hg: make cachedlocalrepo cache appropriate repoview object Before this patch, 'cachedlocalrepo' always caches "visible" repoview object, because 'cachedlocalrepo' uses "visible" repoview returned by 'hg.repository()' without any additional processing. If the client of 'cachedlocalrepo' wants "served" repoview, some objects to be cached are discarded unintentionally. 1. 'cachedlocalrepo' newly caches "visible" repoview object (call it VIEW1) 2. 'cachedlocalrepo' returns VIEW1 to the client of it at 'fetch()' 3. the client gets "served" repoview object by 'filtered("served")' on VIEW1 (call this "served" repoview VIEW2) 4. accessing to 'repo.changelog' implies: - instantiation of changelog via 'localrepository.changelog' - instantiation of "filtered changelog" via 'repoview.changelog' 5. "filtered changelog" above is cached in VIEW2 6. VIEW2 is discarded after processing, because there is no reference to it 7. 'cachedlocalrepo' returns VIEW1 cached at (1) above to the client at next 'fetch()' 8. 'filtered("served")' on VIEW1 at the client side creates new "served" repoview again, because VIEW1 is "visible" (call this new "served" repoview VIEW3) 9. accessing to 'repo.changelog' implies instantiation of filtered changelog again, because "filtered changelog" is cached in VIEW2 at (5), but not in VIEW3 currently used 10. (go to (7) above) As described above, "served" repoview object and "filtered changelog" cached in it are discarded always, even if the repository itself hasn't been changed since last access. For example, in the case of 'hgweb_mod.hgweb', "newly caching" occurs, when: - all cached objects are already assigned to another threads (in this case, repoview is created in 'cachedlocalrepo.copy()') - or, stat of '00changelog.i' is changed from last access (in this case, repoview is created in 'cachedlocalrepo.fetch()') once changes are pushed via HTTP, this always occurs. The root cause of this inefficiency is that 'cachedlocalrepo' always caches "visible" repoview object, even if the client of it wants another view. To make 'cachedlocalrepo' cache appropriate repoview object, this patch adds additional filtering on the repo object returned by 'hg.repository()'. It is assumed that initial repoview object should be already filtered by expected view. After this patch: - 'filtered("served")' on VIEW1 at (3)/(7) above returns VIEW1 itself, because VIEW1 is now "served", and - VIEW2 and VIEW3 equal VIEW1 - therefore, "filtered changelog" is cached in VIEW1, and reused intentionally

--- a/mercurial/hg.py	Sun Feb 14 00:45:17 2016 +0000
+++ b/mercurial/hg.py	Sun Feb 14 01:33:55 2016 +0900
@@ -865,6 +865,7 @@
         assert isinstance(repo, localrepo.localrepository)
         self._repo = repo
         self._state, self.mtime = self._repostate()
+        self._filtername = repo.filtername
 
     def fetch(self):
         """Refresh (if necessary) and return a repository.
@@ -884,7 +885,11 @@
         if state == self._state:
             return self._repo, False
 
-        self._repo = repository(self._repo.baseui, self._repo.url())
+        repo = repository(self._repo.baseui, self._repo.url())
+        if self._filtername:
+            self._repo = repo.filtered(self._filtername)
+        else:
+            self._repo = repo.unfiltered()
         self._state = state
         self.mtime = mtime
 
@@ -912,6 +917,10 @@
         completely independent of the original.
         """
         repo = repository(self._repo.baseui, self._repo.origroot)
+        if self._filtername:
+            repo = repo.filtered(self._filtername)
+        else:
+            repo = repo.unfiltered()
         c = cachedlocalrepo(repo)
         c._state = self._state
         c.mtime = self.mtime