chromeos/settings/timezone_settings.cc

   1 // Copyright 2013 The Chromium Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style license that can be
   3 // found in the LICENSE file.
   4
   5 #include "chromeos/settings/timezone_settings.h"
   6
   7 #include <string>
   8
   9 #include "base/bind.h"
  10 #include "base/files/file_path.h"
  11 #include "base/files/file_util.h"
  12 #include "base/location.h"
  13 #include "base/logging.h"
  14 #include "base/memory/scoped_ptr.h"
  15 #include "base/memory/singleton.h"
  16 #include "base/observer_list.h"
  17 #include "base/stl_util.h"
  18 #include "base/strings/string_util.h"
  19 #include "base/strings/utf_string_conversions.h"
  20 #include "base/sys_info.h"
  21 #include "base/task_runner.h"
  22 #include "base/threading/worker_pool.h"
  23 #include "chromeos/settings/timezone_settings_helper.h"
  24
  25 namespace {
  26
  27 // The filepath to the timezone file that symlinks to the actual timezone file.
  28 const char kTimezoneSymlink[] = "/var/lib/timezone/localtime";
  29 const char kTimezoneSymlink2[] = "/var/lib/timezone/localtime2";
  30
  31 // The directory that contains all the timezone files. So for timezone
  32 // "US/Pacific", the actual timezone file is: "/usr/share/zoneinfo/US/Pacific"
  33 const char kTimezoneFilesDir[] = "/usr/share/zoneinfo/";
  34
  35 // Fallback time zone ID used in case of an unexpected error.
  36 const char kFallbackTimeZoneId[] = "America/Los_Angeles";
  37
  38 // TODO(jungshik): Using Enumerate method in ICU gives 600+ timezones.
  39 // Even after filtering out duplicate entries with a strict identity check,
  40 // we still have 400+ zones. Relaxing the criteria for the timezone
  41 // identity is likely to cut down the number to < 100. Until we
  42 // come up with a better list, we hard-code the following list. It came from
  43 // from Android initially, but more entries have been added.
  44 static const char* kTimeZones[] = {
  45     "Pacific/Midway",
  46     "Pacific/Honolulu",
  47     "America/Anchorage",
  48     "America/Los_Angeles",
  49     "America/Vancouver",
  50     "America/Tijuana",
  51     "America/Phoenix",
  52     "America/Chihuahua",
  53     "America/Denver",
  54     "America/Edmonton",
  55     "America/Mazatlan",
  56     "America/Regina",
  57     "America/Costa_Rica",
  58     "America/Chicago",
  59     "America/Mexico_City",
  60     "America/Winnipeg",
  61     "Pacific/Easter",
  62     "America/Bogota",
  63     "America/Lima",
  64     "America/New_York",
  65     "America/Toronto",
  66     "America/Caracas",
  67     "America/Barbados",
  68     "America/Halifax",
  69     "America/Manaus",
  70     "America/Santiago",
  71     "America/St_Johns",
  72     "America/Araguaina",
  73     "America/Argentina/Buenos_Aires",
  74     "America/Argentina/San_Luis",
  75     "America/Sao_Paulo",
  76     "America/Montevideo",
  77     "America/Godthab",
  78     "Atlantic/South_Georgia",
  79     "Atlantic/Cape_Verde",
  80     "Atlantic/Azores",
  81     "Atlantic/Reykjavik",
  82     "Atlantic/St_Helena",
  83     "Africa/Casablanca",
  84     "Atlantic/Faroe",
  85     "Europe/Dublin",
