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 "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/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/Makassar",
 171     "Asia/Irkutsk",
 172     "Asia/Yakutsk",
 173     "Australia/Perth",
 174     "Australia/Eucla",
 175     "Asia/Seoul",
 176     "Asia/Tokyo",
 177     "Asia/Jayapura",
 178     "Asia/Sakhalin",
 179     "Asia/Vladivostok",
 180     "Asia/Magadan",
 181     "Australia/Darwin",
 182     "Australia/Adelaide",
 183     "Pacific/Guam",
 184     "Australia/Brisbane",
 185     "Australia/Hobart",
 186     "Australia/Sydney",
 187     "Asia/Anadyr",
 188     "Pacific/Port_Moresby",
 189     "Asia/Kamchatka",
 190     "Pacific/Fiji",
 191     "Pacific/Majuro",
 192     "Pacific/Auckland",
 193     "Pacific/Tongatapu",
 194     "Pacific/Apia",
 195     "Pacific/Kiritimati",
 196 };
 197
 198 std::string GetTimezoneIDAsString() {
 199   // Compare with chromiumos/src/platform/init/ui.conf which fixes certain
 200   // incorrect states of the timezone symlink on startup. Thus errors occuring
 201   // here should be rather contrived.
 202
 203   // Look at kTimezoneSymlink, see which timezone we are symlinked to.
 204   char buf[256];
 205   const ssize_t len = readlink(kTimezoneSymlink, buf,
 206                                sizeof(buf)-1);
 207   if (len == -1) {
 208     LOG(ERROR) << "GetTimezoneID: Cannot read timezone symlink "
 209                << kTimezoneSymlink;
 210     return std::string();
 211   }
 212
 213   std::string timezone(buf, len);
 214   // Remove kTimezoneFilesDir from the beginning.
 215   if (timezone.find(kTimezoneFilesDir) != 0) {
 216     LOG(ERROR) << "GetTimezoneID: Timezone symlink is wrong "
 217                << timezone;
 218     return std::string();
 219   }
 220
 221   return timezone.substr(strlen(kTimezoneFilesDir));
 222 }
 223
 224 void SetTimezoneIDFromString(const std::string& id) {
 225   // Change the kTimezoneSymlink symlink to the path for this timezone.
 226   // We want to do this in an atomic way. So we are going to create the symlink
 227   // at kTimezoneSymlink2 and then move it to kTimezoneSymlink
 228
 229   base::FilePath timezone_symlink(kTimezoneSymlink);
 230   base::FilePath timezone_symlink2(kTimezoneSymlink2);
 231   base::FilePath timezone_file(kTimezoneFilesDir + id);
 232
 233   // Make sure timezone_file exists.
 234   if (!base::PathExists(timezone_file)) {
 235     LOG(ERROR) << "SetTimezoneID: Cannot find timezone file "
 236                << timezone_file.value();
 237     return;
 238   }
 239
 240   // Delete old symlink2 if it exists.
 241   base::DeleteFile(timezone_symlink2, false);
 242
 243   // Create new symlink2.
 244   if (symlink(timezone_file.value().c_str(),
 245               timezone_symlink2.value().c_str()) == -1) {
 246     LOG(ERROR) << "SetTimezoneID: Unable to create symlink "
 247                << timezone_symlink2.value() << " to " << timezone_file.value();
 248     return;
 249   }
 250
 251   // Move symlink2 to symlink.
 252   if (!base::ReplaceFile(timezone_symlink2, timezone_symlink, NULL)) {
 253     LOG(ERROR) << "SetTimezoneID: Unable to move symlink "
 254                << timezone_symlink2.value() << " to "
 255                << timezone_symlink.value();
 256   }
 257 }
 258
 259 // Common code of the TimezoneSettings implementations.
 260 class TimezoneSettingsBaseImpl : public chromeos::system::TimezoneSettings {
 261  public:
 262   virtual ~TimezoneSettingsBaseImpl();
 263
 264   // TimezoneSettings implementation:
 265   virtual const icu::TimeZone& GetTimezone() override;
 266   virtual base::string16 GetCurrentTimezoneID() override;
 267   virtual void SetTimezoneFromID(const base::string16& timezone_id) override;
 268   virtual void AddObserver(Observer* observer) override;
 269   virtual void RemoveObserver(Observer* observer) override;
 270   virtual const std::vector<icu::TimeZone*>& GetTimezoneList() const override;
 271
 272  protected:
 273   TimezoneSettingsBaseImpl();
 274
 275   // Returns |timezone| if it is an element of |timezones_|.
