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