Allowing files from S3 to be re-opened. Closes #33

django_s3_storage/storage.py

@@ -24,6 +24,22 @@
 CONTENT_ENCODING_GZIP = "gzip"
 
 
+class S3File(File):
+
+    """
+    A file returned from Amazon S3.
+    """
+
+    def __init__(self, file, name, storage):
+        super().__init__(file, name)
+        self._storage = storage
+
+    def open(self, mode=None):
+        if self.closed:
+            self.file = self._storage.open(self.name, mode or "rb").file
+        return super().open(mode)
+
+
 @deconstructible
 class S3Storage(Storage):
 
@@ -216,7 +232,7 @@ def _get_metadata(self, name):
         }
 
     def _open(self, name, mode="rb"):
-        if (mode != "rb"):
+        if mode != "rb":
             raise ValueError("S3 files can only be opened in read-only mode")
         # Load the key into a temporary file. It would be nice to stream the
         # content, but S3 doesn't support seeking, which is sometimes needed.
@@ -233,7 +249,7 @@ def _open(self, name, mode="rb"):
         if key.content_encoding == CONTENT_ENCODING_GZIP:
             content = gzip.GzipFile(name, "rb", fileobj=content)
         # All done!
-        return File(content, name)
+        return S3File(content, name, self)
 
     def _save(self, name, content):
         # Calculate the file headers and compression.

django_s3_storage/tests.py

@@ -111,6 +111,12 @@ def assertUrlInaccessible(self, url):
     def testOpen(self):
         self.assertEqual(self.storage.open(self.upload_path).read(), self.file_contents)
 
+    def testReOpen(self):
+        handle = self.storage.open(self.upload_path)
+        handle.close()
+        handle.open()
+        self.assertEqual(handle.read(), self.file_contents)
+
     def testCannotOpenInWriteMode(self):
         with self.assertRaises(ValueError) as cm:
             self.storage.open(self.upload_path, "wb")