Merge "proxy: Use the right ranges when going to multiple object serv…

…ers" into stable/pike

swift/proxy/controllers/base.py

@@ -787,14 +787,16 @@ def fast_forward(self, num_bytes):
                            this request. This will change the Range header
                            so that the next req will start where it left off.
 
-        :raises ValueError: if invalid range header
         :raises HTTPRequestedRangeNotSatisfiable: if begin + num_bytes
                                                   > end of range + 1
         :raises RangeAlreadyComplete: if begin + num_bytes == end of range + 1
         """
-        if 'Range' in self.backend_headers:
-            req_range = Range(self.backend_headers['Range'])
+        try:
+            req_range = Range(self.backend_headers.get('Range'))
+        except ValueError:
+            req_range = None
 
+        if req_range:
             begin, end = req_range.ranges[0]
             if begin is None:
                 # this is a -50 range req (last 50 bytes of file)
@@ -818,6 +820,9 @@ def fast_forward(self, num_bytes):
         else:
             self.backend_headers['Range'] = 'bytes=%d-' % num_bytes
 
+        # Reset so if we need to do this more than once, we don't double-up
+        self.bytes_used_from_backend = 0
+
     def pop_range(self):
         """
         Remove the first byterange from our Range header.

test/unit/proxy/controllers/test_base.py

@@ -900,18 +900,32 @@ def getheaders(self):
 
         node = {'ip': '1.2.3.4', 'port': 6200, 'device': 'sda'}
 
-        source1 = TestSource(['abcd', '1234', 'abc', None])
-        source2 = TestSource(['efgh5678'])
+        data = ['abcd', '1234', 'efgh', '5678', 'lots', 'more', 'data']
+
+        # NB: content length on source1 should be correct
+        # but that reversed piece never makes it to the client
+        source1 = TestSource(data[:2] + [data[2][::-1], None] + data[3:])
+        source2 = TestSource(data[2:4] + ['nope', None])
+        source3 = TestSource(data[4:])
         req = Request.blank('/v1/a/c/o')
         handler = GetOrHeadHandler(
             self.app, req, 'Object', None, None, None, {},
             client_chunk_size=8)
 
+        range_headers = []
+        sources = [(source2, node), (source3, node)]
+
+        def mock_get_source_and_node():
+            range_headers.append(handler.backend_headers['Range'])
+            return sources.pop(0)
+
         app_iter = handler._make_app_iter(req, node, source1)
         with mock.patch.object(handler, '_get_source_and_node',
-                               lambda: (source2, node)):
+                               side_effect=mock_get_source_and_node):
             client_chunks = list(app_iter)
-        self.assertEqual(client_chunks, ['abcd1234', 'efgh5678'])
+        self.assertEqual(range_headers, ['bytes=8-27', 'bytes=16-27'])
+        self.assertEqual(client_chunks, [
+            'abcd1234', 'efgh5678', 'lotsmore', 'data'])
 
     def test_client_chunk_size_resuming_chunked(self):