server/lib/activitypub/crawl.ts

   1 import * as Bluebird from 'bluebird'
   2 import { URL } from 'url'
   3 import { ActivityPubOrderedCollection } from '../../../shared/models/activitypub'
   4 import { logger } from '../../helpers/logger'
   5 import { doJSONRequest } from '../../helpers/requests'
   6 import { ACTIVITY_PUB, WEBSERVER } from '../../initializers/constants'
   7
   8 type HandlerFunction<T> = (items: T[]) => (Promise<any> | Bluebird<any>)
   9 type CleanerFunction = (startedDate: Date) => (Promise<any> | Bluebird<any>)
  10
  11 async function crawlCollectionPage <T> (argUrl: string, handler: HandlerFunction<T>, cleaner?: CleanerFunction) {
  12   let url = argUrl
  13
  14   logger.info('Crawling ActivityPub data on %s.', url)
  15
  16   const options = { activityPub: true }
  17
  18   const startDate = new Date()
  19
  20   const response = await doJSONRequest<ActivityPubOrderedCollection<T>>(url, options)
  21   const firstBody = response.body
  22
  23   const limit = ACTIVITY_PUB.FETCH_PAGE_LIMIT
  24   let i = 0
  25   let nextLink = firstBody.first
  26   while (nextLink && i < limit) {
  27     let body: any
  28
  29     if (typeof nextLink === 'string') {
  30       // Don't crawl ourselves
  31       const remoteHost = new URL(nextLink).host
  32       if (remoteHost === WEBSERVER.HOST) continue
  33
  34       url = nextLink
  35
  36       const res = await doJSONRequest<ActivityPubOrderedCollection<T>>(url, options)
  37       body = res.body
  38     } else {
  39       // nextLink is already the object we want
  40       body = nextLink
  41     }
  42
  43     nextLink = body.next
  44     i++
  45
  46     if (Array.isArray(body.orderedItems)) {
  47       const items = body.orderedItems
  48       logger.info('Processing %i ActivityPub items for %s.', items.length, url)
  49
  50       await handler(items)
  51     }
  52   }
  53
  54   if (cleaner) await cleaner(startDate)
  55 }
  56
  57 export {
  58   crawlCollectionPage
  59 }