FreeRDP/winpr/libwinpr/timezone/TimeZoneNameMapUtils.c
akallabeth 52a884ed2e [winpr,timezone] refactor timezone mapping
* add option to use ICU as a fallback mapping (eliminate need for
  WindowsZones mapping list)
* extract timezone related settings from localtime_r and eliminate the
  need to parse the complex TimeZones table
* Add new TimeZoneNameMap to map IANA to windows names (Id, Standard,
  Daylight and Display names)
* Implement GetDynamicTimeZoneInformation
2024-05-08 10:08:08 +02:00

150 lines
3.6 KiB
C

/**
* WinPR: Windows Portable Runtime
* Time Zone Name Map Utils
*
* Copyright 2024 Armin Novak <anovak@thincast.com>
* Copyright 2024 Thincast Technologies GmbH
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
#include <winpr/config.h>
#include <winpr/assert.h>
#include <winpr/string.h>
#include <string.h>
#if defined(WITH_TIMEZONE_ICU)
#include <unicode/ucal.h>
#else
#include "WindowsZones.h"
#endif
#include "TimeZoneNameMap.h"
static const char* return_type(const TimeZoneNameMapEntry* entry, TimeZoneNameType type)
{
WINPR_ASSERT(entry);
switch (type)
{
case TIME_ZONE_NAME_IANA:
return entry->Iana;
case TIME_ZONE_NAME_ID:
return entry->Id;
case TIME_ZONE_NAME_STANDARD:
return entry->StandardName;
case TIME_ZONE_NAME_DISPLAY:
return entry->DisplayName;
case TIME_ZONE_NAME_DAYLIGHT:
return entry->DaylightName;
default:
return NULL;
}
}
#if defined(WITH_TIMEZONE_ICU)
static char* get_wzid_icu(const UChar* utzid, size_t utzid_len)
{
char* res = NULL;
UErrorCode error = U_ZERO_ERROR;
int32_t rc = ucal_getWindowsTimeZoneID(utzid, utzid_len, NULL, 0, &error);
if ((error == U_BUFFER_OVERFLOW_ERROR) && (rc > 0))
{
rc++; // make space for '\0'
UChar* wzid = calloc((size_t)rc + 1, sizeof(UChar));
if (wzid)
{
UErrorCode error2 = U_ZERO_ERROR;
int32_t rc2 = ucal_getWindowsTimeZoneID(utzid, utzid_len, wzid, rc, &error2);
if (U_SUCCESS(error2) && (rc2 > 0))
res = ConvertWCharNToUtf8Alloc(wzid, (size_t)rc, NULL);
free(wzid);
}
}
return res;
}
static char* get(const char* iana)
{
size_t utzid_len = 0;
UChar* utzid = ConvertUtf8ToWCharAlloc(iana, &utzid_len);
if (!utzid)
return NULL;
char* wzid = get_wzid_icu(utzid, utzid_len);
free(utzid);
return wzid;
}
static const char* map_fallback(const char* iana, TimeZoneNameType type)
{
const char* res = NULL;
char* wzid = get(iana);
if (!wzid)
return NULL;
for (size_t x = 0; x < TimeZoneNameMapSize; x++)
{
const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
if (strcmp(wzid, entry->Id) == 0)
{
res = return_type(entry, type);
break;
}
}
free(wzid);
return res;
}
#else
static const char* map_fallback(const char* iana, TimeZoneNameType type)
{
if (!iana)
return NULL;
for (size_t x = 0; x < WindowsTimeZoneIdTableNrElements; x++)
{
const WINDOWS_TZID_ENTRY* const entry = &WindowsTimeZoneIdTable[x];
if (strcmp(entry->tzid, iana) == 0)
return entry->windows;
}
return NULL;
}
#endif
const char* TimeZoneIanaToWindows(const char* iana, TimeZoneNameType type)
{
if (!iana)
return NULL;
for (size_t x = 0; x < TimeZoneNameMapSize; x++)
{
const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
if (strcmp(iana, entry->Iana) == 0)
return return_type(entry, type);
}
const char* wzid = map_fallback(iana, type);
if (!wzid)
return NULL;
for (size_t x = 0; x < TimeZoneNameMapSize; x++)
{
const TimeZoneNameMapEntry* entry = &TimeZoneNameMap[x];
if (strcmp(wzid, entry->Id) == 0)
return return_type(entry, type);
}
return NULL;
}