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/file_util.h"
  11 #include "base/files/file_path.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 "third_party/icu/source/i18n/unicode/timezone.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/Brussels",
  92     "Europe/Budapest",
  93     "Europe/Copenhagen",
  94     "Europe/Ljubljana",
  95     "Europe/Madrid",
  96     "Europe/Oslo",
  97     "Europe/Paris",
  98     "Europe/Prague",
  99     "Europe/Rome",
 100     "Europe/Stockholm",
 101     "Europe/Sarajevo",
 102     "Europe/Tirane",
 103     "Europe/Vienna",
 104     "Europe/Warsaw",
 105     "Europe/Zurich",
 106     "Africa/Windhoek",
 107     "Africa/Lagos",
 108     "Africa/Brazzaville",
 109     "Africa/Cairo",
 110     "Africa/Harare",
 111     "Africa/Maputo",
 112     "Africa/Johannesburg",
 113     "Europe/Athens",
 114     "Europe/Bucharest",
 115     "Europe/Chisinau",
 116     "Europe/Helsinki",
 117     "Europe/Istanbul",
 118     "Europe/Kiev",
 119     "Europe/Riga",
 120     "Europe/Sofia",
 121     "Europe/Tallinn",
 122     "Europe/Vilnius",
 123     "Asia/Amman",
 124     "Asia/Beirut",
 125     "Asia/Jerusalem",
 126     "Africa/Nairobi",
 127     "Asia/Baghdad",
 128     "Asia/Riyadh",
 129     "Asia/Kuwait",
 130     "Europe/Minsk",
 131     "Asia/Tehran",
 132     "Europe/Moscow",
 133     "Asia/Dubai",
 134     "Asia/Tbilisi",
 135     "Indian/Mauritius",
 136     "Asia/Baku",
 137     "Asia/Yerevan",
 138     "Asia/Kabul",
 139     "Asia/Karachi",
 140     "Asia/Ashgabat",
 141     "Asia/Oral",
 142     "Asia/Calcutta",
 143     "Asia/Colombo",
 144     "Asia/Katmandu",
 145     "Asia/Yekaterinburg",
 146     "Asia/Almaty",
 147     "Asia/Dhaka",
 148     "Asia/Rangoon",
 149     "Asia/Bangkok",
 150     "Asia/Jakarta",
 151     "Asia/Omsk",
 152     "Asia/Novosibirsk",
 153     "Asia/Ho_Chi_Minh",
 154     "Asia/Phnom_Penh",
 155     "Asia/Vientiane",
 156     "Asia/Shanghai",
 157     "Asia/Hong_Kong",
 158     "Asia/Kuala_Lumpur",
 159     "Asia/Singapore",
 160     "Asia/Manila",
 161     "Asia/Taipei",
 162     "Asia/Makassar",
 163     "Asia/Krasnoyarsk",
 164     "Australia/Perth",
 165     "Australia/Eucla",
 166     "Asia/Irkutsk",
 167     "Asia/Seoul",
 168     "Asia/Tokyo",
 169     "Asia/Jayapura",
 170     "Australia/Darwin",
 171     "Australia/Adelaide",
 172     "Asia/Yakutsk",
 173     "Pacific/Guam",
 174     "Australia/Brisbane",
 175     "Australia/Hobart",
 176     "Australia/Sydney",
 177     "Pacific/Port_Moresby",
 178     "Asia/Vladivostok",
 179     "Asia/Sakhalin",
 180     "Asia/Magadan",
 181     "Pacific/Fiji",
 182     "Pacific/Majuro",
 183     "Pacific/Auckland",
 184     "Pacific/Tongatapu",
 185     "Pacific/Apia",
 186     "Pacific/Kiritimati",
 187 };
 188
 189 std::string GetTimezoneIDAsString() {
 190   // Compare with chromiumos/src/platform/init/ui.conf which fixes certain
 191   // incorrect states of the timezone symlink on startup. Thus errors occuring
 192   // here should be rather contrived.
