Use StreamingHttpResponse when downloading zip streams

app/api/tasks.py

@@ -11,6 +11,8 @@ from django.core.files.uploadedfile import InMemoryUploadedFile
 from django.db import transaction
 from django.http import FileResponse
 from django.http import HttpResponse
+from django.http import StreamingHttpResponse
+from app.vendor import zipfly
 from rest_framework import status, serializers, viewsets, filters, exceptions, permissions, parsers
 from rest_framework.decorators import action
 from rest_framework.permissions import AllowAny
@@ -340,8 +342,13 @@ def download_file_response(request, filePath, content_disposition, download_file
 
 
 def download_file_stream(request, stream, content_disposition, download_filename=None):
-    response = HttpResponse(FileWrapper(stream),
-                            content_type=(mimetypes.guess_type(download_filename)[0] or "application/zip"))
+    if isinstance(stream, zipfly.ZipStream):
+        f = stream.generator()
+    else:
+        # This should never happen, but just in case..
+        raise exceptions.ValidationError("stream not a zipstream instance")
+    
+    response = StreamingHttpResponse(f, content_type=(mimetypes.guess_type(download_filename)[0] or "application/zip"))
 
     response['Content-Type'] = mimetypes.guess_type(download_filename)[0] or "application/zip"
     response['Content-Disposition'] = "{}; filename={}".format(content_disposition, download_filename)

app/vendor/zipfly.py

@@ -46,7 +46,6 @@ class ZipflyStream(io.RawIOBase):
     def size(self):
         return self._size
 
-
 class ZipFly:
 
     def __init__(self,
@@ -280,13 +279,17 @@ class ZipFly:
 class ZipStream:
     def __init__(self, paths):
         self.paths = paths
-        self.generator = None
+        self._generator = None
 
     def lazy_load(self, chunksize):
-        if self.generator is None:
+        if self._generator is None:
             zfly = ZipFly(paths=self.paths, mode='w', chunksize=chunksize)
-            self.generator = zfly.generator()
+            self._generator = zfly.generator()
 
     def read(self, count):
         self.lazy_load(count)
-        return next(self.generator)
+        return next(self._generator)
+
+    def generator(self):
+        self.lazy_load(0x8000)
+        return self._generator

package.json

@@ -1,6 +1,6 @@
 {
   "name": "WebODM",
-  "version": "2.5.3",
+  "version": "2.5.4",
   "description": "User-friendly, extendable application and API for processing aerial imagery.",
   "main": "index.js",
   "scripts": {