merge /stations/all into /stations

index.js

@@ -9,7 +9,6 @@ const createHealthCheck = require('hafas-client-health-check')
 
 const pkg = require('./package.json')
 const stations = require('./routes/stations')
-const allStations  = require('./routes/all-stations')
 const station = require('./routes/station')
 const lines = require('./routes/lines')
 const line = require('./routes/line')
@@ -25,7 +24,6 @@ const hafas = createHafas('hafas-rest-api: ' + pkg.name)
 const modifyRoutes = (routes) => ({
 	...routes,
 	'/stations': stations,
-	'/stations/all': allStations,
 	'/stations/:id': station,
 	'/lines': lines,
 	'/lines/:id': line,

lib/to-ndjson-buf.js

@@ -0,0 +1,15 @@
+'use strict'
+
+const toNdjsonBuf = (items) => {
+	const chunks = []
+	let i = 0, bytes = 0
+	for (const item of items) {
+		const sep = i++ === 0 ? '' : '\n'
+		const buf = Buffer.from(sep + JSON.stringify(item), 'utf8')
+		chunks.push(buf)
+		bytes += buf.length
+	}
+	return Buffer.concat(chunks, bytes)
+}
+
+module.exports = toNdjsonBuf

lib/vbb-stations.js

@@ -0,0 +1,16 @@
+'use strict'
+
+const {statSync} = require('fs')
+const allStations = require('vbb-stations/full.json')
+
+// We don't have access to the publish date+time of the npm package,
+// so we use the ctime of vbb-stations/full.json as an approximation.
+// todo: this is brittle, find a better way, e.g. a build script
+const timeModified = statSync(require.resolve('vbb-stations/full.json')).ctime
+
+// todo: station.stops?
+
+module.exports = {
+	timeModified,
+	data: allStations,
+}

package.json

@@ -24,11 +24,13 @@
 	"dependencies": {
 		"cli-native": "^1.0.0",
 		"corser": "^2.0.1",
+		"etag": "^1.8.1",
 		"hafas-client-health-check": "^2.1.1",
 		"hafas-rest-api": "^3.3.1",
 		"lodash.omit": "^4.5.0",
 		"ndjson": "^1.5.0",
 		"nocache": "^2.0.0",
+		"serve-buffer": "^2.0.0",
 		"through2-map": "^3.0.0",
 		"vbb-hafas": "^7.0.2",
 		"vbb-lines": "^4.0.0",

routes/stations.js

@@ -1,64 +1,87 @@
 'use strict'
 
-const parse = require('cli-native').to
+const computeEtag = require('etag')
+const serveBuffer = require('serve-buffer')
 const autocomplete = require('vbb-stations-autocomplete')
-const stations = require('vbb-stations')
-const map = require('through2-map')
-const ndjson       = require('ndjson')
+const parse = require('cli-native').to
+const {filterByKeys: createFilter} = require('vbb-stations')
+const {data: stations, timeModified} = require('../lib/vbb-stations')
+const toNdjsonBuf = require('../lib/to-ndjson-buf')
+
+const JSON_MIME = 'application/json'
+const NDJSON_MIME = 'application/x-ndjson'
+
+const asJson = Buffer.from(JSON.stringify(stations), 'utf8')
+const asJsonEtag = computeEtag(asJson)
+const asNdjson = toNdjsonBuf(Object.entries(stations))
+const asNdjsonEtag = computeEtag(asNdjson)
 
-const err400 = (msg) => {
+const err = (msg, statusCode = 500) => {
 	const err = new Error(msg)
-	err.statusCode = 400
+	err.statusCode = statusCode
 	return err
 }
 
-const allStations = stations()
-
-// todo: merge this with db-rest#new-hafas-client/lib/stations
-const complete = (req, res, next) => {
-	const limit = req.query.results && parseInt(req.query.results) || 3
-	const fuzzy = parse(req.query.fuzzy) === true
-	const completion = parse(req.query.completion) !== false
-	const results = autocomplete(req.query.query, limit, fuzzy, completion)
+const complete = (req, res, next, q, onStation, onEnd) => {
+	const limit = q.results && parseInt(q.results) || 3
+	const fuzzy = parse(q.fuzzy) === true
+	const completion = parse(q.completion) !== false
+	const results = autocomplete(q.query, limit, fuzzy, completion)
 
 	const data = []
-	for (let result of results) {
-		// todo: make this more efficient
-		const [station] = stations(result.id)
+	for (const result of results) {
+		const station = stations[result.id]
 		if (!station) continue
 
-		data.push(Object.assign({}, result, station))
+		Object.assign(result, station)
+		onStation(result)
 	}
-
-	res.json(data)
-	next()
+	onEnd()
 }
 
-const filter = (req, res, next) => {
-	if (Object.keys(req.query).length === 0) {
-		return next(err400('Missing properties.'))
+const filter = (req, res, next, q, onStation, onEnd) => {
+	const selector = Object.create(null)
+	for (const prop in q) selector[prop] = parse(q[prop])
+	const filter = createFilter(selector)
+
+	for (const station of Object.values(stations)) {
+		if (filter(station)) onStation(station)
 	}
+	onEnd()
+}
 
-	const props = Object.create(null)
-	for (let prop in req.query) {
-		props[prop] = parse(req.query[prop])
+const stationsRoute = (req, res, next) => {
+	const t = req.accepts([JSON_MIME, NDJSON_MIME])
+	if (t !== JSON_MIME && t !== NDJSON_MIME) {
+		return next(err(JSON + ' or ' + NDJSON_MIME, 406))
 	}
-	const results = stations(props)
 
-	res.type('application/x-ndjson')
-	const out = ndjson.stringify()
-	out
-	.once('error', next)
-	.pipe(res)
-	.once('finish', () => next())
+	res.setHeader('Last-Modified', timeModified.toUTCString())
 
-	for (const station of results) out.write(station)
-	out.end()
-}
+	const head = t === JSON_MIME ? '{\n' : ''
+	const sep = t === JSON_MIME ? ',\n' : '\n'
+	const tail = t === JSON_MIME ? '\n}\n' : '\n'
+	let i = 0
+	const onStation = (s) => {
+		const j = JSON.stringify(s)
+		const field = t === JSON_MIME ? `"${s.id}":` : ''
+		res.write(`${i++ === 0 ? head : sep}${field}${j}`)
+	}
+	const onEnd = () => {
+		if (i > 0) res.end(tail)
+		else res.end(head + tail)
+	}
 
-const stationsRoute = (req, res, next) => {
-	if (req.query.query) complete(req, res, next)
-	else filter(req, res, next)
+	const q = req.query
+	if (Object.keys(q).length === 0) {
+		const data = t === JSON_MIME ? asJson : asNdjson
+		const etag = t === JSON_MIME ? asJsonEtag : asNdjsonEtag
+		serveBuffer(req, res, data, {timeModified, etag})
+	} else if (q.query) {
+		complete(req, res, next, q, onStation, onEnd)
+	} else {
+		filter(req, res, next, q, onStation, onEnd)
+	}
 }
 
 stationsRoute.queryParameters = {