server/lib/cache/abstract-video-static-file-cache.ts

   1 import * as AsyncLRU from 'async-lru'
   2 import { createWriteStream, remove } from 'fs-extra'
   3 import { logger } from '../../helpers/logger'
   4 import { VideoModel } from '../../models/video/video'
   5 import { fetchRemoteVideoStaticFile } from '../activitypub'
   6
   7 export abstract class AbstractVideoStaticFileCache <T> {
   8
   9   protected lru
  10
  11   abstract getFilePath (params: T): Promise<string>
  12
  13   // Load and save the remote file, then return the local path from filesystem
  14   protected abstract loadRemoteFile (key: string): Promise<string>
  15
  16   init (max: number, maxAge: number) {
  17     this.lru = new AsyncLRU({
  18       max,
  19       maxAge,
  20       load: (key, cb) => {
  21         this.loadRemoteFile(key)
  22           .then(res => cb(null, res))
  23           .catch(err => cb(err))
  24       }
  25     })
  26
  27     this.lru.on('evict', (obj: { key: string, value: string }) => {
  28       remove(obj.value)
  29         .then(() => logger.debug('%s evicted from %s', obj.value, this.constructor.name))
  30     })
  31   }
  32
  33   protected loadFromLRU (key: string) {
  34     return new Promise<string>((res, rej) => {
  35       this.lru.get(key, (err, value) => {
  36         err ? rej(err) : res(value)
  37       })
  38     })
  39   }
  40
  41   protected saveRemoteVideoFileAndReturnPath (video: VideoModel, remoteStaticPath: string, destPath: string) {
  42     return new Promise<string>((res, rej) => {
  43       const req = fetchRemoteVideoStaticFile(video, remoteStaticPath, rej)
  44
  45       const stream = createWriteStream(destPath)
  46
  47       req.pipe(stream)
  48          .on('error', (err) => rej(err))
  49          .on('finish', () => res(destPath))
  50     })
  51   }
  52 }