WIP: multiple database services

doc/compodoc_sources/concepts/overall-architecture.md

@@ -1,10 +1,10 @@
 # Overall Structure
 
-This is a rough sketch of the architecture of the core system under discussion. The modules and classes shown here are included in the ndb-core repository.
-![](../../images/architecture_core.png)
-
-An actual, specific software system to be used will be based on the core and extend it:
-![](../../images/architecture_concrete-project.png)
+This is a rough sketch of the architecture of the core system under discussion.
+The modules and classes shown here are included in the ndb-core repository.
+Note that some components and services are explicitly designed to be used and extended when developing feature modules,
+while others will usually not need to be touched or understood when extending the system:
+![](../../images/architecture_modules.png)
 
 ## Folder Structure
 

src/app/app.module.ts

@@ -39,7 +39,6 @@ import { ConfigurableEnumModule } from "./core/basic-datatypes/configurable-enum
 import { FaIconLibrary } from "@fortawesome/angular-fontawesome";
 import { fas } from "@fortawesome/free-solid-svg-icons";
 import { far } from "@fortawesome/free-regular-svg-icons";
-import { DatabaseModule } from "./core/database/database.module";
 import { Angulartics2Matomo, Angulartics2Module } from "angulartics2";
 import {
   DEFAULT_LANGUAGE,
@@ -111,7 +110,6 @@ import { SkillModule } from "./features/skill/skill.module";
     // Core modules
     CoreModule,
     ConfigurableEnumModule,
-    DatabaseModule,
     LanguageModule,
     LatestChangesModule,
     PermissionsModule,

src/app/core/admin/admin-overview/admin-overview.component.ts

@@ -6,7 +6,6 @@ import { MatSnackBar } from "@angular/material/snack-bar";
 import { ConfigService } from "../../config/config.service";
 import { UntilDestroy, untilDestroyed } from "@ngneat/until-destroy";
 import { readFile } from "../../../utils/utils";
-import { Database } from "../../database/database";
 import { ExtendedAlertConfig } from "../../alerts/alert-config";
 import { MatButtonModule } from "@angular/material/button";
 import { RouterLink } from "@angular/router";
@@ -15,6 +14,7 @@ import { DownloadService } from "../../export/download-service/download.service"
 import { MatListModule } from "@angular/material/list";
 import { RouteTarget } from "../../../route-target";
 import { AdminOverviewService } from "./admin-overview.service";
+import { DatabaseResolverService } from "../../database/database-resolver.service";
 
 /**
  * Admin GUI giving administrative users different options/actions.
@@ -36,7 +36,7 @@ export class AdminOverviewComponent implements OnInit {
     private alertService: AlertService,
     private backupService: BackupService,
     private downloadService: DownloadService,
-    private db: Database,
+    private dbResolver: DatabaseResolverService,
     private confirmationDialog: ConfirmationDialogService,
     private snackBar: MatSnackBar,
     private configService: ConfigService,
@@ -51,7 +51,8 @@ export class AdminOverviewComponent implements OnInit {
    * Send a reference of the PouchDB to the browser's developer console for real-time debugging.
    */
   debugDatabase() {
-    console.log(this.db);
+    console.log(this.dbResolver);
+    console.log(this.dbResolver.getDatabase());
   }
 
   /**

src/app/core/admin/backup/backup.service.ts

@@ -1,6 +1,7 @@
 import { Injectable } from "@angular/core";
 import { Database } from "../../database/database";
 import { Config } from "../../config/config";
+import { DatabaseResolverService } from "../../database/database-resolver.service";
 
 /**
  * Create and load backups of the database.
@@ -9,7 +10,12 @@ import { Config } from "../../config/config";
   providedIn: "root",
 })
 export class BackupService {
-  constructor(private db: Database) {}
+  private db: Database;
+
+  constructor(private dbResolver: DatabaseResolverService) {
+    this.db = this.dbResolver.getDatabase();
+    // TODO: backup other databases?
+  }
 
