Add ManagedUserSharedSettingsService.

chrome/browser/managed_mode/managed_user_shared_settings_service.cc

Index: chrome/browser/managed_mode/managed_user_shared_settings_service.cc
diff --git a/chrome/browser/managed_mode/managed_user_shared_settings_service.cc b/chrome/browser/managed_mode/managed_user_shared_settings_service.cc
new file mode 100644
index 0000000000000000000000000000000000000000..13dbeb596ae441870cfe705f3e2473f3aecc74a2
--- /dev/null
+++ b/chrome/browser/managed_mode/managed_user_shared_settings_service.cc
@@ -0,0 +1,328 @@
+// Copyright 2013 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/managed_mode/managed_user_shared_settings_service.h"
+
+#include "base/json/json_reader.h"
+#include "base/json/json_writer.h"
+#include "base/prefs/pref_service.h"
+#include "base/prefs/scoped_user_pref_update.h"
+#include "base/values.h"
+#include "chrome/common/pref_names.h"
+#include "components/user_prefs/pref_registry_syncable.h"
+#include "sync/api/sync_change.h"
+#include "sync/api/sync_data.h"
+#include "sync/api/sync_error.h"
+#include "sync/api/sync_error_factory.h"
+#include "sync/api/sync_merge_result.h"
+#include "sync/protocol/sync.pb.h"
+
+using base::DictionaryValue;
+using base::Value;
+using syncer::MANAGED_USER_SHARED_SETTINGS;
+using syncer::ModelType;
+using syncer::SyncChange;
+using syncer::SyncChangeList;
+using syncer::SyncChangeProcessor;
+using syncer::SyncData;
+using syncer::SyncDataList;
+using syncer::SyncError;
+using syncer::SyncErrorFactory;
+using syncer::SyncMergeResult;
+
+namespace {
+
+const char kAcknowledged[] = "acknowledged";
+const char kValue[] = "value";
+
+DictionaryValue* FindOrCreateDictionary(DictionaryValue* parent,
+                                        const std::string& key) {
+  DictionaryValue* dict = NULL;
+  if (!parent->GetDictionaryWithoutPathExpansion(key, &dict)) {
+    dict = new DictionaryValue;
+    parent->SetWithoutPathExpansion(key, dict);
+  }
+  return dict;
+}
+
+class ScopedManagedUserSharedSettingsUpdate {
+ public:
+  ScopedManagedUserSharedSettingsUpdate(PrefService* prefs,
+                                        const std::string& mu_id)
+      : update_(prefs, prefs::kManagedUserSharedSettings), mu_id_(mu_id) {
+    // A supervised user can only modify their own settings.
+    std::string id = prefs->GetString(prefs::kManagedUserId);
+    DCHECK(id.empty() || id == mu_id);

[Pam (message me for reviews), 2014/01/08 10:30:40]

Suggest also checking that the mu_id is not empty.

[Bernhard Bauer, 2014/01/08 11:42:04]

Done.

+  }
+
+  DictionaryValue* Get() {
+    return FindOrCreateDictionary(update_.Get(), mu_id_);
+  }
+
+ private:
+  DictionaryPrefUpdate update_;
+  std::string mu_id_;
+};
+
+SyncData CreateSyncDataForValue(
+    const std::string& mu_id,
+    const std::string& key,
+    const Value& dict_value) {
+  const DictionaryValue* dict = NULL;
+  if (!dict_value.GetAsDictionary(&dict))
+    return SyncData();
+
+  const Value* value = NULL;
+  if (!dict->Get(kValue, &value))
+    return SyncData();
+
+  bool acknowledged = false;
+  dict->GetBoolean(kAcknowledged, &acknowledged);
+
+  return ManagedUserSharedSettingsService::CreateSyncDataForSetting(
+      mu_id, key, *value, acknowledged);
+}
+
+}  // namespace
+
+
+ManagedUserSharedSettingsService::ManagedUserSharedSettingsService(
+    PrefService* prefs)
+    : prefs_(prefs) {}
+
+ManagedUserSharedSettingsService::~ManagedUserSharedSettingsService() {}
+
+void ManagedUserSharedSettingsService::SetValueInternal(
+    const std::string& mu_id,
+    const std::string& key,
+    const Value& value,
+    bool acknowledged) {
+  ScopedManagedUserSharedSettingsUpdate update(prefs_, mu_id);
+  DictionaryValue* update_dict = update.Get();
+
+  DictionaryValue* dict = NULL;
+  bool has_key = update_dict->GetDictionaryWithoutPathExpansion(key, &dict);
+  if (!has_key) {
+    dict = new DictionaryValue;
+    update_dict->SetWithoutPathExpansion(key, dict);
+  }
+  dict->SetWithoutPathExpansion(kValue, value.DeepCopy());
+  dict->SetBooleanWithoutPathExpansion(kAcknowledged, acknowledged);
+
+  if (!sync_processor_)
+    return;
+
+  SyncData data = CreateSyncDataForSetting(mu_id, key, value, acknowledged);
+  SyncChange::SyncChangeType change_type =
+      has_key ? SyncChange::ACTION_UPDATE : SyncChange::ACTION_ADD;
+  SyncChangeList changes;
+  changes.push_back(SyncChange(FROM_HERE, change_type, data));
+  SyncError error = sync_processor_->ProcessSyncChanges(FROM_HERE, changes);
+  DCHECK(!error.IsSet()) << error.ToString();
+}
+
+const Value* ManagedUserSharedSettingsService::GetValue(
+    const std::string& mu_id,
+    const std::string& key) {
+  const DictionaryValue* data =
+      prefs_->GetDictionary(prefs::kManagedUserSharedSettings);
+  const DictionaryValue* dict = NULL;
+  if (!data->GetDictionaryWithoutPathExpansion(mu_id, &dict))

