wireproto: add getbundle() function

  getbundle(common, heads) -> bundle

Returns the changegroup for all ancestors of heads which are not ancestors of common. For both
sets, the heads are included in the set.

Intended to eventually supercede changegroupsubset and changegroup. Uses heads of common region
to exclude unwanted changesets instead of bases of desired region, which is more useful and
easier to implement.

Designed to be extensible with new optional arguments (which will have to be guarded by
corresponding capabilities).

tests/test-getbundle.t

@@ -0,0 +1,253 b''
+
+= Test the getbundle() protocol function =
+
+Enable graphlog extension:
+
+  $ echo "[extensions]" >> $HGRCPATH
+  $ echo "graphlog=" >> $HGRCPATH
+
+Create a test repository:
+
+  $ hg init repo
+  $ cd repo
+  $ hg debugbuilddag -n -m '+2 :fork +5 :p1 *fork +6 :p2 /p1 :m1 +3' > /dev/null
+  $ hg glog --template '{node}\n'
+  @  2bba2f40f321484159b395a43f20101d4bb7ead0
+  |
+  o  d9e5488323c782fe684573f3043369d199038b6f
+  |
+  o  6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+  |
+  o    733bf0910832b26b768a09172f325f995b5476e1
+  |\
+  | o  b5af5d6ea56d73ce24c40bc3cd19a862f74888ac
+  | |
+  | o  6b57ee934bb2996050540f84cdfc8dcad1e7267d
+  | |
+  | o  2c0ec49482e8abe888b7bd090b5827acfc22b3d7
+  | |
+  | o  c1818a9f5977dd4139a48f93f5425c67d44a9368
+  | |
+  | o  6c725a58ad10aea441540bfd06c507f63e8b9cdd
+  | |
+  | o  18063366a155bd56b5618229ae2ac3e91849aa5e
+  | |
+  | o  a21d913c992197a2eb60b298521ec0f045a04799
+  | |
+  o |  b6b2b682253df2ffedc10e9415e4114202b303c5
+  | |
+  o |  2114148793524fd045998f71a45b0aaf139f752b
+  | |
+  o |  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  | |
+  o |  ea919464b16e003894c48b6cb68df3cd9411b544
+  | |
+  o |  0f82d97ec2778746743fbc996740d409558fda22
+  |/
+  o  6e23b016bc0f0e79c7bd9dd372ccee07055d7fd4
+  |
+  o  10e64d654571f11577745b4d8372e859d9e4df63
+  
+  $ cd ..
+
+
+= Test locally =
+
+Get everything:
+
+  $ hg debuggetbundle repo bundle
+  $ hg debugbundle bundle
+  10e64d654571f11577745b4d8372e859d9e4df63
+  6e23b016bc0f0e79c7bd9dd372ccee07055d7fd4
+  0f82d97ec2778746743fbc996740d409558fda22
+  ea919464b16e003894c48b6cb68df3cd9411b544
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  2114148793524fd045998f71a45b0aaf139f752b
+  b6b2b682253df2ffedc10e9415e4114202b303c5
+  a21d913c992197a2eb60b298521ec0f045a04799
+  18063366a155bd56b5618229ae2ac3e91849aa5e
+  6c725a58ad10aea441540bfd06c507f63e8b9cdd
+  c1818a9f5977dd4139a48f93f5425c67d44a9368
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d
+  b5af5d6ea56d73ce24c40bc3cd19a862f74888ac
+  733bf0910832b26b768a09172f325f995b5476e1
+  6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+  d9e5488323c782fe684573f3043369d199038b6f
+  2bba2f40f321484159b395a43f20101d4bb7ead0
+
+Get part of linear run:
+
+  $ hg debuggetbundle repo bundle -H d9e5488323c782fe684573f3043369d199038b6f -C 733bf0910832b26b768a09172f325f995b5476e1
+  $ hg debugbundle bundle
+  6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+  d9e5488323c782fe684573f3043369d199038b6f
+
+Get missing branch and merge:
+
+  $ hg debuggetbundle repo bundle -H d9e5488323c782fe684573f3043369d199038b6f -C 6b57ee934bb2996050540f84cdfc8dcad1e7267d
+  $ hg debugbundle bundle
+  0f82d97ec2778746743fbc996740d409558fda22
+  ea919464b16e003894c48b6cb68df3cd9411b544
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  2114148793524fd045998f71a45b0aaf139f752b
+  b6b2b682253df2ffedc10e9415e4114202b303c5
+  b5af5d6ea56d73ce24c40bc3cd19a862f74888ac
+  733bf0910832b26b768a09172f325f995b5476e1
+  6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+  d9e5488323c782fe684573f3043369d199038b6f
+
+Get from only one head:
+
+  $ hg debuggetbundle repo bundle -H 6c725a58ad10aea441540bfd06c507f63e8b9cdd -C 6e23b016bc0f0e79c7bd9dd372ccee07055d7fd4
+  $ hg debugbundle bundle
+  a21d913c992197a2eb60b298521ec0f045a04799
+  18063366a155bd56b5618229ae2ac3e91849aa5e
