// Copyright (c) 2011 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 "base/i18n/case_conversion.h" #include #include #include "base/numerics/safe_conversions.h" #include "base/strings/string_util.h" #include "third_party/icu/source/common/unicode/uchar.h" #include "third_party/icu/source/common/unicode/unistr.h" #include "third_party/icu/source/common/unicode/ustring.h" namespace base { namespace i18n { namespace { // Provides a uniform interface for upper/lower/folding which take take // slightly varying parameters. typedef int32_t (*CaseMapperFunction)(UChar* dest, int32_t dest_capacity, const UChar* src, int32_t src_length, UErrorCode* error); int32_t ToUpperMapper(UChar* dest, int32_t dest_capacity, const UChar* src, int32_t src_length, UErrorCode* error) { // Use default locale. return u_strToUpper(dest, dest_capacity, src, src_length, nullptr, error); } int32_t ToLowerMapper(UChar* dest, int32_t dest_capacity, const UChar* src, int32_t src_length, UErrorCode* error) { // Use default locale. return u_strToLower(dest, dest_capacity, src, src_length, nullptr, error); } int32_t FoldCaseMapper(UChar* dest, int32_t dest_capacity, const UChar* src, int32_t src_length, UErrorCode* error) { return u_strFoldCase(dest, dest_capacity, src, src_length, U_FOLD_CASE_DEFAULT, error); } // Provides similar functionality as UnicodeString::caseMap but on // std::u16string. std::u16string CaseMap(StringPiece16 string, CaseMapperFunction case_mapper) { std::u16string dest; if (string.empty()) return dest; // Provide an initial guess that the string length won't change. The typical // strings we use will very rarely change length in this process, so don't // optimize for that case. dest.resize(string.size()); UErrorCode error; do { error = U_ZERO_ERROR; // ICU won't terminate the string if there's not enough room for the null // terminator, but will otherwise. So we don't need to save room for that. // Don't use WriteInto, which assumes null terminators. int32_t new_length = case_mapper( &dest[0], saturated_cast(dest.size()), string.data(), saturated_cast(string.size()), &error); dest.resize(new_length); } while (error == U_BUFFER_OVERFLOW_ERROR); return dest; } } // namespace std::u16string ToLower(StringPiece16 string) { return CaseMap(string, &ToLowerMapper); } std::u16string ToUpper(StringPiece16 string) { return CaseMap(string, &ToUpperMapper); } std::u16string FoldCase(StringPiece16 string) { return CaseMap(string, &FoldCaseMapper); } } // namespace i18n } // namespace base