[Pam (message me for reviews), 2014/01/08 10:30:40]

It would be worth documenting these three nested dictionaries in the header.
e.g., the need for a innermost level to hold "value" and "acknowledged" isn't
self-evident to someone not familiar with the setup.

[Bernhard Bauer, 2014/01/08 11:42:04]

Done.

+    return NULL;
+
+  const DictionaryValue* settings = NULL;
+  if (!dict->GetDictionaryWithoutPathExpansion(key, &settings))
+    return NULL;
+
+  const Value* value = NULL;
+  if (!settings->GetWithoutPathExpansion(kValue, &value))
+    return NULL;
+
+  return value;
+}
+
+void ManagedUserSharedSettingsService::SetValue(
+    const std::string& mu_id,
+    const std::string& key,
+    const Value& value) {
+  SetValueInternal(mu_id, key, value, true);
+}
+
+scoped_ptr<ManagedUserSharedSettingsService::CallbackList::Subscription>
+ManagedUserSharedSettingsService::Subscribe(
+    const ManagedUserSharedSettingsService::Callback& cb) {
+  return callbacks_.Add(cb);
+}
+
+// static
+void ManagedUserSharedSettingsService::RegisterProfilePrefs(
+    user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterDictionaryPref(
+      prefs::kManagedUserSharedSettings,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+}
+
+// static
+SyncData ManagedUserSharedSettingsService::CreateSyncDataForSetting(
+    const std::string& mu_id,
+    const std::string& key,
+    const Value& value,
+    bool acknowledged) {
+  std::string json_value;
+  base::JSONWriter::Write(&value, &json_value);
+  ::sync_pb::EntitySpecifics specifics;
+  specifics.mutable_managed_user_shared_setting()->set_mu_id(mu_id);
+  specifics.mutable_managed_user_shared_setting()->set_key(key);
+  specifics.mutable_managed_user_shared_setting()->set_value(json_value);
+  specifics.mutable_managed_user_shared_setting()->set_acknowledged(
+      acknowledged);
+  std::string title = mu_id + ":" + key;
+  return SyncData::CreateLocalData(title, title, specifics);
+}
+
+void ManagedUserSharedSettingsService::Shutdown() {}
+
+syncer::SyncMergeResult
+ManagedUserSharedSettingsService::MergeDataAndStartSyncing(
+    syncer::ModelType type,
+    const syncer::SyncDataList& initial_sync_data,
+    scoped_ptr<syncer::SyncChangeProcessor> sync_processor,
+    scoped_ptr<syncer::SyncErrorFactory> error_handler) {
+  DCHECK_EQ(MANAGED_USER_SHARED_SETTINGS, type);
+  sync_processor_ = sync_processor.Pass();
+  error_handler_ = error_handler.Pass();
+
+  std::map<std::string, std::set<std::string> > seen_keys;

[Pam (message me for reviews), 2014/01/08 10:30:40]

How 'bout some inline comments?

[Bernhard Bauer, 2014/01/08 11:42:04]

Done.

