4 files changed, 47 insertions, 12 deletions

diff --git a/server/helpers/promise-cache.ts b/server/helpers/promise-cache.ts
new file mode 100644
index 000000000..07e8a9962
--- /dev/null
+++ b/server/helpers/promise-cache.ts
@@ -0,0 +1,21 @@
+export class PromiseCache <A, R> {
+  private readonly running = new Map<string, Promise<R>>()
+
+  constructor (
+    private readonly fn: (arg: A) => Promise<R>,
+    private readonly keyBuilder: (arg: A) => string
+  ) {
+  }
+
+  run (arg: A) {
+    const key = this.keyBuilder(arg)
+
+    if (this.running.has(key)) return this.running.get(key)
+
+    const p = this.fn(arg)
+
+    this.running.set(key, p)
+
+    return p.finally(() => this.running.delete(key))
+  }
+}
diff --git a/server/lib/activitypub/actors/get.ts b/server/lib/activitypub/actors/get.ts
index de93aa964..501ff74e3 100644
--- a/server/lib/activitypub/actors/get.ts
+++ b/server/lib/activitypub/actors/get.ts
@@ -56,7 +56,7 @@ async function getOrCreateAPActor (
   if (actor.Account) (actor as MActorAccountChannelIdActor).Account.Actor = actor
   if (actor.VideoChannel) (actor as MActorAccountChannelIdActor).VideoChannel.Actor = actor
 
-  const { actor: actorRefreshed, refreshed } = await refreshActorIfNeeded(actor, fetchType)
+  const { actor: actorRefreshed, refreshed } = await refreshActorIfNeeded({ actor, fetchedType: fetchType })
   if (!actorRefreshed) throw new Error('Actor ' + actor.url + ' does not exist anymore.')
 
   await scheduleOutboxFetchIfNeeded(actor, created, refreshed, updateCollections)
diff --git a/server/lib/activitypub/actors/refresh.ts b/server/lib/activitypub/actors/refresh.ts
index 1f7cfcd8f..b2fe3932f 100644
--- a/server/lib/activitypub/actors/refresh.ts
+++ b/server/lib/activitypub/actors/refresh.ts
@@ -1,4 +1,5 @@
 import { logger, loggerTagsFactory } from '@server/helpers/logger'
+import { PromiseCache } from '@server/helpers/promise-cache'
 import { PeerTubeRequestError } from '@server/helpers/requests'
 import { ActorLoadByUrlType } from '@server/lib/model-loaders'
 import { ActorModel } from '@server/models/actor/actor'
@@ -8,11 +9,30 @@ import { fetchRemoteActor } from './shared'
 import { APActorUpdater } from './updater'
 import { getUrlFromWebfinger } from './webfinger'
 
-async function refreshActorIfNeeded <T extends MActorFull | MActorAccountChannelId> (
-  actorArg: T,
+type RefreshResult <T> = Promise<{ actor: T | MActorFull, refreshed: boolean }>
+
+type RefreshOptions <T> = {
+  actor: T
   fetchedType: ActorLoadByUrlType
-): Promise<{ actor: T | MActorFull, refreshed: boolean }> {
-  if (!actorArg.isOutdated()) return { actor: actorArg, refreshed: false }
+}
+
+const promiseCache = new PromiseCache(doRefresh, (options: RefreshOptions<MActorFull | MActorAccountChannelId>) => options.actor.url)
+
+function refreshActorIfNeeded <T extends MActorFull | MActorAccountChannelId> (options: RefreshOptions<T>): RefreshResult <T> {
+  const actorArg = options.actor
+  if (!actorArg.isOutdated()) return Promise.resolve({ actor: actorArg, refreshed: false })
+
+  return promiseCache.run(options)
+}
+
+export {
+  refreshActorIfNeeded
+}
+
+// ---------------------------------------------------------------------------
+
+async function doRefresh <T extends MActorFull | MActorAccountChannelId> (options: RefreshOptions<T>): RefreshResult <MActorFull> {
+  const { actor: actorArg, fetchedType } = options
 
   // We need more attributes
   const actor = fetchedType === 'all'
@@ -52,12 +72,6 @@ async function refreshActorIfNeeded <T extends MActorFull | MActorAccountChannel
   }
 }
 
-export {
-  refreshActorIfNeeded
-}
-
-// ---------------------------------------------------------------------------
-
 function getActorUrl (actor: MActorFull) {
   return getUrlFromWebfinger(actor.preferredUsername + '@' + actor.getHost())
     .catch(err => {
diff --git a/server/lib/job-queue/handlers/activitypub-refresher.ts b/server/lib/job-queue/handlers/activitypub-refresher.ts
index f1c7d01b6..d97e50ebc 100644
--- a/server/lib/job-queue/handlers/activitypub-refresher.ts
+++ b/server/lib/job-queue/handlers/activitypub-refresher.ts
@@ -47,7 +47,7 @@ async function refreshActor (actorUrl: string) {
   const actor = await ActorModel.loadByUrlAndPopulateAccountAndChannel(actorUrl)
 
   if (actor) {
-    await refreshActorIfNeeded(actor, fetchType)
+    await refreshActorIfNeeded({ actor, fetchedType: fetchType })
   }
 }