+  6c725a58ad10aea441540bfd06c507f63e8b9cdd
+
+Get parts of two branches:
+
+  $ hg debuggetbundle repo bundle -H 6b57ee934bb2996050540f84cdfc8dcad1e7267d -C c1818a9f5977dd4139a48f93f5425c67d44a9368 -H 2114148793524fd045998f71a45b0aaf139f752b -C ea919464b16e003894c48b6cb68df3cd9411b544
+  $ hg debugbundle bundle
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  2114148793524fd045998f71a45b0aaf139f752b
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d
+
+Check that we get all needed file changes:
+
+  $ hg debugbundle bundle --all
+  format: id, p1, p2, cset, len(delta)
+  
+  changelog
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc ea919464b16e003894c48b6cb68df3cd9411b544 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 99
+  2114148793524fd045998f71a45b0aaf139f752b 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 99
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7 c1818a9f5977dd4139a48f93f5425c67d44a9368 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 102
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 102
+  
+  manifest
+  dac7984588fc4eea7acbf39693a9c1b06f5b175d 591f732a3faf1fb903815273f3c199a514a61ccb 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 113
+  0772616e6b48a76afb6c1458e193cbb3dae2e4ff dac7984588fc4eea7acbf39693a9c1b06f5b175d 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 113
+  eb498cd9af6c44108e43041e951ce829e29f6c80 bff2f4817ced57b386caf7c4e3e36a4bc9af7e93 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 295
+  b15709c071ddd2d93188508ba156196ab4f19620 eb498cd9af6c44108e43041e951ce829e29f6c80 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 114
+  
+  mf
+  4f73f97080266ab8e0c0561ca8d0da3eaf65b695 301ca08d026bb72cb4258a9d211bdf7ca0bcd810 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 17
+  c7b583de053293870e145f45bd2d61643563fd06 4f73f97080266ab8e0c0561ca8d0da3eaf65b695 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 18
+  266ee3c0302a5a18f1cf96817ac79a51836179e9 edc0f6b8db80d68ae6aff2b19f7e5347ab68fa63 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 149
+  698c6a36220548cd3903ca7dada27c59aa500c52 266ee3c0302a5a18f1cf96817ac79a51836179e9 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 19
+  
+  nf11
+  33fbc651630ffa7ccbebfe4eb91320a873e7291c 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 16
+  
+  nf12
+  ddce0544363f037e9fb889faca058f52dc01c0a5 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 16
+  
+  nf4
+  3c1407305701051cbed9f9cb9a68bdfb5997c235 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 15
+  
+  nf5
+  0dbd89c185f53a1727c54cd1ce256482fa23968e 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 15
+
+Get branch and merge:
+
+  $ hg debuggetbundle repo bundle -C 10e64d654571f11577745b4d8372e859d9e4df63 -H 6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+  $ hg debugbundle bundle
+  6e23b016bc0f0e79c7bd9dd372ccee07055d7fd4
+  0f82d97ec2778746743fbc996740d409558fda22
+  ea919464b16e003894c48b6cb68df3cd9411b544
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  2114148793524fd045998f71a45b0aaf139f752b
+  b6b2b682253df2ffedc10e9415e4114202b303c5
+  a21d913c992197a2eb60b298521ec0f045a04799
+  18063366a155bd56b5618229ae2ac3e91849aa5e
+  6c725a58ad10aea441540bfd06c507f63e8b9cdd
+  c1818a9f5977dd4139a48f93f5425c67d44a9368
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d
+  b5af5d6ea56d73ce24c40bc3cd19a862f74888ac
+  733bf0910832b26b768a09172f325f995b5476e1
+  6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+
+
+= Test via HTTP =
+
+Get everything:
+
+  $ hg serve -R repo -p $HGPORT -d --pid-file=hg.pid -E error.log -A access.log
+  $ cat hg.pid >> $DAEMON_PIDS
+  $ hg debuggetbundle http://localhost:$HGPORT/ bundle
+  $ hg debugbundle bundle
+  10e64d654571f11577745b4d8372e859d9e4df63
+  6e23b016bc0f0e79c7bd9dd372ccee07055d7fd4
+  0f82d97ec2778746743fbc996740d409558fda22
+  ea919464b16e003894c48b6cb68df3cd9411b544
