feat(storage): force save abd exist hook to prevent data lost

packages/core/storage/package.json

@@ -36,6 +36,7 @@
     "url": "https://github.com/AliMD/alwatr/issues"
   },
   "dependencies": {
+    "exit-hook": "^3.1.0",
     "tslib": "^2.3.1"
   }
 }

packages/core/storage/src/storage.ts

@@ -1,11 +1,12 @@
 import {resolve} from 'node:path';
 
 import {alwatrRegisteredList, createLogger} from '@alwatr/logger';
+import {exitHook} from 'exit-hook';
 
 import {readJsonFile, writeJsonFile} from './util.js';
 
 import type {DocumentObject, DocumentListStorage, AlwatrStorageConfig} from './type.js';
-import type {AlwatrLogger} from '@alwatr/logger';
+
 
 export {DocumentObject, DocumentListStorage, AlwatrStorageConfig as Config};
 
@@ -34,12 +35,22 @@ export class AlwatrStorage<DocumentType extends DocumentObject> {
   /**
    * Storage name like database table name.
    */
-  readonly name: string;
+  readonly name;
 
   /**
    * Storage file full path.
    */
-  readonly storagePath: string;
+  readonly storagePath;
+
+  /**
+   * Save debounce timeout for minimal disk iops usage.
+   */
+  readonly saveDebounce;
+
+  /**
+   * Write pretty formatted JSON file.
+   */
+  readonly saveBeautiful;
 
   /**
    * Ready promise resolved when the storage is ready.
@@ -53,7 +64,7 @@ export class AlwatrStorage<DocumentType extends DocumentObject> {
    * const user = userStorage.get('user-1');
    * ```
    */
-  readyPromise: Promise<void>;
+  readyPromise;
 
   /**
    * Ready state set to true when the storage is ready and readyPromise resolved.
@@ -63,7 +74,7 @@ export class AlwatrStorage<DocumentType extends DocumentObject> {
   }
 
   protected _readyState = false;
-  protected _logger: AlwatrLogger;
+  protected _logger;
   protected _storage: DocumentListStorage<DocumentType> = {};
   protected _keys: Array<string> | null = null;
 
@@ -89,8 +100,11 @@ export class AlwatrStorage<DocumentType extends DocumentObject> {
   constructor(config: AlwatrStorageConfig) {
     this._logger = createLogger(`alwatr-storage:${config.name}`);
     this._logger.logMethodArgs('constructor', config);
+    this.forceSave = this.forceSave.bind(this);
     this.name = config.name;
     this.storagePath = resolve(`${config.path ?? './db'}/${config.name}.json`);
+    this.saveDebounce = config.saveDebounce ?? 100;
+    this.saveBeautiful = config.saveBeautiful || false;
     this.readyPromise = this._load();
   }
 
@@ -102,6 +116,7 @@ export class AlwatrStorage<DocumentType extends DocumentObject> {
     this._logger.logMethod('_load');
     this._storage = (await readJsonFile<DocumentListStorage<DocumentType>>(this.storagePath)) ?? {};
     this._readyState = true;
+    exitHook(this.forceSave);
     this._logger.logProperty('readyState', this.readyState);
   }
 
@@ -228,25 +243,34 @@ export class AlwatrStorage<DocumentType extends DocumentObject> {
    * Save the storage to disk.
    */
   save(): void {
-    this._logger.logMethod('save.request');
+    this._logger.logMethod('save');
     if (this._readyState !== true) throw new Error('storage_not_ready');
-
     if (this._saveTimer != null) return; // save already requested
+    this._saveTimer = setTimeout(this.forceSave, this.saveDebounce);
+  }
 
-    this._saveTimer = setTimeout(() => {
-      this._logger.logMethod('save.action');
+  /**
+   * Save the storage to disk without any debounce.
+   */
+  forceSave(): void {
+    this._logger.logMethod('forceSave');
+    if (this._saveTimer != null) {
+      clearTimeout(this._saveTimer);
       this._saveTimer = null;
-      // TODO: catch errors
-      writeJsonFile(this.storagePath, this._storage);
-    }, 100);
+    }
+
+    writeJsonFile(this.storagePath, this._storage, this.saveBeautiful ? 2 : 0);
   }
 
