diff --git a/mercurial/bundle2.py b/mercurial/bundle2.py
--- a/mercurial/bundle2.py
+++ b/mercurial/bundle2.py
@@ -820,7 +820,7 @@ def handlechangegroup(op, inpart):
     # we need to make sure we trigger the creation of a transaction object used
     # for the whole processing scope.
     op.gettransaction()
-    cg = changegroup.unbundle10(inpart, 'UN')
+    cg = changegroup.cg1unpacker(inpart, 'UN')
     ret = changegroup.addchangegroup(op.repo, cg, 'bundle2', 'bundle2')
     op.records.add('changegroup', {'return': ret})
     if op.reply is not None:
diff --git a/mercurial/changegroup.py b/mercurial/changegroup.py
--- a/mercurial/changegroup.py
+++ b/mercurial/changegroup.py
@@ -12,7 +12,7 @@ import mdiff, util, dagutil
 import struct, os, bz2, zlib, tempfile
 import discovery, error, phases, branchmap
 
-_BUNDLE10_DELTA_HEADER = "20s20s20s20s"
+_CHANGEGROUPV1_DELTA_HEADER = "20s20s20s20s"
 
 def readexactly(stream, n):
     '''read n bytes from stream.read and abort if less was available'''
@@ -123,8 +123,8 @@ def decompressor(fh, alg):
         raise util.Abort("unknown bundle compression '%s'" % alg)
     return util.chunkbuffer(generator(fh))
 
-class unbundle10(object):
-    deltaheader = _BUNDLE10_DELTA_HEADER
+class cg1unpacker(object):
+    deltaheader = _CHANGEGROUPV1_DELTA_HEADER
     deltaheadersize = struct.calcsize(deltaheader)
     def __init__(self, fh, alg):
         self._stream = decompressor(fh, alg)
@@ -227,8 +227,8 @@ class headerlessfixup(object):
             return d
         return readexactly(self._fh, n)
 
-class bundle10(object):
-    deltaheader = _BUNDLE10_DELTA_HEADER
+class cg1packer(object):
+    deltaheader = _CHANGEGROUPV1_DELTA_HEADER
     def __init__(self, repo, bundlecaps=None):
         """Given a source repo, construct a bundler.
 
@@ -456,7 +456,7 @@ def getsubset(repo, outgoing, bundler, s
     repo.hook('preoutgoing', throw=True, source=source)
     _changegroupinfo(repo, csets, source)
     gengroup = bundler.generate(commonrevs, csets, fastpathlinkrev, source)
-    return unbundle10(util.chunkbuffer(gengroup), 'UN')
+    return cg1unpacker(util.chunkbuffer(gengroup), 'UN')
 
 def changegroupsubset(repo, roots, heads, source):
     """Compute a changegroup consisting of all the nodes that are
@@ -480,17 +480,17 @@ def changegroupsubset(repo, roots, heads
     for n in roots:
         discbases.extend([p for p in cl.parents(n) if p != nullid])
     outgoing = discovery.outgoing(cl, discbases, heads)
-    bundler = bundle10(repo)
+    bundler = cg1packer(repo)
     return getsubset(repo, outgoing, bundler, source)
 
-def getlocalbundle(repo, source, outgoing, bundlecaps=None):
+def getlocalchangegroup(repo, source, outgoing, bundlecaps=None):
     """Like getbundle, but taking a discovery.outgoing as an argument.
 
     This is only implemented for local repos and reuses potentially
     precomputed sets in outgoing."""
     if not outgoing.missing:
         return None
-    bundler = bundle10(repo, bundlecaps)
+    bundler = cg1packer(repo, bundlecaps)
     return getsubset(repo, outgoing, bundler, source)
 
 def _computeoutgoing(repo, heads, common):
@@ -512,7 +512,7 @@ def _computeoutgoing(repo, heads, common
         heads = cl.heads()
     return discovery.outgoing(cl, common, heads)
 
-def getbundle(repo, source, heads=None, common=None, bundlecaps=None):
+def getchangegroup(repo, source, heads=None, common=None, bundlecaps=None):
     """Like changegroupsubset, but returns the set difference between the
     ancestors of heads and the ancestors common.
 
