Resumable backup import

ts/textsecure/WebAPI.ts

@@ -69,6 +69,7 @@ import { handleStatusCode, translateError } from './Utils';
 import * as log from '../logging/log';
 import { maybeParseUrl, urlPathFromComponents } from '../util/url';
 import { SECOND } from '../util/durations';
+import { safeParseNumber } from '../util/numbers';
 import type { IWebSocketResource } from './WebsocketResources';
 import { Environment, getEnvironment } from '../environment';
 
@@ -1187,6 +1188,8 @@ export type GetBackupStreamOptionsType = Readonly<{
   backupDir: string;
   backupName: string;
   headers: Record<string, string>;
+  downloadOffset: number;
+  onProgress: (currentBytes: number, totalBytes: number) => void;
 }>;
 
 export const getBackupInfoResponseSchema = z.object({
@@ -2825,12 +2828,18 @@ export function initialize({
       cdn,
       backupDir,
       backupName,
+      downloadOffset,
+      onProgress,
     }: GetBackupStreamOptionsType): Promise<Readable> {
       return _getAttachment({
         cdnPath: `/backups/${encodeURIComponent(backupDir)}/${encodeURIComponent(backupName)}`,
         cdnNumber: cdn,
         redactor: _createRedactor(backupDir, backupName),
         headers,
+        options: {
+          downloadOffset,
+          onProgress,
+        },
       });
     }
 
@@ -3555,6 +3564,7 @@ export function initialize({
         disableRetries?: boolean;
         timeout?: number;
         downloadOffset?: number;
+        onProgress?: (currentBytes: number, totalBytes: number) => void;
       };
     }): Promise<Readable> {
       const abortController = new AbortController();
@@ -3568,6 +3578,8 @@ export function initialize({
 
       registerInflightRequest(cancelRequest);
 
+      let totalBytes = 0;
+
       // This is going to the CDN, not the service, so we use _outerAjax
       try {
         const targetHeaders = { ...headers };
@@ -3587,7 +3599,22 @@ export function initialize({
           abortSignal: abortController.signal,
         });
 
-        if (targetHeaders.range != null) {
+        if (targetHeaders.range == null) {
+          const contentLength =
+            streamWithDetails.response.headers.get('content-length');
+          strictAssert(
+            contentLength != null,
+            'Attachment Content-Length is absent'
+          );
+
+          const maybeSize = safeParseNumber(contentLength);
+          strictAssert(
+            maybeSize != null,
+            'Attachment Content-Length is not a number'
+          );
+
+          totalBytes = maybeSize;
+        } else {
           strictAssert(
             streamWithDetails.response.status === 206,
             `Expected 206 status code for offset ${options?.downloadOffset}`
@@ -3596,6 +3623,19 @@ export function initialize({
             !streamWithDetails.contentType?.includes('multipart'),
             `Expected non-multipart response for ${cdnUrl}${cdnPath}`
           );
+
+          const range = streamWithDetails.response.headers.get('content-range');
+          strictAssert(range != null, 'Attachment Content-Range is absent');
+
+          const match = PARSE_RANGE_HEADER.exec(range);
+          strictAssert(match != null, 'Attachment Content-Range is invalid');
+          const maybeSize = safeParseNumber(match[1]);
+          strictAssert(
+            maybeSize != null,
+            'Attachment Content-Range[1] is not a number'
+          );
+
+          totalBytes = maybeSize;
         }
       } finally {
         if (!streamWithDetails) {
@@ -3620,6 +3660,17 @@ export function initialize({
         })
         .pipe(timeoutStream);
 
+      if (options?.onProgress) {
+        const { onProgress } = options;
+        let currentBytes = options.downloadOffset ?? 0;
+
+        combinedStream.pause();
+        combinedStream.on('data', chunk => {
+          currentBytes += chunk.byteLength;
+          onProgress(currentBytes, totalBytes);
+        });
+      }
+
       return combinedStream;
     }