[fsp] Separate logic for saving/restoring state to a separate class.

chrome/browser/chromeos/file_system_provider/registry.cc

+// Copyright 2014 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/file_system_provider/registry.h"
+
+#include "base/files/file_path.h"
+#include "base/prefs/pref_service.h"
+#include "base/prefs/scoped_user_pref_update.h"
+#include "base/stl_util.h"
+#include "chrome/browser/chromeos/file_system_provider/mount_path_util.h"
+#include "chrome/browser/chromeos/file_system_provider/observer.h"
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system.h"
+#include "chrome/browser/chromeos/file_system_provider/provided_file_system_info.h"
+#include "chrome/browser/chromeos/file_system_provider/service_factory.h"
+#include "chrome/browser/profiles/profile.h"
+#include "chrome/common/pref_names.h"
+#include "components/pref_registry/pref_registry_syncable.h"
+#include "extensions/browser/extension_registry.h"
+#include "extensions/browser/extension_system.h"
+#include "storage/browser/fileapi/external_mount_points.h"
+
+namespace chromeos {
+namespace file_system_provider {
+
+const char kPrefKeyFileSystemId[] = "file-system-id";
+const char kPrefKeyDisplayName[] = "display-name";
+const char kPrefKeyWritable[] = "writable";
+const char kPrefKeySupportsNotifyTag[] = "supports-notify-tag";
+const char kPrefKeyObservedEntries[] = "observed-entries";
+const char kPrefKeyObservedEntryEntryPath[] = "entry-path";
+const char kPrefKeyObservedEntryRecursive[] = "recursive";
+const char kPrefKeyObservedEntryLastTag[] = "last-tag";
+
+void RegisterProfilePrefs(user_prefs::PrefRegistrySyncable* registry) {
+  registry->RegisterDictionaryPref(
+      prefs::kFileSystemProviderMounted,
+      user_prefs::PrefRegistrySyncable::UNSYNCABLE_PREF);
+}
+
+Registry::Registry(Profile* profile) : profile_(profile) {
+}
+
+Registry::~Registry() {
+}
+
+void Registry::RememberFileSystem(
+    const ProvidedFileSystemInfo& file_system_info,
+    const ObservedEntries& observed_entries) {
+  base::DictionaryValue* const file_system = new base::DictionaryValue();
+  file_system->SetStringWithoutPathExpansion(kPrefKeyFileSystemId,
+                                             file_system_info.file_system_id());
+  file_system->SetStringWithoutPathExpansion(kPrefKeyDisplayName,
+                                             file_system_info.display_name());
+  file_system->SetBooleanWithoutPathExpansion(kPrefKeyWritable,
+                                              file_system_info.writable());
+  file_system->SetBooleanWithoutPathExpansion(
+      kPrefKeySupportsNotifyTag, file_system_info.supports_notify_tag());
+
+  base::DictionaryValue* const observed_entries_value =
+      new base::DictionaryValue();
+  file_system->SetWithoutPathExpansion(kPrefKeyObservedEntries,
+                                       observed_entries_value);
+
+  for (const auto& it : observed_entries) {
+    base::DictionaryValue* const observed_entry = new base::DictionaryValue();
+    observed_entries_value->SetWithoutPathExpansion(it.first.value(),
+                                                    observed_entry);
+    observed_entry->SetStringWithoutPathExpansion(
+        kPrefKeyObservedEntryEntryPath, it.second.entry_path.value());
+    observed_entry->SetBooleanWithoutPathExpansion(
+        kPrefKeyObservedEntryRecursive, it.second.recursive);
+    observed_entry->SetStringWithoutPathExpansion(kPrefKeyObservedEntryLastTag,
+                                                  it.second.last_tag);
+  }
+
+  PrefService* const pref_service = profile_->GetPrefs();
+  DCHECK(pref_service);
+
+  DictionaryPrefUpdate dict_update(pref_service,
+                                   prefs::kFileSystemProviderMounted);
+
+  base::DictionaryValue* file_systems_per_extension = NULL;
+  if (!dict_update->GetDictionaryWithoutPathExpansion(
+          file_system_info.extension_id(), &file_systems_per_extension)) {
+    file_systems_per_extension = new base::DictionaryValue();
+    dict_update->SetWithoutPathExpansion(file_system_info.extension_id(),
+                                         file_systems_per_extension);
+  }
+
+  file_systems_per_extension->SetWithoutPathExpansion(
+      file_system_info.file_system_id(), file_system);
+}
+
+void Registry::ForgetFileSystem(const std::string& extension_id,
+                                const std::string& file_system_id) {
+  PrefService* const pref_service = profile_->GetPrefs();
+  DCHECK(pref_service);
+
+  DictionaryPrefUpdate dict_update(pref_service,
+                                   prefs::kFileSystemProviderMounted);
+
+  base::DictionaryValue* file_systems_per_extension = NULL;
+  if (!dict_update->GetDictionaryWithoutPathExpansion(
+          extension_id, &file_systems_per_extension))
+    return;  // Nothing to forget.
+
+  file_systems_per_extension->RemoveWithoutPathExpansion(file_system_id, NULL);
+  if (!file_systems_per_extension->size())
+    dict_update->Remove(extension_id, NULL);
+}
+
+scoped_ptr<Registry::RestoredFileSystems> Registry::RestoreFileSystems(
+    const std::string& extension_id) {
+  PrefService* const pref_service = profile_->GetPrefs();
+  DCHECK(pref_service);
+
+  const base::DictionaryValue* const file_systems =
+      pref_service->GetDictionary(prefs::kFileSystemProviderMounted);
+  DCHECK(file_systems);
+
+  const base::DictionaryValue* file_systems_per_extension = NULL;
+  if (!file_systems->GetDictionaryWithoutPathExpansion(
+          extension_id, &file_systems_per_extension)) {
+    return make_scoped_ptr(new RestoredFileSystems);  // Nothing to restore.
