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