# HG changeset patch
# User Augie Fackler <augie@google.com>
# Date 2020-02-05 21:58:50
# Node ID bbecb6d80aa72ba3f8b4bfb3c853697b2cbb466b
# Parent  63d84c18247ae6adda88c4e1755560750a721a93

manifest: rewrite filesnotin to not make superfluous manifest copies

This also skips using diff() when all we care about is the filenames. I'm
expecting the built in set logic to be plenty fast. For really large manifests
with a matcher in play this should copy substantially less data around.

Differential Revision: https://phab.mercurial-scm.org/D8082

diff --git a/mercurial/manifest.py b/mercurial/manifest.py
--- a/mercurial/manifest.py
+++ b/mercurial/manifest.py
@@ -23,6 +23,7 @@ from .pycompat import getattr
 from . import (
     encoding,
     error,
+    match as matchmod,
     mdiff,
     pathutil,
     policy,
@@ -482,17 +483,11 @@ class manifestdict(object):
 
     def filesnotin(self, m2, match=None):
         '''Set of files in this manifest that are not in the other'''
-        if match:
-            m1 = self.matches(match)
-            m2 = m2.matches(match)
-            return m1.filesnotin(m2)
-        diff = self.diff(m2)
-        files = set(
-            filepath
-            for filepath, hashflags in pycompat.iteritems(diff)
-            if hashflags[1][0] is None
-        )
-        return files
+        if match is not None:
+            match = matchmod.badmatch(match, lambda path, msg: None)
+            sm2 = set(m2.walk(match))
+            return {f for f in self.walk(match) if f not in sm2}
+        return {f for f in self if f not in m2}
 
     @propertycache
     def _dirs(self):