# HG changeset patch
# User Peter Arrenbrecht <peter.arrenbrecht@gmail.com>
# Date 2012-07-13 19:47:06
# Node ID 1ac628cd7113e993bb54ebe1893a4f0d81fc6405
# Parent  5884812686f76eeb0c6c4bd100b2ee0f33f8fa6a

peer: introduce real peer classes

This change separates peer implementations from the repository implementation.
localpeer currently is a simple pass-through to localrepository, except for
legacy calls, which have already been removed from localpeer. This ensures that
the local client code only uses the most modern peer API when talking to local
repos.

Peers have a .local() method which returns either None or the underlying
localrepository (or descendant thereof). Repos have a .peer() method to return
a freshly constructed localpeer. The latter is used by hg.peer(), and also to
allow folks to pass either a peer or a repo to some generic helper methods.
We might want to get rid of .peer() eventually.

The only user of locallegacypeer is debugdiscovery, which uses it to pose as a
pre-setdiscovery client. But we decided to leave the old API defined in
locallegacypeer for clarity and maybe for other uses in the future.

It might be nice to actually define the peer API directly in peer.py as stub
methods. One problem there is, however, that localpeer implements
lock/addchangegroup, whereas the true remote peers implement unbundle.
It might be desireable to get rid of this distinction eventually.

diff --git a/hgext/largefiles/proto.py b/hgext/largefiles/proto.py
--- a/hgext/largefiles/proto.py
+++ b/hgext/largefiles/proto.py
@@ -6,7 +6,7 @@
 import os
 import urllib2
 
-from mercurial import error, httprepo, util, wireproto
+from mercurial import error, httppeer, util, wireproto
 from mercurial.wireproto import batchable, future
 from mercurial.i18n import _
 
@@ -82,7 +82,7 @@ def wirereposetup(ui, repo):
             # unfortunately, httprepository._callpush tries to convert its
             # input file-like into a bundle before sending it, so we can't use
             # it ...
-            if issubclass(self.__class__, httprepo.httprepository):
+            if issubclass(self.__class__, httppeer.httppeer):
                 res = None
                 try:
                     res = self._call('putlfile', data=fd, sha=sha,
diff --git a/hgext/largefiles/uisetup.py b/hgext/largefiles/uisetup.py
--- a/hgext/largefiles/uisetup.py
+++ b/hgext/largefiles/uisetup.py
@@ -9,7 +9,7 @@
 '''setup for largefiles extension: uisetup'''
 
 from mercurial import archival, cmdutil, commands, extensions, filemerge, hg, \
-    httprepo, localrepo, merge, sshrepo, sshserver, wireproto
+    httppeer, localrepo, merge, sshpeer, sshserver, wireproto
 from mercurial.i18n import _
 from mercurial.hgweb import hgweb_mod, protocol, webcommands
 from mercurial.subrepo import hgsubrepo
@@ -143,10 +143,10 @@ def uisetup(ui):
 
     # can't do this in reposetup because it needs to have happened before
     # wirerepo.__init__ is called
-    proto.ssholdcallstream = sshrepo.sshrepository._callstream
-    proto.httpoldcallstream = httprepo.httprepository._callstream
-    sshrepo.sshrepository._callstream = proto.sshrepocallstream
-    httprepo.httprepository._callstream = proto.httprepocallstream
+    proto.ssholdcallstream = sshpeer.sshpeer._callstream
+    proto.httpoldcallstream = httppeer.httppeer._callstream
+    sshpeer.sshpeer._callstream = proto.sshrepocallstream
+    httppeer.httppeer._callstream = proto.httprepocallstream
 
