kysely-sqlite-worker

kysely dialect for better-sqlite, execute sql in node:worker_threads

the type is also availiable for better-sqlite3-multiple-ciphers

Install

bun add kysely kysely-sqlite-worker better-sqlite3

Usage

import { SqliteWorkerDialect } from 'kysely-sqlite-worker'

const dialect = new SqliteWorkerDialect({
  source: ':memory:',
})

Custom Worker

in worker.ts

import { createOnMessageCallback, defaultCreateDatabaseFn } from 'kysely-sqlite-worker'

createOnMessageCallback(
  (fileName, options) => {
    const db = defaultCreateDatabaseFn(fileName, options)
    db.loadExtension(/* ... */)
    return db
  },
  (executor, { type, payload }) => {
    if (type === 'export') {
      return executor.db.export()
    }
    throw new Error(`Unknown worker request: ${type}`)
  },
)

Config

export type SqliteWorkerDialectConfig = {
  /**
   * db file path or existing buffer
   */
  source: string | Buffer | (() => Promisable<string | Buffer>)
  /**
   * better-sqlite3 initiate option
   */
  dbOption?: Options
  workerPath?: string
  onCreateConnection?: (
    connection: DatabaseConnection,
    options?: AbortableOperationOptions,
  ) => Promisable<void>
}

Custom worker requests use connection.request(type, payload) from the main thread. They are serialized with SQL execution.

Notice

The worker script defaults to the packaged worker file for the current runtime format (worker.mjs for ESM and worker.cjs for CJS), and you can customize the path with workerPath.