summaryrefslogtreecommitdiff
path: root/obnamlib/fmt_ga/cowdelta.py
diff options
context:
space:
mode:
Diffstat (limited to 'obnamlib/fmt_ga/cowdelta.py')
-rw-r--r--obnamlib/fmt_ga/cowdelta.py40
1 files changed, 40 insertions, 0 deletions
diff --git a/obnamlib/fmt_ga/cowdelta.py b/obnamlib/fmt_ga/cowdelta.py
new file mode 100644
index 00000000..a5413d54
--- /dev/null
+++ b/obnamlib/fmt_ga/cowdelta.py
@@ -0,0 +1,40 @@
+# Copyright 2017 Lars Wirzenius
+#
+# This program is free software: you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation, either version 3 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program. If not, see <http://www.gnu.org/licenses/>.
+#
+# =*= License: GPL-3+ =*=
+
+
+class CowDelta(object):
+
+ def __init__(self):
+ self._dict = {}
+
+ def __contains__(self, key):
+ return key in self._dict
+
+ def keys(self):
+ return self._dict.keys()
+
+ def set(self, key, value):
+ self._dict[key] = value
+
+ def get(self, key):
+ return self._dict[key]
+
+ def remove(self, key):
+ self._dict[key] = removed_key
+
+
+removed_key = object()