     # don't die on seeing a repo with the largefiles requirement
     localrepo.localrepository.supported |= set(['largefiles'])
diff --git a/mercurial/commands.py b/mercurial/commands.py
--- a/mercurial/commands.py
+++ b/mercurial/commands.py
@@ -16,7 +16,7 @@ import sshserver, hgweb, hgweb.server, c
 import merge as mergemod
 import minirst, revset, fileset
 import dagparser, context, simplemerge, graphmod
-import random, setdiscovery, treediscovery, dagutil, pvec
+import random, setdiscovery, treediscovery, dagutil, pvec, localrepo
 import phases, obsolete
 
 table = {}
@@ -1789,6 +1789,9 @@ def debugdiscovery(ui, repo, remoteurl="
             if localheads:
                 raise util.Abort('cannot use localheads with old style '
                                  'discovery')
+            if not util.safehasattr(remote, 'branches'):
+                # enable in-client legacy support
+                remote = localrepo.locallegacypeer(remote.local())
             common, _in, hds = treediscovery.findcommonincoming(repo, remote,
                                                                 force=True)
             common = set(common)
diff --git a/mercurial/hg.py b/mercurial/hg.py
--- a/mercurial/hg.py
+++ b/mercurial/hg.py
@@ -9,7 +9,7 @@
 from i18n import _
 from lock import release
 from node import hex, nullid
-import localrepo, bundlerepo, httprepo, sshrepo, statichttprepo, bookmarks
+import localrepo, bundlerepo, httppeer, sshpeer, statichttprepo, bookmarks
 import lock, util, extensions, error, node, scmutil
 import cmdutil, discovery
 import merge as mergemod
@@ -65,9 +65,9 @@ def parseurl(path, branches=None):
 schemes = {
     'bundle': bundlerepo,
     'file': _local,
-    'http': httprepo,
-    'https': httprepo,
-    'ssh': sshrepo,
+    'http': httppeer,
+    'https': httppeer,
+    'ssh': sshpeer,
     'static-http': statichttprepo,
 }
 
diff --git a/mercurial/httprepo.py b/mercurial/httppeer.py
rename from mercurial/httprepo.py
rename to mercurial/httppeer.py
--- a/mercurial/httprepo.py
+++ b/mercurial/httppeer.py
@@ -1,4 +1,4 @@
-# httprepo.py - HTTP repository proxy classes for mercurial
+# httppeer.py - HTTP repository proxy classes for mercurial
 #
 # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
 # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
@@ -23,7 +23,7 @@ def zgenerator(f):
         raise IOError(None, _('connection ended unexpectedly'))
     yield zd.flush()
 
-class httprepository(wireproto.wirerepository):
+class httppeer(wireproto.wirepeer):
     def __init__(self, ui, path):
         self.path = path
         self.caps = None
@@ -56,7 +56,7 @@ class httprepository(wireproto.wirerepos
     def _fetchcaps(self):
         self.caps = set(self._call('capabilities').split())
 
-    def get_caps(self):
+    def _capabilities(self):
         if self.caps is None:
             try:
                 self._fetchcaps()
@@ -66,8 +66,6 @@ class httprepository(wireproto.wirerepos
                           (' '.join(self.caps or ['none'])))
         return self.caps
 
-    capabilities = property(get_caps)
-
     def lock(self):
         raise util.Abort(_('operation not supported over http'))
 
@@ -215,21 +213,21 @@ class httprepository(wireproto.wirerepos
     def _decompress(self, stream):
         return util.chunkbuffer(zgenerator(stream))
 
-class httpsrepository(httprepository):
+class httpspeer(httppeer):
     def __init__(self, ui, path):
         if not url.has_https:
             raise util.Abort(_('Python support for SSL and HTTPS '
                                'is not installed'))
-        httprepository.__init__(self, ui, path)
+        httppeer.__init__(self, ui, path)
 
