Refactor the windows policy provider to use AsynchronousPolicyProvider.

chrome/browser/policy/configuration_policy_provider_win.cc

 // Copyright (c) 2010 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/policy/configuration_policy_provider_win.h"
 
-#include <userenv.h>
-
-#include <algorithm>
-
-#include "base/logging.h"
-#include "base/object_watcher.h"
-#include "base/scoped_ptr.h"
-#include "base/string_number_conversions.h"
-#include "base/string_piece.h"
-#include "base/string_util.h"
-#include "base/sys_string_conversions.h"
-#include "base/thread_restrictions.h"
-#include "base/utf_string_conversions.h"
-#include "base/values.h"
-#include "base/win/registry.h"
-#include "chrome/common/policy_constants.h"
-
-using base::win::RegKey;
+#include "chrome/browser/policy/asynchronous_policy_provider.h"
+#include "chrome/browser/policy/configuration_policy_loader_win.h"
+#include "chrome/browser/policy/configuration_policy_provider_delegate_win.h"
 
 namespace policy {
 
-namespace {
-
-bool ReadRegistryStringValue(RegKey* key, const string16& name,
-                             string16* result) {
-  DWORD value_size = 0;
-  DWORD key_type = 0;
-  scoped_array<uint8> buffer;
-
-  if (!key->ReadValue(name.c_str(), 0, &value_size, &key_type))
-    return false;
-  if (key_type != REG_SZ)
-    return false;
-
-  // According to the Microsoft documentation, the string
-  // buffer may not be explicitly 0-terminated. Allocate a
-  // slightly larger buffer and pre-fill to zeros to guarantee
-  // the 0-termination.
-  buffer.reset(new uint8[value_size + 2]);
-  memset(buffer.get(), 0, value_size + 2);
-  key->ReadValue(name.c_str(), buffer.get(), &value_size, NULL);
-  result->assign(reinterpret_cast<const wchar_t*>(buffer.get()));
-  return true;
-}
-
-}  // namespace
-
 // Period at which to run the reload task in case the group policy change
 // watchers fail.
 const int kReloadIntervalMinutes = 15;
 
-ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::
-    GroupPolicyChangeWatcher(
-        base::WeakPtr<ConfigurationPolicyProviderWin> provider,
-        int reload_interval_minutes)
-        : provider_(provider),
-          user_policy_changed_event_(false, false),
-          machine_policy_changed_event_(false, false),
-          user_policy_watcher_failed_(false),
-          machine_policy_watcher_failed_(false),
-          reload_interval_minutes_(reload_interval_minutes),
-          reload_task_(NULL) {
-  if (!RegisterGPNotification(user_policy_changed_event_.handle(), false)) {
-    PLOG(WARNING) << "Failed to register user group policy notification";
-    user_policy_watcher_failed_ = true;
-  }
-  if (!RegisterGPNotification(machine_policy_changed_event_.handle(), true)) {
-    PLOG(WARNING) << "Failed to register machine group policy notification.";
-    machine_policy_watcher_failed_ = true;
-  }
-}
-
-ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::
-    ~GroupPolicyChangeWatcher() {
-  if (MessageLoop::current())
-    MessageLoop::current()->RemoveDestructionObserver(this);
-  DCHECK(!reload_task_);
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::Start() {
-  MessageLoop::current()->AddDestructionObserver(this);
-  SetupWatches();
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::Stop() {
-  user_policy_watcher_.StopWatching();
-  machine_policy_watcher_.StopWatching();
-  if (reload_task_) {
-    reload_task_->Cancel();
-    reload_task_ = NULL;
-  }
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::SetupWatches() {
-  if (reload_task_) {
-    reload_task_->Cancel();
-    reload_task_ = NULL;
-  }
-
-  if (!user_policy_watcher_failed_) {
-    if (!user_policy_watcher_.GetWatchedObject() &&
-        !user_policy_watcher_.StartWatching(
-            user_policy_changed_event_.handle(), this)) {
-      LOG(WARNING) << "Failed to start watch for user policy change event";
-      user_policy_watcher_failed_ = true;
-    }
-  }
-  if (!machine_policy_watcher_failed_) {
-    if (!machine_policy_watcher_.GetWatchedObject() &&
-        !machine_policy_watcher_.StartWatching(
-            machine_policy_changed_event_.handle(), this)) {
-      LOG(WARNING) << "Failed to start watch for machine policy change event";
-      machine_policy_watcher_failed_ = true;
-    }
-  }
-
-  if (user_policy_watcher_failed_ || machine_policy_watcher_failed_) {
-    reload_task_ =
-        NewRunnableMethod(this, &GroupPolicyChangeWatcher::ReloadFromTask);
-    int64 delay =
-        base::TimeDelta::FromMinutes(reload_interval_minutes_).InMilliseconds();
-    MessageLoop::current()->PostDelayedTask(FROM_HERE, reload_task_, delay);
-  }
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::Reload() {
-  if (provider_.get())
-    provider_->NotifyStoreOfPolicyChange();
-  SetupWatches();
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::
-    ReloadFromTask() {
-  // Make sure to not call Cancel() on the task, since it might hold the last
-  // reference that keeps this object alive.
-  reload_task_ = NULL;
-  Reload();
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::
-    OnObjectSignaled(HANDLE object) {
-  DCHECK(object == user_policy_changed_event_.handle() ||
-         object == machine_policy_changed_event_.handle())
-      << "unexpected object signaled policy reload, obj = "
-      << std::showbase << std::hex << object;
-  Reload();
-}
-
-void ConfigurationPolicyProviderWin::GroupPolicyChangeWatcher::
-    WillDestroyCurrentMessageLoop() {
-  reload_task_ = NULL;
-  MessageLoop::current()->RemoveDestructionObserver(this);
-}
-
 ConfigurationPolicyProviderWin::ConfigurationPolicyProviderWin(
     const PolicyDefinitionList* policy_list)
-    : ConfigurationPolicyProvider(policy_list) {
-  watcher_ = new GroupPolicyChangeWatcher(this->AsWeakPtr(),
-                                          kReloadIntervalMinutes);
-  watcher_->Start();
-}
-
-ConfigurationPolicyProviderWin::~ConfigurationPolicyProviderWin() {
-  watcher_->Stop();
-}
-
-bool ConfigurationPolicyProviderWin::GetRegistryPolicyString(
-    const string16& name, string16* result) const {
-  string16 path = string16(kRegistrySubKey);
-  RegKey policy_key;
-  // First try the global policy.
-  if (policy_key.Open(HKEY_LOCAL_MACHINE, path.c_str(), KEY_READ)) {
-    if (ReadRegistryStringValue(&policy_key, name, result))
-      return true;
-    policy_key.Close();
-  }
-  // Fall back on user-specific policy.
-  if (!policy_key.Open(HKEY_CURRENT_USER, path.c_str(), KEY_READ))
-    return false;
-  return ReadRegistryStringValue(&policy_key, name, result);
-}
-
-bool ConfigurationPolicyProviderWin::GetRegistryPolicyStringList(
-    const string16& key, ListValue* result) const {
-  string16 path = string16(kRegistrySubKey);
-  path += ASCIIToUTF16("\\") + key;
-  RegKey policy_key;
-  if (!policy_key.Open(HKEY_LOCAL_MACHINE, path.c_str(), KEY_READ)) {
-    policy_key.Close();
-    // Fall back on user-specific policy.
-    if (!policy_key.Open(HKEY_CURRENT_USER, path.c_str(), KEY_READ))
-      return false;
-  }
-  string16 policy_string;
-  int index = 0;
-  while (ReadRegistryStringValue(&policy_key, base::IntToString16(++index),
-                                 &policy_string)) {
-    result->Append(Value::CreateStringValue(policy_string));
-  }
-  return true;
-}
-
-bool ConfigurationPolicyProviderWin::GetRegistryPolicyBoolean(
-    const string16& value_name, bool* result) const {
-  DWORD value;
-  RegKey hkcu_policy_key(HKEY_LOCAL_MACHINE, kRegistrySubKey, KEY_READ);
-  if (hkcu_policy_key.ReadValueDW(value_name.c_str(), &value)) {
-    *result = value != 0;
-    return true;
-  }
-
-  RegKey hklm_policy_key(HKEY_CURRENT_USER, kRegistrySubKey, KEY_READ);
-  if (hklm_policy_key.ReadValueDW(value_name.c_str(), &value)) {
-    *result = value != 0;
-    return true;
-  }
-  return false;
-}
-
-bool ConfigurationPolicyProviderWin::GetRegistryPolicyInteger(
-    const string16& value_name, uint32* result) const {
-  DWORD value;
-  RegKey hkcu_policy_key(HKEY_LOCAL_MACHINE, kRegistrySubKey, KEY_READ);
-  if (hkcu_policy_key.ReadValueDW(value_name.c_str(), &value)) {
-    *result = value;
-    return true;
-  }
-
-  RegKey hklm_policy_key(HKEY_CURRENT_USER, kRegistrySubKey, KEY_READ);
-  if (hklm_policy_key.ReadValueDW(value_name.c_str(), &value)) {
-    *result = value;
-    return true;
-  }
-  return false;
-}
-
-bool ConfigurationPolicyProviderWin::Provide(
-    ConfigurationPolicyStoreInterface* store) {
-  // This function calls GetRegistryPolicy* which hit up the registry. Those
-  // are I/O functions not allowed to be called on the main thread.
-  // http://crbug.com/66453
-  base::ThreadRestrictions::ScopedAllowIO allow_io;
-  const PolicyDefinitionList* policy_list(policy_definition_list());
-  for (const PolicyDefinitionList::Entry* current = policy_list->begin;
-       current != policy_list->end; ++current) {
-    std::wstring name = UTF8ToWide(current->name);
-    switch (current->value_type) {
-      case Value::TYPE_STRING: {
-        std::wstring string_value;
-        if (GetRegistryPolicyString(name.c_str(), &string_value)) {
-          store->Apply(current->policy_type,
-                       Value::CreateStringValue(string_value));
-        }
-        break;
-      }
-      case Value::TYPE_LIST: {
-        scoped_ptr<ListValue> list_value(new ListValue);
-        if (GetRegistryPolicyStringList(name.c_str(), list_value.get()))
-          store->Apply(current->policy_type, list_value.release());
-        break;
-      }
-      case Value::TYPE_BOOLEAN: {
-        bool bool_value;
-        if (GetRegistryPolicyBoolean(name.c_str(), &bool_value)) {
-          store->Apply(current->policy_type,
-                       Value::CreateBooleanValue(bool_value));
-        }
-        break;
-      }
-      case Value::TYPE_INTEGER: {
-        uint32 int_value;
-        if (GetRegistryPolicyInteger(name.c_str(), &int_value)) {
-          store->Apply(current->policy_type,
-                       Value::CreateIntegerValue(int_value));
-        }
-        break;
-      }
-      default:
-        NOTREACHED();
-        return false;
-    }
-  }
-
-  return true;
-}
+    : AsynchronousPolicyProvider(
+          policy_list,
+          new ConfigurationPolicyLoaderWin(
+              new ConfigurationPolicyProviderDelegateWin(policy_list),
+              kReloadIntervalMinutes)) {}
 
 }  // namespace policy