client: advertise capabilities correctly per-service

git capabilities are per-service, and we should correctly advertise
capabilities to either upload-pack, receive-pack, or both.

Change-Id: Id6cf579fa698a10a56b43adc055fa6c0d25c6942

dulwich/client.py

@@ -45,9 +45,9 @@ def _fileno_can_read(fileno):
     """Check if a file descriptor is readable."""
     return len(select.select([fileno], [], [], 0)[0]) > 0
 
-
-CAPABILITIES = ["multi_ack", "side-band-64k", "ofs-delta"]
-
+COMMON_CAPABILITIES = ["ofs-delta"]
+FETCH_CAPABILITIES = ["multi_ack", "side-band-64k"] + COMMON_CAPABILITIES
+SEND_CAPABILITIES = [] + COMMON_CAPABILITIES
 
 class GitClient(object):
     """Git smart server client.
@@ -68,12 +68,10 @@ class GitClient(object):
         """
         self.proto = Protocol(read, write, report_activity)
         self._can_read = can_read
-        self._capabilities = list(CAPABILITIES)
+        self._fetch_capabilities = list(FETCH_CAPABILITIES)
+        self._send_capabilities = list(SEND_CAPABILITIES)
         if thin_packs:
-            self._capabilities.append("thin-pack")
-
-    def capabilities(self):
-        return " ".join(self._capabilities)
+            self._fetch_capabilities.append("thin-pack")
 
     def read_refs(self):
         server_capabilities = None
@@ -86,6 +84,7 @@ class GitClient(object):
             refs[ref] = sha
         return refs, server_capabilities
 
+    # TODO(durin42): add side-band-64k capability support here and advertise it
     def send_pack(self, path, determine_wants, generate_pack_contents):
         """Upload a pack to a remote repository.
 
@@ -108,7 +107,9 @@ class GitClient(object):
                 if sent_capabilities:
                     self.proto.write_pkt_line("%s %s %s" % (old_sha1, new_sha1, refname))
                 else:
-                    self.proto.write_pkt_line("%s %s %s\0%s" % (old_sha1, new_sha1, refname, self.capabilities()))
+                    self.proto.write_pkt_line(
+                      "%s %s %s\0%s" % (old_sha1, new_sha1, refname,
+                                        ' '.join(self._send_capabilities)))
                     sent_capabilities = True
             if not new_sha1 in (have, ZERO_SHA):
                 want.append(new_sha1)
@@ -166,7 +167,8 @@ class GitClient(object):
             self.proto.write_pkt_line(None)
             return refs
         assert isinstance(wants, list) and type(wants[0]) == str
-        self.proto.write_pkt_line("want %s %s\n" % (wants[0], self.capabilities()))
+        self.proto.write_pkt_line("want %s %s\n" % (
+            wants[0], ' '.join(self._fetch_capabilities)))
         for want in wants[1:]:
             self.proto.write_pkt_line("want %s\n" % want)
         self.proto.write_pkt_line(None)
@@ -189,6 +191,8 @@ class GitClient(object):
             if len(parts) < 3 or parts[2] != "continue":
                 break
             pkt = self.proto.read_pkt_line()
+        # TODO(durin42): this is broken if the server didn't support the
+        # side-band-64k capability.
         for pkt in self.proto.read_pkt_seq():
             channel = ord(pkt[0])
             pkt = pkt[1:]

dulwich/tests/test_client.py

@@ -1,16 +1,16 @@
 # test_client.py -- Tests for the git protocol, client side
 # Copyright (C) 2009 Jelmer Vernooij <jelmer@samba.org>
-# 
+#
 # This program is free software; you can redistribute it and/or
 # modify it under the terms of the GNU General Public License
 # as published by the Free Software Foundation; version 2
 # or (at your option) any later version of the License.
-# 
+#
 # This program is distributed in the hope that it will be useful,
 # but WITHOUT ANY WARRANTY; without even the implied warranty of
 # MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 # GNU General Public License for more details.
-# 
+#
 # You should have received a copy of the GNU General Public License
 # along with this program; if not, write to the Free Software
 # Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston,
@@ -23,16 +23,22 @@ from dulwich.client import (
     GitClient,
     )
 
+
+# TODO(durin42): add unit-level tests of GitClient
 class GitClientTests(TestCase):
 
     def setUp(self):
         self.rout = StringIO()
         self.rin = StringIO()
-        self.client = GitClient(lambda x: True, self.rin.read, 
+        self.client = GitClient(lambda x: True, self.rin.read,
             self.rout.write)
 
     def test_caps(self):
-        self.assertEquals(['multi_ack', 'side-band-64k', 'ofs-delta', 'thin-pack'], self.client._capabilities)
+        self.assertEquals(set(['multi_ack', 'side-band-64k', 'ofs-delta',
+                               'thin-pack']),
+                          set(self.client._fetch_capabilities))
+        self.assertEquals(set(['ofs-delta']),
+                          set(self.client._send_capabilities))
 
     def test_fetch_pack_none(self):
         self.rin.write(