From 509504c7c8c171582a9ca5e7637a75678b079fac Mon Sep 17 00:00:00 2001
From: Jannis R <mail@jannisr.de>
Date: Fri, 1 May 2020 20:15:27 +0200
Subject: [PATCH] caching using cached-hafas-client

see also derhuerst/hvv-rest@8db740b
---
 .gitignore   |  1 +
 api.js       | 32 +++++++++++++++++++++++++++++---
 package.json |  2 ++
 readme.md    |  6 ++++++
 4 files changed, 38 insertions(+), 3 deletions(-)

diff --git a/.gitignore b/.gitignore
index e32ede0..33a78ae 100644
--- a/.gitignore
+++ b/.gitignore
@@ -6,3 +6,4 @@ node_modules
 npm-debug.log
 
 /package-lock.json
+/dump.rdb
diff --git a/api.js b/api.js
index 3d44f86..fba85df 100644
--- a/api.js
+++ b/api.js
@@ -3,15 +3,41 @@
 const createHafas = require('db-hafas')
 const createApi = require('hafas-rest-api')
 const createHealthCheck = require('hafas-client-health-check')
+const {createClient: createRedis} = require('redis')
+const withCache = require('cached-hafas-client')
+const redisStore = require('cached-hafas-client/stores/redis')
 
 const pkg = require('./package.json')
 const stations = require('./routes/stations')
 const station = require('./routes/station')
 
-const hafas = createHafas(pkg.name)
-
 const berlinHbf = '8011160'
-const healthCheck = createHealthCheck(hafas, berlinHbf)
+
+let hafas = createHafas(pkg.name)
+let healthCheck = createHealthCheck(hafas, berlinHbf)
+
+if (process.env.REDIS_URL) {
+	const redis = createRedis({
+		url: process.env.REDIS_URL,
+	})
+	redis.on('error', (err) => {
+		api.locals.logger.error(err)
+	})
+	hafas = withCache(hafas, redisStore(redis))
+
+	const checkHafas = healthCheck
+	const checkRedis = () => new Promise((resolve, reject) => {
+		setTimeout(reject, 1000, new Error('didn\'t receive a PONG'))
+		redis.ping((err, res) => {
+			if (err) reject(err)
+			else resolve(res === 'PONG')
+		})
+	})
+	healthCheck = async () => (
+		(await checkHafas()) === true &&
+		(await checkRedis()) === true
+	)
+}
 
 const modifyRoutes = (routes) => {
 	routes['/stations/:id'] = station
diff --git a/package.json b/package.json
index 5775165..9ae1e6c 100644
--- a/package.json
+++ b/package.json
@@ -22,6 +22,7 @@
 		"node": ">=10"
 	},
 	"dependencies": {
+		"cached-hafas-client": "^3.1.1",
 		"cli-native": "^1.0.0",
 		"db-hafas": "^5.0.2",
 		"db-stations": "^3.0.0",
@@ -29,6 +30,7 @@
 		"etag": "^1.8.1",
 		"hafas-client-health-check": "^2.1.1",
 		"hafas-rest-api": "^3.3.0",
+		"redis": "^3.0.2",
 		"serve-buffer": "^2.0.0"
 	},
 	"devDependencies": {
diff --git a/readme.md b/readme.md
index e8d34f5..2f07090 100644
--- a/readme.md
+++ b/readme.md
@@ -15,6 +15,8 @@
 
 ## installing & running
 
+`bvg-rest` expects a [Redis](https://redis.io/) server running on `127.0.0.1:6379` (default port), but you can set the `REDIS_URL` environment variable to change this.
+
 ### via Docker
 
 A Docker image [is available as `derhuerst/db-rest:5`](https://hub.docker.com/r/derhuerst/db-rest:5).
@@ -23,6 +25,8 @@ A Docker image [is available as `derhuerst/db-rest:5`](https://hub.docker.com/r/
 docker run -d -p 3000:3000 derhuerst/db-rest:5
 ```
 
+*Note:* The Docker image does not contain the Redis server.
+
 ### manually
 
 ```shell
@@ -30,6 +34,8 @@ git clone https://github.com/derhuerst/db-rest.git
 cd db-rest
 git checkout 5
 npm install --production
+
+redis-server &
 npm start
 ```