mpd/src/lib/icu/Collate.cxx
2021-10-13 12:07:05 +02:00

128 lines
2.7 KiB
C++

/*
* Copyright 2003-2021 The Music Player Daemon Project
* http://www.musicpd.org
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License along
* with this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#include "Collate.hxx"
#include "util/AllocatedString.hxx"
#include "config.h"
#ifdef HAVE_ICU
#include "Util.hxx"
#include "util/RuntimeError.hxx"
#include <unicode/ucol.h>
#include <unicode/ustring.h>
#else
#include <algorithm>
#ifndef _WIN32
#include <string>
#endif
#endif
#ifdef _WIN32
#include "Win32.hxx"
#include "util/AllocatedString.hxx"
#include <windows.h>
#endif
#include <cassert>
#include <memory>
#include <stdexcept>
#include <string.h>
#ifdef HAVE_ICU
static UCollator *collator;
#endif
#ifdef HAVE_ICU
void
IcuCollateInit()
{
assert(collator == nullptr);
UErrorCode code = U_ZERO_ERROR;
collator = ucol_open("", &code);
if (collator == nullptr)
throw FormatRuntimeError("ucol_open() failed: %s",
u_errorName(code));
}
void
IcuCollateFinish() noexcept
{
assert(collator != nullptr);
ucol_close(collator);
}
#endif
[[gnu::pure]]
int
IcuCollate(std::string_view a, std::string_view b) noexcept
{
#ifdef HAVE_ICU
assert(collator != nullptr);
UErrorCode code = U_ZERO_ERROR;
return (int)ucol_strcollUTF8(collator, a.data(), a.size(),
b.data(), b.size(), &code);
#elif defined(_WIN32)
BasicAllocatedString<wchar_t> wa, wb;
try {
wa = MultiByteToWideChar(CP_UTF8, a);
} catch (...) {
try {
wb = MultiByteToWideChar(CP_UTF8, b);
return -1;
} catch (...) {
return 0;
}
}
try {
wb = MultiByteToWideChar(CP_UTF8, b);
} catch (...) {
return 1;
}
auto result = CompareStringEx(LOCALE_NAME_INVARIANT,
NORM_IGNORECASE,
wa.c_str(), -1,
wb.c_str(), -1,
nullptr, nullptr, 0);
if (result != 0)
/* "To maintain the C runtime convention of comparing
strings, the value 2 can be subtracted from a
nonzero return value." */
result -= 2;
return result;
#else
/* need to duplicate for the fallback because std::string_view
is not null-terminated */
return strcoll(std::string(a).c_str(), std::string(b).c_str());
#endif
}