localrepo: store path and vfs location of cached properties

localrepo: store path and vfs location of cached properties

This information is used to make transaction handle these files
specially, in order to avoid file stat ambiguity of them.

Gathering information about cached files via annotation classes can
avoid overlooking properties newly introduced in the future.

--- a/mercurial/localrepo.py	Mon Jul 03 11:22:00 2017 +0200
+++ b/mercurial/localrepo.py	Tue Jul 04 23:13:46 2017 +0900
@@ -66,6 +66,11 @@
 urlerr = util.urlerr
 urlreq = util.urlreq
 
+# set of (path, vfs-location) tuples. vfs-location is:
+# - 'plain for vfs relative paths
+# - '' for svfs relative paths
+_cachedfiles = set()
+
 class _basefilecache(scmutil.filecache):
     """All filecache usage on repo are done for logic that should be unfiltered
     """
@@ -80,11 +85,21 @@
 
 class repofilecache(_basefilecache):
     """filecache for files in .hg but outside of .hg/store"""
+    def __init__(self, *paths):
+        super(repofilecache, self).__init__(*paths)
+        for path in paths:
+            _cachedfiles.add((path, 'plain'))
+
     def join(self, obj, fname):
         return obj.vfs.join(fname)
 
 class storecache(_basefilecache):
     """filecache for files in the store"""
+    def __init__(self, *paths):
+        super(storecache, self).__init__(*paths)
+        for path in paths:
+            _cachedfiles.add((path, ''))
+
     def join(self, obj, fname):
         return obj.sjoin(fname)