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  2114148793524fd045998f71a45b0aaf139f752b
+  b6b2b682253df2ffedc10e9415e4114202b303c5
+  a21d913c992197a2eb60b298521ec0f045a04799
+  18063366a155bd56b5618229ae2ac3e91849aa5e
+  6c725a58ad10aea441540bfd06c507f63e8b9cdd
+  c1818a9f5977dd4139a48f93f5425c67d44a9368
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d
+  b5af5d6ea56d73ce24c40bc3cd19a862f74888ac
+  733bf0910832b26b768a09172f325f995b5476e1
+  6e9a5adf5437e49c746288cf95c5ac34fa8f2f72
+  d9e5488323c782fe684573f3043369d199038b6f
+  2bba2f40f321484159b395a43f20101d4bb7ead0
+
+Get parts of two branches:
+
+  $ hg debuggetbundle http://localhost:$HGPORT/ bundle -H 6b57ee934bb2996050540f84cdfc8dcad1e7267d -C c1818a9f5977dd4139a48f93f5425c67d44a9368 -H 2114148793524fd045998f71a45b0aaf139f752b -C ea919464b16e003894c48b6cb68df3cd9411b544
+  $ hg debugbundle bundle
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc
+  2114148793524fd045998f71a45b0aaf139f752b
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d
+
+Check that we get all needed file changes:
+
+  $ hg debugbundle bundle --all
+  format: id, p1, p2, cset, len(delta)
+  
+  changelog
+  74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc ea919464b16e003894c48b6cb68df3cd9411b544 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 99
+  2114148793524fd045998f71a45b0aaf139f752b 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 99
+  2c0ec49482e8abe888b7bd090b5827acfc22b3d7 c1818a9f5977dd4139a48f93f5425c67d44a9368 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 102
+  6b57ee934bb2996050540f84cdfc8dcad1e7267d 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 102
+  
+  manifest
+  dac7984588fc4eea7acbf39693a9c1b06f5b175d 591f732a3faf1fb903815273f3c199a514a61ccb 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 113
+  0772616e6b48a76afb6c1458e193cbb3dae2e4ff dac7984588fc4eea7acbf39693a9c1b06f5b175d 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 113
+  eb498cd9af6c44108e43041e951ce829e29f6c80 bff2f4817ced57b386caf7c4e3e36a4bc9af7e93 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 295
+  b15709c071ddd2d93188508ba156196ab4f19620 eb498cd9af6c44108e43041e951ce829e29f6c80 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 114
+  
+  mf
+  4f73f97080266ab8e0c0561ca8d0da3eaf65b695 301ca08d026bb72cb4258a9d211bdf7ca0bcd810 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 17
+  c7b583de053293870e145f45bd2d61643563fd06 4f73f97080266ab8e0c0561ca8d0da3eaf65b695 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 18
+  266ee3c0302a5a18f1cf96817ac79a51836179e9 edc0f6b8db80d68ae6aff2b19f7e5347ab68fa63 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 149
+  698c6a36220548cd3903ca7dada27c59aa500c52 266ee3c0302a5a18f1cf96817ac79a51836179e9 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 19
+  
+  nf11
+  33fbc651630ffa7ccbebfe4eb91320a873e7291c 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 2c0ec49482e8abe888b7bd090b5827acfc22b3d7 16
+  
+  nf12
+  ddce0544363f037e9fb889faca058f52dc01c0a5 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 6b57ee934bb2996050540f84cdfc8dcad1e7267d 16
+  
+  nf4
+  3c1407305701051cbed9f9cb9a68bdfb5997c235 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 74a573f2ae100f1cedfad9aa7b96f8eaab1dabfc 15
+  
+  nf5
+  0dbd89c185f53a1727c54cd1ce256482fa23968e 0000000000000000000000000000000000000000 0000000000000000000000000000000000000000 2114148793524fd045998f71a45b0aaf139f752b 15
+
+Verify we hit the HTTP server:
+
+  $ cat access.log
+  * - - [*] "GET /?cmd=capabilities HTTP/1.1" 200 - (glob)
+  * - - [*] "GET /?cmd=getbundle HTTP/1.1" 200 - (glob)
+  * - - [*] "GET /?cmd=capabilities HTTP/1.1" 200 - (glob)
+  * - - [*] "GET /?cmd=getbundle&common=c1818a9f5977dd4139a48f93f5425c67d44a9368+ea919464b16e003894c48b6cb68df3cd9411b544&heads=6b57ee934bb2996050540f84cdfc8dcad1e7267d+2114148793524fd045998f71a45b0aaf139f752b HTTP/1.1" 200 - (glob)
+
+  $ cat error.log
+

