diff mercurial/httppeer.py @ 40024:86b22a4cfab1

wireprotov2: client support for advertising redirect targets

With the server now able to emit a redirect target descriptor, we can
start to teach the client to recognize it.

This commit implements support for filtering the advertised
redirect targets against supported features and for advertising
compatible redirect targets as part of command requests. It also
adds the minimal boilerplate required to fail when a content
redirect is seen.

The server doesn't yet do anything with the advertised redirect
targets. And the client can't yet follow redirects if it did. But
at least we're putting bytes on the wire.

Differential Revision: https://phab.mercurial-scm.org/D4776

--- a/mercurial/httppeer.py	Wed Sep 26 17:46:48 2018 -0700
+++ b/mercurial/httppeer.py	Wed Sep 26 15:02:19 2018 -0700
@@ -508,7 +508,8 @@
     def _abort(self, exception):
         raise exception
 
-def sendv2request(ui, opener, requestbuilder, apiurl, permission, requests):
+def sendv2request(ui, opener, requestbuilder, apiurl, permission, requests,
+                  redirect):
     reactor = wireprotoframing.clientreactor(hasmultiplesend=False,
                                              buffersends=True)
 
@@ -525,7 +526,8 @@
     for command, args, f in requests:
         ui.debug('sending command %s: %s\n' % (
             command, stringutil.pprint(args, indent=2)))
-        assert not list(handler.callcommand(command, args, f))
+        assert not list(handler.callcommand(command, args, f,
+                                            redirect=redirect))
 
     # TODO stream this.
     body = b''.join(map(bytes, handler.flushcommands()))
@@ -567,12 +569,14 @@
 
 @interfaceutil.implementer(repository.ipeercommandexecutor)
 class httpv2executor(object):
-    def __init__(self, ui, opener, requestbuilder, apiurl, descriptor):
+    def __init__(self, ui, opener, requestbuilder, apiurl, descriptor,
+                 redirect):
         self._ui = ui
         self._opener = opener
         self._requestbuilder = requestbuilder
         self._apiurl = apiurl
         self._descriptor = descriptor
+        self._redirect = redirect
         self._sent = False
         self._closed = False
         self._neededpermissions = set()
@@ -672,7 +676,7 @@
 
         handler, resp = sendv2request(
             self._ui, self._opener, self._requestbuilder, self._apiurl,
-            permission, calls)
+            permission, calls, self._redirect)
 
         # TODO we probably want to validate the HTTP code, media type, etc.
 
@@ -734,6 +738,8 @@
         self._requestbuilder = requestbuilder
         self._descriptor = apidescriptor
 
+        self._redirect = wireprotov2peer.supportedredirects(ui, apidescriptor)
+
     # Start of ipeerconnection.
 
     def url(self):
@@ -791,7 +797,7 @@
 
     def commandexecutor(self):
         return httpv2executor(self.ui, self._opener, self._requestbuilder,
-                              self._apiurl, self._descriptor)
+                              self._apiurl, self._descriptor, self._redirect)
 
 # Registry of API service names to metadata about peers that handle it.
 #