 def instance(ui, path, create):
     if create:
         raise util.Abort(_('cannot create new http repository'))
     try:
         if path.startswith('https:'):
-            inst = httpsrepository(ui, path)
+            inst = httpspeer(ui, path)
         else:
-            inst = httprepository(ui, path)
+            inst = httppeer(ui, path)
         try:
             # Try to do useful work when checking compatibility.
             # Usually saves a roundtrip since we want the caps anyway.
diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -6,7 +6,7 @@
 # GNU General Public License version 2 or any later version.
 from node import bin, hex, nullid, nullrev, short
 from i18n import _
-import repo, changegroup, subrepo, discovery, pushkey, obsolete
+import peer, changegroup, subrepo, discovery, pushkey, obsolete
 import changelog, dirstate, filelog, manifest, context, bookmarks, phases
 import lock, transaction, store, encoding, base85
 import scmutil, util, extensions, hook, error, revset
@@ -23,9 +23,90 @@ class storecache(filecache):
     def join(self, obj, fname):
         return obj.sjoin(fname)
 
-class localrepository(repo.repository):
-    capabilities = set(('lookup', 'changegroupsubset', 'branchmap', 'pushkey',
-                        'known', 'getbundle'))
+MODERNCAPS = set(('lookup', 'branchmap', 'pushkey', 'known', 'getbundle'))
+LEGACYCAPS = MODERNCAPS.union(set(['changegroupsubset']))
+
+class localpeer(peer.peerrepository):
+    '''peer for a local repo; reflects only the most recent API'''
+
+    def __init__(self, repo, caps=MODERNCAPS):
+        peer.peerrepository.__init__(self)
+        self._repo = repo
+        self.ui = repo.ui
+        self._caps = repo._restrictcapabilities(caps)
+        self.requirements = repo.requirements
+        self.supportedformats = repo.supportedformats
+
+    def close(self):
+        self._repo.close()
+
+    def _capabilities(self):
+        return self._caps
+
+    def local(self):
+        return self._repo
+
+    def cancopy(self):
+        return self._repo.cancopy() # so bundlerepo can override
+
+    def url(self):
+        return self._repo.url()
+
+    def lookup(self, key):
+        return self._repo.lookup(key)
+
+    def branchmap(self):
+        return self._repo.branchmap()
+
+    def heads(self):
+        return self._repo.heads()
+
+    def known(self, nodes):
+        return self._repo.known(nodes)
+
+    def getbundle(self, source, heads=None, common=None):
+        return self._repo.getbundle(source, heads=heads, common=common)
+
+    # TODO We might want to move the next two calls into legacypeer and add
+    # unbundle instead.
+
+    def lock(self):
+        return self._repo.lock()
+
+    def addchangegroup(self, cg, source, url):
+        return self._repo.addchangegroup(cg, source, url)
+
+    def pushkey(self, namespace, key, old, new):
+        return self._repo.pushkey(namespace, key, old, new)
+
+    def listkeys(self, namespace):
+        return self._repo.listkeys(namespace)
+
+    def debugwireargs(self, one, two, three=None, four=None, five=None):
+        '''used to test argument passing over the wire'''
+        return "%s %s %s %s %s" % (one, two, three, four, five)
+
+class locallegacypeer(localpeer):
+    '''peer extension which implements legacy methods too; used for tests with
+    restricted capabilities'''
+
+    def __init__(self, repo):
+        localpeer.__init__(self, repo, caps=LEGACYCAPS)
+
+    def branches(self, nodes):
+        return self._repo.branches(nodes)
+
+    def between(self, pairs):
+        return self._repo.between(pairs)
+
+    def changegroup(self, basenodes, source):
+        return self._repo.changegroup(basenodes, source)
+
+    def changegroupsubset(self, bases, heads, source):
+        return self._repo.changegroupsubset(bases, heads, source)
+
+class localrepository(object):
+
     supportedformats = set(('revlogv1', 'generaldelta'))
     supported = supportedformats | set(('store', 'fncache', 'shared',
                                         'dotencode'))
@@ -36,7 +117,6 @@ class localrepository(repo.repository):
         return self.requirements[:]
 
     def __init__(self, baseui, path=None, create=False):
-        repo.repository.__init__(self)
         self.wopener = scmutil.opener(path, expand=True)
         self.wvfs = self.wopener
         self.root = self.wvfs.base
@@ -126,6 +206,12 @@ class localrepository(repo.repository):
         # Maps a property name to its util.filecacheentry
         self._filecache = {}
 
