import * as AsyncLRU from 'async-lru' import { createWriteStream, remove } from 'fs-extra' import { logger } from '../../helpers/logger' import { VideoModel } from '../../models/video/video' import { fetchRemoteVideoStaticFile } from '../activitypub' export abstract class AbstractVideoStaticFileCache { protected lru abstract getFilePath (params: T): Promise // Load and save the remote file, then return the local path from filesystem protected abstract loadRemoteFile (key: string): Promise init (max: number, maxAge: number) { this.lru = new AsyncLRU({ max, maxAge, load: (key, cb) => { this.loadRemoteFile(key) .then(res => cb(null, res)) .catch(err => cb(err)) } }) this.lru.on('evict', (obj: { key: string, value: string }) => { remove(obj.value) .then(() => logger.debug('%s evicted from %s', obj.value, this.constructor.name)) }) } protected loadFromLRU (key: string) { return new Promise((res, rej) => { this.lru.get(key, (err, value) => { err ? rej(err) : res(value) }) }) } protected saveRemoteVideoFileAndReturnPath (video: VideoModel, remoteStaticPath: string, destPath: string) { return new Promise((res, rej) => { const req = fetchRemoteVideoStaticFile(video, remoteStaticPath, rej) const stream = createWriteStream(destPath) req.pipe(stream) .on('error', (err) => rej(err)) .on('finish', () => res(destPath)) }) } }