mercurial/commands.py

@@ -1270,6 +1270,29 b' def debugbundle(ui, bundlepath, all=None'
     finally:
         f.close()
 
+def debuggetbundle(ui, repopath, bundlepath, head=None, common=None, **opts):
+    """retrieves a bundle from a repo
+
+    Every ID must be a full-length hex node id string. Saves the bundle to the
+    given file.
+    """
+    repo = hg.repository(ui, repopath)
+    if not repo.capable('getbundle'):
+        raise util.Abort("getbundle() not supported by target repository")
+    args = {}
+    if common:
+        args['common'] = [bin(s) for s in common]
+    if head:
+        args['heads'] = [bin(s) for s in head]
+    bundle = repo.getbundle('debug', **args)
+
+    bundletype = opts.get('type', 'bzip2').lower()
+    btypes = {'none': 'HG10UN', 'bzip2': 'HG10BZ', 'gzip': 'HG10GZ'}
+    bundletype = btypes.get(bundletype)
+    if bundletype not in changegroup.bundletypes:
+        raise util.Abort(_('unknown bundle type specified with --type'))
+    changegroup.writebundle(bundle, bundlepath, bundletype)
+
 def debugpushkey(ui, repopath, namespace, *keyinfo):
     '''access the pushkey key/value protocol
 
@@ -4497,6 +4520,13 b' table = {'
          _('[-e] DATE [RANGE]')),
     "debugdata": (debugdata, [], _('FILE REV')),
     "debugfsinfo": (debugfsinfo, [], _('[PATH]')),
+    "debuggetbundle":
+        (debuggetbundle,
+         [('H', 'head', [], _('id of head node'), _('ID')),
+          ('C', 'common', [], _('id of common node'), _('ID')),
+          ('t', 'type', 'bzip2', _('bundle compression type to use'), _('TYPE')),
+         ],
+         _('REPO FILE [-H|-C ID]...')),
     "debugignore": (debugignore, [], ''),
     "debugindex": (debugindex,
                    [('f', 'format', 0, _('revlog format'), _('FORMAT'))],
@@ -4869,6 +4899,6 b' table = {'
 
