getbundle: support of listkeys argument when bundle2 is used

A new ``listkeys`` is supported by getbundle. It is a list of namespaces whose
content should be included in the bundle.

An appropriate entry has been added to the wireproto map of getbundle arguments
and a new bundle2 capability is advertised.

There are still no codes that request such parts in core mercurial.

mercurial/exchange.py

@@ -9,7 +9,7 b' from i18n import _'
 from node import hex, nullid
 import errno, urllib
 import util, scmutil, changegroup, base85, error
-import discovery, phases, obsolete, bookmarks, bundle2
+import discovery, phases, obsolete, bookmarks, bundle2, pushkey
 
 def readbundle(ui, fh, fname, vfs=None):
     header = changegroup.readexactly(fh, 4)
@@ -678,6 +678,12 b' def getbundle(repo, source, heads=None, '
     bundler = bundle2.bundle20(repo.ui, b2caps)
     if cg:
         bundler.newpart('b2x:changegroup', data=cg.getchunks())
+    listkeys = kwargs.get('listkeys', ())
+    for namespace in listkeys:
+        part = bundler.newpart('b2x:listkeys')
+        part.addparam('namespace', namespace)
+        keys = repo.listkeys(namespace).items()
+        part.data = pushkey.encodekeys(keys)
     _getbundleextrapart(bundler, repo, source, heads=heads, common=common,
                         bundlecaps=bundlecaps, **kwargs)
     return util.chunkbuffer(bundler.getchunks())

mercurial/localrepo.py

@@ -180,7 +180,8 b' class localrepository(object):'
     requirements = ['revlogv1']
     filtername = None
 
-    bundle2caps = {'HG2X': ()}
+    bundle2caps = {'HG2X': (),
+                   'b2x:listkeys': ()}
 
     # a list of (ui, featureset) functions.
     # only functions defined in module of enabled extensions are invoked

mercurial/wireproto.py

@@ -202,7 +202,8 b' def unescapearg(escaped):'
 # :plain: string with no transformation needed.
 gboptsmap = {'heads':  'nodes',
              'common': 'nodes',
-             'bundlecaps': 'csv'}
+             'bundlecaps': 'csv',
+             'listkeys': 'csv'}
 
 # client side