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