   /**
    * Unload storage data and free ram usage.
    */
   unload(): void {
     this._logger.logMethod('unload');
-    this._readyState = false;
+    if (this._readyState) {
+      this._readyState = false;
+      this.forceSave();
+    }
     this._storage = {};
     this.readyPromise = Promise.reject(new Error('storage_unloaded'));
   }

packages/core/storage/src/type.ts

@@ -26,6 +26,16 @@ export type AlwatrStorageConfig = {
    * @default './db'
    */
   path?: string;
+
+  /**
+   * Save debounce timeout for minimal disk iops usage.
+   */
+  saveDebounce?: number;
+
+  /**
+   * Write pretty formatted JSON file.
+   */
+  saveBeautiful?: boolean;
 };
 
 export type AlwatrStorageProviderConfig = {

packages/core/storage/src/util.ts

@@ -1,4 +1,4 @@
-import {existsSync, promises as fs} from 'fs';
+import {existsSync, mkdirSync, readFileSync, writeFileSync, renameSync} from 'fs';
 import {resolve, dirname} from 'node:path';
 
 import type {JSON} from './type.js';
@@ -8,7 +8,7 @@ import type {JSON} from './type.js';
 /**
  * Enhanced read json file.
  * @example
- * const fileContent = await readJsonFile('./file.json');
+ * const fileContent = readJsonFile('./file.json');
  */
 export async function readJsonFile<T extends JSON>(path: string): Promise<T | null> {
   // Check the path is exist
@@ -19,7 +19,7 @@ export async function readJsonFile<T extends JSON>(path: string): Promise<T | nu
 
   let fileContent;
   try {
-    fileContent = await fs.readFile(path, {encoding: 'utf-8'});
+    fileContent = readFileSync(path, {encoding: 'utf-8'});
   } catch (err) {
     throw new Error('read_file_failed');
   }
@@ -34,28 +34,41 @@ export async function readJsonFile<T extends JSON>(path: string): Promise<T | nu
 /**
  * Enhanced write json file.
  * @example
- * await writeJsonFile('./file.json', { a:1, b:2, c:3 });
+ * writeJsonFile('./file.json', { a:1, b:2, c:3 });
  */
-export async function writeJsonFile<T extends JSON>(path: string, dataObject: T): Promise<void> {
+export async function writeJsonFile<T extends JSON>(
+    path: string,
+    dataObject: T,
+    space?: string | number | undefined,
+): Promise<void> {
   // Check the path is exist
   try {
     path = resolve(path);
     if (!existsSync(path)) {
-      await fs.mkdir(dirname(path), {recursive: true});
+      mkdirSync(dirname(path), {recursive: true});
     }
   } catch (err) {
     throw new Error('make_dir_failed');
   }
 
+  try {
+    if (existsSync(path)) {
+      renameSync(path, path + '.bk');
+    }
+  } catch (err) {
+    // @TODO: handle in forceSave and log with logger
+    console.error('cannot rename file!');
+  }
+
   let jsonContent;
   try {
-    jsonContent = JSON.stringify(dataObject, null, 2);
+    jsonContent = JSON.stringify(dataObject, null, space);
   } catch (err) {
     throw new Error('stringify_failed');
   }
 
   try {
-    await fs.writeFile(path, jsonContent, {encoding: 'utf-8', flag: 'w'});
+    writeFileSync(path, jsonContent, {encoding: 'utf-8', flag: 'w'});
   } catch (err) {
     throw new Error('write_file_failed');
   }

yarn.lock

@@ -2893,6 +2893,11 @@ execa@^5.0.0:
     signal-exit "^3.0.3"
     strip-final-newline "^2.0.0"
 
+exit-hook@^3.1.0:
+  version "3.1.0"
+  resolved "https://registry.yarnpkg.com/exit-hook/-/exit-hook-3.1.0.tgz#0ba691facf29637930ead13e727cdc61860331b9"
+  integrity sha512-KiF9SiLZsKhSutx4V9sG2InYb0v1+2sfKlGD18et8/aGg2m4ij6MJbUHy/cnqJf4ncE7rWjqchE2SNIi4Lgg4A==
+
 expand-brackets@^2.1.4:
   version "2.1.4"
   resolved "https://registry.yarnpkg.com/expand-brackets/-/expand-brackets-2.1.4.tgz#b77735e315ce30f6b6eff0f83b04151a22449622"