[PATCH 1 of 5 STABLE] filecache: refactor path join logic to a function

[Idan Kamara]

# HG changeset patch
# User Idan Kamara <idankk86 at gmail.com>
# Date 1330616398 -7200
# Branch stable
# Node ID fa8488565afde5375feac30b7df4f9352932d2aa
# Parent  8ae7626d8bf1c41998bc62dbb929ae032c6ab6ff
filecache: refactor path join logic to a function

New users of filecache use different names for the function used to compute
the runtime path of the cached file.

Users should subclass filecache and provide their own version of this
function to call the appropriate join function on 'obj' (an instance
of the class that its member function was decorated).

diff --git a/mercurial/localrepo.py b/mercurial/localrepo.py
--- a/mercurial/localrepo.py
+++ b/mercurial/localrepo.py
@@ -19,6 +19,11 @@
 propertycache = util.propertycache
 filecache = scmutil.filecache
 
+class storecache(filecache):
+    """filecache for files in the store"""
+    def join(self, obj, fname):
+        return obj.sjoin(fname)
+
 class localrepository(repo.repository):
     capabilities = set(('lookup', 'changegroupsubset', 'branchmap', 'pushkey',
                         'known', 'getbundle'))
@@ -176,7 +181,7 @@
     def _writebookmarks(self, marks):
       bookmarks.write(self)
 
-    @filecache('phaseroots', True)
+    @storecache('phaseroots')
     def _phaseroots(self):
         self._dirtyphases = False
         phaseroots = phases.readroots(self)
@@ -195,7 +200,7 @@
                     cache[rev] = phase
         return cache
 
-    @filecache('00changelog.i', True)
+    @storecache('00changelog.i')
     def changelog(self):
         c = changelog.changelog(self.sopener)
         if 'HG_PENDING' in os.environ:
@@ -204,7 +209,7 @@
                 c.readpending('00changelog.i.a')
         return c
 
-    @filecache('00manifest.i', True)
+    @storecache('00manifest.i')
     def manifest(self):
         return manifest.manifest(self.sopener)
 
diff --git a/mercurial/scmutil.py b/mercurial/scmutil.py
--- a/mercurial/scmutil.py
+++ b/mercurial/scmutil.py
@@ -793,9 +793,17 @@
     to tell us if a file has been replaced. If it can't, we fallback to
     recreating the object on every call (essentially the same behaviour as
     propertycache).'''
-    def __init__(self, path, instore=False):
+    def __init__(self, path):
         self.path = path
-        self.instore = instore
+
+    def join(self, obj, fname):
+        """Used to compute the runtime path of the cached file.
+
+        Users should subclass filecache and provide their own version of this
+        function to call the appropriate join function on 'obj' (an instance
+        of the class that its member function was decorated).
+        """
+        return obj.join(fname)
 
     def __call__(self, func):
         self.func = func
@@ -813,7 +821,7 @@
             if entry.changed():
                 entry.obj = self.func(obj)
         else:
-            path = self.instore and obj.sjoin(self.path) or obj.join(self.path)
+            path = self.join(obj, self.path)
 
             # We stat -before- creating the object so our cache doesn't lie if
             # a writer modified between the time we read and stat