| // Copyright 2016 The Chromium Authors. All rights reserved. |
| // Use of this source code is governed by a BSD-style license that can be |
| // found in the LICENSE file. |
| |
| #include "components/autofill/core/browser/address_rewriter.h" |
| |
| #include <memory> |
| #include <unordered_map> |
| |
| #include "base/i18n/case_conversion.h" |
| #include "base/memory/singleton.h" |
| #include "base/strings/utf_string_conversions.h" |
| #include "third_party/re2/src/re2/re2.h" |
| |
| namespace autofill { |
| namespace { |
| |
| // Import in the internal rule table symbols. The data is defined in |
| // components/autofill/core/browser/address_rewriter_rules.cc |
| using internal::Rule; |
| using internal::RegionInfo; |
| using internal::kRuleTable; |
| using internal::kRuleTableSize; |
| |
| // Aliases for the types used by the compiled rules cache. |
| using CompiledRule = std::pair<std::unique_ptr<re2::RE2>, re2::StringPiece>; |
| using CompiledRuleVector = std::vector<CompiledRule>; |
| using CompiledRuleCache = std::unordered_map<std::string, CompiledRuleVector>; |
| |
| // Helper function to find the rules associated with |region|. Note that this |
| // requires that kRuleTable be sorted by region. |
| static const RegionInfo* GetRegionInfo(const base::StringPiece& region) { |
| const RegionInfo* begin = kRuleTable; |
| const RegionInfo* end = kRuleTable + kRuleTableSize; |
| const RegionInfo* iter = std::lower_bound(begin, end, region); |
| if (iter != end && region == iter->region) |
| return iter; |
| return nullptr; |
| } |
| |
| // The cache of compiled string replacement rules, keyed by region. This class |
| // is a singleton that compiles the rules for a given region the first time |
| // they are requested. |
| class Cache { |
| public: |
| // Return the singleton instance of the cache. |
| static Cache* GetInstance() { return base::Singleton<Cache>::get(); } |
| |
| // If the rules for |region| have already been compiled and cached, return a |
| // pointer to them. Otherwise, find the rules for |region| (returning nullptr |
| // if there are no such rules exist), compile them, cache them, and return a |
| // pointer to the cached rules. |
| const CompiledRuleVector* GetRulesForRegion(const std::string& region) { |
| // Take the lock so that we don't update the data cache concurrently. Note |
| // that the returned data is const and can be concurrently accessed, just |
| // not the data cache. |
| base::AutoLock auto_lock(lock_); |
| |
| // If we find a cached set of rules, return a pointer to the data. |
| auto cache_iter = data_.find(region); |
| if (cache_iter != data_.end()) |
| return &cache_iter->second; |
| |
| // Cache miss. Look for the raw rules. If none, then return nullptr. |
| const RegionInfo* region_info = GetRegionInfo(region); |
| if (region_info == nullptr) |
| return nullptr; |
| |
| // Add a new rule vector the the cache and populate it with compiled rules. |
| re2::RE2::Options options; |
| options.set_utf8(true); |
| options.set_word_boundary(true); |
| CompiledRuleVector& compiled_rules = data_[region]; |
| compiled_rules.reserve(region_info->num_rules); |
| for (size_t i = 0; i < region_info->num_rules; ++i) { |
| const Rule& rule = region_info->rules[i]; |
| std::unique_ptr<re2::RE2> pattern(new re2::RE2(rule.pattern, options)); |
| re2::StringPiece rewrite(rule.rewrite); |
| compiled_rules.emplace_back(std::move(pattern), std::move(rewrite)); |
| } |
| |
| // Return a pointer to the data. |
| return &compiled_rules; |
| } |
| |
| private: |
| Cache() {} |
| |
| // Synchronizes access to |data_|, ensuring that a given set of rules is |
| // only compiled once. |
| base::Lock lock_; |
| |
| // The cache of compiled rules, keyed by region. |
| CompiledRuleCache data_; |
| |
| friend struct base::DefaultSingletonTraits<Cache>; |
| DISALLOW_COPY_AND_ASSIGN(Cache); |
| }; |
| |
| } // namespace |
| |
| AddressRewriter AddressRewriter::ForCountryCode( |
| const base::string16& country_code) { |
| const std::string region = |
| base::UTF16ToUTF8(base::i18n::ToUpper(country_code)); |
| const CompiledRuleVector* rules = |
| Cache::GetInstance()->GetRulesForRegion(region); |
| AddressRewriter rewriter; |
| rewriter.impl_ = rules; |
| return rewriter; |
| } |
| |
| base::string16 AddressRewriter::Rewrite(const base::string16& text) const { |
| if (impl_ == nullptr) |
| return base::CollapseWhitespace(text, true); |
| |
| // Apply all of the string replacement rules. We don't have to worry about |
| // whitespace during these passes because the patterns are all whitespace |
| // tolerant regular expressions. |
| std::string utf8_text = base::UTF16ToUTF8(text); |
| for (const auto& rule : *static_cast<const CompiledRuleVector*>(impl_)) { |
| RE2::GlobalReplace(&utf8_text, *rule.first, rule.second); |
| } |
| |
| // Collapse whitespace before returning the final value. |
| return base::UTF8ToUTF16(base::CollapseWhitespaceASCII(utf8_text, true)); |
| } |
| |
| } // namespace autofill |