httppeer: move requestbuilder defaults into makepeer() argument

Upcoming commits will move the initial ?cmd=capabilities handshake
request out of httppeer so the handshake can be performed before a
peer instance is constructed. In order to do this, we'll need to
refactor code for making HTTP requests.

The type used to construct HTTP requests is configurable. If we'll
be making HTTP requests outside of httppeer, we should be able to
use a custom request builder. So move the definition of that type
into makepeer().

Extensions can monkeypatch the function and override the argument
value.

Differential Revision: https://phab.mercurial-scm.org/D3232

mercurial/debugcommands.py

@@ -2915,7 +2915,8 b' def debugwireproto(ui, repo, path=None, '
             raise error.Abort(_('--peer %s not supported with HTTP peers') %
                               opts['peer'])
         else:
-            peer = httppeer.httppeer(ui, path, url, opener)
+            peer = httppeer.httppeer(ui, path, url, opener,
+                                     requestbuilder=httppeer.urlreq.request)
             peer._fetchcaps()
 
         # We /could/ populate stdin/stdout with sock.makefile()...

mercurial/httppeer.py

@@ -139,15 +139,13 b' class _multifile(object):'
         self._index = 0
 
 class httppeer(wireproto.wirepeer):
-    def __init__(self, ui, path, url, opener):
+    def __init__(self, ui, path, url, opener, requestbuilder):
         self.ui = ui
         self._path = path
         self._url = url
         self._caps = None
         self._urlopener = opener
-        # This is an its own attribute to facilitate extensions overriding
-        # the default type.
-        self._requestbuilder = urlreq.request
+        self._requestbuilder = requestbuilder
 
     def __del__(self):
         for h in self._urlopener.handlers:
@@ -570,7 +568,12 b' class httpv2peer(object):'
 
         return results
 
-def makepeer(ui, path):
+def makepeer(ui, path, requestbuilder=urlreq.request):
+    """Construct an appropriate HTTP peer instance.
+
+    ``requestbuilder`` is the type used for constructing HTTP requests.
+    It exists as an argument so extensions can override the default.
+    """
     u = util.url(path)
     if u.query or u.fragment:
         raise error.Abort(_('unsupported URL component: "%s"') %
@@ -582,7 +585,7 b' def makepeer(ui, path):'
 
     opener = urlmod.opener(ui, authinfo)
 
-    return httppeer(ui, path, url, opener)
+    return httppeer(ui, path, url, opener, requestbuilder)
 
 def instance(ui, path, create):
     if create:

tests/test-check-interfaces.py

@@ -70,7 +70,7 b' class dummyopener(object):'
 # Facilitates testing sshpeer without requiring an SSH server.
 class badpeer(httppeer.httppeer):
     def __init__(self):
-        super(badpeer, self).__init__(None, None, None, dummyopener())
+        super(badpeer, self).__init__(None, None, None, dummyopener(), None)
         self.badattribute = True
 
     def badmethod(self):
@@ -89,7 +89,7 b' def main():'
 
     ziverify.verifyClass(repository.ipeerbaselegacycommands,
                          httppeer.httppeer)
-    checkzobject(httppeer.httppeer(None, None, None, dummyopener()))
+    checkzobject(httppeer.httppeer(None, None, None, dummyopener(), None))
 
     ziverify.verifyClass(repository.ipeerbase,
                          localrepo.localpeer)