Refactor the windows policy provider to use AsynchronousPolicyProvider.

chrome/browser/policy/configuration_policy_provider_delegate_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_delegate_win.h"
+
+#include "base/string_number_conversions.h"
+#include "base/utf_string_conversions.h"
+#include "base/win/registry.h"
+#include "chrome/common/policy_constants.h"
+
+using base::win::RegKey;
+
+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
+
+namespace policy {
+
+ConfigurationPolicyProviderDelegateWin::ConfigurationPolicyProviderDelegateWin(
+    const ConfigurationPolicyProvider::PolicyDefinitionList*
+        policy_definition_list)
+    : policy_definition_list_(policy_definition_list) {
+}
+
+DictionaryValue* ConfigurationPolicyProviderDelegateWin::Load() {
+  DictionaryValue* result = new DictionaryValue();
+  const ConfigurationPolicyProvider::PolicyDefinitionList::Entry* current;
+  for (current = policy_definition_list_->begin;
+       current != policy_definition_list_->end;
+       ++current) {
+    const string16 name(ASCIIToUTF16(current->name));
+    switch (current->value_type) {
+      case Value::TYPE_STRING: {
+        string16 string_value;
+        if (GetRegistryPolicyString(name, &string_value)) {
+          result->SetString(current->name, string_value);
+        }
+        break;
+      }
+      case Value::TYPE_LIST: {
+        scoped_ptr<ListValue> list_value(new ListValue);
+        if (GetRegistryPolicyStringList(name, list_value.get()))
+          result->Set(current->name, list_value.release());
+        break;
+      }
+      case Value::TYPE_BOOLEAN: {
+        bool bool_value;
+        if (GetRegistryPolicyBoolean(name, &bool_value)) {
+          result->SetBoolean(current->name, bool_value);
+        }
+        break;
+      }
+      case Value::TYPE_INTEGER: {
+        uint32 int_value;
+        if (GetRegistryPolicyInteger(name, &int_value)) {
+          result->SetInteger(current->name, int_value);
+        }
+        break;
+      }
+      default:
+        NOTREACHED();
+    }
+  }
+  return result;
+}
+
+bool ConfigurationPolicyProviderDelegateWin::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 ConfigurationPolicyProviderDelegateWin::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 ConfigurationPolicyProviderDelegateWin::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 ConfigurationPolicyProviderDelegateWin::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;
+}
+
+}  // namespace policy