+  }
+
+  scoped_ptr<RestoredFileSystems> restored_file_systems(
+      new RestoredFileSystems);
+
+  for (base::DictionaryValue::Iterator it(*file_systems_per_extension);
+       !it.IsAtEnd();
+       it.Advance()) {
+    const base::Value* file_system_value = NULL;
+    const base::DictionaryValue* file_system = NULL;
+    file_systems_per_extension->GetWithoutPathExpansion(it.key(),
+                                                        &file_system_value);
+    DCHECK(file_system_value);
+
+    std::string file_system_id;
+    std::string display_name;
+    bool writable = false;
+    bool supports_notify_tag = false;
+
+    if (!file_system_value->GetAsDictionary(&file_system) ||
+        !file_system->GetStringWithoutPathExpansion(kPrefKeyFileSystemId,
+                                                    &file_system_id) ||
+        !file_system->GetStringWithoutPathExpansion(kPrefKeyDisplayName,
+                                                    &display_name) ||
+        !file_system->GetBooleanWithoutPathExpansion(kPrefKeyWritable,
+                                                     &writable) ||
+        !file_system->GetBooleanWithoutPathExpansion(kPrefKeySupportsNotifyTag,
+                                                     &supports_notify_tag) ||
+        file_system_id.empty() || display_name.empty()) {
+      LOG(ERROR)
+          << "Malformed provided file system information in preferences.";
+      continue;
+    }
+
+    MountOptions options;
+    options.file_system_id = file_system_id;
+    options.display_name = display_name;
+    options.writable = writable;
+    options.supports_notify_tag = supports_notify_tag;
+
+    RestoredFileSystem restored_file_system;
+    restored_file_system.extension_id = extension_id;
+    restored_file_system.options = options;
+
+    // Restore observed entries. It's optional, since this field is new.
+    const base::DictionaryValue* observed_entries = NULL;
+    if (file_system->GetDictionaryWithoutPathExpansion(kPrefKeyObservedEntries,
+                                                       &observed_entries)) {
+      for (base::DictionaryValue::Iterator it(*observed_entries); !it.IsAtEnd();
+           it.Advance()) {
+        const base::Value* observed_entry_value = NULL;
+        const base::DictionaryValue* observed_entry = NULL;
+        observed_entries->GetWithoutPathExpansion(it.key(),
+                                                  &observed_entry_value);
+        DCHECK(file_system_value);
+
+        std::string entry_path;
+        bool recursive = false;
+        std::string last_tag;
+
+        if (!observed_entry_value->GetAsDictionary(&observed_entry) ||
+            !observed_entry->GetStringWithoutPathExpansion(
+                kPrefKeyObservedEntryEntryPath, &entry_path) ||
+            !observed_entry->GetBooleanWithoutPathExpansion(
+                kPrefKeyObservedEntryRecursive, &recursive) ||
+            !observed_entry->GetStringWithoutPathExpansion(
+                kPrefKeyObservedEntryLastTag, &last_tag) ||
+            it.key() != entry_path || entry_path.empty() ||
+            (!options.supports_notify_tag && !last_tag.empty())) {
+          LOG(ERROR) << "Malformed observed entry information in preferences.";
+          continue;
+        }
+
+        ObservedEntry restored_observed_entry;
+        restored_observed_entry.entry_path =
+            base::FilePath::FromUTF8Unsafe(entry_path);
+        restored_observed_entry.recursive = recursive;
+        restored_observed_entry.last_tag = last_tag;
+        restored_file_system
+            .observed_entries[base::FilePath::FromUTF8Unsafe(entry_path)] =
+            restored_observed_entry;
+      }
+    }
+    restored_file_systems->push_back(restored_file_system);
+  }
+
+  return restored_file_systems.Pass();
+}
+
+void Registry::UpdateObservedEntryTag(
+    const ProvidedFileSystemInfo& file_system_info,
+    const ObservedEntry& observed_entry) {
+  PrefService* const pref_service = profile_->GetPrefs();
+  DCHECK(pref_service);
+
+  // TODO(mtomasz): Consider optimizing it by moving information about observed
+  // entries, or even file systems to leveldb.
+  DictionaryPrefUpdate dict_update(pref_service,
+                                   prefs::kFileSystemProviderMounted);
+
+  // All of the following checks should not happen in healthy environment.
+  // However, since they rely on storage, DCHECKs can't be used.
+  base::DictionaryValue* file_systems_per_extension = NULL;
+  base::DictionaryValue* file_system = NULL;
+  base::DictionaryValue* observed_entries = NULL;
+  base::DictionaryValue* observed_entry_value = NULL;
+  if (!dict_update->GetDictionaryWithoutPathExpansion(
+          file_system_info.extension_id(), &file_systems_per_extension) ||
+      !file_systems_per_extension->GetDictionaryWithoutPathExpansion(
+          file_system_info.file_system_id(), &file_system) ||
+      !file_system->GetDictionaryWithoutPathExpansion(kPrefKeyObservedEntries,
+                                                      &observed_entries) ||
+      !observed_entries->GetDictionaryWithoutPathExpansion(
+          observed_entry.entry_path.value(), &observed_entry_value)) {
+    // Broken preferences.
+    LOG(ERROR) << "Broken preferences detected while updating a tag.";
+    return;
+  }
+
+  observed_entry_value->SetStringWithoutPathExpansion(
+      kPrefKeyObservedEntryLastTag, observed_entry.last_tag);
+}
+
+}  // namespace file_system_provider
+}  // namespace chromeos