[PATCH 7 of 7] fncache: clean up fncache during strips

[Durham Goode]

# HG changeset patch
# User Durham Goode <durham at fb.com>
# Date 1395700995 25200
#      Mon Mar 24 15:43:15 2014 -0700
# Node ID c1c369c34385c8fa0229f76b3b4b18b08cb46b2c
# Parent  cd50cd7c59b02cf90a7a2abc94a6d546d4012f34
fncache: clean up fncache during strips

Previously the fncache was cleaned up at read time by noticing when it was out
of sync. This caused writes to happen outside the scope of transactions and
could have caused race conditions. With this change, we'll keep the fncache
up-to-date as we go by removing old entries during repair.strip.

diff --git a/mercurial/repair.py b/mercurial/repair.py
--- a/mercurial/repair.py
+++ b/mercurial/repair.py
@@ -134,6 +134,8 @@
             for i in xrange(offset, len(tr.entries)):
                 file, troffset, ignore = tr.entries[i]
                 repo.sopener(file, 'a').truncate(troffset)
+                if troffset == 0:
+                    repo.store.markremoved(file)
             tr.close()
         except: # re-raises
             tr.abort()
diff --git a/mercurial/store.py b/mercurial/store.py
--- a/mercurial/store.py
+++ b/mercurial/store.py
@@ -343,6 +343,9 @@
     def invalidatecaches(self):
         pass
 
+    def markremoved(self, fn):
+        pass
+
     def __contains__(self, path):
         '''Checks if the store contains path'''
         path = "/".join(("data", path))
@@ -421,6 +424,13 @@
             self._dirty = True
             self.entries.add(fn)
 
+    def remove(self, fn):
+        if self.entries is None:
+            self._load()
+        if fn in self.entries:
+            self._dirty = True
+            self.entries.remove(fn)
+
     def __contains__(self, fn):
         if self.entries is None:
             self._load()
@@ -495,6 +505,9 @@
     def invalidatecaches(self):
         self.fncache.entries = None
 
+    def markremoved(self, fn):
+        self.fncache.remove(fn)
+
     def _exists(self, f):
         ef = self.encode(f)
         try:
diff --git a/tests/test-strip.t b/tests/test-strip.t
--- a/tests/test-strip.t
+++ b/tests/test-strip.t
@@ -336,6 +336,19 @@
   saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
   $ restore
 
+verify fncache is kept up-to-date
+
+  $ touch a
+  $ hg ci -qAm a
+  $ cat .hg/store/fncache | sort
+  data/a.i
+  data/bar.i
+  $ hg strip tip
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  saved backup bundle to $TESTTMP/test/.hg/strip-backup/*-backup.hg (glob)
+  $ cat .hg/store/fncache
+  data/bar.i
+
 stripping an empty revset
 
   $ hg strip "1 and not 1"