# HG changeset patch
# User Laurent Charignon <lcharignon@fb.com>
# Date 2015-08-07 05:10:31
# Node ID 6f4a280298c13c56cf0f982f1082b69f6aaa765a
# Parent  ff89383a97db7063d6685a6b65832dc5b871657c

changelog: add way to call the reachableroots C implementation

This patch is part of a series of patches to speed up the computation of
revset.reachableroots by introducing a C implementation. The main motivation is
to speed up smartlog on big repositories. At the end of the series, on our big
repositories the computation of reachableroots is 10-50x faster and smartlog on
is 2x-5x faster.

This patch allows us to call the new C implementation of reachableroots from
python by creating an entry point in the changelog class.

diff --git a/mercurial/changelog.py b/mercurial/changelog.py
--- a/mercurial/changelog.py
+++ b/mercurial/changelog.py
@@ -18,6 +18,7 @@ from . import (
     encoding,
     error,
     revlog,
+    revset,
     util,
 )
 
@@ -184,6 +185,16 @@ class changelog(revlog.revlog):
         self.rev(self.node(0))
         return self._nodecache
 
+    def reachableroots(self, minroot, heads, roots, includepath=False):
+        reachable = self.index.reachableroots(minroot, heads, roots,
+                                              includepath)
+        if reachable is None:
+            # The C code hasn't been able to initialize a list, something went
+            # really wrong, let's rely on the pure implementation in that case
+            raise AttributeError()
+        else:
+            return revset.baseset(sorted(reachable))
+
     def headrevs(self):
         if self.filteredrevs:
             try: