add: redis

capitulo_5/5.5.3/package.json

@@ -19,6 +19,7 @@
     "debug": "4.3.1",
     "dnscache": "^1.0.2",
     "express": "^4.17.1",
-    "pg": "8.5.1"
+    "pg": "8.5.1",
+    "redis": "3.0.2"
   }
 }

capitulo_5/5.5.3/server/config/redis.js

@@ -0,0 +1,9 @@
+import { createClient } from 'redis';
+import { promisify } from 'util';
+const client = createClient({
+  host: 'localhost',
+  port: 6379
+})
+client.on('error', (e) => console.log(e))
+export const getAsync = promisify(client.get).bind(client)
+export const setAsync = promisify(client.set).bind(client)

capitulo_5/5.5.3/server/repository/Stormtrooper.js

@@ -1,4 +1,5 @@
 import db from '../config/pg.js'
+import { setAsync } from '../config/redis.js'
 
 const sql = `SELECT
   st.id, st.name, st.nickname,
@@ -17,6 +18,12 @@ const Stormtrooper = {
   byId(id) {
     return db.query(`${sql} WHERE st.id = $1::int`, [id])
       .then(result => result.rows && result.rows[0])
+      .then(result => {
+        const SIX_MINUTES = 60 * 6
+        setAsync(`trooper:${id}`, JSON.stringify(result), 'EX', SIX_MINUTES)
+          .catch(e => console.log(e))
+        return result
+      })
   },
   create(data) {
     const sql = `INSERT INTO stormtroopers (name, nickname, id_patent)

capitulo_5/5.5.3/server/routes/trooper.js

@@ -1,20 +1,26 @@
 import { Router } from 'express'
 import createError from 'http-errors'
 import controller from '../controller/Stormtrooper.js'
+import { getAsync } from '../config/redis.js'
 const trooperRoutes = new Router()
-
 const verifyId = (request, response, next) => {
   const id = request.params.id
   if (!/^[0-9]+$/.test(id)) {
     return next(createError(422, 'invalid id'))
   }
   next()
 }
-
+const fromCache = (request, response, next) => {
+  getAsync(`trooper:${request.params.id}`)
+    .then(result => {
+      if (!result) return next()
+      response.send(JSON.parse(result))
+    })
+    .catch(_ => next())
+}
 trooperRoutes.get('/', controller.list)
-trooperRoutes.get('/:id', verifyId, controller.byId)
+trooperRoutes.get('/:id', verifyId, fromCache, controller.byId)
 trooperRoutes.post('/', controller.create)
 trooperRoutes.put('/:id', verifyId, controller.updateById)
 trooperRoutes.delete('/:id', verifyId, controller.deleteById)
-
 export default trooperRoutes