  86     "Europe/Lisbon",
  87     "Europe/London",
  88     "Europe/Amsterdam",
  89     "Europe/Belgrade",
  90     "Europe/Berlin",
  91     "Europe/Bratislava",
  92     "Europe/Brussels",
  93     "Europe/Budapest",
  94     "Europe/Copenhagen",
  95     "Europe/Ljubljana",
  96     "Europe/Madrid",
  97     "Europe/Malta",
  98     "Europe/Oslo",
  99     "Europe/Paris",
 100     "Europe/Prague",
 101     "Europe/Rome",
 102     "Europe/Stockholm",
 103     "Europe/Sarajevo",
 104     "Europe/Tirane",
 105     "Europe/Vaduz",
 106     "Europe/Vienna",
 107     "Europe/Warsaw",
 108     "Europe/Zagreb",
 109     "Europe/Zurich",
 110     "Africa/Windhoek",
 111     "Africa/Lagos",
 112     "Africa/Brazzaville",
 113     "Africa/Cairo",
 114     "Africa/Harare",
 115     "Africa/Maputo",
 116     "Africa/Johannesburg",
 117     "Europe/Kaliningrad",
 118     "Europe/Athens",
 119     "Europe/Bucharest",
 120     "Europe/Chisinau",
 121     "Europe/Helsinki",
 122     "Europe/Istanbul",
 123     "Europe/Kiev",
 124     "Europe/Riga",
 125     "Europe/Sofia",
 126     "Europe/Tallinn",
 127     "Europe/Vilnius",
 128     "Asia/Amman",
 129     "Asia/Beirut",
 130     "Asia/Jerusalem",
 131     "Africa/Nairobi",
 132     "Asia/Baghdad",
 133     "Asia/Riyadh",
 134     "Asia/Kuwait",
 135     "Europe/Minsk",
 136     "Europe/Moscow",
 137     "Asia/Tehran",
 138     "Europe/Samara",
 139     "Asia/Dubai",
 140     "Asia/Tbilisi",
 141     "Indian/Mauritius",
 142     "Asia/Baku",
 143     "Asia/Yerevan",
 144     "Asia/Kabul",
 145     "Asia/Karachi",
 146     "Asia/Ashgabat",
 147     "Asia/Oral",
 148     "Asia/Yekaterinburg",
 149     "Asia/Calcutta",
 150     "Asia/Colombo",
 151     "Asia/Katmandu",
 152     "Asia/Omsk",
 153     "Asia/Almaty",
 154     "Asia/Dhaka",
 155     "Asia/Novosibirsk",
 156     "Asia/Rangoon",
 157     "Asia/Bangkok",
 158     "Asia/Jakarta",
 159     "Asia/Krasnoyarsk",
 160     "Asia/Novokuznetsk",
 161     "Asia/Ho_Chi_Minh",
 162     "Asia/Phnom_Penh",
 163     "Asia/Vientiane",
 164     "Asia/Shanghai",
 165     "Asia/Hong_Kong",
 166     "Asia/Kuala_Lumpur",
 167     "Asia/Singapore",
 168     "Asia/Manila",
 169     "Asia/Taipei",
 170     "Asia/Ulaanbaatar",
 171     "Asia/Makassar",
 172     "Asia/Irkutsk",
 173     "Asia/Yakutsk",
 174     "Australia/Perth",
 175     "Australia/Eucla",
 176     "Asia/Seoul",
 177     "Asia/Tokyo",
 178     "Asia/Jayapura",
 179     "Asia/Sakhalin",
 180     "Asia/Vladivostok",
 181     "Asia/Magadan",
 182     "Australia/Darwin",
 183     "Australia/Adelaide",
 184     "Pacific/Guam",
 185     "Australia/Brisbane",
 186     "Australia/Hobart",
 187     "Australia/Sydney",
 188     "Asia/Anadyr",
 189     "Pacific/Port_Moresby",
 190     "Asia/Kamchatka",
 191     "Pacific/Fiji",
 192     "Pacific/Majuro",
 193     "Pacific/Auckland",
 194     "Pacific/Tongatapu",
 195     "Pacific/Apia",
 196     "Pacific/Kiritimati",
 197 };
 198
 199 std::string GetTimezoneIDAsString() {
 200   // Compare with chromiumos/src/platform/init/ui.conf which fixes certain
 201   // incorrect states of the timezone symlink on startup. Thus errors occuring
 202   // here should be rather contrived.
