Fixed #383 -- Stream large file reads from S3

jschneier · Aug 12, 2018 · ea0986d · ea0986d
1 parent 08e3da2
commit ea0986d
Showing 1 changed file with 3 additions and 1 deletion.
diff --git a/storages/backends/s3boto3.py b/storages/backends/s3boto3.py
@@ -62,6 +62,8 @@ class S3Boto3StorageFile(File):
     buffer_size = setting('AWS_S3_FILE_BUFFER_SIZE', 5242880)
 
     def __init__(self, name, mode, storage, buffer_size=None):
+        if 'r' in mode and 'w' in mode:
+            raise ValueError("Can't combine 'r' and 'w' in mode.")
         self._storage = storage
         self.name = name[len(self._storage.location):].lstrip('/')
         self._mode = mode
@@ -93,7 +95,7 @@ def _get_file(self):
             )
             if 'r' in self._mode:
                 self._is_dirty = False
-                self._file.write(self.obj.get()['Body'].read())
+                self.obj.download_fileobj(self._file)
                 self._file.seek(0)
             if self._storage.gzip and self.obj.content_encoding == 'gzip':
                 self._file = GzipFile(mode=self._mode, fileobj=self._file, mtime=0.0)