sqlite-transaction

SQLite transaction manager for SlimIO events addon. Designed to work with the sqlite npm package.

Requirements

• Node.js v12 or higher

Getting Started

This package is available in the Node Package Repository and can be easily installed with npm or yarn.

$ npm i @slimio/sqlite-transaction
# or
$ yarn add @slimio/sqlite-transaction

Usage example

Take the following example with an SQLite DB (with a table users).

const tM = new TransactionManager(db, {
    interval: 500,
    verbose: true
});
tM.registerSubject("user", {
    insert: "INSERT INTO users (username, password) VALUES (?, ?)"
});

tM.once("user.insert", (openAt, data, aData) => {
    console.log(`User insertion requested at: ${new Date(openAt)}, now successfully inserted!`);
});

const tId = tM.open("insert", "user", ["fraxken", "admin"]);
const ret = tM.attachData(tId, { foo: "bar" });

API

constructor< S >(db: sqlite.Database, options?: TransactionManager.ConstructorOptions)

Create a new SQLite transaction manager. The first argument must be an SQLite db (from the npm package sqlite). Available options are described by the following interface:

interface ConstructorOptions {
    interval?: number;
    verbose?: boolean;
}

Default values are interval 5000 (milliseconds) and verbose false.

const sqlite = require("sqlite");
const transactionManager = require("@slimio/sqlite-transaction");

const db = await sqlite.open("./db.sqlite");
const tM = new transactionManager(db, { interval: 1000 });

registerSubject(name: TransactionManager.Subject, actions: TransactionManager.Actions): this

Register a new Subject on the Transaction Manager object. The subject name must be typeof string or symbol. The actions argument must be described by a JavaScript Object as follow:

interface Actions {
    insert?: string;
    delete?: string;
    update?: string;
}

tM.registerSubject("test", {
    update: "...",
    delete: "..."
});

loadSubjectsFromFile(fileLocation: string): Promise< void >

Load subjects from a given .json file. The file must be indented as follow:

{
    "subjectName": {
        "insert": "INSERT INTO table (field) VALUES ('val')",
        "update": "..."
    }
}

Example

await tM.loadSubjectsFromFile("./subjects.json");

open(action: TransactionManager.Action, subject: keyof S, data: any[]): string

Open a new request that will be queue and handled in a SQLite transaction. action and subject arguments are not mandatory and must be valid. Action must be either insert, update or delete.

The action must exist on the given subject.

attachData(transactId: string, data: any): boolean

close(transactId: string): boolean

exit(): void

Roadmap

• Ability to lock/unlock requests (db handle priority).
• Reduce/Agregate same requests (alarm with row occurence for example).

Dependencies

Name	Refactoring	Security Risk	Usage
@slimio/timer	Minor	Low	Driftless Timer

License

MIT