 203
 204   // Look at kTimezoneSymlink, see which timezone we are symlinked to.
 205   char buf[256];
 206   const ssize_t len = readlink(kTimezoneSymlink, buf,
 207                                sizeof(buf)-1);
 208   if (len == -1) {
 209     LOG(ERROR) << "GetTimezoneID: Cannot read timezone symlink "
 210                << kTimezoneSymlink;
 211     return std::string();
 212   }
 213
 214   std::string timezone(buf, len);
 215   // Remove kTimezoneFilesDir from the beginning.
 216   if (timezone.find(kTimezoneFilesDir) != 0) {
 217     LOG(ERROR) << "GetTimezoneID: Timezone symlink is wrong "
 218                << timezone;
 219     return std::string();
 220   }
 221
 222   return timezone.substr(strlen(kTimezoneFilesDir));
 223 }
 224
 225 void SetTimezoneIDFromString(const std::string& id) {
 226   // Change the kTimezoneSymlink symlink to the path for this timezone.
 227   // We want to do this in an atomic way. So we are going to create the symlink
 228   // at kTimezoneSymlink2 and then move it to kTimezoneSymlink
 229
 230   base::FilePath timezone_symlink(kTimezoneSymlink);
 231   base::FilePath timezone_symlink2(kTimezoneSymlink2);
 232   base::FilePath timezone_file(kTimezoneFilesDir + id);
 233
 234   // Make sure timezone_file exists.
 235   if (!base::PathExists(timezone_file)) {
 236     LOG(ERROR) << "SetTimezoneID: Cannot find timezone file "
 237                << timezone_file.value();
 238     return;
 239   }
 240
 241   // Delete old symlink2 if it exists.
 242   base::DeleteFile(timezone_symlink2, false);
 243
 244   // Create new symlink2.
 245   if (symlink(timezone_file.value().c_str(),
 246               timezone_symlink2.value().c_str()) == -1) {
 247     LOG(ERROR) << "SetTimezoneID: Unable to create symlink "
 248                << timezone_symlink2.value() << " to " << timezone_file.value();
 249     return;
 250   }
 251
 252   // Move symlink2 to symlink.
 253   if (!base::ReplaceFile(timezone_symlink2, timezone_symlink, NULL)) {
 254     LOG(ERROR) << "SetTimezoneID: Unable to move symlink "
 255                << timezone_symlink2.value() << " to "
 256                << timezone_symlink.value();
 257   }
 258 }
 259
 260 // Common code of the TimezoneSettings implementations.
 261 class TimezoneSettingsBaseImpl : public chromeos::system::TimezoneSettings {
 262  public:
 263   ~TimezoneSettingsBaseImpl() override;
 264
 265   // TimezoneSettings implementation:
 266   const icu::TimeZone& GetTimezone() override;
 267   base::string16 GetCurrentTimezoneID() override;
 268   void SetTimezoneFromID(const base::string16& timezone_id) override;
 269   void AddObserver(Observer* observer) override;
 270   void RemoveObserver(Observer* observer) override;
 271   const std::vector<icu::TimeZone*>& GetTimezoneList() const override;
 272
 273  protected:
 274   TimezoneSettingsBaseImpl();
 275
 276   // Returns |timezone| if it is an element of |timezones_|.
 277   // Otherwise, returns a timezone from |timezones_|, if such exists, that has
 278   // the same rule as the given |timezone|.
 279   // Otherwise, returns NULL.
 280   // Note multiple timezones with the same time zone rules may exist
 281   // e.g.
 282   //   US/Pacific == America/Los_Angeles
 283   const icu::TimeZone* GetKnownTimezoneOrNull(
 284       const icu::TimeZone& timezone) const;
 285
 286   base::ObserverList<Observer> observers_;
 287   std::vector<icu::TimeZone*> timezones_;
 288   scoped_ptr<icu::TimeZone> timezone_;
 289
 290  private:
 291   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsBaseImpl);
 292 };
 293
 294 // The TimezoneSettings implementation used in production.
