Patchwork [19,of,21,V2] speedy: turn index create functions into update functions

diff --git a/hgext/speedy/index.py b/hgext/speedy/index.py
--- a/hgext/speedy/index.py
+++ b/hgext/speedy/index.py
@@ -8,34 +8,39 @@ 
 Indices are data structures in the form of key-value mappings used
 by the server to speed up computations.
 
-Each index has a corresponding maker function that takes as parameter
-an iterable with change contexs from which the index is to be created
-and returns the index in a form of a dict.
+Each index has a corresponding updater function that:
+    * Takes as parameters a current index and an iterable with new
+      change contexs.
+    * Computes the entries that have to be updated/inserted to reflect
+      the changes in the new chagesets.
+    * Returns a list of (key, value) pairs of such entries.
 """
 
-def makeuserchgs(ctxs):
-    """Return the `userchgs` index.
+def userchgsentries(index, ctxs):
+    """Return new entries for the `userchgs` index.
 
     `userchgs` is keyed by username, with each value being a list
         of changes commited by that user.
     """
     newentries = {}
     for ctx in ctxs:
-        newentries.setdefault(ctx.user(), []).append(ctx.node())
-    return newentries
+        user = ctx.user()
+        if user not in newentries:
+            newentries[user] = index.get(user, [])
+        newentries[user].append(ctx.node())
+    return list(newentries.iteritems())
 
 
-def makechgdate(ctxs):
-    """Return the `chgdate` index.
+def chgdateentries(index, ctxs):
+    """Return new entries for the `chgdate` index.
 
     `chgdate` is keyed by change id, with each value being a commit date
         of that change.
     """
-    return dict([(ctx.node(), ctx.date()[0]) for ctx in ctxs])
+    return [(ctx.node(), ctx.date()[0]) for ctx in ctxs]
 
-
-def makefilechgs(ctxs):
-    """Return the `filechgs` index.
+def filechgsentries(index, ctxs):
+    """Return new entries for the `filechgs` index.
 
     `filechgs` is keyed by paths (files or directories), with each value
         being a list of commits touching this path (for direcories it is
@@ -51,15 +56,17 @@ 
             for i in range(len(dirs)):
                 paths.add('/'.join(dirs[0:i+1]))
         for path in paths:
-            filechgs.setdefault(path, []).append(ctx.node())
-    return filechgs
+            if path not in filechgs:
+                filechgs[path] = index.get(path, [])
+            filechgs[path].append(ctx.node())
+    return list(filechgs.iteritems())
 
-def makefiles(ctxs):
-    """Return the `files` index.
+def filesentries(index, ctxs):
+    """Return new entries for the `files` index.
 
     `files` is keyed by file name, with each value being an empty string
     """
     files = set()
     for ctx in ctxs:
         files.update(ctx.files())
-    return dict([(fn, '') for fn in files])
+    return [(fn, '') for fn in files]
diff --git a/hgext/speedy/server.py b/hgext/speedy/server.py
--- a/hgext/speedy/server.py
+++ b/hgext/speedy/server.py
@@ -122,16 +122,16 @@ 
         return self._literalpath(matchingfiles)
 
 indicecfg = {
-    'userchgs': index.makeuserchgs,
-    'chgdate': index.makechgdate,
-    'filechgs': index.makefilechgs,
-    'files': index.makefiles,
+    'userchgs': index.userchgsentries,
+    'chgdate': index.chgdateentries,
+    'filechgs': index.filechgsentries,
+    'files': index.filesentries,
 }
 
 def makeserver(repo):
     """Return an initialized metaserver instance."""
     ctxs = [repo[r] for r in xrange(0, len(repo))]
-    indices = dict([(name, create(ctxs)) for name, create in
+    indices = dict([(name, dict(newentries({}, ctxs))) for name, newentries in
         indicecfg.iteritems()])
     return metaserver(repo, indices)