// ***************************************************************************** // * This file is part of the FreeFileSync project. It is distributed under * // * GNU General Public License: https://www.gnu.org/licenses/gpl-3.0 * // * Copyright (C) Zenju (zenju AT freefilesync DOT org) - All Rights Reserved * // ***************************************************************************** #include "zstring.h" #include #include "sys_error.h" using namespace zen; Zstring getUnicodeNormalFormNonAscii(const Zstring& str) { //Example: const char* decomposed = "\x6f\xcc\x81"; // const char* precomposed = "\xc3\xb3"; assert(!isAsciiString(str)); //includes "not-empty" check assert(str.find(Zchar('\0')) == Zstring::npos); //don't expect embedded nulls! try { gchar* outStr = ::g_utf8_normalize(str.c_str(), str.length(), G_NORMALIZE_DEFAULT_COMPOSE); if (!outStr) throw SysError(formatSystemError("g_utf8_normalize", L"", L"Conversion failed.")); ZEN_ON_SCOPE_EXIT(::g_free(outStr)); return outStr; } catch (const SysError& e) { throw std::runtime_error(std::string(__FILE__) + '[' + numberTo(__LINE__) + "] Error normalizing string:" + '\n' + utfTo(str) + "\n\n" + utfTo(e.toString())); } } Zstring getUnicodeNormalForm(const Zstring& str) { //fast pre-check: if (isAsciiString(str)) //perf: in the range of 3.5ns return str; static_assert(std::is_same_v&>, "god bless our ref-counting! => save output string memory consumption!"); return getUnicodeNormalFormNonAscii(str); } Zstring getUpperCaseNonAscii(const Zstring& str) { Zstring strNorm = getUnicodeNormalFormNonAscii(str); try { Zstring output; output.reserve(strNorm.size()); UtfDecoder decoder(strNorm.c_str(), strNorm.size()); while (const std::optional cp = decoder.getNext()) codePointToUtf(::g_unichar_toupper(*cp), [&](char c) { output += c; }); //don't use std::towupper: *incomplete* and locale-dependent! static_assert(sizeof(impl::CodePoint) == sizeof(gunichar)); return output; } catch (const SysError& e) { throw std::runtime_error(std::string(__FILE__) + '[' + numberTo(__LINE__) + "] Error converting string to upper case:" + '\n' + utfTo(str) + "\n\n" + utfTo(e.toString())); } } Zstring getUpperCase(const Zstring& str) { if (isAsciiString(str)) //fast path: in the range of 3.5ns { Zstring output = str; for (Zchar& c : output) //identical to LCMapStringEx(), g_unichar_toupper(), CFStringUppercase() [verified!] c = asciiToUpper(c); // return output; } //else: slow path -------------------------------------- return getUpperCaseNonAscii(str); } namespace { std::weak_ordering compareNoCaseUtf8(const char* lhs, size_t lhsLen, const char* rhs, size_t rhsLen) { //expect Unicode normalized strings! assert(std::string(lhs, lhsLen) == getUnicodeNormalForm(std::string(lhs, lhsLen))); assert(std::string(rhs, rhsLen) == getUnicodeNormalForm(std::string(rhs, rhsLen))); //- strncasecmp implements ASCII CI-comparsion only! => signature is broken for UTF8-input; toupper() similarly doesn't support Unicode //- wcsncasecmp: https://opensource.apple.com/source/Libc/Libc-763.12/string/wcsncasecmp-fbsd.c // => re-implement comparison based on g_unichar_tolower() to avoid memory allocations UtfDecoder decL(lhs, lhsLen); UtfDecoder decR(rhs, rhsLen); for (;;) { const std::optional cpL = decL.getNext(); const std::optional cpR = decR.getNext(); if (!cpL || !cpR) return !cpR <=> !cpL; static_assert(sizeof(gunichar) == sizeof(impl::CodePoint)); static_assert(std::is_unsigned_v, "unsigned char-comparison is the convention!"); //ordering: "to lower" converts to higher code points than "to upper" const gunichar charL = ::g_unichar_toupper(*cpL); //note: tolower can be ambiguous, so don't use: const gunichar charR = ::g_unichar_toupper(*cpR); //e.g. "Σ" (upper case) can be lower-case "ς" in the end of the word or "σ" in the middle. if (charL != charR) return charL <=> charR; } } } std::weak_ordering compareNatural(const Zstring& lhs, const Zstring& rhs) { /* Unicode normal forms: Windows: CompareString() already ignores NFD/NFC differences: nice... Linux: g_unichar_toupper() can't