 276   // Otherwise, returns a timezone from |timezones_|, if such exists, that has
 277   // the same rule as the given |timezone|.
 278   // Otherwise, returns NULL.
 279   // Note multiple timezones with the same time zone offset may exist
 280   // e.g.
 281   //   US/Pacific == America/Los_Angeles
 282   const icu::TimeZone* GetKnownTimezoneOrNull(
 283       const icu::TimeZone& timezone) const;
 284
 285   ObserverList<Observer> observers_;
 286   std::vector<icu::TimeZone*> timezones_;
 287   scoped_ptr<icu::TimeZone> timezone_;
 288
 289  private:
 290   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsBaseImpl);
 291 };
 292
 293 // The TimezoneSettings implementation used in production.
 294 class TimezoneSettingsImpl : public TimezoneSettingsBaseImpl {
 295  public:
 296   // TimezoneSettings implementation:
 297   virtual void SetTimezone(const icu::TimeZone& timezone) override;
 298
 299   static TimezoneSettingsImpl* GetInstance();
 300
 301  private:
 302   friend struct DefaultSingletonTraits<TimezoneSettingsImpl>;
 303
 304   TimezoneSettingsImpl();
 305
 306   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsImpl);
 307 };
 308
 309 // The stub TimezoneSettings implementation used on Linux desktop.
 310 class TimezoneSettingsStubImpl : public TimezoneSettingsBaseImpl {
 311  public:
 312   // TimezoneSettings implementation:
 313   virtual void SetTimezone(const icu::TimeZone& timezone) override;
 314
 315   static TimezoneSettingsStubImpl* GetInstance();
 316
 317  private:
 318   friend struct DefaultSingletonTraits<TimezoneSettingsStubImpl>;
 319
 320   TimezoneSettingsStubImpl();
 321
 322   DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsStubImpl);
 323 };
 324
 325 TimezoneSettingsBaseImpl::~TimezoneSettingsBaseImpl() {
 326   STLDeleteElements(&timezones_);
 327 }
 328
 329 const icu::TimeZone& TimezoneSettingsBaseImpl::GetTimezone() {
 330   return *timezone_.get();
 331 }
 332
 333 base::string16 TimezoneSettingsBaseImpl::GetCurrentTimezoneID() {
 334   return chromeos::system::TimezoneSettings::GetTimezoneID(GetTimezone());
 335 }
 336
 337 void TimezoneSettingsBaseImpl::SetTimezoneFromID(
 338     const base::string16& timezone_id) {
 339   scoped_ptr<icu::TimeZone> timezone(icu::TimeZone::createTimeZone(
 340       icu::UnicodeString(timezone_id.c_str(), timezone_id.size())));
 341   SetTimezone(*timezone);
 342 }
 343
 344 void TimezoneSettingsBaseImpl::AddObserver(Observer* observer) {
 345   observers_.AddObserver(observer);
 346 }
 347
 348 void TimezoneSettingsBaseImpl::RemoveObserver(Observer* observer) {
 349   observers_.RemoveObserver(observer);
 350 }
 351
 352 const std::vector<icu::TimeZone*>&
 353 TimezoneSettingsBaseImpl::GetTimezoneList() const {
 354   return timezones_;
 355 }
 356
 357 TimezoneSettingsBaseImpl::TimezoneSettingsBaseImpl() {
 358   for (size_t i = 0; i < arraysize(kTimeZones); ++i) {
 359     timezones_.push_back(icu::TimeZone::createTimeZone(
 360         icu::UnicodeString(kTimeZones[i], -1, US_INV)));
 361   }
 362 }
 363
 364 const icu::TimeZone* TimezoneSettingsBaseImpl::GetKnownTimezoneOrNull(
 365     const icu::TimeZone& timezone) const {
 366   const icu::TimeZone* known_timezone = NULL;
 367   for (std::vector<icu::TimeZone*>::const_iterator iter = timezones_.begin();
 368        iter != timezones_.end(); ++iter) {
 369     const icu::TimeZone* entry = *iter;
 370     if (*entry == timezone)
 371       return entry;
 372     if (entry->hasSameRules(timezone))
 373       known_timezone = entry;
 374   }
 375
 376   // May return NULL if we did not find a matching timezone in our list.