   /**
    * Creates an array holding all elements of the database.

src/app/core/database/database-factory.service.ts

@@ -0,0 +1,30 @@
+import { inject, Injectable } from "@angular/core";
+import { Database } from "./database";
+import { PouchDatabase } from "./pouch-database";
+import { KeycloakAuthService } from "../session/auth/keycloak/keycloak-auth.service";
+import { environment } from "../../../environments/environment";
+import { SessionType } from "../session/session-type";
+
+/**
+ * Provides a method to generate Database instances.
+ *
+ * (can be re-implemented to cater to different Database implementations).
+ */
+@Injectable({
+  providedIn: "root",
+})
+export class DatabaseFactoryService {
+  private authService = inject(KeycloakAuthService);
+
+  createDatabase(dbName: string): Database {
+    const db = new PouchDatabase(this.authService);
+
+    if (environment.session_type === SessionType.mock) {
+      db.initInMemoryDB(dbName);
+    } else {
+      db.initIndexedDB(dbName);
+    }
+
+    return db;
+  }
+}

src/app/core/database/database-resolver.service.spec.ts

@@ -0,0 +1,16 @@
+import { TestBed } from '@angular/core/testing';
+
+import { DatabaseResolverService } from './database-resolver.service';
+
+describe('DatabaseResolverService', () => {
+  let service: DatabaseResolverService;
+
+  beforeEach(() => {
+    TestBed.configureTestingModule({});
+    service = TestBed.inject(DatabaseResolverService);
+  });
+
+  it('should be created', () => {
+    expect(service).toBeTruthy();
+  });
+});

src/app/core/database/database-resolver.service.ts

@@ -0,0 +1,38 @@
+import { inject, Injectable } from "@angular/core";
+import { Database } from "./database";
+import { SessionInfo } from "../session/auth/session-info";
+import { environment } from "../../../environments/environment";
+import { DatabaseFactoryService } from "./database-factory.service";
+
+/**
+ * Manages access to individual databases,
+ * as data may be stored across multiple different instances.
+ */
+@Injectable({
+  providedIn: "root",
+})
+export class DatabaseResolverService {
+  static readonly DEFAULT_DB = "app";
+
+  private databases: Map<string, Database> = new Map();
+  private databaseFactory = inject(DatabaseFactoryService);
+
+  getDatabase(dbName: string = DatabaseResolverService.DEFAULT_DB): Database {
+    return this.databases.get(dbName);
+  }
+
+  resetDatabases() {}
+
+  async initDatabasesForSession(session: SessionInfo) {
+    this.initializeAppDatabaseForCurrentUser(session);
+    // TODO: init other DBs
+  }
+
+  private initializeAppDatabaseForCurrentUser(user: SessionInfo) {
+    const userDBName = `${user.name}-${environment.DB_NAME}`;
+    const userDb = this.databaseFactory.createDatabase(userDBName);
+    this.databases.set(environment.DB_NAME, userDb);
+
+    // TODO: have removed fallback to old "app" IndexedDB database here; check sentry if this may cause larger impact
+  }
+}

src/app/core/database/database.ts

@@ -20,6 +20,10 @@ import { Observable } from "rxjs";
 /**
  * An implementation of this abstract class provides functions for direct database access.
  * This interface is an extension of the [PouchDB API](https://pouchdb.com/api.html).
+ *
+ * PLEASE NOTE:
+ * Direct access to the Database layer is rarely necessary, and you should probably use EntityMapperService instead.
+ * Database is not an Angular Service and has to be accessed through the DatabaseResolverService.
  */
 export abstract class Database {
   /**