+  for (SyncDataList::const_iterator it = initial_sync_data.begin();
+       it != initial_sync_data.end();
+       ++it) {
+    DCHECK_EQ(MANAGED_USER_SHARED_SETTINGS, it->GetDataType());
+    const ::sync_pb::ManagedUserSharedSettingSpecifics&
+        managed_user_shared_setting =
+            it->GetSpecifics().managed_user_shared_setting();
+    scoped_ptr<Value> value(
+        base::JSONReader::Read(managed_user_shared_setting.value()));
+    const std::string& mu_id = managed_user_shared_setting.mu_id();
+    ScopedManagedUserSharedSettingsUpdate update(prefs_, mu_id);
+    const std::string& key = managed_user_shared_setting.key();
+    DictionaryValue* dict = FindOrCreateDictionary(update.Get(), key);
+    dict->SetWithoutPathExpansion(kValue, value.release());
+    DCHECK(managed_user_shared_setting.acknowledged());
+    dict->SetBooleanWithoutPathExpansion(
+        kAcknowledged, managed_user_shared_setting.acknowledged());
+    callbacks_.Notify(mu_id, key);
+
+    seen_keys[mu_id].insert(key);
+  }
+
+  SyncChangeList change_list;
+  const DictionaryValue* all_settings =
+      prefs_->GetDictionary(prefs::kManagedUserSharedSettings);
+  for (DictionaryValue::Iterator it(*all_settings); !it.IsAtEnd();
+       it.Advance()) {
+    const DictionaryValue* dict = NULL;
+    bool success = it.value().GetAsDictionary(&dict);
+    DCHECK(success);
+
+    const std::set<std::string>& seen = seen_keys[it.key()];
+    for (DictionaryValue::Iterator jt(*dict); !jt.IsAtEnd(); jt.Advance()) {
+      if (seen.count(jt.key()) > 0)
+        continue;
+
+      SyncData data = CreateSyncDataForValue(it.key(), jt.key(), jt.value());
+      DCHECK(data.IsValid());
+      change_list.push_back(
+          SyncChange(FROM_HERE, SyncChange::ACTION_ADD, data));
+    }
+  }
+
+  SyncMergeResult result(MANAGED_USER_SHARED_SETTINGS);
+  // Process all the accumulated changes.
+  if (change_list.size() > 0) {
+    result.set_error(
+        sync_processor_->ProcessSyncChanges(FROM_HERE, change_list));
+  }
+
+  // TODO(bauerb): Statistics?
+  return result;
+}
+
+void ManagedUserSharedSettingsService::StopSyncing(syncer::ModelType type) {
+  DCHECK_EQ(MANAGED_USER_SHARED_SETTINGS, type);
+  sync_processor_.reset();
+  error_handler_.reset();
+}
+
+syncer::SyncDataList ManagedUserSharedSettingsService::GetAllSyncData(
+    syncer::ModelType type) const {
+  DCHECK_EQ(MANAGED_USER_SHARED_SETTINGS, type);
+  SyncDataList data;
+  const DictionaryValue* all_settings =
+      prefs_->GetDictionary(prefs::kManagedUserSharedSettings);
+  for (DictionaryValue::Iterator it(*all_settings); !it.IsAtEnd();
+       it.Advance()) {
+    const DictionaryValue* dict = NULL;
+    bool success = it.value().GetAsDictionary(&dict);
+    DCHECK(success);
+    for (DictionaryValue::Iterator jt(*dict); !jt.IsAtEnd(); jt.Advance()) {
+      data.push_back(CreateSyncDataForValue(it.key(), jt.key(), jt.value()));
+    }
+  }
+  return data;
+}
+
+syncer::SyncError ManagedUserSharedSettingsService::ProcessSyncChanges(
+    const tracked_objects::Location& from_here,
+    const syncer::SyncChangeList& change_list) {
+  for (SyncChangeList::const_iterator it = change_list.begin();
+       it != change_list.end();
+       ++it) {
+    SyncData data = it->sync_data();
+    DCHECK_EQ(MANAGED_USER_SHARED_SETTINGS, data.GetDataType());
+    const ::sync_pb::ManagedUserSharedSettingSpecifics&
+        managed_user_shared_setting =
+            data.GetSpecifics().managed_user_shared_setting();
+    const std::string& key = managed_user_shared_setting.key();
+    const std::string& mu_id = managed_user_shared_setting.mu_id();
+    ScopedManagedUserSharedSettingsUpdate update(prefs_, mu_id);
+    DictionaryValue* update_dict = update.Get();
+    DictionaryValue* dict = NULL;
+    bool has_key = update_dict->GetDictionaryWithoutPathExpansion(key, &dict);
+    switch (it->change_type()) {
+      case SyncChange::ACTION_ADD:
+      case SyncChange::ACTION_UPDATE: {
+        if (has_key) {
+          // For an update action, the managed user should already exist.

[Pam (message me for reviews), 2014/01/08 10:30:40]

This comment is backwards from the logic; i.e., it's really checking "if the MU
already exists, this should be an update action".

I am led to wonder why it matters (why sync cares), but that's outside the scope
of this review.

[Bernhard Bauer, 2014/01/08 11:42:04]

It's a sanity check to make sure that the copy of the data that we have in the
Sync database stays in Sync (ha!) with the copy in Preferences.

+          DCHECK_EQ(SyncChange::ACTION_UPDATE, it->change_type());
+        } else {
+          // For an add action, it should not.
+          DCHECK_EQ(SyncChange::ACTION_ADD, it->change_type());
+          dict = new DictionaryValue;
+          update_dict->SetWithoutPathExpansion(key, dict);
+        }
+        scoped_ptr<Value> value(
+            base::JSONReader::Read(managed_user_shared_setting.value()));
+        dict->SetWithoutPathExpansion(kValue, value.release());
+        dict->SetBooleanWithoutPathExpansion(
+            kAcknowledged, managed_user_shared_setting.acknowledged());
+        break;
+      }
+      case SyncChange::ACTION_DELETE: {
+        if (has_key)
+          update_dict->RemoveWithoutPathExpansion(key, NULL);
+        else
+          NOTREACHED() << "Trying to delete nonexistent key " << key;
+        break;
+      }
+      case SyncChange::ACTION_INVALID: {
+        NOTREACHED();
+        break;
+      }
+    }
+    callbacks_.Notify(mu_id, key);
+  }
+
+  SyncError error;
+  return error;
+}