Use bulk-delete middleware when available

When issuing `delete` commands that would require three or more
individual deletes, check whether the cluster supports bulk deletes
and use that if it's available.

Additionally, a new option is added to the `delete` command:

  * --prefix <prefix>

    Delete all objects that start with <prefix>. This is similar to the
    --prefix option for the `list` command.

Example:

$ swift delete c --prefix obj_prefix/

    ...will delete from container "c" all objects whose name begins with
    "obj_prefix/", such as "obj_prefix/foo" and "obj_prefix/bar".

Change-Id: I6b9504848d6ef562cf4f570bbcd17db4e3da8264

1 files changed, 28 insertions, 0 deletions

diff --git a/tests/unit/test_utils.py b/tests/unit/test_utils.py
index 3439f4a..fe50f55 100644
--- a/tests/unit/test_utils.py
+++ b/tests/unit/test_utils.py
@@ -290,3 +290,31 @@ class TestLengthWrapper(testtools.TestCase):
                 self.assertEqual(segment_length, len(read_data))
                 self.assertEqual(s, read_data)
                 self.assertEqual(md5(s).hexdigest(), data.get_md5sum())
+
+
+class TestGroupers(testtools.TestCase):
+    def test_n_at_a_time(self):
+        result = list(u.n_at_a_time(range(100), 9))
+        self.assertEqual([9] * 11 + [1], list(map(len, result)))
+
+        result = list(u.n_at_a_time(range(100), 10))
+        self.assertEqual([10] * 10, list(map(len, result)))
+
+        result = list(u.n_at_a_time(range(100), 11))
+        self.assertEqual([11] * 9 + [1], list(map(len, result)))
+
+        result = list(u.n_at_a_time(range(100), 12))
+        self.assertEqual([12] * 8 + [4], list(map(len, result)))
+
+    def test_n_groups(self):
+        result = list(u.n_groups(range(100), 9))
+        self.assertEqual([12] * 8 + [4], list(map(len, result)))
+
+        result = list(u.n_groups(range(100), 10))
+        self.assertEqual([10] * 10, list(map(len, result)))
+
+        result = list(u.n_groups(range(100), 11))
+        self.assertEqual([10] * 10, list(map(len, result)))
+
+        result = list(u.n_groups(range(100), 12))
+        self.assertEqual([9] * 11 + [1], list(map(len, result)))