Migrate PreferencesRepository from location/nearby to third_party/nearby

PiperOrigin-RevId: 524185819
2026-09-16 15:36:12 -04:00 · 2023-04-13 21:19:12 -07:00
parent b023a666b9
commit 00bba36219
13 changed files with 651 additions and 1 deletions
@@ -0,0 +1,145 @@
+// Copyright 2023 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     https://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+#include "internal/platform/implementation/windows/preferences_repository.h"
+
+#include <exception>
+#include <filesystem>  // NOLINT(build/c++17)
+#include <fstream>
+#include <optional>
+
+#include "nlohmann/json.hpp"
+#include "nlohmann/json_fwd.hpp"
+#include "internal/platform/logging.h"
+
+namespace nearby {
+namespace windows {
+namespace {
+using json = ::nlohmann::json;
+
+constexpr char kPreferencesFileName[] = "preferences.json";
+constexpr char kPreferencesBackupFileName[] = "preferences_bak.json";
+
+}  // namespace
+
+json PreferencesRepository::LoadPreferences() {
+  absl::MutexLock lock(&mutex_);
+  std::optional<json> preferences = AttemptLoad();
+  if (preferences.has_value()) {
+    return preferences.value();
+  }
+
+  NEARBY_LOGS(ERROR) << "Could not load preferences file, trying backup.";
+
+  // In the future we should switch to using a transaction log or another
+  // stable method which doesn't pose a risk of losing settings
+  preferences = RestoreFromBackup();
+  if (preferences.has_value()) {
+    NEARBY_LOGS(ERROR) << "Successfully recovered from backup.";
+    return preferences.value();
+  }
+
+  NEARBY_LOGS(ERROR) << "Failed to load preferences file from back up.";
+
+  return json::object();
+}
+
+bool PreferencesRepository::SavePreferences(json preferences) {
+  absl::MutexLock lock(&mutex_);
+  try {
+    std::filesystem::path path = path_;
+    if (!std::filesystem::exists(path) &&
+        !std::filesystem::create_directories(path)) {
+      NEARBY_LOGS(ERROR) << "Failed to create preferences path.";
+      return false;
+    }
+
+    std::filesystem::path full_name = path / kPreferencesFileName;
+    std::filesystem::path full_name_backup = path / kPreferencesBackupFileName;
+
+    // Create a backup without moving the bytes on disk
+    if (std::filesystem::exists(full_name)) {
+      NEARBY_LOGS(INFO) << "Making backup of preferences file.";
+      std::filesystem::rename(full_name, full_name_backup);
+    }
+
+    std::ofstream preferences_file(full_name.c_str());
+    preferences_file << preferences;
+    preferences_file.close();
+
+    // Make sure the file wasn't saved in a corrupted state
+    if (!AttemptLoad().has_value()) {
+      NEARBY_LOGS(ERROR) << "Preferences saved to disk in corrupted state. "
+                            "Restoring from backup.";
+
+      if (!RestoreFromBackup().has_value()) {
+        NEARBY_LOGS(ERROR) << "Failed to restore preferences file.";
+        return false;
+      }
+    }
+  } catch (const std::exception& e) {
+    NEARBY_LOGS(ERROR) << "Failed to save preferences file: " << e.what();
+    return false;
+  }
+
+  return true;
+}
+
+std::optional<json> PreferencesRepository::AttemptLoad() {
+  std::filesystem::path path = path_;
+  std::filesystem::path full_name = path / kPreferencesFileName;
+  if (!std::filesystem::exists(path) || !std::filesystem::exists(full_name)) {
+    return std::nullopt;
+  }
+
+  try {
+    std::ifstream preferences_file(full_name.c_str());
+    if (!preferences_file.good()) {
+      return std::nullopt;
+    }
+
+    json preferences = json::parse(preferences_file, nullptr, false);
+    preferences_file.close();
+
+    if (preferences.is_discarded()) {
+      NEARBY_LOGS(ERROR) << "Preferences file corrupted.";
+      return std::nullopt;
+    }
+
+    return preferences;
+  } catch (const std::exception& e) {
+    NEARBY_LOGS(ERROR) << "Exception while loading preferences: " << e.what();
+    return std::nullopt;
+  }
+}
+
+std::optional<json> PreferencesRepository::RestoreFromBackup() {
+  std::filesystem::path path = path_;
+  std::filesystem::path full_name = path / kPreferencesFileName;
+  std::filesystem::path full_name_backup = path / kPreferencesBackupFileName;
+
+  if (!std::filesystem::exists(full_name_backup)) {
+    NEARBY_LOGS(WARNING)
+        << "Backup requested but no backup preferences file found.";
+    return std::nullopt;
+  }
+
+  std::filesystem::rename(full_name_backup, full_name);
+
+  NEARBY_LOGS(INFO) << "Attempting load from backup preferences.";
+  return AttemptLoad();
+}
+
+}  // namespace windows
+}  // namespace nearby