 193
 194   // Look at kTimezoneSymlink, see which timezone we are symlinked to.
 195   char buf[256];
 196   const ssize_t len = readlink(kTimezoneSymlink, buf,
 197                                sizeof(buf)-1);
 198   if (len == -1) {
 199     LOG(ERROR) << "GetTimezoneID: Cannot read timezone symlink "
 200                << kTimezoneSymlink;
 201     return std::string();
 202   }
 203
 204   std::string timezone(buf, len);
 205   // Remove kTimezoneFilesDir from the beginning.
 206   if (timezone.find(kTimezoneFilesDir) != 0) {
 207     LOG(ERROR) << "GetTimezoneID: Timezone symlink is wrong "
 208                << timezone;
 209     return std::string();
 210   }
 211
 212   return timezone.substr(strlen(kTimezoneFilesDir));
 213 }
 214
 215 void SetTimezoneIDFromString(const std::string& id) {
 216   // Change the kTimezoneSymlink symlink to the path for this timezone.
 217   // We want to do this in an atomic way. So we are going to create the symlink
 218   // at kTimezoneSymlink2 and then move it to kTimezoneSymlink
 219
 220   base::FilePath timezone_symlink(kTimezoneSymlink);
 221   base::FilePath timezone_symlink2(kTimezoneSymlink2);
 222   base::FilePath timezone_file(kTimezoneFilesDir + id);
 223
 224   // Make sure timezone_file exists.
 225   if (!base::PathExists(timezone_file)) {
 226     LOG(ERROR) << "SetTimezoneID: Cannot find timezone file "
 227                << timezone_file.value();
 228     return;
 229   }
 230
 231   // Delete old symlink2 if it exists.
 232   base::DeleteFile(timezone_symlink2, false);
 233
 234   // Create new symlink2.
 235   if (symlink(timezone_file.value().c_str(),
 236               timezone_symlink2.value().c_str()) == -1) {
 237     LOG(ERROR) << "SetTimezoneID: Unable to create symlink "
 238                << timezone_symlink2.value() << " to " << timezone_file.value();
 239     return;
 240   }
 241
 242   // Move symlink2 to symlink.
 243   if (!base::ReplaceFile(timezone_symlink2, timezone_symlink, NULL)) {
 244     LOG(ERROR) << "SetTimezoneID: Unable to move symlink "
 245                << timezone_symlink2.value() << " to "
 246                << timezone_symlink.value();
 247   }
 248 }
 249
 250 // Common code of the TimezoneSettings implementations.
 251 class TimezoneSettingsBaseImpl : public chromeos::system::TimezoneSettings {
 252  public:
 253   virtual ~TimezoneSettingsBaseImpl();
 254
 255   // TimezoneSettings implementation:
 256   virtual const icu::TimeZone& GetTimezone() OVERRIDE;
 257   virtual base::string16 GetCurrentTimezoneID() OVERRIDE;
 258   virtual void SetTimezoneFromID(const base::string16& timezone_id) OVERRIDE;
 259   virtual void AddObserver(Observer* observer) OVERRIDE;
 260   virtual void RemoveObserver(Observer* observer) OVERRIDE;
 261   virtual const std::vector<icu::TimeZone*>& GetTimezoneList() const OVERRIDE;
 262
 263  protected:
 264   TimezoneSettingsBaseImpl();
 265
 266   // Returns |timezone| if it is an element of |timezones_|.
 267   // Otherwise, returns a timezone from |timezones_|, if such exists, that has
 268   // the same rule as the given |timezone|.
 269   // Otherwise, returns NULL.
 270   // Note multiple timezones with the same time zone offset may exist
 271   // e.g.
 272   //   US/Pacific == America/Los_Angeles
 273   const icu::TimeZone* GetKnownTimezoneOrNull(
 274       const icu::TimeZone& timezone) const;
 275
 276   ObserverList<Observer> observers_;
 277   std::vector<icu::TimeZone*> timezones_;
 278   scoped_ptr<icu::TimeZone> timezone_;
 279
 280  private:
 281   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsBaseImpl);
 282 };
 283
 284 // The TimezoneSettings implementation used in production.
