D4328: dagutil: use revlog.parentrevs() for resolving parent revisions

[indygreg (Gregory Szorc)]

indygreg created this revision.
Herald added a subscriber: mercurial-devel.
Herald added a reviewer: hg-reviewers.

REVISION SUMMARY
  And remove parents() since it is no longer used.
  
  revlog.parentrevs() is almost the same as parents(). The main
  difference is that parentrevs() can return nullrev. dagop.headrevs()
  already handles nullrev. We add an inline check for nullrev in the
  other call site to account for the difference.
  
  .. api:: parents() removed from dagutil classes
  
    Use parentrevs() on the storage object instead.

REPOSITORY
  rHG Mercurial

REVISION DETAIL
  https://phab.mercurial-scm.org/D4328

AFFECTED FILES
  mercurial/dagop.py
  mercurial/dagutil.py

CHANGE DETAILS

diff --git a/mercurial/dagutil.py b/mercurial/dagutil.py
--- a/mercurial/dagutil.py
+++ b/mercurial/dagutil.py
@@ -20,21 +20,6 @@
     def __init__(self, revlog):
         self._revlog = revlog
 
-    def parents(self, ix):
-        rlog = self._revlog
-        idx = rlog.index
-        revdata = idx[ix]
-        prev = revdata[5]
-        if prev != nullrev:
-            prev2 = revdata[6]
-            if prev2 == nullrev:
-                return [prev]
-            return [prev, prev2]
-        prev2 = revdata[6]
-        if prev2 != nullrev:
-            return [prev2]
-        return []
-
     def linearize(self, ixs):
         '''linearize and topologically sort a list of revisions
 
@@ -45,7 +30,7 @@
         parent, then adding the rev itself to the output list.
         '''
         sorted = []
-        visit = list(dagop.headrevs(ixs, self.parents))
+        visit = list(dagop.headrevs(ixs, self._revlog.parentrevs))
         visit.sort(reverse=True)
         finished = set()
 
@@ -58,7 +43,7 @@
                     finished.add(cur)
             else:
                 visit.append(-cur - 1)
-                visit += [p for p in self.parents(cur)
-                          if p in ixs and p not in finished]
+                visit += [p for p in self._revlog.parentrevs(cur)
+                          if p != nullrev and p in ixs and p not in finished]
         assert len(sorted) == len(ixs)
         return sorted
diff --git a/mercurial/dagop.py b/mercurial/dagop.py
--- a/mercurial/dagop.py
+++ b/mercurial/dagop.py
@@ -723,13 +723,18 @@
     revision number and returns an iterable of parent revision numbers, possibly
     including nullrev.
 
-    Returns a set of revision numbers that are DAG heads within the passed subset.
+    Returns a set of revision numbers that are DAG heads within the passed
+    subset.
+
+    ``nullrev`` is never included in the returned set, even if it is provided in
+    the input set.
     """
-    headrevs = set()
+    headrevs = set(revs)
 
     for rev in revs:
         for prev in parentsfn(rev):
-            if prev != node.nullrev:
-                headrevs.discard(prev)
+            headrevs.discard(prev)
+
+    headrevs.discard(node.nullrev)
 
     return headrevs



To: indygreg, #hg-reviewers
Cc: mercurial-devel