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 peer, changegroup, subrepo, discovery, pushkey, obsolete
+import peer, changegroup, subrepo, discovery, pushkey, obsolete, repoview
 import changelog, dirstate, filelog, manifest, context, bookmarks, phases
 import lock, transaction, store, encoding, base85
 import scmutil, util, extensions, hook, error, revset
@@ -303,6 +303,14 @@ class localrepository(object):
         Intended to be ovewritten by filtered repo."""
         return self
 
+    def filtered(self, name):
+        """Return a filtered version of a repository"""
+        # build a new class with the mixin and the current class
+        # (possibily subclass of the repo)
+        class proxycls(repoview.repoview, self.unfiltered().__class__):
+            pass
+        return proxycls(self, name)
+
     @repofilecache('bookmarks')
     def _bookmarks(self):
         return bookmarks.bmstore(self)
diff --git a/mercurial/repoview.py b/mercurial/repoview.py
new file mode 100644
--- /dev/null
+++ b/mercurial/repoview.py
@@ -0,0 +1,94 @@
+# repoview.py - Filtered view of a localrepo object
+#
+# Copyright 2012 Pierre-Yves David <pierre-yves.david@ens-lyon.org>
+#                Logilab SA        <contact@logilab.fr>
+#
+# This software may be used and distributed according to the terms of the
+# GNU General Public License version 2 or any later version.
+
+import copy
+
+# function to compute filtered set
+filtertable = {}
+
+def filteredrevs(repo, filtername):
+    """returns set of filtered revision for this filter name"""
+    return filtertable[filtername](repo.unfiltered())
+
+class repoview(object):
+    """Provide a read/write view of a repo through a filtered changelog
+
+    This object is used to access a filtered version of a repository without
+    altering the original repository object itself. We can not alter the
+    original object for two main reasons:
+    - It prevents the use of a repo with multiple filters at the same time. In
+      particular when multiple threads are involved.
+    - It makes scope of the filtering harder to control.
+
+    This object behaves very closely to the original repository. All attribute
+    operations are done on the original repository:
+    - An access to `repoview.someattr` actually returns `repo.someattr`,
+    - A write to `repoview.someattr` actually sets value of `repo.someattr`,
+    - A deletion of `repoview.someattr` actually drops `someattr`
+      from `repo.__dict__`.
+
+    The only exception is the `changelog` property. It is overridden to return
+    a (surface) copy of `repo.changelog` with some revisions filtered. The
+    `filtername` attribute of the view control the revisions that need to be
+    filtered.  (the fact the changelog is copied is an implementation detail).
+
+    Unlike attributes, this object intercepts all method calls. This means that
+    all methods are run on the `repoview` object with the filtered `changelog`
+    property. For this purpose the simple `repoview` class must be mixed with
+    the actual class of the repository. This ensures that the resulting
+    `repoview` object have the very same methods than the repo object. This
+    leads to the property below.
+
+        repoview.method() --> repo.__class__.method(repoview)
+
+    The inheritance has to be done dynamically because `repo` can be of any
+    subclasses of `localrepo`. Eg: `bundlerepo` or `httprepo`.
+    """
+
+    def __init__(self, repo, filtername):
+        object.__setattr__(self, '_unfilteredrepo', repo)
+        object.__setattr__(self, 'filtername', filtername)
+
+    # not a cacheproperty on purpose we shall implement a proper cache later
+    @property
+    def changelog(self):
+        """return a filtered version of the changeset
+
+        this changelog must not be used for writing"""
+        # some cache may be implemented later
+        cl = copy.copy(self._unfilteredrepo.changelog)
+        cl.filteredrevs = filteredrevs(self._unfilteredrepo, self.filtername)
+        return cl
+
+    def unfiltered(self):
+        """Return an unfiltered version of a repo"""
+        return self._unfilteredrepo
+
+    def filtered(self, name):
+        """Return a filtered version of a repository"""
+        if name == self.filtername:
+            return self
+        return self.unfiltered().filtered(name)
+
+    # everything access are forwarded to the proxied repo
+    def __getattr__(self, attr):
+        return getattr(self._unfilteredrepo, attr)
+
+    def __setattr__(self, attr, value):
+        return setattr(self._unfilteredrepo, attr, value)
+
+    def __delattr__(self, attr):
+        return delattr(self._unfilteredrepo, attr)
+
+    # The `requirement` attribut is initialiazed during __init__. But
+    # __getattr__ won't be called as it also exists on the class. We need
+    # explicit forwarding to main repo here
+    @property
+    def requirements(self):
+        return self._unfilteredrepo.requirements
+