 285 class TimezoneSettingsImpl : public TimezoneSettingsBaseImpl {
 286  public:
 287   // TimezoneSettings implementation:
 288   virtual void SetTimezone(const icu::TimeZone& timezone) OVERRIDE;
 289
 290   static TimezoneSettingsImpl* GetInstance();
 291
 292  private:
 293   friend struct DefaultSingletonTraits<TimezoneSettingsImpl>;
 294
 295   TimezoneSettingsImpl();
 296
 297   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsImpl);
 298 };
 299
 300 // The stub TimezoneSettings implementation used on Linux desktop.
 301 class TimezoneSettingsStubImpl : public TimezoneSettingsBaseImpl {
 302  public:
 303   // TimezoneSettings implementation:
 304   virtual void SetTimezone(const icu::TimeZone& timezone) OVERRIDE;
 305
 306   static TimezoneSettingsStubImpl* GetInstance();
 307
 308  private:
 309   friend struct DefaultSingletonTraits<TimezoneSettingsStubImpl>;
 310
 311   TimezoneSettingsStubImpl();
 312
 313   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsStubImpl);
 314 };
 315
 316 TimezoneSettingsBaseImpl::~TimezoneSettingsBaseImpl() {
 317   STLDeleteElements(&timezones_);
 318 }
 319
 320 const icu::TimeZone& TimezoneSettingsBaseImpl::GetTimezone() {
 321   return *timezone_.get();
 322 }
 323
 324 base::string16 TimezoneSettingsBaseImpl::GetCurrentTimezoneID() {
 325   return chromeos::system::TimezoneSettings::GetTimezoneID(GetTimezone());
 326 }
 327
 328 void TimezoneSettingsBaseImpl::SetTimezoneFromID(
 329     const base::string16& timezone_id) {
 330   scoped_ptr<icu::TimeZone> timezone(icu::TimeZone::createTimeZone(
 331       icu::UnicodeString(timezone_id.c_str(), timezone_id.size())));
 332   SetTimezone(*timezone);
 333 }
 334
 335 void TimezoneSettingsBaseImpl::AddObserver(Observer* observer) {
 336   observers_.AddObserver(observer);
 337 }
 338
 339 void TimezoneSettingsBaseImpl::RemoveObserver(Observer* observer) {
 340   observers_.RemoveObserver(observer);
 341 }
 342
 343 const std::vector<icu::TimeZone*>&
 344 TimezoneSettingsBaseImpl::GetTimezoneList() const {
 345   return timezones_;
 346 }
 347
 348 TimezoneSettingsBaseImpl::TimezoneSettingsBaseImpl() {
 349   for (size_t i = 0; i < arraysize(kTimeZones); ++i) {
 350     timezones_.push_back(icu::TimeZone::createTimeZone(
 351         icu::UnicodeString(kTimeZones[i], -1, US_INV)));
 352   }
 353 }
 354
 355 const icu::TimeZone* TimezoneSettingsBaseImpl::GetKnownTimezoneOrNull(
 356     const icu::TimeZone& timezone) const {
 357   const icu::TimeZone* known_timezone = NULL;
 358   for (std::vector<icu::TimeZone*>::const_iterator iter = timezones_.begin();
 359        iter != timezones_.end(); ++iter) {
 360     const icu::TimeZone* entry = *iter;
 361     if (*entry == timezone)
 362       return entry;
 363     if (entry->hasSameRules(timezone))
 364       known_timezone = entry;
 365   }
 366
 367   // May return NULL if we did not find a matching timezone in our list.
 368   return known_timezone;
 369 }
 370
 371 void TimezoneSettingsImpl::SetTimezone(const icu::TimeZone& timezone) {
 372   // Replace |timezone| by a known timezone with the same rules. If none exists
 373   // go on with |timezone|.