 norepo = ("clone init version help debugcommands debugcomplete"
           " debugdate debuginstall debugfsinfo debugpushkey debugwireargs"
-          " debugknown debugbundle")
+          " debugknown debuggetbundle debugbundle")
 optionalrepo = ("identify paths serve showconfig debugancestor debugdag"
                 " debugdata debugindex debugindexdot")

mercurial/hgweb/hgweb_mod.py

@@ -17,6 +17,7 b' import webcommands, protocol, webutil'
 perms = {
     'changegroup': 'pull',
     'changegroupsubset': 'pull',
+    'getbundle': 'pull',
     'stream_out': 'pull',
     'listkeys': 'pull',
     'unbundle': 'push',

mercurial/localrepo.py

@@ -21,7 +21,7 b' propertycache = util.propertycache'
 
 class localrepository(repo.repository):
     capabilities = set(('lookup', 'changegroupsubset', 'branchmap', 'pushkey',
-                        'known'))
+                        'known', 'getbundle'))
     supportedformats = set(('revlogv1', 'parentdelta'))
     supported = supportedformats | set(('store', 'fncache', 'shared',
                                         'dotencode'))
@@ -1443,16 +1443,41 b' class localrepository(repo.repository):'
         Another wrinkle is doing the reverse, figuring out which changeset in
         the changegroup a particular filenode or manifestnode belongs to.
         """
+        cl = self.changelog
+        if not bases:
+            bases = [nullid]
+        csets, bases, heads = cl.nodesbetween(bases, heads)
+        # We assume that all ancestors of bases are known
+        common = set(cl.ancestors(*[cl.rev(n) for n in bases]))
+        return self._changegroupsubset(common, csets, heads, source)
+
+    def getbundle(self, source, heads=None, common=None):
+        """Like changegroupsubset, but returns the set difference between the
+        ancestors of heads and the ancestors common.
+
+        If heads is None, use the local heads. If common is None, use [nullid].
+
+        The nodes in common might not all be known locally due to the way the
+        current discovery protocol works.
+        """
+        cl = self.changelog
+        if common:
+            nm = cl.nodemap
+            common = [n for n in common if n in nm]
+        else:
+            common = [nullid]
+        if not heads:
+            heads = cl.heads()
+        common, missing = cl.findcommonmissing(common, heads)
+        return self._changegroupsubset(common, missing, heads, source)
+
+    def _changegroupsubset(self, commonrevs, csets, heads, source):
 
         cl = self.changelog
         mf = self.manifest
         mfs = {} # needed manifests
         fnodes = {} # needed file nodes
 
-        if not bases:
-            bases = [nullid]
-        csets, bases, heads = cl.nodesbetween(bases, heads)
-
         # can we go through the fast path ?
         heads.sort()
         if heads == sorted(self.heads()):
@@ -1462,9 +1487,6 b' class localrepository(repo.repository):'
         self.hook('preoutgoing', throw=True, source=source)
         self.changegroupinfo(csets, source)
 
-        # We assume that all ancestors of bases are known
-        commonrevs = set(cl.ancestors(*[cl.rev(n) for n in bases]))
-
         # A function generating function that sets up the initial environment
         # the inner function.
         def filenode_collector(changedfiles):

mercurial/revlog.py

@@ -399,11 +399,12 b' class revlog(object):'
                     yield i
                     break
 
-    def findmissing(self, common=None, heads=None):
-        """Return the ancestors of heads that are not ancestors of common.
+    def findcommonmissing(self, common=None, heads=None):
+        """Return a tuple of the ancestors of common and the ancestors of heads
+        that are not ancestors of common.
 