+    def close(self):
+        pass
+
+    def _restrictcapabilities(self, caps):
+        return caps
+
     def _applyrequirements(self, requirements):
         self.requirements = requirements
         self.sopener.options = dict((r, 1) for r in requirements
@@ -175,6 +261,9 @@ class localrepository(repo.repository):
                 parts.pop()
         return False
 
+    def peer(self):
+        return localpeer(self) # not cached to avoid reference cycle
+
     @filecache('bookmarks')
     def _bookmarks(self):
         return bookmarks.read(self)
@@ -668,6 +757,9 @@ class localrepository(repo.repository):
     def local(self):
         return self
 
+    def cancopy(self):
+        return self.local() # so statichttprepo's override of local() works
+
     def join(self, f):
         return os.path.join(self.path, f)
 
diff --git a/mercurial/repo.py b/mercurial/peer.py
rename from mercurial/repo.py
rename to mercurial/peer.py
--- a/mercurial/repo.py
+++ b/mercurial/peer.py
@@ -1,4 +1,4 @@
-# repo.py - repository base classes for mercurial
+# peer.py - repository base classes for mercurial
 #
 # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
 # Copyright 2006 Vadim Gelfer <vadim.gelfer@gmail.com>
@@ -9,16 +9,18 @@
 from i18n import _
 import error
 
-class repository(object):
+class peerrepository(object):
+
     def capable(self, name):
         '''tell whether repo supports named capability.
         return False if not supported.
         if boolean capability, return True.
         if string capability, return string.'''
-        if name in self.capabilities:
+        caps = self._capabilities()
+        if name in caps:
             return True
         name_eq = name + '='
-        for cap in self.capabilities:
+        for cap in caps:
             if cap.startswith(name_eq):
                 return cap[len(name_eq):]
         return False
@@ -31,13 +33,17 @@ class repository(object):
                   'support the %r capability') % (purpose, name))
 
     def local(self):
-        return False
+        '''return peer as a localrepo, or None'''
+        return None
+
+    def peer(self):
+        return self
 
     def peer(self):
         return self
 
     def cancopy(self):
-        return self.local()
+        return False
 
     def close(self):
         pass
diff --git a/mercurial/sshrepo.py b/mercurial/sshpeer.py
rename from mercurial/sshrepo.py
rename to mercurial/sshpeer.py
--- a/mercurial/sshrepo.py
+++ b/mercurial/sshpeer.py
@@ -1,4 +1,4 @@
-# sshrepo.py - ssh repository proxy class for mercurial
+# sshpeer.py - ssh repository proxy class for mercurial
 #
 # Copyright 2005, 2006 Matt Mackall <mpm@selenic.com>
 #
@@ -25,7 +25,7 @@ def _serverquote(s):
         return s
     return "'%s'" % s.replace("'", "'\\''")
 
-class sshrepository(wireproto.wirerepository):
+class sshpeer(wireproto.wirepeer):
     def __init__(self, ui, path, create=False):
         self._url = path
         self.ui = ui
@@ -90,12 +90,15 @@ class sshrepository(wireproto.wirereposi
             self._abort(error.RepoError(_('no suitable response from '
                                           'remote hg')))
 
-        self.capabilities = set()
+        self._caps = set()
         for l in reversed(lines):
             if l.startswith("capabilities:"):
-                self.capabilities.update(l[:-1].split(":")[1].split())
+                self._caps.update(l[:-1].split(":")[1].split())
                 break
 
+    def _capabilities(self):
+        return self._caps
+
     def readerr(self):
         while True:
             size = util.fstat(self.pipee).st_size
@@ -233,4 +236,4 @@ class sshrepository(wireproto.wirereposi
         except ValueError:
             self._abort(error.ResponseError(_("unexpected response:"), r))
 