 295 class TimezoneSettingsImpl : public TimezoneSettingsBaseImpl {
 296  public:
 297   // TimezoneSettings implementation:
 298   void SetTimezone(const icu::TimeZone& timezone) override;
 299
 300   static TimezoneSettingsImpl* GetInstance();
 301
 302  private:
 303   friend struct DefaultSingletonTraits<TimezoneSettingsImpl>;
 304
 305   TimezoneSettingsImpl();
 306
 307   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsImpl);
 308 };
 309
 310 // The stub TimezoneSettings implementation used on Linux desktop.
 311 class TimezoneSettingsStubImpl : public TimezoneSettingsBaseImpl {
 312  public:
 313   // TimezoneSettings implementation:
 314   void SetTimezone(const icu::TimeZone& timezone) override;
 315
 316   static TimezoneSettingsStubImpl* GetInstance();
 317
 318  private:
 319   friend struct DefaultSingletonTraits<TimezoneSettingsStubImpl>;
 320
 321   TimezoneSettingsStubImpl();
 322
 323   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsStubImpl);
 324 };
 325
 326 TimezoneSettingsBaseImpl::~TimezoneSettingsBaseImpl() {
 327   STLDeleteElements(&timezones_);
 328 }
 329
 330 const icu::TimeZone& TimezoneSettingsBaseImpl::GetTimezone() {
 331   return *timezone_.get();
 332 }
 333
 334 base::string16 TimezoneSettingsBaseImpl::GetCurrentTimezoneID() {
 335   return chromeos::system::TimezoneSettings::GetTimezoneID(GetTimezone());
 336 }
 337
 338 void TimezoneSettingsBaseImpl::SetTimezoneFromID(
 339     const base::string16& timezone_id) {
 340   scoped_ptr<icu::TimeZone> timezone(icu::TimeZone::createTimeZone(
 341       icu::UnicodeString(timezone_id.c_str(), timezone_id.size())));
 342   SetTimezone(*timezone);
 343 }
 344
 345 void TimezoneSettingsBaseImpl::AddObserver(Observer* observer) {
 346   observers_.AddObserver(observer);
 347 }
 348
 349 void TimezoneSettingsBaseImpl::RemoveObserver(Observer* observer) {
 350   observers_.RemoveObserver(observer);
 351 }
 352
 353 const std::vector<icu::TimeZone*>&
 354 TimezoneSettingsBaseImpl::GetTimezoneList() const {
 355   return timezones_;
 356 }
 357
 358 TimezoneSettingsBaseImpl::TimezoneSettingsBaseImpl() {
 359   for (size_t i = 0; i < arraysize(kTimeZones); ++i) {
 360     timezones_.push_back(icu::TimeZone::createTimeZone(
 361         icu::UnicodeString(kTimeZones[i], -1, US_INV)));
 362   }
 363 }
 364
 365 const icu::TimeZone* TimezoneSettingsBaseImpl::GetKnownTimezoneOrNull(
 366     const icu::TimeZone& timezone) const {
 367   return chromeos::system::GetKnownTimezoneOrNull(timezone, timezones_);
 368 }
 369
 370 void TimezoneSettingsImpl::SetTimezone(const icu::TimeZone& timezone) {
 371   // Replace |timezone| by a known timezone with the same rules. If none exists
 372   // go on with |timezone|.
 373   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(timezone);
 374   if (!known_timezone)
 375     known_timezone = &timezone;
 376
 377   timezone_.reset(known_timezone->clone());
 378   std::string id = base::UTF16ToUTF8(GetTimezoneID(*known_timezone));
 379   VLOG(1) << "Setting timezone to " << id;
 380   // It's safe to change the timezone config files in the background as the
 381   // following operations don't depend on the completion of the config change.