-        More specifically, return a list of nodes N such that every N
-        satisfies the following constraints:
+        More specifically, the second element is a list of nodes N such that
+        every N satisfies the following constraints:
 
           1. N is an ancestor of some node in 'heads'
           2. N is not an ancestor of any node in 'common'
@@ -441,7 +442,25 b' class revlog(object):'
                         visit.append(p)
         missing = list(missing)
         missing.sort()
-        return [self.node(r) for r in missing]
+        return has, [self.node(r) for r in missing]
+
+    def findmissing(self, common=None, heads=None):
+        """Return the ancestors of heads that are not ancestors of common.
+
+        More specifically, return a list of nodes N such that every N
+        satisfies the following constraints:
+
+          1. N is an ancestor of some node in 'heads'
+          2. N is not an ancestor of any node in 'common'
+
+        The list is sorted by revision number, meaning it is
+        topologically sorted.
+
+        'heads' and 'common' are both lists of node IDs.  If heads is
+        not supplied, uses all of the revlog's heads.  If common is not
+        supplied, uses nullid."""
+        _common, missing = self.findcommonmissing(common, heads)
+        return missing
 
     def nodesbetween(self, roots=None, heads=None):
         """Return a topological path from 'roots' to 'heads'.

mercurial/wireproto.py

@@ -123,6 +123,16 b' class wirerepository(repo.repository):'
                              bases=bases, heads=heads)
         return changegroupmod.unbundle10(self._decompress(f), 'UN')
 
+    def getbundle(self, source, heads=None, common=None):
+        self.requirecap('getbundle', _('look up remote changes'))
+        opts = {}
+        if heads is not None:
+            opts['heads'] = encodelist(heads)
+        if common is not None:
+            opts['common'] = encodelist(common)
+        f = self._callstream("getbundle", **opts)
+        return changegroupmod.unbundle10(self._decompress(f), 'UN')
+
     def unbundle(self, cg, heads, source):
         '''Send cg (a readable file-like object representing the
         changegroup to push, typically a chunkbuffer object) to the
@@ -206,7 +216,7 b' def branches(repo, proto, nodes):'
     return "".join(r)
 
 def capabilities(repo, proto):
-    caps = 'lookup changegroupsubset branchmap pushkey known'.split()
+    caps = 'lookup changegroupsubset branchmap pushkey known getbundle'.split()
     if _allowstream(repo.ui):
         requiredformats = repo.requirements & repo.supportedformats
         # if our local revlogs are just revlogv1, add 'stream' cap
@@ -234,6 +244,13 b' def debugwireargs(repo, proto, one, two,'
     opts = options('debugwireargs', ['three', 'four'], others)
     return repo.debugwireargs(one, two, **opts)
 
+def getbundle(repo, proto, others):
+    opts = options('getbundle', ['heads', 'common'], others)
+    for k, v in opts.iteritems():
+        opts[k] = decodelist(v)
+    cg = repo.getbundle('serve', **opts)
+    return streamres(proto.groupchunks(cg))
+
 def heads(repo, proto):
     h = repo.heads()
     return encodelist(h) + "\n"
@@ -382,6 +399,7 b' commands = {'
     'changegroup': (changegroup, 'roots'),
     'changegroupsubset': (changegroupsubset, 'bases heads'),
     'debugwireargs': (debugwireargs, 'one two *'),
+    'getbundle': (getbundle, '*'),
     'heads': (heads, ''),
     'hello': (hello, ''),
     'known': (known, 'nodes'),

tests/test-debugcomplete.t

@@ -76,6 +76,7 b' Show debug commands if there are no othe'
   debugdata
   debugdate
   debugfsinfo
+  debuggetbundle
   debugignore
   debugindex
   debugindexdot
@@ -219,6 +220,7 b' Show all commands + options'
   debugdata: 
   debugdate: extended
   debugfsinfo: 
+  debuggetbundle: head, common, type
   debugignore: 
   debugindex: format
   debugindexdot: 

tests/test-hgweb-commands.t

@@ -905,7 +905,7 b' capabilities'
   $ "$TESTDIR/get-with-headers.py" 127.0.0.1:$HGPORT '?cmd=capabilities'; echo
   200 Script output follows
   
-  lookup changegroupsubset branchmap pushkey known unbundle=HG10GZ,HG10BZ,HG10UN
+  lookup changegroupsubset branchmap pushkey known getbundle unbundle=HG10GZ,HG10BZ,HG10UN
 
 heads