-instance = sshrepository
+instance = sshpeer
diff --git a/mercurial/statichttprepo.py b/mercurial/statichttprepo.py
--- a/mercurial/statichttprepo.py
+++ b/mercurial/statichttprepo.py
@@ -76,6 +76,10 @@ def build_opener(ui, authinfo):
 
     return statichttpopener
 
+class statichttppeer(localrepo.localpeer):
+    def local(self):
+        return None
+
 class statichttprepository(localrepo.localrepository):
     def __init__(self, ui, path):
         self._url = path
@@ -116,6 +120,7 @@ class statichttprepository(localrepo.loc
         self.svfs = self.sopener
         self.sjoin = self.store.join
         self._filecache = {}
+        self.requirements = requirements
 
         self.manifest = manifest.manifest(self.sopener)
         self.changelog = changelog.changelog(self.sopener)
@@ -125,7 +130,9 @@ class statichttprepository(localrepo.loc
         self._branchcachetip = None
         self.encodepats = None
         self.decodepats = None
-        self.capabilities.difference_update(["pushkey"])
+
+    def _restrictcapabilities(self, caps):
+        return caps.difference(["pushkey"])
 
     def url(self):
         return self._url
@@ -133,6 +140,9 @@ class statichttprepository(localrepo.loc
     def local(self):
         return False
 
+    def peer(self):
+        return statichttppeer(self)
+
     def lock(self, wait=True):
         raise util.Abort(_('cannot lock static-http repository'))
 
diff --git a/mercurial/wireproto.py b/mercurial/wireproto.py
--- a/mercurial/wireproto.py
+++ b/mercurial/wireproto.py
@@ -9,7 +9,7 @@ import urllib, tempfile, os, sys
 from i18n import _
 from node import bin, hex
 import changegroup as changegroupmod
-import repo, error, encoding, util, store
+import peer, error, encoding, util, store
 import phases
 
 # abstract batching support
@@ -149,7 +149,7 @@ def unescapearg(escaped):
 def todict(**args):
     return args
 
-class wirerepository(repo.repository):
+class wirepeer(peer.peerrepository):
 
     def batch(self):
         return remotebatch(self)
diff --git a/tests/notcapable b/tests/notcapable
--- a/tests/notcapable
+++ b/tests/notcapable
@@ -6,13 +6,18 @@ then
 fi
 
 cat > notcapable-$CAP.py << EOF
-from mercurial import extensions, repo
+from mercurial import extensions, peer, localrepo
 def extsetup():
-    extensions.wrapfunction(repo.repository, 'capable', wrapper)
-def wrapper(orig, self, name, *args, **kwargs):
+    extensions.wrapfunction(peer.peerrepository, 'capable', wrapcapable)
+    extensions.wrapfunction(localrepo.localrepository, 'peer', wrappeer)
+def wrapcapable(orig, self, name, *args, **kwargs):
     if name in '$CAP'.split(' '):
         return False
     return orig(self, name, *args, **kwargs)
+def wrappeer(orig, self):
+    # Since we're disabling some newer features, we need to make sure local
+    # repos add in the legacy features again.
+    return localrepo.locallegacypeer(self)
 EOF
 
 echo '[extensions]' >> $HGRCPATH
diff --git a/tests/test-wireproto.py b/tests/test-wireproto.py
--- a/tests/test-wireproto.py
+++ b/tests/test-wireproto.py
@@ -9,7 +9,7 @@ class proto(object):
         names = spec.split()
         return [args[n] for n in names]
 
-class clientrepo(wireproto.wirerepository):
+class clientpeer(wireproto.wirepeer):
     def __init__(self, serverrepo):
         self.serverrepo = serverrepo
     def _call(self, cmd, **args):
@@ -36,7 +36,7 @@ def greet(repo, proto, name):
 wireproto.commands['greet'] = (greet, 'name',)
 
 srv = serverrepo()
-clt = clientrepo(srv)
+clt = clientpeer(srv)
 
 print clt.greet("Foobar")
 b = clt.batch()