 374   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(timezone);
 375   if (!known_timezone)
 376     known_timezone = &timezone;
 377
 378   timezone_.reset(known_timezone->clone());
 379   std::string id = base::UTF16ToUTF8(GetTimezoneID(*known_timezone));
 380   VLOG(1) << "Setting timezone to " << id;
 381   // It's safe to change the timezone config files in the background as the
 382   // following operations don't depend on the completion of the config change.
 383   base::WorkerPool::GetTaskRunner(true /* task is slow */)->
 384       PostTask(FROM_HERE, base::Bind(&SetTimezoneIDFromString, id));
 385   icu::TimeZone::setDefault(*known_timezone);
 386   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(*known_timezone));
 387 }
 388
 389 // static
 390 TimezoneSettingsImpl* TimezoneSettingsImpl::GetInstance() {
 391   return Singleton<TimezoneSettingsImpl,
 392                    DefaultSingletonTraits<TimezoneSettingsImpl> >::get();
 393 }
 394
 395 TimezoneSettingsImpl::TimezoneSettingsImpl() {
 396   std::string id = GetTimezoneIDAsString();
 397   if (id.empty()) {
 398     id = kFallbackTimeZoneId;
 399     LOG(ERROR) << "Got an empty string for timezone, default to '" << id;
 400   }
 401
 402   timezone_.reset(icu::TimeZone::createTimeZone(
 403       icu::UnicodeString::fromUTF8(id)));
 404
 405   // Store a known timezone equivalent to id in |timezone_|.
 406   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(*timezone_);
 407   if (known_timezone != NULL && *known_timezone != *timezone_)
 408     // Not necessary to update the filesystem because |known_timezone| has the
 409     // same rules.
 410     timezone_.reset(known_timezone->clone());
 411
 412   icu::TimeZone::setDefault(*timezone_);
 413   VLOG(1) << "Timezone initially set to " << id;
 414 }
 415
 416 void TimezoneSettingsStubImpl::SetTimezone(const icu::TimeZone& timezone) {
 417   // Replace |timezone| by a known timezone with the same rules. If none exists
 418   // go on with |timezone|.
 419   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(timezone);
 420   if (!known_timezone)
 421     known_timezone = &timezone;
 422
 423   timezone_.reset(known_timezone->clone());
 424   icu::TimeZone::setDefault(*known_timezone);
 425   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(*known_timezone));
 426 }
 427
 428 // static
 429 TimezoneSettingsStubImpl* TimezoneSettingsStubImpl::GetInstance() {
 430   return Singleton<TimezoneSettingsStubImpl,
 431       DefaultSingletonTraits<TimezoneSettingsStubImpl> >::get();
 432 }
 433
 434 TimezoneSettingsStubImpl::TimezoneSettingsStubImpl() {
 435   timezone_.reset(icu::TimeZone::createDefault());
 436   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(*timezone_);
 437   if (known_timezone != NULL && *known_timezone != *timezone_)
 438     timezone_.reset(known_timezone->clone());
 439 }
 440
 441 }  // namespace
 442
 443 namespace chromeos {
 444 namespace system {
 445
 446 TimezoneSettings::Observer::~Observer() {}
 447
 448 // static
 449 TimezoneSettings* TimezoneSettings::GetInstance() {
 450   if (base::SysInfo::IsRunningOnChromeOS()) {
 451     return TimezoneSettingsImpl::GetInstance();
 452   } else {
 453     return TimezoneSettingsStubImpl::GetInstance();
 454   }
 455 }
 456
 457 // static
 458 base::string16 TimezoneSettings::GetTimezoneID(const icu::TimeZone& timezone) {
 459   icu::UnicodeString id;
 460   timezone.getID(id);
 461   return base::string16(id.getBuffer(), id.length());
 462 }
 463
 464 }  // namespace system
 465 }  // namespace chromeos