Split SystemAccess into TimezoneSettings, StatisticsProvider, and SyslogsProvider.

chrome/browser/chromeos/system/timezone_settings.cc

+// Copyright (c) 2011 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+#include "chrome/browser/chromeos/system/timezone_settings.h"
+
+#include "base/file_path.h"
+#include "base/file_util.h"
+#include "base/logging.h"
+#include "base/observer_list.h"
+#include "base/memory/scoped_ptr.h"
+#include "base/memory/singleton.h"
+#include "base/string_util.h"
+#include "base/utf_string_conversions.h"
+
+namespace chromeos {
+namespace system {
+
+namespace {
+
+// The filepath to the timezone file that symlinks to the actual timezone file.
+const char kTimezoneSymlink[] = "/var/lib/timezone/localtime";
+const char kTimezoneSymlink2[] = "/var/lib/timezone/localtime2";
+
+// The directory that contains all the timezone files. So for timezone
+// "US/Pacific", the actual timezone file is: "/usr/share/zoneinfo/US/Pacific"
+const char kTimezoneFilesDir[] = "/usr/share/zoneinfo/";
+
+// Fallback time zone ID used in case of an unexpected error.
+const char kFallbackTimeZoneId[] = "America/Los_Angeles";
+
+}  // namespace
+
+class TimezoneSettingsImpl : public TimezoneSettings {
+ public:
+  // TimezoneSettings.implementation:
+  virtual const icu::TimeZone& GetTimezone();
+  virtual void SetTimezone(const icu::TimeZone& timezone);
+  virtual void AddObserver(Observer* observer);
+  virtual void RemoveObserver(Observer* observer);
+
+  static TimezoneSettingsImpl* GetInstance();
+
+ private:
+  friend struct DefaultSingletonTraits<TimezoneSettingsImpl>;
+
+  TimezoneSettingsImpl();
+
+  scoped_ptr<icu::TimeZone> timezone_;
+  ObserverList<Observer> observers_;
+
+  DISALLOW_COPY_AND_ASSIGN(TimezoneSettingsImpl);
+};
+
+std::string GetTimezoneIDAsString() {
+  // Look at kTimezoneSymlink, see which timezone we are symlinked to.
+  char buf[256];
+  const ssize_t len = readlink(kTimezoneSymlink, buf,
+                               sizeof(buf)-1);
+  if (len == -1) {
+    LOG(ERROR) << "GetTimezoneID: Cannot read timezone symlink "
+               << kTimezoneSymlink;
+    return std::string();
+  }
+
+  std::string timezone(buf, len);
+  // Remove kTimezoneFilesDir from the beginning.
+  if (timezone.find(kTimezoneFilesDir) != 0) {
+    LOG(ERROR) << "GetTimezoneID: Timezone symlink is wrong "
+               << timezone;
+    return std::string();
+  }
+
+  return timezone.substr(strlen(kTimezoneFilesDir));
+}
+
+void SetTimezoneIDFromString(const std::string& id) {
+  // Change the kTimezoneSymlink symlink to the path for this timezone.
+  // We want to do this in an atomic way. So we are going to create the symlink
+  // at kTimezoneSymlink2 and then move it to kTimezoneSymlink
+
+  FilePath timezone_symlink(kTimezoneSymlink);
+  FilePath timezone_symlink2(kTimezoneSymlink2);
+  FilePath timezone_file(kTimezoneFilesDir + id);
+
+  // Make sure timezone_file exists.
+  if (!file_util::PathExists(timezone_file)) {
+    LOG(ERROR) << "SetTimezoneID: Cannot find timezone file "
+               << timezone_file.value();
+    return;
+  }
+
+  // Delete old symlink2 if it exists.
+  file_util::Delete(timezone_symlink2, false);
+
+  // Create new symlink2.
+  if (symlink(timezone_file.value().c_str(),
+              timezone_symlink2.value().c_str()) == -1) {
+    LOG(ERROR) << "SetTimezoneID: Unable to create symlink "
+               << timezone_symlink2.value() << " to " << timezone_file.value();
+    return;
+  }
+
+  // Move symlink2 to symlink.
+  if (!file_util::ReplaceFile(timezone_symlink2, timezone_symlink)) {
+    LOG(ERROR) << "SetTimezoneID: Unable to move symlink "
+               << timezone_symlink2.value() << " to "
+               << timezone_symlink.value();
+  }
+}
+
+const icu::TimeZone& TimezoneSettingsImpl::GetTimezone() {
+  return *timezone_.get();
+}
+
+void TimezoneSettingsImpl::SetTimezone(const icu::TimeZone& timezone) {
+  timezone_.reset(timezone.clone());
+  icu::UnicodeString unicode;
+  timezone.getID(unicode);
+  std::string id;
+  UTF16ToUTF8(unicode.getBuffer(), unicode.length(), &id);
+  VLOG(1) << "Setting timezone to " << id;
+  SetTimezoneIDFromString(id);
+  icu::TimeZone::setDefault(timezone);
+  FOR_EACH_OBSERVER(Observer, observers_, TimezoneChanged(timezone));
+}
+
+void TimezoneSettingsImpl::AddObserver(Observer* observer) {
+  observers_.AddObserver(observer);
+}
+
+void TimezoneSettingsImpl::RemoveObserver(Observer* observer) {
+  observers_.RemoveObserver(observer);
+}
+
+TimezoneSettingsImpl::TimezoneSettingsImpl() {
+  // Get Timezone
+  std::string id = GetTimezoneIDAsString();
+  if (id.empty()) {
+    id = kFallbackTimeZoneId;
+    LOG(ERROR) << "Got an empty string for timezone, default to " << id;
+  }
+  icu::TimeZone* timezone =
+      icu::TimeZone::createTimeZone(icu::UnicodeString::fromUTF8(id));
+  timezone_.reset(timezone);
+  icu::TimeZone::setDefault(*timezone);
+  VLOG(1) << "Timezone is " << id;
+}
+
+TimezoneSettingsImpl* TimezoneSettingsImpl::GetInstance() {
+  return Singleton<TimezoneSettingsImpl,
+                   DefaultSingletonTraits<TimezoneSettingsImpl> >::get();
+}
+
+TimezoneSettings* TimezoneSettings::GetInstance() {
+  return TimezoneSettingsImpl::GetInstance();
+}
+
+}  // namespace system
+}  // namespace chromeos
+
+// Allows InvokeLater without adding refcounting. TimezoneSettingsImpl is a
+// Singleton and won't be deleted until it's last InvokeLater is run.
+DISABLE_RUNNABLE_METHOD_REFCOUNT(chromeos::system::TimezoneSettingsImpl);