 382   base::WorkerPool::GetTaskRunner(true /* task is slow */)->
 383       PostTask(FROM_HERE, base::Bind(&SetTimezoneIDFromString, id));
 384   icu::TimeZone::setDefault(*known_timezone);
 385   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(*known_timezone));
 386 }
 387
 388 // static
 389 TimezoneSettingsImpl* TimezoneSettingsImpl::GetInstance() {
 390   return Singleton<TimezoneSettingsImpl,
 391                    DefaultSingletonTraits<TimezoneSettingsImpl> >::get();
 392 }
 393
 394 TimezoneSettingsImpl::TimezoneSettingsImpl() {
 395   std::string id = GetTimezoneIDAsString();
 396   if (id.empty()) {
 397     id = kFallbackTimeZoneId;
 398     LOG(ERROR) << "Got an empty string for timezone, default to '" << id;
 399   }
 400
 401   timezone_.reset(icu::TimeZone::createTimeZone(
 402       icu::UnicodeString::fromUTF8(id)));
 403
 404   // Store a known timezone equivalent to id in |timezone_|.
 405   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(*timezone_);
 406   if (known_timezone != NULL && *known_timezone != *timezone_)
 407     // Not necessary to update the filesystem because |known_timezone| has the
 408     // same rules.
 409     timezone_.reset(known_timezone->clone());
 410
 411   icu::TimeZone::setDefault(*timezone_);
 412   VLOG(1) << "Timezone initially set to " << id;
 413   icu::UnicodeString resolvedId;
 414   std::string resolvedIdStr;
 415   timezone_->getID(resolvedId);
 416   VLOG(1) << "Timezone initially resolved to "
 417           << resolvedId.toUTF8String(resolvedIdStr);
 418 }
 419
 420 void TimezoneSettingsStubImpl::SetTimezone(const icu::TimeZone& timezone) {
 421   // Replace |timezone| by a known timezone with the same rules. If none exists
 422   // go on with |timezone|.
 423   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(timezone);
 424   if (!known_timezone)
 425     known_timezone = &timezone;
 426
 427   std::string id = base::UTF16ToUTF8(GetTimezoneID(*known_timezone));
 428   VLOG(1) << "Setting timezone to " << id;
 429   timezone_.reset(known_timezone->clone());
 430   icu::TimeZone::setDefault(*known_timezone);
 431   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(*known_timezone));
 432 }
 433
 434 // static
 435 TimezoneSettingsStubImpl* TimezoneSettingsStubImpl::GetInstance() {
 436   return Singleton<TimezoneSettingsStubImpl,
 437       DefaultSingletonTraits<TimezoneSettingsStubImpl> >::get();
 438 }
 439
 440 TimezoneSettingsStubImpl::TimezoneSettingsStubImpl() {
 441   timezone_.reset(icu::TimeZone::createDefault());
 442   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(*timezone_);
 443   if (known_timezone != NULL && *known_timezone != *timezone_)
 444     timezone_.reset(known_timezone->clone());
 445 }
 446
 447 }  // namespace
 448
 449 namespace chromeos {
 450 namespace system {
 451
 452 TimezoneSettings::Observer::~Observer() {}
 453
 454 // static
 455 TimezoneSettings* TimezoneSettings::GetInstance() {
 456   if (base::SysInfo::IsRunningOnChromeOS()) {
 457     return TimezoneSettingsImpl::GetInstance();
 458   } else {
 459     return TimezoneSettingsStubImpl::GetInstance();
 460   }
 461 }
 462
 463 // static
 464 base::string16 TimezoneSettings::GetTimezoneID(const icu::TimeZone& timezone) {
 465   icu::UnicodeString id;
 466   timezone.getID(id);
 467   return base::string16(id.getBuffer(), id.length());
 468 }
 469
 470 }  // namespace system
 471 }  // namespace chromeos