iter->second->conditions();
1024     if (conditions.empty())
1025       continue;
1026     URLMatcherConditionSet::Conditions::const_iterator condition_iter =
1027         conditions.begin();
1028     StringPattern::ID trigger = condition_iter->string_pattern()->id();
1029     // We skip the first element in the following loop.
1030     ++condition_iter;
1031     for (; condition_iter != conditions.end(); ++condition_iter) {
1032       StringPattern::ID current_id =
1033           condition_iter->string_pattern()->id();
1034       if (substring_pattern_frequencies[trigger] >
1035           substring_pattern_frequencies[current_id]) {
1036         trigger = current_id;
1037       }
1038     }
1039
1040     const URLMatcherConditionSet::QueryConditions& query_conditions =
1041         condition_set_iter->second->query_conditions();
1042     for (URLMatcherConditionSet::QueryConditions::const_iterator
1043              query_condition_iter = query_conditions.begin();
1044          query_condition_iter != query_conditions.end();
1045          ++query_condition_iter) {
1046       StringPattern::ID current_id =
1047           query_condition_iter->string_pattern()->id();
1048       if (substring_pattern_frequencies[trigger] >
1049           substring_pattern_frequencies[current_id]) {
1050         trigger = current_id;
1051       }
1052     }
1053
1054     substring_match_triggers_[trigger].insert(condition_set_iter->second->id());
1055   }
1056 }
1057
1058 void URLMatcher::UpdateConditionFactory() {
1059   std::set<StringPattern::ID> used_patterns;
1060   for (URLMatcherConditionSets::const_iterator condition_set_iter =
1061       url_matcher_condition_sets_.begin();
1062       condition_set_iter != url_matcher_condition_sets_.end();
1063       ++condition_set_iter) {
1064     const URLMatcherConditionSet::Conditions& conditions =
1065         condition_set_iter->second->conditions();
1066     for (URLMatcherConditionSet::Conditions::const_iterator condition_iter =
1067          conditions.begin(); condition_iter != conditions.end();
1068          ++condition_iter) {
1069       used_patterns.insert(condition_iter->string_pattern()->id());
1070     }
1071     const URLMatcherConditionSet::QueryConditions& query_conditions =
1072         condition_set_iter->second->query_conditions();
1073     for (URLMatcherConditionSet::QueryConditions::const_iterator
1074              query_condition_iter = query_conditions.begin();
1075          query_condition_iter != query_conditions.end();
1076          ++query_condition_iter) {
1077       used_patterns.insert(query_condition_iter->string_pattern()->id());
1078     }
1079   }
1080   condition_factory_.ForgetUnusedPatterns(used_patterns);
1081 }
1082
1083 void URLMatcher::UpdateInternalDatastructures() {
1084   UpdateSubstringSetMatcher(false);
1085   UpdateSubstringSetMatcher(true);
1086   UpdateRegexSetMatcher();
1087   UpdateTriggers();
1088   UpdateConditionFactory();
1089 }
1090
1091 }  // namespace url_matcher