ignore differences macOS: CFStringCompare() considers differences */ try { const Zstring& lhsNorm = getUnicodeNormalForm(lhs); const Zstring& rhsNorm = getUnicodeNormalForm(rhs); const char* strL = lhsNorm.c_str(); const char* strR = rhsNorm.c_str(); const char* const strEndL = strL + lhsNorm.size(); const char* const strEndR = strR + rhsNorm.size(); /* - compare strings after conceptually creating blocks of whitespace/numbers/text - implement strict weak ordering! - don't follow broken "strnatcasecmp": https://github.com/php/php-src/blob/master/ext/standard/strnatcmp.c 1. incorrect non-ASCII CI-comparison 2. incorrect bounds checks 3. incorrect trimming of *all* whitespace 4. arbitrary handling of leading 0 only at string begin 5. incorrect handling of whitespace following a number 6. code is a mess */ for (;;) { if (strL == strEndL || strR == strEndR) return (strL != strEndL) <=> (strR != strEndR); //"nothing" before "something" //note: "something" never would have been condensed to "nothing" further below => can finish evaluation here const bool wsL = isWhiteSpace(*strL); const bool wsR = isWhiteSpace(*strR); if (wsL != wsR) return !wsL <=> !wsR; //whitespace before non-ws! if (wsL) { ++strL, ++strR; while (strL != strEndL && isWhiteSpace(*strL)) ++strL; while (strR != strEndR && isWhiteSpace(*strR)) ++strR; continue; } const bool digitL = isDigit(*strL); const bool digitR = isDigit(*strR); if (digitL != digitR) return !digitL <=> !digitR; //numbers before chars! if (digitL) { while (strL != strEndL && *strL == '0') ++strL; while (strR != strEndR && *strR == '0') ++strR; int rv = 0; for (;; ++strL, ++strR) { const bool endL = strL == strEndL || !isDigit(*strL); const bool endR = strR == strEndR || !isDigit(*strR); if (endL != endR) return !endL <=> !endR; //more digits means bigger number if (endL) break; //same number of digits if (rv == 0 && *strL != *strR) rv = *strL - *strR; //found first digit difference comparing from left } if (rv != 0) return rv <=> 0; continue; } //compare full junks of text: consider unicode encoding! const char* textBeginL = strL++; const char* textBeginR = strR++; //current char is neither white space nor digit at this point! while (strL != strEndL && !isWhiteSpace(*strL) && !isDigit(*strL)) ++strL; while (strR != strEndR && !isWhiteSpace(*strR) && !isDigit(*strR)) ++strR; if (const std::weak_ordering cmp = compareNoCaseUtf8(textBeginL, strL - textBeginL, textBeginR, strR - textBeginR); cmp != std::weak_ordering::equivalent) return cmp; } } catch (const SysError& e) { throw std::runtime_error(std::string(__FILE__) + '[' + numberTo(__LINE__) + "] Error comparing strings:" + '\n' + utfTo(lhs) + '\n' + utfTo(rhs) + "\n\n" + utfTo(e.toString())); } } std::weak_ordering compareNoCase(const Zstring& lhs, const Zstring& rhs) { //fast path: no memory allocations => ~ 6x speedup if (isAsciiString(lhs) && isAsciiString(rhs)) { const size_t minSize = std::min(lhs.size(), rhs.size()); for (size_t i = 0; i < minSize; ++i) { //ordering: do NOT call compareAsciiNoCase(), which uses asciiToLower()! const Zchar lUp = asciiToUpper(lhs[i]); // const Zchar rUp = asciiToUpper(rhs[i]); //no surprises: emulate getUpperCase() [verified!] if (lUp != rUp) // return lUp <=> rUp; // } return lhs.size() <=> rhs.size(); } //-------------------------------------- //can't we instead skip isAsciiString() and compare chars as long as isAsciiChar()? // => NOPE! e.g. decomposed Unicode! A seemingly single isAsciiChar() might be followed by a combining character!!! return getUpperCase(lhs) <=> getUpperCase(rhs); } bool equalNoCase(const Zstring& lhs, const Zstring& rhs) { //fast-path: no need for extra memory allocations const bool isAsciiL = isAsciiString(lhs); const bool isAsciiR = isAsciiString(rhs); if (isAsciiL != isAsciiR) return false; if (isAsciiL) { if (lhs.size() != rhs.size()) return false; for (size_t i = 0; i < lhs.size(); ++i) if (asciiToUpper(lhs[i]) != asciiToUpper(rhs[i])) return false; return true; } return getUpperCaseNonAscii(lhs) == getUpperCaseNonAscii(rhs); }