Building REST APIs with Fastify
- Just how fast it is.
- Reducing Overhead.
- Fastify's plug-in based model.
- Getting Started.
Introduction
- General Purpose, low overhead web framework.
- Very good for building fast HTTP APIs that use JSON as data format.
- Extremely modular system based on plugins.
Reducing the overhead
Number of Requests/sec to send {"hello": world} as a JSON response
fast-json-stringify
- Performant version of V8's JSON.stringify() function.
- Used to double the throughput of the rendering of JSON.
- Uses schemas and new Function () in a safe manner to outperform JSON.stringify().
const fastJSON = require('fast-json-stringify')
const schema = {
// the object type we want to stringify
type: 'object',
// define all object properties
properties: {
username: {
type: 'string'
},
fullName: {
type: 'string'
},
age: {
type: 'integer'
}
}
}
const stringify = fastJSON(schema)
console.log(stringify({
username: 'johndoe',
fullName: 'John Doe',
age: 30
}))
{ "username": "johndoe", "fullName": "John Doe", "age": 30 }find-my-way
Server Lifecycle
Fastify Plug-ins
- Full encapsulation of plugins.
- They can handle asynchronous code.
- It guarantees load order and close order of plugins.
Registering Plug-ins
fastify.register(
require('./my-plugin'),
{ options }
)'use strict'
const fastify = require('fastify')()
fastify.get('/', function (req, reply) {
reply.send({ hello: 'world' })
})
fastify.listen(3000)Getting Started
Building a plugin to connect to MongoDb
const fastifyPlugin = require('fastify-plugin')
const MongoClient = require('mongodb').MongoClient
async function dbConnector (fastify, options) {
const url = options.url
delete options.url
const db = await MongoClient.connect(url, options)
fastify.decorate('mongo', db)
}
// Wrapping a plugin function with fastify-plugin exposes the decorators,
// hooks, and middlewares declared inside the plugin to the parent scope.
module.exports = fastifyPlugin(dbConnector)Register the MongoDb Plug-in
'use strict'
const fastify = require('fastify')()
fastify.register(require('../plugins/mongodb'), {
url: 'mongodb://localhost:27017/'
})
fastify.get('/', function (req, reply) {
reply.send({ hello: 'world' })
})
fastify.listen(3000)Declaring routes
let cartController = require('../controllers/cartController')
let routes = [
{
method: 'GET',
url: '/api/user/:id/cart',
handler: cartController.getCartForUser
},
{
method: 'POST',
url: '/api/user/:id/cart',
handler: cartController.addItemToUserCart
},
]
module.exports = routes;Registering Routes
'use strict'
const fastify = require('fastify')()
const routes = require('./routes/index');
fastify.register(require('../plugins/mongodb'), {
url: 'mongodb://localhost:27017/'
})
routes.forEach((route, index) => {
fastify.log.info('>>New route registered: ', route.url, 'method: ', route.method);
fastify.route(route);
});
fastify.listen(3000)Writing route handlers
let cartController = {};
cartController.getCartForUser = async function (request, reply) {
const mongodb = this.db;
const userId = request.params.id;
const cart = await mongodb.collection('productCart').findOne({
UserID: userId
});
reply.send(cart);
};cartController.addItemToUserCart = async function (request, reply) {
const mongodb = this.db;
const userId = request.params.id;
const product = request.body.product;
const filter = {UserID: userId};
const newPrice = product.map(prod => prod.Price * prod.Quantity).reduce((acc, curr) => acc + curr);
const update = {$set: {Product: product}, $inc: { TotalPrice: newPrice}};
await mongodb.collection('productCart').findOneAndUpdate(filter, update, {upsert: true, useFindAndModify: true});
let cart = await mongodb.collection('productCart').findOne({
UserID: userId
});
reply.send(cart);
};
module.exports = cartController;