Introduce incognito preference settings.

chrome/browser/prefs/pref_service.cc

-// Copyright (c) 2010 The Chromium Authors. All rights reserved.
+// 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/prefs/pref_service.h"
 
 #include <algorithm>
 #include <string>
 
 #include "app/l10n_util.h"
 #include "base/command_line.h"
 #include "base/file_path.h"
 #include "base/file_util.h"
 #include "base/logging.h"
 #include "base/message_loop.h"
 #include "base/metrics/histogram.h"
 #include "base/stl_util-inl.h"
 #include "base/string_number_conversions.h"
 #include "base/string_util.h"
 #include "base/sys_string_conversions.h"
 #include "base/utf_string_conversions.h"
 #include "build/build_config.h"
 #include "chrome/browser/browser_thread.h"
+#include "chrome/browser/extensions/extension_pref_store.h"
 #include "chrome/browser/policy/configuration_policy_pref_store.h"
 #include "chrome/browser/prefs/command_line_pref_store.h"
 #include "chrome/browser/prefs/default_pref_store.h"
+#include "chrome/browser/prefs/overlay_persistent_pref_store.h"
 #include "chrome/browser/prefs/pref_notifier_impl.h"
 #include "chrome/browser/prefs/pref_value_store.h"
 #include "chrome/common/json_pref_store.h"
 #include "chrome/common/notification_service.h"
 #include "grit/chromium_strings.h"
 #include "grit/generated_resources.h"
 
 namespace {
 
 // A helper function for RegisterLocalized*Pref that creates a Value* based on
@@ skipping 70 matching lines @@
   ConfigurationPolicyPrefStore* device_management =
       ConfigurationPolicyPrefStore::CreateDeviceManagementPolicyPrefStore(
           profile);
   CommandLinePrefStore* command_line =
       new CommandLinePrefStore(CommandLine::ForCurrentProcess());
   JsonPrefStore* user = new JsonPrefStore(
       pref_filename,
       BrowserThread::GetMessageLoopProxyForThread(BrowserThread::FILE));
   ConfigurationPolicyPrefStore* recommended =
       ConfigurationPolicyPrefStore::CreateRecommendedPolicyPrefStore();
+  DefaultPrefStore* default_pref_store = new DefaultPrefStore();
 
   return new PrefService(managed, device_management, extension_prefs,
-                         command_line, user, recommended);
+                         command_line, user, recommended, default_pref_store);
+}
+
+PrefService* PrefService::CreateIncognitoPrefService(
+    PrefStore* incognito_extension_prefs) {
+  return new PrefService(
+      managed_platform_prefs_,
+      device_management_prefs_,
+      incognito_extension_prefs,
+      command_line_prefs_,
+      new OverlayPersistentPrefStore(user_pref_store_.get()),
+      recommended_prefs_,
+      default_store_);

[danno, 2011/01/14 13:05:09]

In previous versions, there was an effort to keep the knowledge of stores other
than the default and user store out of the PrefService. This change seems to
revisit this strategy. Why can the PrefValueStore not have a CloneAndSpecialize
method or equivalent that obviates the need to explicitly track the pref stores
in the PrefService?

[battre, 2011/01/20 17:59:29]

Done.

 }
 
 PrefService::PrefService(PrefStore* managed_platform_prefs,
                          PrefStore* device_management_prefs,
                          PrefStore* extension_prefs,
                          PrefStore* command_line_prefs,
                          PersistentPrefStore* user_prefs,
-                         PrefStore* recommended_prefs)
-    : user_pref_store_(user_prefs) {
+                         PrefStore* recommended_prefs,
+                         DefaultPrefStore* default_store)
+    : managed_platform_prefs_(managed_platform_prefs),
+      device_management_prefs_(device_management_prefs),
+      extension_prefs_(extension_prefs),
+      command_line_prefs_(command_line_prefs),
+      recommended_prefs_(recommended_prefs),
+      user_pref_store_(user_prefs),
+      default_store_(default_store) {
   pref_notifier_.reset(new PrefNotifierImpl(this));
-  default_store_ = new DefaultPrefStore();
   pref_value_store_ =
-      new PrefValueStore(managed_platform_prefs,
-                         device_management_prefs,
-                         extension_prefs,
-                         command_line_prefs,
+      new PrefValueStore(managed_platform_prefs_,
+                         device_management_prefs_,
+                         extension_prefs_,
+                         command_line_prefs_,
                          user_pref_store_,
-                         recommended_prefs,
+                         recommended_prefs_,
                          default_store_,
                          pref_notifier_.get());
   InitFromStorage();
 }
 
 PrefService::~PrefService() {
   DCHECK(CalledOnValidThread());
   STLDeleteContainerPointers(prefs_.begin(), prefs_.end());
   prefs_.clear();
 }
@@ skipping 170 matching lines @@
   bool rv = pref->GetValue()->GetAsString(&result);
   DCHECK(rv);
 #if defined(OS_POSIX)
   // We store filepaths as UTF8, so convert it back to the system type.
   result = base::SysWideToNativeMB(UTF8ToWide(result));
 #endif
   return FilePath(result);
 }
 
 bool PrefService::HasPrefPath(const char* path) const {
-  return pref_value_store_->HasPrefPath(path);
+  const Preference* pref = FindPreference(path);
+  return pref && !pref->IsDefaultValue();
 }
 
