Implemented base class for cached settings storages

src/lib/components/MaintenancePopup.js

@@ -272,12 +272,12 @@ export class MaintenancePopup extends BaseComponent {
       }
     });
 
-    const unsubscribeFromMaintenanceSettings = MaintenanceSettings.subscribe(settings => {
-      if (settings.activeProfileId === lastActiveProfileId) {
+    const unsubscribeFromMaintenanceSettings = this.#maintenanceSettings.subscribe(settings => {
+      if (settings.activeProfile === lastActiveProfileId) {
         return;
       }
 
-      lastActiveProfileId = settings.activeProfileId;
+      lastActiveProfileId = settings.activeProfile;
 
       this.#maintenanceSettings
         .resolveActiveProfileAsObject()

src/lib/extension/base/CacheableSettings.js

@@ -0,0 +1,79 @@
+import ConfigurationController from "$lib/extension/ConfigurationController.js";
+
+export default class CacheableSettings {
+  /** @type {ConfigurationController} */
+  #controller;
+  /** @type {Map<string, any>} */
+  #cachedValues = new Map();
+  /** @type {function[]} */
+  #disposables = [];
+
+  constructor(settingsNamespace) {
+    this.#controller = new ConfigurationController(settingsNamespace);
+
+    this.#disposables.push(
+      this.#controller.subscribeToChanges(settings => {
+        for (const key of Object.keys(settings)) {
+          this.#cachedValues.set(key, settings[key]);
+        }
+      })
+    );
+  }
+
+  /**
+   * @template SettingType
+   * @param {string} settingName
+   * @param {SettingType} defaultValue
+   * @return {Promise<SettingType>}
+   * @protected
+   */
+  async _resolveSetting(settingName, defaultValue) {
+    if (this.#cachedValues.has(settingName)) {
+      return this.#cachedValues.get(settingName);
+    }
+
+    const settingValue = await this.#controller.readSetting(settingName, defaultValue);
+
+    this.#cachedValues.set(settingName, settingValue);
+
+    return settingValue;
+  }
+
+  /**
+   * @param {string} settingName Name of the setting to write.
+   * @param {*} value Value to pass.
+   * @param {boolean} [force=false] Ignore the cache and force the update.
+   * @return {Promise<void>}
+   * @protected
+   */
+  async _writeSetting(settingName, value, force = false) {
+    if (
+      !force
+      && this.#cachedValues.has(settingName)
+      && this.#cachedValues.get(settingName) === value
+    ) {
+      return;
+    }
+
+    return this.#controller.writeSetting(settingName, value);
+  }
+
+  /**
+   * Subscribe to the changes made to the storage.
+   * @param {function(Object): void} callback Callback which will receive list of settings.
+   * @return {function(): void} Unsubscribe function.
+   */
+  subscribe(callback) {
+    const unsubscribeCallback = this.#controller.subscribeToChanges(callback);
+
+    this.#disposables.push(unsubscribeCallback);
+
+    return unsubscribeCallback;
+  }
+
+  dispose() {
+    for (let disposeCallback of this.#disposables) {
+      disposeCallback();
+    }
+  }
+}

src/lib/extension/settings/MaintenanceSettings.js

@@ -1,21 +1,10 @@
 import ConfigurationController from "$lib/extension/ConfigurationController.js";
 import MaintenanceProfile from "$lib/extension/entities/MaintenanceProfile.js";
+import CacheableSettings from "$lib/extension/base/CacheableSettings.js";
 
-export default class MaintenanceSettings {
-  #isInitialized = false;
-  #activeProfileId = null;
-
+export default class MaintenanceSettings extends CacheableSettings {
   constructor() {
-    void this.#initializeSettings();
-  }
-
-  async #initializeSettings() {
-    MaintenanceSettings.#controller.subscribeToChanges(settings => {
-      this.#activeProfileId = settings.activeProfile || null;
-    });
-
-    this.#activeProfileId = await MaintenanceSettings.#controller.readSetting("activeProfile", null);
-    this.#isInitialized = true;
+    super("maintenance");
   }
 
   /**
@@ -24,18 +13,7 @@ export default class MaintenanceSettings {
    * @return {Promise<string|null>}
    */
   async resolveActiveProfileId() {
-    if (!this.#isInitialized && !this.#activeProfileId) {
-      this.#activeProfileId = await MaintenanceSettings.#controller.readSetting(
-        "activeProfile",
-        null
-      );
-    }
-
-    if (!this.#activeProfileId) {
-      return null;
-    }
-
-    return this.#activeProfileId;
+    return this._resolveSetting("activeProfile", null);
   }
 
   /**
@@ -59,31 +37,27 @@ export default class MaintenanceSettings {
    * @return {Promise<void>}
    */
   async setActiveProfileId(profileId) {
-    this.#activeProfileId = profileId;
-
-    await MaintenanceSettings.#controller.writeSetting("activeProfile", profileId);
+    await this._writeSetting("activeProfile", profileId);
   }
 
-  /**
-   * Controller for interaction with the settings stored in the extension's storage.
-   *
-   * @type {ConfigurationController}
-   */
-  static #controller = new ConfigurationController("maintenance");
-
   /**
    * Subscribe to the changes in the maintenance-related settings.
    *
-   * @param {function({activeProfileId: string|null}): void} callback Callback to call when the settings change. The new settings are
-   * passed as an argument.
+   * @param {function(MaintenanceSettingsObject): void} callback Callback to call when the settings change. The new
+   * settings are passed as an argument.
    *
    * @return {function(): void} Unsubscribe function.
    */
-  static subscribe(callback) {
-    return MaintenanceSettings.#controller.subscribeToChanges(settings => {
+  subscribe(callback) {
+    return super.subscribe(settings => {
       callback({
-        activeProfileId: settings.activeProfile || null,
+        activeProfile: settings.activeProfile || null,
       });
     });
   }
 }
+
+/**
+ * @typedef {Object} MaintenanceSettingsObject
+ * @property {string|null} activeProfile
+ */