Add RepositoryInterface.get_client_checksum_key

6 files changed, 34 insertions, 9 deletions

diff --git a/obnamlib/delegator.py b/obnamlib/delegator.py
index c873374a..441505e3 100644
--- a/obnamlib/delegator.py
+++ b/obnamlib/delegator.py
@@ -267,6 +267,10 @@ class RepositoryDelegator(obnamlib.RepositoryInterface):
         return client.set_file_keys_from_metadata(
             generation_id.gen_number, filename, metadata)
 
+    def get_client_checksum_key(self, client_name):
+        client = self._lookup_client(client_name)
+        return client.get_client_checksum_key()
+
     def get_file_chunk_ids(self, generation_id, filename):
         client = self._lookup_client_by_generation(generation_id)
         return client.get_file_chunk_ids(generation_id.gen_number, filename)
diff --git a/obnamlib/fmt_6/repo_fmt_6.py b/obnamlib/fmt_6/repo_fmt_6.py
index 6f95ee3c..d56439f3 100644
--- a/obnamlib/fmt_6/repo_fmt_6.py
+++ b/obnamlib/fmt_6/repo_fmt_6.py
@@ -993,6 +993,9 @@ class RepositoryFormat6(obnamlib.RepositoryInterface):
                 client_name=client_name,
                 key_name=obnamlib.repo_key_name(key))
 
+    def get_client_checksum_key(self, client_name):
+        return obnamlib.REPO_FILE_MD5
+
     def get_file_chunk_ids(self, generation_id, filename):
         self._require_existing_file(generation_id, filename)
         client_name, gen_number = self._unpack_gen_id(generation_id)
diff --git a/obnamlib/fmt_ga/client.py b/obnamlib/fmt_ga/client.py
index b204c720..d29c85a6 100644
--- a/obnamlib/fmt_ga/client.py
+++ b/obnamlib/fmt_ga/client.py
@@ -53,6 +53,11 @@ class GAClient(object):
     def set_default_checksum_algorithm(self, name):
         self._default_checksum_algorithm = name
 
+    def get_client_checksum_key(self):
+        self._load_data()
+        assert self._checksum_algorithm is not None
+        return obnamlib.get_checksum_algorithm_key(self._checksum_algorithm)
+
     def set_dir_bag_size(self, size):
         self._dir_bag_size = size
         if self._blob_store:
diff --git a/obnamlib/repo_interface.py b/obnamlib/repo_interface.py
index 6ab93ccd..3bba872f 100644
--- a/obnamlib/repo_interface.py
+++ b/obnamlib/repo_interface.py
@@ -575,6 +575,10 @@ class RepositoryInterface(object):
         '''Return list of allowed per-client keys for thist format.'''
         raise NotImplementedError()
 
+    def get_client_checksum_key(self, client_name):
+        '''Return file key for preferred checksum for client, or None.'''
+        raise NotImplementedError()
+
     def get_client_key(self, client_name, key):
         '''Return current value of a key for a given client.
 
@@ -779,7 +783,6 @@ class RepositoryInterface(object):
             self.set_file_key(generation_id, filename, key, None)
 
     def get_file_chunk_ids(self, generation_id, filename):
-
         '''Get the list of chunk ids for a file.'''
         raise NotImplementedError()
 
@@ -1945,6 +1948,17 @@ class RepositoryInterfaceTests(unittest.TestCase):  # pragma: no cover
             gen_id_2, '/foo/bar', obnamlib.REPO_FILE_SYMLINK_TARGET)
         self.assertEqual(value_2, 'second')
 
+    def test_returns_an_acceptable_checksum_file_key_or_none(self):
+        self.setup_client()
+        self.assertTrue(
+            self.repo.get_client_checksum_key('fooclient') in
+            [None,
+             obnamlib.REPO_FILE_MD5,
+             obnamlib.REPO_FILE_SHA224,
+             obnamlib.REPO_FILE_SHA256,
+             obnamlib.REPO_FILE_SHA384,
+             obnamlib.REPO_FILE_SHA512])
+
     def test_new_file_has_no_chunk_ids(self):
         gen_id = self.create_generation()
         self.repo.add_file(gen_id, '/foo/bar')
diff --git a/obnamlib/whole_file_checksummer.py b/obnamlib/whole_file_checksummer.py
index 517c09a1..b08655b9 100644
--- a/obnamlib/whole_file_checksummer.py
+++ b/obnamlib/whole_file_checksummer.py
@@ -35,11 +35,10 @@ class WholeFileCheckSummer(object):
 
     '''
 
-    def __init__(self, repo):
-        self._summer = self._create_checksum_algorithm(repo)
+    def __init__(self, file_key):
+        self._summer = self._create_checksum_algorithm(file_key)
 
-    def _create_checksum_algorithm(self, repo):
-        file_key = repo.get_file_checksum_key()
+    def _create_checksum_algorithm(self, file_key):
         if file_key is None:
             return _NullChecksum()
         name = obnamlib.get_checksum_algorithm_name(file_key)
diff --git a/obnamlib/whole_file_checksummer_tests.py b/obnamlib/whole_file_checksummer_tests.py
index c2addbec..c06becab 100644
--- a/obnamlib/whole_file_checksummer_tests.py
+++ b/obnamlib/whole_file_checksummer_tests.py
@@ -25,7 +25,7 @@ class WholeFileCheckSummerTests(unittest.TestCase):
 
     def test_computes_nothing_if_repo_wants_no_checksum(self):
         repo = FakeRepository(None)
-        summer = obnamlib.WholeFileCheckSummer(repo)
+        summer = obnamlib.WholeFileCheckSummer(None)
         chunk = 'hello'
         token = repo.prepare_chunk_for_indexes(chunk)
         summer.append_chunk(chunk, token)
@@ -33,7 +33,7 @@ class WholeFileCheckSummerTests(unittest.TestCase):
 
     def test_computes_checksum_for_md5(self):
         repo = FakeRepository(obnamlib.REPO_FILE_MD5)
-        summer = obnamlib.WholeFileCheckSummer(repo)
+        summer = obnamlib.WholeFileCheckSummer(obnamlib.REPO_FILE_MD5)
         chunk = 'hello'
         token = repo.prepare_chunk_for_indexes(chunk)
         summer.append_chunk(chunk, token)
@@ -43,7 +43,7 @@ class WholeFileCheckSummerTests(unittest.TestCase):
 
     def test_computes_checksum_for_sha512(self):
         repo = FakeRepository(obnamlib.REPO_FILE_SHA512)
-        summer = obnamlib.WholeFileCheckSummer(repo)
+        summer = obnamlib.WholeFileCheckSummer(obnamlib.REPO_FILE_SHA512)
         chunk = 'hello'
         token = repo.prepare_chunk_for_indexes(chunk)
         summer.append_chunk(chunk, token)
@@ -58,7 +58,7 @@ class FakeRepository(object):
     def __init__(self, file_key):
         self._file_key = file_key
 
-    def get_file_checksum_key(self):
+    def get_client_checksum_key(self, client_name):
         return self._file_key
 
     def prepare_chunk_for_indexes(self, data):