Add Green Albatross repository format

1 files changed, 84 insertions, 0 deletions

diff --git a/obnamlib/fmt_ga/chunk_store.py b/obnamlib/fmt_ga/chunk_store.py
new file mode 100644
index 00000000..2a0562b9
--- /dev/null
+++ b/obnamlib/fmt_ga/chunk_store.py
@@ -0,0 +1,84 @@
+# Copyright 2015  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+ =*=
+
+
+import os
+import random
+
+import obnamlib
+
+
+class GAChunkStore(object):
+
+    def __init__(self):
+        self._fs = None
+        self._dirname = 'chunk-store'
+
+    def set_fs(self, fs):
+        self._fs = fs
+
+    def put_chunk_content(self, content):
+        self._fs.create_and_init_toplevel(self._dirname)
+        while True:
+            chunk_id = self._random_chunk_id()
+            filename = self._chunk_filename(chunk_id)
+            try:
+                self._fs.write_file(filename, content)
+            except OSError, e: # pragma: no cover
+                if e.errno == errno.EEXIST:
+                    continue
+                raise
+            else:
+                return chunk_id
+
+    def get_chunk_content(self, chunk_id):
+        filename = self._chunk_filename(chunk_id)
+        if not self._fs.exists(filename):
+            raise obnamlib.RepositoryChunkDoesNotExist(
+                chunk_id=chunk_id,
+                filename=filename)
+        return self._fs.cat(filename)
+
+    def has_chunk(self, chunk_id):
+        filename = self._chunk_filename(chunk_id)
+        return self._fs.exists(filename)
+
+    def remove_chunk(self, chunk_id):
+        filename = self._chunk_filename(chunk_id)
+        if not self._fs.exists(filename):
+            raise obnamlib.RepositoryChunkDoesNotExist(
+                chunk_id=chunk_id,
+                filename=filename)
+        self._fs.remove(filename)
+
+    def get_chunk_ids(self):
+        if not self._fs.exists(self._dirname):
+            return []
+        basenames = self._fs.listdir(self._dirname)
+        return [
+            self._parse_chunk_filename(x)
+            for x in basenames
+            if x.endswith('.chunk')]
+
+    def _random_chunk_id(self):
+        return random.randint(0, obnamlib.MAX_ID)
+
+    def _chunk_filename(self, chunk_id):
+        return os.path.join(self._dirname, '%d.chunk' % chunk_id)
+
+    def _parse_chunk_filename(self, filename):
+        return int(filename[:-len('.chunk')])