src/app/core/database/pouch-database.ts

@@ -20,7 +20,6 @@ import { Logging } from "../logging/logging.service";
 import PouchDB from "pouchdb-browser";
 import memory from "pouchdb-adapter-memory";
 import { PerformanceAnalysisLogging } from "../../utils/performance-analysis-logging";
-import { Injectable, Optional } from "@angular/core";
 import { firstValueFrom, Observable, Subject } from "rxjs";
 import { filter } from "rxjs/operators";
 import { HttpStatusCode } from "@angular/common/http";
@@ -34,7 +33,6 @@ import { KeycloakAuthService } from "../session/auth/keycloak/keycloak-auth.serv
  * Additional convenience functions on top of the PouchDB API
  * should be implemented in the abstract {@link Database}.
  */
-@Injectable()
 export class PouchDatabase extends Database {
   /**
    * Small helper function which creates a database with in-memory PouchDB initialized
@@ -66,9 +64,13 @@ export class PouchDatabase extends Database {
 
   /**
    * Create a PouchDB database manager.
+   * @param authService (Optional) the authentication service that may require additional auth headers for remote DB access
    */
-  constructor(@Optional() private authService?: KeycloakAuthService) {
+  constructor(private authService?: KeycloakAuthService) {
     super();
+
+    // TODO: refactor to run the init method directly from constructor and remove databaseInitialized
+    //  now that DatabaseResolver handles creation and provider we don't have to separate creation and initialization anymore
   }
 
   /**

src/app/core/demo-data/demo-data-initializer.service.ts

@@ -6,14 +6,13 @@ import { DemoDataGeneratingProgressDialogComponent } from "./demo-data-generatin
 import { SessionManagerService } from "../session/session-service/session-manager.service";
 import { LocalAuthService } from "../session/auth/local/local-auth.service";
 import { SessionInfo, SessionSubject } from "../session/auth/session-info";
-import { Logging } from "../logging/logging.service";
-import { Database } from "../database/database";
 import { PouchDatabase } from "../database/pouch-database";
 import { environment } from "../../../environments/environment";
 import { LoginState } from "../session/session-states/login-state.enum";
 import { LoginStateSubject, SessionType } from "../session/session-type";
 import memory from "pouchdb-adapter-memory";
 import PouchDB from "pouchdb-browser";
+import { DatabaseResolverService } from "../database/database-resolver.service";
 
 /**
  * This service handles everything related to the demo-mode
@@ -25,7 +24,6 @@ import PouchDB from "pouchdb-browser";
 @Injectable()
 export class DemoDataInitializerService {
   private liveSyncHandle: PouchDB.Replication.Sync<any>;
-  private pouchDatabase: PouchDatabase;
   private readonly normalUser: SessionInfo = {
     name: DemoUserGeneratorService.DEFAULT_USERNAME,
     id: DemoUserGeneratorService.DEFAULT_USERNAME,
@@ -38,12 +36,13 @@ export class DemoDataInitializerService {
     roles: ["user_app", "admin_app"],
     entityId: `User:${DemoUserGeneratorService.ADMIN_USERNAME}`,
   };
+
   constructor(
     private demoDataService: DemoDataService,
     private localAuthService: LocalAuthService,
     private sessionManager: SessionManagerService,
     private dialog: MatDialog,
-    private database: Database,
+    private dbResolver: DatabaseResolverService,
     private loginState: LoginStateSubject,
     private sessionInfo: SessionSubject,
   ) {}
@@ -52,13 +51,6 @@ export class DemoDataInitializerService {
     const dialogRef = this.dialog.open(
       DemoDataGeneratingProgressDialogComponent,
     );
-    if (this.database instanceof PouchDatabase) {
-      this.pouchDatabase = this.database;
-    } else {
-      Logging.warn(
-        "Cannot create demo data with session: " + environment.session_type,
-      );
-    }
 
