# HG changeset patch
# User Pierre-Yves David <pierre-yves.david@fb.com>
# Date 1412395290 25200
# Node ID 586d7058ea480907fa0f8473ba070b9088ce21d6
# Parent  61ecabeeadb3a9998efb0a55ab38a8ea7a59b048
generatorset: get list-based fast iterations after the generator is consumed

When all revisions are known, we shortcut most of the class logic to use list
iteration instead. The cost of the sort is expected to be non-significant. The
list creation and sorting could be done lazily in the future. We have to copy
the list to not break existing iterator created before we finished consuming the
generator.

diff -r 61ecabeeadb3 -r 586d7058ea48 mercurial/revset.py
--- a/mercurial/revset.py	Fri Oct 03 20:48:28 2014 -0700
+++ b/mercurial/revset.py	Fri Oct 03 21:01:30 2014 -0700
@@ -2621,6 +2621,7 @@
         gen: a generator producing the values for the generatorset.
         """
         self._gen = gen
+        self._asclist = None
         self._cache = {}
         self._genlist = []
         self._finished = False
@@ -2712,7 +2713,13 @@
             cache[item] = True
             genlist(item)
             yield item
-        self._finished = True
+        if not self._finished:
+            self._finished = True
+            asc = self._genlist[:]
+            asc.sort()
+            self._asclist = asc
+            self.fastasc = asc.__iter__
+            self.fastdesc = asc.__reversed__
 
     def set(self):
         return self