redis-idempotence v1.0.5

redis-idempotence

Library to easily implement the idempotence model in an api made in fastify.

Installation

yarn add redis-idempotence

Implementation (handler)

Import the handler method from redis-idempotence and define the values like this:

import { handler } from 'redis-idempotence';

const exampleRouteHandler = handler({
    serviceName: 'cm-service-example-name',
    keyId: ['key1', 'key2'],
    expireTime? : 60,
});

Explain fields

Implementation of the route

Finally, we implement the route in the following way:

application.post(`/example-route`, exampleRouteHandler, exampleRoute);

If you use schemas or any other additional configuration, you can implement it in the following way:

application.post(
    `/example-route`,
    { schema: your - schema, ...exampleRouteHandler },
    exampleRoute,
);

Note

You must have a redis instance ready for the library to work. Define the following values as environment variables: REDIS_HOST and REDIS_PORT

Implementation (Cacheable)

Sometimes we have a method than we want to cache the response because it is call many times in our project with the same arguments, for this case we can use the Cacheable method like a decorator.

import { Cacheable } from 'redis-idempotence';

export class ExampleDAO {
    private db = // Your database - Remember it's a example

        // Remember it's only a example
    @Cacheable('exampleKey', { expireTime: 60, unless: (result) => result === null })

    async getExampleData(date: string): Promise<ExampleDTO> { // Read Warning
        const sqlQuery = `SELECT example_data FROM example_table WHERE date = $1`;

        const response = await this.db.oneOrNone<ExampleDTO>(sqlQuery, [
            date,
        ]);
        return response;
    }
}

Explain fields

Warning

You have to be careful with the arguments you send in the method, if you send a object and it have data that change many like a date, the hash will be different and the cache will not work.

For example, a complete format of the date it like: 2022-01-01T01:02:03.000Z, (Date change every second) if you send a date with this format the cache will not work, you can send the date with the format 2022-01-01 and it will work.

REDIS_CONNECTION_LOCAL_ENV

This is an environment variable that must be defined, its value is boolean and will betrue when the redis to be used is defined locally, that is, within the same docker container as the application(docker compose ). Here is an example:

File docker - compose.yml

version: '3.7'
services:
    redis:
        image: redis:7.0.4
        restart: always
        command: redis-server --bind 0.0.0.0

In this case the redis is defined in the docker-compose, in the same file the container of our application will be defined. REDIS_CONNECTION_LOCAL_ENV will have a value of true and will refer to the redis container called redis the connection will be automatic.

If the redis is defined in another container, the value of REDIS_CONNECTION_LOCAL_ENV will be false and the REDIS_HOST and REDIS_PORT environment variables must be defined.

License

MIT - You can see the license here