 const PrefService::Preference* PrefService::FindPreference(
     const char* pref_name) const {
   DCHECK(CalledOnValidThread());
-  Preference p(this, pref_name);
+  Preference p(this, pref_name, Value::TYPE_NULL);
   PreferenceSet::const_iterator it = prefs_.find(&p);
-  return it == prefs_.end() ? NULL : *it;
+  if (it != prefs_.end())
+    return *it;
+  const Value::ValueType type = default_store_->GetType(pref_name);
+  if (type == Value::TYPE_NULL)
+    return NULL;
+  Preference* new_pref = new Preference(this, pref_name, type);
+  prefs_.insert(new_pref);
+  return new_pref;
 }
 
 bool PrefService::ReadOnly() const {
   return user_pref_store_->ReadOnly();
 }
 
 PrefNotifier* PrefService::pref_notifier() const {
   return pref_notifier_.get();
 }
 
 bool PrefService::IsManagedPreference(const char* pref_name) const {
   const Preference* pref = FindPreference(pref_name);
-  if (pref && pref->IsManaged()) {
-    return true;
-  }
-  return false;
+  return pref && pref->IsManaged();
 }
 
 const DictionaryValue* PrefService::GetDictionary(const char* path) const {
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to read an unregistered pref: " << path;
     return NULL;
   }
@@ skipping 35 matching lines @@
 
   if (FindPreference(path)) {
     NOTREACHED() << "Tried to register duplicate pref " << path;
     return;
   }
 
   Value::ValueType orig_type = default_value->GetType();
   DCHECK(orig_type != Value::TYPE_NULL && orig_type != Value::TYPE_BINARY) <<
          "invalid preference type: " << orig_type;
 
-  // We set the default value of dictionaries and lists to be null so it's
-  // easier for callers to check for empty dict/list prefs. The PrefValueStore
-  // accepts ownership of the value (null or default_value).
-  if (Value::TYPE_LIST == orig_type || Value::TYPE_DICTIONARY == orig_type) {
-    default_store_->SetDefaultValue(path, Value::CreateNullValue());
-  } else {
-    // Hand off ownership.
-    default_store_->SetDefaultValue(path, scoped_value.release());
-  }
-
-  pref_value_store_->RegisterPreferenceType(path, orig_type);
-  prefs_.insert(new Preference(this, path));
+  // Hand off ownership.
+  default_store_->SetDefaultValue(path, scoped_value.release());
 }
 
 void PrefService::ClearPref(const char* path) {
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to clear an unregistered pref: " << path;
     return;
   }
   user_pref_store_->RemoveValue(path);
 }
 
 void PrefService::Set(const char* path, const Value& value) {
   DCHECK(CalledOnValidThread());
 
   const Preference* pref = FindPreference(path);
   if (!pref) {
     NOTREACHED() << "Trying to write an unregistered pref: " << path;
     return;
   }
 
-  // Allow dictionary and list types to be set to null, which removes their
-  // user values.
-  if (value.GetType() == Value::TYPE_NULL &&
-      (pref->GetType() == Value::TYPE_DICTIONARY ||
-       pref->GetType() == Value::TYPE_LIST)) {
-    user_pref_store_->RemoveValue(path);
-  } else if (pref->GetType() != value.GetType()) {
+  if (pref->GetType() != value.GetType()) {
     NOTREACHED() << "Trying to set pref " << path
                  << " of type " << pref->GetType()
                  << " to value of type " << value.GetType();
   } else {
     user_pref_store_->SetValue(path, value.DeepCopy());
   }
 }
 
 void PrefService::SetBoolean(const char* path, bool value) {
   SetUserPrefValue(path, Value::CreateBooleanValue(value));
@@ skipping 121 matching lines @@
     return;
   }
 
   user_pref_store_->SetValue(path, new_value);
 }
 
 ///////////////////////////////////////////////////////////////////////////////
 // PrefService::Preference
 
 PrefService::Preference::Preference(const PrefService* service,
-                                    const char* name)
+                                    const char* name,
+                                    Value::ValueType type)
       : name_(name),
+        type_(type),
         pref_service_(service) {
   DCHECK(name);
   DCHECK(service);
 }
 
 Value::ValueType PrefService::Preference::GetType() const {
-  return pref_service_->pref_value_store_->GetRegisteredType(name_);
+  return type_;
 }
 
 const Value* PrefService::Preference::GetValue() const {
   DCHECK(pref_service_->FindPreference(name_.c_str())) <<
       "Must register pref before getting its value";
 
   Value* found_value = NULL;
-  if (pref_service_->pref_value_store_->GetValue(name_, &found_value))
+  if (pref_service_->pref_value_store_->GetValue(name_, type_, &found_value)) {
+    DCHECK(found_value->IsType(type_));
     return found_value;
+  }
 
   // Every registered preference has at least a default value.
   NOTREACHED() << "no valid value found for registered pref " << name_;
   return NULL;
 }
 
 bool PrefService::Preference::IsManaged() const {
   PrefValueStore* pref_value_store = pref_service_->pref_value_store_;
   return pref_value_store->PrefValueInManagedPlatformStore(name_.c_str()) ||
       pref_value_store->PrefValueInDeviceManagementStore(name_.c_str());
@@ skipping 21 matching lines @@
 
 bool PrefService::Preference::IsDefaultValue() const {
   return pref_service_->pref_value_store_->
       PrefValueFromDefaultStore(name_.c_str());
 }
 
 bool PrefService::Preference::IsUserModifiable() const {
   return pref_service_->pref_value_store_->
       PrefValueUserModifiable(name_.c_str());
 }