@@ -522,7 +522,7 @@ def getbundle(repo, source, heads=None, 
     current discovery protocol works.
     """
     outgoing = _computeoutgoing(repo, heads, common)
-    return getlocalbundle(repo, source, outgoing, bundlecaps=bundlecaps)
+    return getlocalchangegroup(repo, source, outgoing, bundlecaps=bundlecaps)
 
 def changegroup(repo, basenodes, source):
     # to avoid a race we use changegroupsubset() (issue1320)
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -1159,8 +1159,8 @@ def bundle(ui, repo, fname, dest=None, *
                                "a destination"))
         common = [repo.lookup(rev) for rev in base]
         heads = revs and map(repo.lookup, revs) or revs
-        cg = changegroup.getbundle(repo, 'bundle', heads=heads, common=common,
-                                   bundlecaps=bundlecaps)
+        cg = changegroup.getchangegroup(repo, 'bundle', heads=heads,
+                                         common=common, bundlecaps=bundlecaps)
         outgoing = None
     else:
         dest = ui.expandpath(dest or 'default-push', dest or 'default')
@@ -1172,7 +1172,8 @@ def bundle(ui, repo, fname, dest=None, *
                                                 onlyheads=heads,
                                                 force=opts.get('force'),
                                                 portable=True)
-        cg = changegroup.getlocalbundle(repo, 'bundle', outgoing, bundlecaps)
+        cg = changegroup.getlocalchangegroup(repo, 'bundle', outgoing,
+                                             bundlecaps)
     if not cg:
         scmutil.nochangesfound(ui, repo, outgoing and outgoing.excluded)
         return 1
diff --git a/mercurial/exchange.py b/mercurial/exchange.py
--- a/mercurial/exchange.py
+++ b/mercurial/exchange.py
@@ -31,7 +31,7 @@ def readbundle(ui, fh, fname, vfs=None):
     if version == '10':
         if alg is None:
             alg = changegroup.readexactly(fh, 2)
-        return changegroup.unbundle10(fh, alg)
+        return changegroup.cg1unpacker(fh, alg)
     elif version == '2X':
         return bundle2.unbundle20(ui, fh, header=magic + version)
     else:
@@ -401,7 +401,7 @@ def _pushb2ctx(pushop, bundler):
                                      pushop.outgoing)
     if not pushop.force:
         bundler.newpart('B2X:CHECK:HEADS', data=iter(pushop.remoteheads))
-    cg = changegroup.getlocalbundle(pushop.repo, 'push', pushop.outgoing)
+    cg = changegroup.getlocalchangegroup(pushop.repo, 'push', pushop.outgoing)
     cgpart = bundler.newpart('B2X:CHANGEGROUP', data=cg.getchunks())
     def handlereply(op):
         """extract addchangroup returns from server reply"""
@@ -536,14 +536,14 @@ def _pushchangeset(pushop):
                             or pushop.repo.changelog.filteredrevs):
         # push everything,
         # use the fast path, no race possible on push
-        bundler = changegroup.bundle10(pushop.repo, bundlecaps)
+        bundler = changegroup.cg1packer(pushop.repo, bundlecaps)
         cg = changegroup.getsubset(pushop.repo,
                                    outgoing,
                                    bundler,
                                    'push',
                                    fastpath=True)
     else:
-        cg = changegroup.getlocalbundle(pushop.repo, 'push', outgoing,
+        cg = changegroup.getlocalchangegroup(pushop.repo, 'push', outgoing,
                                         bundlecaps)
 
     # apply changegroup to remote
@@ -969,7 +969,7 @@ def getbundle(repo, source, heads=None, 
     passed. For now, the bundle can contain only changegroup, but this will
     changes when more part type will be available for bundle2.
 
