[meld/VersionControlRework: 4/123] meld.vc: All remaining VCs are 'cached', for what it's worth

[Kai Willadsen <kaiw src gnome org>]

commit b1af7f9b4bd188ef763edde6913b32d68ee634e4
Author: Kai Willadsen <kai willadsen gmail com>
Date:   Sat Mar 21 14:03:44 2015 +1000

    meld.vc: All remaining VCs are 'cached', for what it's worth

 meld/vc/_vc.py       |   36 ++++++++++++------------------------
 meld/vc/bzr.py       |    2 +-
 meld/vc/git.py       |    2 +-
 meld/vc/mercurial.py |    2 +-
 meld/vc/svn.py       |    2 +-
 5 files changed, 16 insertions(+), 28 deletions(-)
---
diff --git a/meld/vc/_vc.py b/meld/vc/_vc.py
index 94740e9..eeb5f60 100644
--- a/meld/vc/_vc.py
+++ b/meld/vc/_vc.py
@@ -128,6 +128,7 @@ class Vc(object):
         self.root, self.location = self.is_in_repo(path)
         if not self.root:
             raise ValueError
+        self._tree_cache = None
 
     def commit_command(self, message):
         raise NotImplementedError()
@@ -201,11 +202,19 @@ class Vc(object):
     def get_working_directory(self, workdir):
         return workdir
 
-    def cache_inventory(self, topdir):
-        pass
+    def cache_inventory(self, directory):
+        self._tree_cache = self._lookup_tree_cache(directory)
 
     def uncache_inventory(self):
-        pass
+        self._tree_cache = None
+
+    def _lookup_tree_cache(self, directory):
+        raise NotImplementedError()
+
+    def _get_tree_cache(self, directory):
+        if self._tree_cache is None:
+            self.cache_inventory(directory)
+        return self._tree_cache
 
     def update_file_state(self, path):
         """ Update the state of a specific file.  For example after a file
@@ -293,27 +302,6 @@ class Vc(object):
         raise NotImplementedError
 
 
-class CachedVc(Vc):
-
-    def __init__(self, location):
-        super(CachedVc, self).__init__(location)
-        self._tree_cache = None
-
-    def cache_inventory(self, directory):
-        self._tree_cache = self._lookup_tree_cache(directory)
-
-    def uncache_inventory(self):
-        self._tree_cache = None
-
-    def _lookup_tree_cache(self, directory):
-        raise NotImplementedError()
-
-    def _get_tree_cache(self, directory):
-        if self._tree_cache is None:
-            self.cache_inventory(directory)
-        return self._tree_cache
-
-
 class InvalidVCPath(ValueError):
     """Raised when a VC module is passed an invalid (or not present) path."""
 
diff --git a/meld/vc/bzr.py b/meld/vc/bzr.py
index f07fc5f..93de89d 100644
--- a/meld/vc/bzr.py
+++ b/meld/vc/bzr.py
@@ -34,7 +34,7 @@ import tempfile
 from . import _vc
 
 
-class Vc(_vc.CachedVc):
+class Vc(_vc.Vc):
 
     CMD = "bzr"
     CMDARGS = ["--no-aliases", "--no-plugins"]
diff --git a/meld/vc/git.py b/meld/vc/git.py
index 23f982e..00c4bc2 100644
--- a/meld/vc/git.py
+++ b/meld/vc/git.py
@@ -38,7 +38,7 @@ from meld.conf import _, ngettext
 from . import _vc
 
 
-class Vc(_vc.CachedVc):
+class Vc(_vc.Vc):
 
     CMD = "git"
     NAME = "Git"
diff --git a/meld/vc/mercurial.py b/meld/vc/mercurial.py
index fb839a5..b45e95f 100644
--- a/meld/vc/mercurial.py
+++ b/meld/vc/mercurial.py
@@ -30,7 +30,7 @@ import tempfile
 from . import _vc
 
 
-class Vc(_vc.CachedVc):
+class Vc(_vc.Vc):
 
     CMD = "hg"
     NAME = "Mercurial"
diff --git a/meld/vc/svn.py b/meld/vc/svn.py
index d48ebbf..d639141 100644
--- a/meld/vc/svn.py
+++ b/meld/vc/svn.py
@@ -33,7 +33,7 @@ import subprocess
 from . import _vc
 
 
-class Vc(_vc.CachedVc):
+class Vc(_vc.Vc):
 
     CMD = "svn"
     NAME = "Subversion"