Add concurrency limit when loading previews

Added P-Queue to limit the number of concurrent requests related to the
media source when loading previews.

This will prevent such calls to block other operations like uploads.

package.json

@@ -82,6 +82,7 @@
     "owncloud-design-system": "^1.1.1",
     "owncloud-sdk": "^1.0.0-523",
     "p-limit": "^2.2.1",
+    "p-queue": "^6.1.1",
     "parse-json": "^5.0.0",
     "path": "^0.12.7",
     "requirejs": "^2.3.6",

src/plugins/mediaSource.js

@@ -1,4 +1,5 @@
 import store from '../store'
+const { default: PQueue } = require('p-queue')
 
 export default {
   install (Vue) {
@@ -44,9 +45,14 @@ export default {
     })
 
     Vue.mixin({
+      data: function () {
+        return {
+          mediaSourceQueue: new PQueue({ concurrency: 2 })
+        }
+      },
       methods: {
         mediaSource (source, returnAs = 'url', headers = null) {
-          return _mediaSource(source, returnAs, headers)
+          return this.mediaSourceQueue.add(() => _mediaSource(source, returnAs, headers))
         }
       }
     })

yarn.lock

@@ -6824,13 +6824,28 @@ p-map@^3.0.0:
   dependencies:
     aggregate-error "^3.0.0"
 
+p-queue@^6.1.1:
+  version "6.3.0"
+  resolved "https://registry.yarnpkg.com/p-queue/-/p-queue-6.3.0.tgz#19bfa4485db7e6a0c135049ff6716375880d9c3a"
+  integrity sha512-fg5dJlFpd5+3CgG3/0ogpVZUeJbjiyXFg0nu53hrOYsybqSiDyxyOpad0Rm6tAiGjgztAwkyvhlYHC53OiAJOA==
+  dependencies:
+    eventemitter3 "^4.0.0"
+    p-timeout "^3.1.0"
+
 p-retry@^3.0.1:
   version "3.0.1"
   resolved "https://registry.yarnpkg.com/p-retry/-/p-retry-3.0.1.tgz#316b4c8893e2c8dc1cfa891f406c4b422bebf328"
   integrity sha512-XE6G4+YTTkT2a0UWb2kjZe8xNwf8bIbnqpc/IS/idOBVhyves0mK5OJgeocjx7q5pvX/6m23xuzVPYT1uGM73w==
   dependencies:
     retry "^0.12.0"
 
+p-timeout@^3.1.0:
+  version "3.2.0"
+  resolved "https://registry.yarnpkg.com/p-timeout/-/p-timeout-3.2.0.tgz#c7e17abc971d2a7962ef83626b35d635acf23dfe"
+  integrity sha512-rhIwUycgwwKcP9yTOOFK/AKsAopjjCakVqLHePO3CC6Mir1Z99xT+R63jZxAT5lFZLa2inS5h+ZS2GvR99/FBg==
+  dependencies:
+    p-finally "^1.0.0"
+
 p-try@^1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/p-try/-/p-try-1.0.0.tgz#cbc79cdbaf8fd4228e13f621f2b1a237c1b207b3"