-    This is different from changegroup.getbundle that only returns an HG10
+    This is different from changegroup.getchangegroup that only returns an HG10
     changegroup bundle. They may eventually get reunited in the future when we
     have a clearer idea of the API we what to query different data.
 
@@ -979,8 +979,8 @@ def getbundle(repo, source, heads=None, 
     cg = None
     if kwargs.get('cg', True):
         # build changegroup bundle here.
-        cg = changegroup.getbundle(repo, source, heads=heads,
-                                   common=common, bundlecaps=bundlecaps)
+        cg = changegroup.getchangegroup(repo, source, heads=heads,
+                                         common=common, bundlecaps=bundlecaps)
     elif 'HG2X' not in bundlecaps:
         raise ValueError(_('request for bundle10 must include changegroup'))
     if bundlecaps is None or 'HG2X' not in bundlecaps:
diff --git a/mercurial/sshserver.py b/mercurial/sshserver.py
--- a/mercurial/sshserver.py
+++ b/mercurial/sshserver.py
@@ -142,7 +142,7 @@ class sshserver(wireproto.abstractserver
             return
 
         self.sendresponse("")
-        cg = changegroup.unbundle10(self.fin, "UN")
+        cg = changegroup.cg1unpacker(self.fin, "UN")
         r = changegroup.addchangegroup(self.repo, cg, 'serve', self._client())
         self.lock.release()
         return str(r)
diff --git a/mercurial/wireproto.py b/mercurial/wireproto.py
--- a/mercurial/wireproto.py
+++ b/mercurial/wireproto.py
@@ -328,7 +328,7 @@ class wirepeer(peer.peerrepository):
     def changegroup(self, nodes, kind):
         n = encodelist(nodes)
         f = self._callcompressable("changegroup", roots=n)
-        return changegroupmod.unbundle10(f, 'UN')
+        return changegroupmod.cg1unpacker(f, 'UN')
 
     def changegroupsubset(self, bases, heads, kind):
         self.requirecap('changegroupsubset', _('look up remote changes'))
@@ -336,7 +336,7 @@ class wirepeer(peer.peerrepository):
         heads = encodelist(heads)
         f = self._callcompressable("changegroupsubset",
                                    bases=bases, heads=heads)
-        return changegroupmod.unbundle10(f, 'UN')
+        return changegroupmod.cg1unpacker(f, 'UN')
 
     def getbundle(self, source, **kwargs):
         self.requirecap('getbundle', _('look up remote changes'))
@@ -362,7 +362,7 @@ class wirepeer(peer.peerrepository):
         if bundlecaps is not None and 'HG2X' in bundlecaps:
             return bundle2.unbundle20(self.ui, f)
         else:
-            return changegroupmod.unbundle10(f, 'UN')
+            return changegroupmod.cg1unpacker(f, 'UN')
 
     def unbundle(self, cg, heads, source):
         '''Send cg (a readable file-like object representing the
diff --git a/tests/test-bundle2.t b/tests/test-bundle2.t
--- a/tests/test-bundle2.t
+++ b/tests/test-bundle2.t
@@ -106,7 +106,7 @@ Create an extension to test bundle2 API
   >             headmissing = [c.node() for c in repo.set('heads(%ld)', revs)]
   >             headcommon  = [c.node() for c in repo.set('parents(%ld) - %ld', revs, revs)]
   >             outgoing = discovery.outgoing(repo.changelog, headcommon, headmissing)
-  >             cg = changegroup.getlocalbundle(repo, 'test:bundle2', outgoing, None)
+  >             cg = changegroup.getlocalchangegroup(repo, 'test:bundle2', outgoing, None)
   >             bundler.newpart('b2x:changegroup', data=cg.getchunks())
   > 
   >     if opts['parts']: