Merge pull request #2343 from mikiher/caching

Simple API Caching for /libraries* requests

server/Server.js

@@ -32,13 +32,13 @@ const PodcastManager = require('./managers/PodcastManager')
 const AudioMetadataMangaer = require('./managers/AudioMetadataManager')
 const RssFeedManager = require('./managers/RssFeedManager')
 const CronManager = require('./managers/CronManager')
+const ApiCacheManager = require('./managers/ApiCacheManager')
 const LibraryScanner = require('./scanner/LibraryScanner')
 
 //Import the main Passport and Express-Session library
 const passport = require('passport')
 const expressSession = require('express-session')
 
-
 class Server {
   constructor(SOURCE, PORT, HOST, UID, GID, CONFIG_PATH, METADATA_PATH, ROUTER_BASE_PATH) {
     this.Port = PORT
@@ -73,6 +73,7 @@ class Server {
     this.audioMetadataManager = new AudioMetadataMangaer()
     this.rssFeedManager = new RssFeedManager()
     this.cronManager = new CronManager(this.podcastManager)
+    this.apiCacheManager = new ApiCacheManager()
 
     // Routers
     this.apiRouter = new ApiRouter(this)
@@ -117,6 +118,7 @@ class Server {
 
     const libraries = await Database.libraryModel.getAllOldLibraries()
     await this.cronManager.init(libraries)
+    this.apiCacheManager.init()
 
     if (Database.serverSettings.scannerDisableWatcher) {
       Logger.info(`[Server] Watcher is disabled`)

server/SocketAuthority.js

@@ -192,9 +192,9 @@ class SocketAuthority {
 
     this.adminEmitter('user_online', client.user.toJSONForPublic(this.Server.playbackSessionManager.sessions))
 
-    // Update user lastSeen
+    // Update user lastSeen without firing sequelize bulk update hooks
     user.lastSeen = Date.now()
-    await Database.updateUser(user)
+    await Database.userModel.updateFromOld(user, false)
 
     const initialPayload = {
       userId: client.user.id,

server/managers/ApiCacheManager.js

@@ -0,0 +1,54 @@
+const { LRUCache } = require('lru-cache')
+const Logger = require('../Logger')
+const Database = require('../Database')
+
+class ApiCacheManager {
+
+  defaultCacheOptions = { max: 1000, maxSize: 10 * 1000 * 1000, sizeCalculation: item => (item.body.length + JSON.stringify(item.headers).length) }
+  defaultTtlOptions = { ttl: 30 * 60 * 1000 }
+
+  constructor(cache = new LRUCache(this.defaultCacheOptions), ttlOptions = this.defaultTtlOptions) {
+    this.cache = cache
+    this.ttlOptions = ttlOptions
+  }
+
+  init(database = Database) {
+    let hooks = ['afterCreate', 'afterUpdate', 'afterDestroy', 'afterBulkCreate', 'afterBulkUpdate', 'afterBulkDestroy']
+    hooks.forEach(hook => database.sequelize.addHook(hook, (model) => this.clear(model, hook)))
+  }
+
+  clear(model, hook) {
+    Logger.debug(`[ApiCacheManager] ${model.constructor.name}.${hook}: Clearing cache`)
+    this.cache.clear()
+  }
+
+  get middleware() {
+    return (req, res, next) => {
+      const key = { user: req.user.username, url: req.url }
+      const stringifiedKey = JSON.stringify(key)
+      Logger.debug(`[ApiCacheManager] count: ${this.cache.size} size: ${this.cache.calculatedSize}`)
+      const cached = this.cache.get(stringifiedKey)
+      if (cached) {
+        Logger.debug(`[ApiCacheManager] Cache hit: ${stringifiedKey}`)
+        res.set(cached.headers)
+        res.status(cached.statusCode)
+        res.send(cached.body)
+        return
+      }
+      res.originalSend = res.send
+      res.send = (body) => {
+        Logger.debug(`[ApiCacheManager] Cache miss: ${stringifiedKey}`)
+        const cached = { body, headers: res.getHeaders(), statusCode: res.statusCode }
+        if (key.url.search(/^\/libraries\/.*?\/personalized/) !== -1) {
+          Logger.debug(`[ApiCacheManager] Caching with ${this.ttlOptions.ttl} ms TTL`)
+          this.cache.set(stringifiedKey, cached, this.ttlOptions)
+        } else {
+          this.cache.set(stringifiedKey, cached)
+        }
+        res.originalSend(body)
+      }
+      next()
+    }
+  }
+}
+module.exports = ApiCacheManager

server/models/User.js

@@ -99,11 +99,13 @@ class User extends Model {
    * Update User from old user model
    * 
    * @param {oldUser} oldUser 
+   * @param {boolean} [hooks=true] Run before / after bulk update hooks?
    * @returns {Promise<boolean>}
    */
-  static updateFromOld(oldUser) {
+  static updateFromOld(oldUser, hooks = true) {
     const user = this.getFromOld(oldUser)
     return this.update(user, {
+      hooks: !!hooks,
       where: {
         id: user.id
       }

server/routers/ApiRouter.js

@@ -48,6 +48,7 @@ class ApiRouter {
     this.cronManager = Server.cronManager
     this.notificationManager = Server.notificationManager
     this.emailManager = Server.emailManager
+    this.apiCacheManager = Server.apiCacheManager
 
     this.router = express()
     this.router.disable('x-powered-by')
@@ -58,6 +59,7 @@ class ApiRouter {
     //
     // Library Routes
     //
+    this.router.get(/^\/libraries/, this.apiCacheManager.middleware)
     this.router.post('/libraries', LibraryController.create.bind(this))
     this.router.get('/libraries', LibraryController.findAll.bind(this))
     this.router.get('/libraries/:id', LibraryController.middleware.bind(this), LibraryController.findOne.bind(this))