Hellion/server/core/lib/actor-follow-health-cache.ts

import { ACTOR_FOLLOW_SCORE } from '../initializers/constants.js'
import { logger } from '../helpers/logger.js'

// Cache follows scores, instead of writing them too often in database
// Keep data in memory, we don't really need Redis here as we don't really care to loose some scores
class ActorFollowHealthCache {

  private static instance: ActorFollowHealthCache

  private pendingFollowsScore: { [ url: string ]: number } = {}

  private pendingBadServer = new Set<number>()
  private pendingGoodServer = new Set<number>()

  private readonly badInboxes = new Set<string>()

  private constructor () {}

  static get Instance () {
    return this.instance || (this.instance = new this())
  }

  updateActorFollowsHealth (goodInboxes: string[], badInboxes: string[]) {
    this.badInboxes.clear()

    if (goodInboxes.length === 0 && badInboxes.length === 0) return

    logger.info(
      'Updating %d good actor follows and %d bad actor follows scores in cache.',
      goodInboxes.length, badInboxes.length, { badInboxes }
    )

    for (const goodInbox of goodInboxes) {
      if (this.pendingFollowsScore[goodInbox] === undefined) this.pendingFollowsScore[goodInbox] = 0

      this.pendingFollowsScore[goodInbox] += ACTOR_FOLLOW_SCORE.BONUS
    }

    for (const badInbox of badInboxes) {
      if (this.pendingFollowsScore[badInbox] === undefined) this.pendingFollowsScore[badInbox] = 0

      this.pendingFollowsScore[badInbox] += ACTOR_FOLLOW_SCORE.PENALTY
      this.badInboxes.add(badInbox)
    }
  }

  isBadInbox (inboxUrl: string) {
    return this.badInboxes.has(inboxUrl)
  }

  addBadServerId (serverId: number) {
    this.pendingBadServer.add(serverId)
  }

  getBadFollowingServerIds () {
    return Array.from(this.pendingBadServer)
  }

  clearBadFollowingServerIds () {
    this.pendingBadServer = new Set<number>()
  }

  addGoodServerId (serverId: number) {
    this.pendingGoodServer.add(serverId)
  }

  getGoodFollowingServerIds () {
    return Array.from(this.pendingGoodServer)
  }

  clearGoodFollowingServerIds () {
    this.pendingGoodServer = new Set<number>()
  }

  getPendingFollowsScore () {
    return this.pendingFollowsScore
  }

  clearPendingFollowsScore () {
    this.pendingFollowsScore = {}
  }
}

export {
  ActorFollowHealthCache
}