Change remove_generation to return list of chunks

This will be useful for actually implementing removal of unused chunks
in green-albatross.

3 files changed, 11 insertions, 2 deletions

diff --git a/obnamlib/fmt_6/repo_fmt_6.py b/obnamlib/fmt_6/repo_fmt_6.py
index 25156e78..cd389af2 100644
--- a/obnamlib/fmt_6/repo_fmt_6.py
+++ b/obnamlib/fmt_6/repo_fmt_6.py
@@ -561,6 +561,8 @@ class RepositoryFormat6(obnamlib.RepositoryInterface):
         open_client_info.client.start_changes(create_tree=False)
         open_client_info.client.remove_generation(gen_number)
 
+        return []  # We handle chunk removal ourselves.
+
     def get_generation_chunk_ids(self, generation_id):
         # This intentionally doesn't construct chunk ids for in-tree
         # data, because that's very slow, as it requires iterating
diff --git a/obnamlib/fmt_ga/client.py b/obnamlib/fmt_ga/client.py
index d07bea77..b267aae0 100644
--- a/obnamlib/fmt_ga/client.py
+++ b/obnamlib/fmt_ga/client.py
@@ -203,6 +203,8 @@ class GAClient(object):
 
         self._generations.set_generations(remaining)
 
+        return []  # FIXME
+
     def get_generation_key(self, gen_number, key):
         self._load_data()
         generation = self._lookup_generation_by_gen_number(gen_number)
diff --git a/obnamlib/repo_interface.py b/obnamlib/repo_interface.py
index 1a076ea6..4df397a9 100644
--- a/obnamlib/repo_interface.py
+++ b/obnamlib/repo_interface.py
@@ -644,6 +644,9 @@ class RepositoryInterface(object):
 
         The removed generation may be the currently unfinished one.
 
+        Return a list of chunk ids that are no longer used by this
+        client.
+
         '''
         raise NotImplementedError()
 
@@ -1562,16 +1565,18 @@ class RepositoryInterfaceTests(unittest.TestCase):  # pragma: no cover
 
     def test_removes_unfinished_generation(self):
         gen_id = self.create_generation()
-        self.repo.remove_generation(gen_id)
+        chunk_ids = self.repo.remove_generation(gen_id)
         self.assertEqual(self.repo.get_client_generation_ids('fooclient'), [])
+        self.assertEqual(type(chunk_ids), list)
 
     def test_removes_finished_generation(self):
         gen_id = self.create_generation()
         self.repo.commit_client('fooclient')
         self.repo.unlock_client('fooclient')
         self.repo.lock_client('fooclient')
-        self.repo.remove_generation(gen_id)
+        chunk_ids = self.repo.remove_generation(gen_id)
         self.assertEqual(self.repo.get_client_generation_ids('fooclient'), [])
+        self.assertEqual(type(chunk_ids), list)
 
     def test_removing_removed_generation_fails(self):
         gen_id = self.create_generation()