 377   return known_timezone;
 378 }
 379
 380 void TimezoneSettingsImpl::SetTimezone(const icu::TimeZone& timezone) {
 381   // Replace |timezone| by a known timezone with the same rules. If none exists
 382   // go on with |timezone|.
 383   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(timezone);
 384   if (!known_timezone)
 385     known_timezone = &timezone;
 386
 387   timezone_.reset(known_timezone->clone());
 388   std::string id = base::UTF16ToUTF8(GetTimezoneID(*known_timezone));
 389   VLOG(1) << "Setting timezone to " << id;
 390   // It's safe to change the timezone config files in the background as the
 391   // following operations don't depend on the completion of the config change.
 392   base::WorkerPool::GetTaskRunner(true /* task is slow */)->
 393       PostTask(FROM_HERE, base::Bind(&SetTimezoneIDFromString, id));
 394   icu::TimeZone::setDefault(*known_timezone);
 395   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(*known_timezone));
 396 }
 397
 398 // static
 399 TimezoneSettingsImpl* TimezoneSettingsImpl::GetInstance() {
 400   return Singleton<TimezoneSettingsImpl,
 401                    DefaultSingletonTraits<TimezoneSettingsImpl> >::get();
 402 }
 403
 404 TimezoneSettingsImpl::TimezoneSettingsImpl() {
 405   std::string id = GetTimezoneIDAsString();
 406   if (id.empty()) {
 407     id = kFallbackTimeZoneId;
 408     LOG(ERROR) << "Got an empty string for timezone, default to '" << id;
 409   }
 410
 411   timezone_.reset(icu::TimeZone::createTimeZone(
 412       icu::UnicodeString::fromUTF8(id)));
 413
 414   // Store a known timezone equivalent to id in |timezone_|.
 415   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(*timezone_);
 416   if (known_timezone != NULL && *known_timezone != *timezone_)
 417     // Not necessary to update the filesystem because |known_timezone| has the
 418     // same rules.
 419     timezone_.reset(known_timezone->clone());
 420
 421   icu::TimeZone::setDefault(*timezone_);
 422   VLOG(1) << "Timezone initially set to " << id;
 423 }
 424
 425 void TimezoneSettingsStubImpl::SetTimezone(const icu::TimeZone& timezone) {
 426   // Replace |timezone| by a known timezone with the same rules. If none exists
 427   // go on with |timezone|.
 428   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(timezone);
 429   if (!known_timezone)
 430     known_timezone = &timezone;
 431
 432   timezone_.reset(known_timezone->clone());
 433   icu::TimeZone::setDefault(*known_timezone);
 434   FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(*known_timezone));
 435 }
 436
 437 // static
 438 TimezoneSettingsStubImpl* TimezoneSettingsStubImpl::GetInstance() {
 439   return Singleton<TimezoneSettingsStubImpl,
 440       DefaultSingletonTraits<TimezoneSettingsStubImpl> >::get();
 441 }
 442
 443 TimezoneSettingsStubImpl::TimezoneSettingsStubImpl() {
 444   timezone_.reset(icu::TimeZone::createDefault());
 445   const icu::TimeZone* known_timezone = GetKnownTimezoneOrNull(*timezone_);
 446   if (known_timezone != NULL && *known_timezone != *timezone_)
 447     timezone_.reset(known_timezone->clone());
 448 }
 449
 450 }  // namespace
 451
 452 namespace chromeos {
 453 namespace system {
 454
 455 TimezoneSettings::Observer::~Observer() {}
 456
 457 // static
 458 TimezoneSettings* TimezoneSettings::GetInstance() {
 459   if (base::SysInfo::IsRunningOnChromeOS()) {
 460     return TimezoneSettingsImpl::GetInstance();
 461   } else {
 462     return TimezoneSettingsStubImpl::GetInstance();
 463   }
 464 }
 465
 466 // static
 467 base::string16 TimezoneSettings::GetTimezoneID(const icu::TimeZone& timezone) {
 468   icu::UnicodeString id;
 469   timezone.getID(id);
 470   return base::string16(id.getBuffer(), id.length());
 471 }
 472
 473 }  // namespace system
 474 }  // namespace chromeos