     this.localAuthService.saveUser(this.normalUser);
     this.localAuthService.saveUser(this.adminUser);
@@ -95,7 +87,9 @@ export class DemoDataInitializerService {
     } else {
       demoUserDB = new PouchDB(dbName);
     }
-    const currentUserDB = this.pouchDatabase.getPouchDB();
+    const currentUserDB = (
+      this.dbResolver.getDatabase() as PouchDatabase
+    ).getPouchDB();
     await currentUserDB.sync(demoUserDB, { batch_size: 500 });
     this.liveSyncHandle = currentUserDB.sync(demoUserDB, {
       live: true,

src/app/core/demo-data/demo-data.service.ts

@@ -24,7 +24,7 @@ import {
 } from "@angular/core";
 import { DemoDataGenerator } from "./demo-data-generator";
 import { EntityMapperService } from "../entity/entity-mapper/entity-mapper.service";
-import { Database } from "../database/database";
+import { DatabaseResolverService } from "../database/database-resolver.service";
 
 /**
  * General config object to pass all initially register DemoDataGenerators
@@ -58,7 +58,7 @@ export class DemoDataService {
     private entityMapper: EntityMapperService,
     private injector: Injector,
     private config: DemoDataServiceConfig,
-    private database: Database,
+    private dbResolver: DatabaseResolverService,
   ) {}
 
   private registerAllProvidedDemoDataGenerators() {
@@ -75,7 +75,7 @@ export class DemoDataService {
    * and add all the generated entities to the Database.
    */
   async publishDemoData() {
-    if (!(await this.database.isEmpty())) {
+    if (!(await this.dbResolver.getDatabase().isEmpty())) {
       return;
     }
     this.registerAllProvidedDemoDataGenerators();

src/app/core/entity/database-indexing/database-indexing.service.ts

@@ -16,12 +16,13 @@
  */
 
 import { Injectable } from "@angular/core";
-import { Database, QueryOptions } from "../../database/database";
+import { QueryOptions } from "../../database/database";
 import { BehaviorSubject, firstValueFrom, Observable } from "rxjs";
 import { BackgroundProcessState } from "../../ui/sync-status/background-process-state.interface";
 import { Entity, EntityConstructor } from "../model/entity";
 import { EntitySchemaService } from "../schema/entity-schema.service";
 import { first } from "rxjs/operators";
+import { DatabaseResolverService } from "../../database/database-resolver.service";
 
 /**
  * Manage database query index creation and use, working as a facade in front of the Database service.
@@ -41,7 +42,7 @@ export class DatabaseIndexingService {
   }
 
   constructor(
-    private db: Database,
+    private dbResolver: DatabaseResolverService,
     private entitySchemaService: EntitySchemaService,
   ) {}
 
@@ -52,15 +53,20 @@ export class DatabaseIndexingService {
    *
    * @param designDoc The design document (see @link{Database}) describing the query/index.
    */
-  async createIndex(designDoc: any): Promise<void> {
+  async createIndex(
+    designDoc: any,
+    db: string = DatabaseResolverService.DEFAULT_DB,
+  ): Promise<void> {
     const indexDetails = designDoc._id.replace(/_design\//, "");
     const indexState: BackgroundProcessState = {
       title: $localize`Preparing data (Indexing)`,
       details: indexDetails,
       pending: true,
     };
 
-    const indexCreationPromise = this.db.saveDatabaseIndex(designDoc);
+    const indexCreationPromise = this.dbResolver
+      .getDatabase(db)
+      .saveDatabaseIndex(designDoc);
     this._indicesRegistered.next([
       ...this._indicesRegistered.value.filter(
         (state) => state.details !== indexDetails,
@@ -213,12 +219,13 @@ export class DatabaseIndexingService {
     indexName: string,
     options: QueryOptions,
     doNotWaitForIndexCreation?: boolean,
+    db: string = DatabaseResolverService.DEFAULT_DB,
   ): Promise<any> {
     if (!doNotWaitForIndexCreation) {
       await this.waitForIndexAvailable(indexName);
     }
 
-    return this.db.query(indexName, options);
+    return this.dbResolver.getDatabase(db).query(indexName, options);
   }
 
   /**