feat(backups): add progress to incremental mirror (#9901)

@xen-orchestra/disk-transform/src/Disk.mts

@@ -1,4 +1,4 @@
-import { ProgressHandler } from './ProgressHandler.mjs'
+import { ComposedProgressHandler, ProgressHandler } from './ProgressHandler.mjs'
 
 export type DiskBlockData = Buffer
 export type DiskBlock = {
@@ -11,7 +11,11 @@ export type BytesLength = number
 export abstract class Disk {
   #generatedDiskBlocks = 0
   #parent?: Disk
-  progressHandler?: ProgressHandler
+  #progressHandler = new ComposedProgressHandler()
+
+  get progressHandler(): ProgressHandler {
+    return this.#progressHandler
+  }
   get parent(): Disk | undefined {
     return this.#parent
   }
@@ -66,9 +70,9 @@ export abstract class Disk {
     return Promise.resolve(true)
   }
 
-  // @todo readRawData will be needed for file level restore
-  // @todo rename will be needed for merge
-  // @todo : should the alias part moved from remote/vhd ?
+  addProgressHandler(progressHandler: ProgressHandler) {
+    this.#progressHandler.add(progressHandler)
+  }
 }
 
 /**

@xen-orchestra/disk-transform/src/Disk.test.mts

@@ -42,12 +42,12 @@ test('Disk class', async t => {
 
   await t.test('diskBlocks calls progressHandler.done when consumer exits early', async () => {
     let doneCalled = false
-    disk.progressHandler = {
+    disk.addProgressHandler({
       setProgress: async () => {},
       done: async () => {
         doneCalled = true
       },
-    }
+    })
     disk.blocks[4] = true
     disk.blocks[5] = true
     disk.blocks[6] = true

@xen-orchestra/disk-transform/src/ProgressHandler.mts

@@ -2,3 +2,17 @@ export interface ProgressHandler {
   setProgress(total: number): void | Promise<void>
   done(): void | Promise<void>
 }
+
+export class ComposedProgressHandler implements ProgressHandler {
+  #handlers: Array<ProgressHandler> = []
+  async setProgress(total: number) {
+    await Promise.all(this.#handlers.map(handler => handler.setProgress(total)))
+  }
+  async done() {
+    await Promise.all(this.#handlers.map(handler => handler.done()))
+  }
+
+  add(handler: ProgressHandler) {
+    this.#handlers.push(handler)
+  }
+}