Turso WASM Implementation

The Turso WASM implementation uses the @tursodatabase/database-wasm library, providing SQLite functionality in web browsers and other WASM-compatible environments.

INFO

This implementation uses SharedArrayBuffer and OPFS which require the following server headers to be set:

• Cross-Origin-Opener-Policy: same-origin
• Cross-Origin-Embedder-Policy: require-corp

Installation

npm install applesauce-sqlite @tursodatabase/database-wasm

Basic Usage

Unlike other implementations, Turso WASM requires you to create and initialize the database instance yourself before passing it to the TursoWasmEventDatabase constructor:

import { EventStore } from "applesauce-core";
import { TursoWasmEventDatabase } from "applesauce-sqlite/turso-wasm";
import { connect } from "@tursodatabase/database-wasm";

// Create a database connection
const db = await connect("my-database.db");

// Create and initialize the event database in one step
const database = await TursoWasmEventDatabase.fromDatabase(db);

// Create EventStore with Turso WASM backend
const eventStore = new EventStore(database);

// Use as normal
eventStore.add(someNostrEvent);

Options

The TursoWasmEventDatabase.fromDatabase() method accepts the following options:

const database = await TursoWasmEventDatabase.fromDatabase(db, {
  search: true, // Enable full-text search (default: false)
  searchContentFormatter: customFormatter, // Custom search content formatter
});

Search Support

Enable full-text search using SQLite's FTS5 extension:

const database = await TursoWasmEventDatabase.fromDatabase(db, {
  search: true,
});

// Now you can search events
const results = eventStore.getByFilters({
  search: "bitcoin lightning",
});

Custom Search Formatter

Customize how content is indexed for search:

const database = await TursoWasmEventDatabase.fromDatabase(db, {
  search: true,
  searchContentFormatter: (event) => {
    // Extract searchable content from event
    return event.content + " " + event.tags.map((t) => t[1]).join(" ");
  },
});

Advanced Usage

Database Connection Management

The Turso WASM implementation requires you to manage the database connection lifecycle:

import { connect } from "@tursodatabase/database-wasm";

// Create connection
const db = await connect("my-database.db");

// Create and initialize event database in one step
const database = await TursoWasmEventDatabase.fromDatabase(db, { search: true });

// ... use the database

// Close when done
await database.close();

Using with Existing Database Instance

You can use any existing Turso WASM Database instance:

import { connect } from "@tursodatabase/database-wasm";
import { TursoWasmEventDatabase } from "applesauce-sqlite/turso-wasm";

// Your existing database setup
const db = await connect("existing-database.db");

// Create and initialize event database in one step
const database = await TursoWasmEventDatabase.fromDatabase(db, { search: true });

Rebuilding Search Index

If you need to rebuild the search index (e.g., after changing the search formatter):

await database.rebuildSearchIndex();

Closing the Database

Always close the database when done:

await database.close();

Or use automatic cleanup with Symbol.dispose:

{
  const database = await TursoWasmEventDatabase.fromDatabase(db);
  // ... use database
} // Automatically closed when out of scope