changegroup: move node sorting into deltagroup()

changegroup: move node sorting into deltagroup()

The 3 callers of deltagroup() all sort nodes and convert to
integer revs immediately before calling deltagroup().

Stepping back a bit, aside from the constraints on node ordering
that always apply (namely that a node must follow its ancestor),
it makes sense for sorting to be an implementation detail of the
store. Moving the sorting into deltagroup() will open the door
for moving sorting into a storage API.

The test for the changelog in deltagroup() to impact the sorting
method is a bit hacky. I suspect this will be resolved once
we establish a formal interface for delta group generation
and port changelog to it.

Differential Revision: https://phab.mercurial-scm.org/D4224

--- a/mercurial/changegroup.py	Tue Aug 21 21:05:15 2018 -0400
+++ b/mercurial/changegroup.py	Thu Aug 09 14:31:25 2018 -0700
@@ -771,7 +771,8 @@
         ellipsis=True,
     )
 
-def deltagroup(repo, revs, store, ischangelog, lookup, forcedeltaparentprev,
+def deltagroup(repo, store, nodes, ischangelog, lookup, forcedeltaparentprev,
+               allowreorder,
                units=None,
                ellipses=False, clrevtolocalrev=None, fullclnodes=None,
                precomputedellipsis=None):
@@ -782,7 +783,7 @@
     If units is not None, progress detail will be generated, units specifies
     the type of revlog that is touched (changelog, manifest, etc.).
     """
-    if not revs:
+    if not nodes:
         return
 
     # We perform two passes over the revisions whose data we will emit.
@@ -797,6 +798,17 @@
 
     cl = repo.changelog
 
+    if ischangelog:
+        # Changelog doesn't benefit from reordering revisions. So send
+        # out revisions in store order.
+        # TODO the API would be cleaner if this were controlled by the
+        # store producing the deltas.
+        revs = sorted(cl.rev(n) for n in nodes)
+    elif ellipses:
+        revs = _sortnodesellipsis(store, nodes, cl, lookup)
+    else:
+        revs = _sortnodesnormal(store, nodes, allowreorder)
+
     # In the first pass, collect info about the deltas we'll be
     # generating.
     requests = []
@@ -1099,10 +1111,6 @@
 
             return x
 
-        # Changelog doesn't benefit from reordering revisions. So send out
-        # revisions in store order.
-        revs = sorted(cl.rev(n) for n in nodes)
-
         state = {
             'clrevorder': clrevorder,
             'mfs': mfs,
@@ -1111,8 +1119,10 @@
         }
 
         gen = deltagroup(
-            self._repo, revs, cl, True, lookupcl,
+            self._repo, cl, nodes, True, lookupcl,
             self._forcedeltaparentprev,
+            # Reorder settings are currently ignored for changelog.
+            True,
             ellipses=self._ellipses,
             units=_('changesets'),
             clrevtolocalrev={},
@@ -1129,7 +1139,6 @@
         change what is sent based in pulls vs pushes, etc.
         """
         repo = self._repo
-        cl = repo.changelog
         mfl = repo.manifestlog
         dirlog = mfl._revlog.dirlog
         tmfnodes = {'': mfs}
@@ -1192,16 +1201,9 @@
 
             lookupfn = makelookupmflinknode(dir, nodes)
 
-            if self._ellipses:
-                revs = _sortnodesellipsis(store, prunednodes, cl,
-                                          lookupfn)
-            else:
-                revs = _sortnodesnormal(store, prunednodes,
-                                        self._reorder)
-
             deltas = deltagroup(
-                self._repo, revs, store, False, lookupfn,
-                self._forcedeltaparentprev,
+                self._repo, store, prunednodes, False, lookupfn,
+                self._forcedeltaparentprev, self._reorder,
                 ellipses=self._ellipses,
                 units=_('manifests'),
                 clrevtolocalrev=clrevtolocalrev,
@@ -1260,7 +1262,6 @@
             linknodes = normallinknodes
 
         repo = self._repo
-        cl = repo.changelog
         progress = repo.ui.makeprogress(_('bundling'), unit=_('files'),
                                         total=len(changedfiles))
         for i, fname in enumerate(sorted(changedfiles)):
@@ -1284,18 +1285,11 @@
             if not filenodes:
                 continue
 
-            if self._ellipses:
-                revs = _sortnodesellipsis(filerevlog, filenodes,
-                                          cl, lookupfilelog)
-            else:
-                revs = _sortnodesnormal(filerevlog, filenodes,
-                                        self._reorder)
-
             progress.update(i + 1, item=fname)
 
             deltas = deltagroup(
-                self._repo, revs, filerevlog, False, lookupfilelog,
-                self._forcedeltaparentprev,
+                self._repo, filerevlog, filenodes, False, lookupfilelog,
+                self._forcedeltaparentprev, self._reorder,
                 ellipses=self._ellipses,
                 clrevtolocalrev=clrevtolocalrev,
                 fullclnodes=self._fullclnodes,