Allow reading from object body on download

Currently, get_object returns a generator. This allows access to the
object's data in multiples of 'resp_chunk_size'.

This patch adds a read function to also allow accessing the object data
using read(size).

This allows, for example, the consumer of an object (where no byte range
has been specified) to read up to certain boundaries while streaming to
a new Large Object with segments of a specified size.

Reading and chunking can be safely mixed.

Related-Bug: 1367925
Co-Authored-By: Clay Gerrard <clay.gerrard@gmail.com>
Change-Id: I1cfb67f45afc7015fd896f1a89bebae048871769

1 files changed, 18 insertions, 3 deletions

diff --git a/tests/functional/test_swiftclient.py b/tests/functional/test_swiftclient.py
index f5d14aa..ea44169 100644
--- a/tests/functional/test_swiftclient.py
+++ b/tests/functional/test_swiftclient.py
@@ -16,7 +16,6 @@
 import os
 import testtools
 import time
-import types
 from io import BytesIO
 
 from six.moves import configparser
@@ -256,8 +255,24 @@ class TestFunctional(testtools.TestCase):
         hdrs, body = self.conn.get_object(
             self.containername, self.objectname,
             resp_chunk_size=10)
-        self.assertTrue(isinstance(body, types.GeneratorType))
-        self.assertEqual(self.test_data, b''.join(body))
+        downloaded_contents = b''
+        while True:
+            try:
+                chunk = next(body)
+            except StopIteration:
+                break
+            downloaded_contents += chunk
+        self.assertEqual(self.test_data, downloaded_contents)
+
+        # Download in chunks, should also work with read
+        hdrs, body = self.conn.get_object(
+            self.containername, self.objectname,
+            resp_chunk_size=10)
+        num_bytes = 5
+        downloaded_contents = body.read(num_bytes)
+        self.assertEqual(num_bytes, len(downloaded_contents))
+        downloaded_contents += body.read()
+        self.assertEqual(self.test_data, downloaded_contents)
 
     def test_post_account(self):
         self.conn.post_account({'x-account-meta-data': 'Something'})