wip: split db classes/interfaces

packages/web/src/db/adapters/AsyncDatabaseConnection.ts

@@ -0,0 +1,25 @@
+import { BatchedUpdateNotification, QueryResult } from '@powersync/common';
+
+/**
+ * Proxied query result does not contain a function for accessing row values
+ */
+export type ProxiedQueryResult = Omit<QueryResult, 'rows'> & {
+  rows: {
+    _array: any[];
+    length: number;
+  };
+};
+export type OnTableChangeCallback = (event: BatchedUpdateNotification) => void;
+
+/**
+ * @internal
+ * An async Database connection which provides basic async SQL methods.
+ * This is usually a proxied through a web worker.
+ */
+export interface AsyncDatabaseConnection {
+  init(): Promise<void>;
+  close(): Promise<void>;
+  execute(sql: string, params?: any[]): Promise<ProxiedQueryResult>;
+  executeBatch(sql: string, params?: any[]): Promise<ProxiedQueryResult>;
+  registerOnTableChange(callback: OnTableChangeCallback): () => void;
+}

packages/web/src/db/adapters/ProxiedDatabaseConnection.ts

@@ -0,0 +1,8 @@
+import { AsyncDatabaseConnection } from './AsyncDatabaseConnection';
+
+export interface ProxiedDatabaseConnection extends AsyncDatabaseConnection {
+  /**
+   * Get a MessagePort which can be used to share the internals of this connection.
+   */
+  getMessagePort(): MessagePort;
+}

packages/web/src/db/adapters/wa-sqlite/WASQLiteConnection.ts

@@ -2,6 +2,7 @@ import * as SQLite from '@journeyapps/wa-sqlite';
 import { BaseObserver, BatchedUpdateNotification } from '@powersync/common';
 import { Mutex } from 'async-mutex';
 import { OnTableChangeCallback, WASQLExecuteResult } from '../../../shared/types';
+import { AsyncDatabaseConnection } from '../AsyncDatabaseConnection';
 
 /**
  * List of currently tested virtual filesystems
@@ -95,8 +96,10 @@ export const DEFAULT_MODULE_FACTORIES = {
 
 /**
  * @internal
+ * WA-SQLite connection which directly interfaces with WA-SQLite.
+ * This is usually instantiated inside a worker.
  */
-export class WASqliteConnection extends BaseObserver<WASQLiteConnectionListener> {
+export class WASqliteConnection extends BaseObserver<WASQLiteConnectionListener> implements AsyncDatabaseConnection {
   private _sqliteAPI: SQLiteAPI | null = null;
   private _dbP: number | null = null;
   private _moduleFactory: WASQLiteModuleFactory;
@@ -236,7 +239,7 @@ export class WASqliteConnection extends BaseObserver<WASQLiteConnectionListener>
   }
 
   async close() {
-    return this.sqliteAPI.close(this.dbP);
+    await this.sqliteAPI.close(this.dbP);
   }
 
   registerOnTableChange(callback: OnTableChangeCallback) {