chore(xo-server/backups-ng): dont fork streams if 1 target

packages/xo-server/src/xo-mixins/backups-ng/index.js

@@ -671,7 +671,8 @@ export default class BackupNg {
 
     const remotes = unboxIds(job.remotes)
     const srs = unboxIds(job.srs)
-    if (remotes.length === 0 && srs.length === 0) {
+    const nTargets = remotes.length + srs.length
+    if (nTargets === 0) {
       throw new Error('export retention must be 0 without remotes and SRs')
     }
 
@@ -695,6 +696,15 @@ export default class BackupNg {
       const exportTask = xva.task
       xva = xva.pipe(createSizeStream())
 
+      const forkExport =
+        nTargets === 0
+          ? () => xva
+          : () => {
+            const fork = xva.pipe(new PassThrough())
+            fork.task = exportTask
+            return fork
+          }
+
       const dataBasename = `${basename}.xva`
 
       const metadata: MetadataFull = {
@@ -715,7 +725,7 @@ export default class BackupNg {
       await waitAll(
         [
           ...remotes.map(async remoteId => {
-            const fork = xva.pipe(new PassThrough())
+            const fork = forkExport()
 
             const handler = await app.getRemoteHandler(remoteId)
 
@@ -742,8 +752,7 @@ export default class BackupNg {
             }
           }),
           ...srs.map(async srId => {
-            const fork = xva.pipe(new PassThrough())
+            const fork = forkExport()
-            fork.task = exportTask
 
             const xapi = app.getXapi(srId)
             const sr = xapi.getObject(srId)
@@ -841,9 +850,14 @@ export default class BackupNg {
       const jsonMetadata = JSON.stringify(metadata)
 
       // create a fork of the delta export
-      const forkExport = (() => {
+      const forkExport =
+        nTargets === 1
+          ? () => deltaExport
+          : (() => {
             // replace the stream factories by fork factories
-        const streams: any = mapValues(deltaExport.streams, lazyStream => {
+            const streams: any = mapValues(
+              deltaExport.streams,
+              lazyStream => {
                 let forks = []
                 return () => {
                   if (forks === undefined) {
@@ -876,7 +890,8 @@ export default class BackupNg {
                     forks.push({ reject, resolve })
                   })
                 }
-        })
+              }
+            )
             return () => {
               return {
                 __proto__: deltaExport,