new module: combox/silo.py

- Contains the ComboxSilo class which provides an interface to access
  the db that stores information about files in the combox directory.

Tests for this module is at tests/silo_test.py

1 files changed, 99 insertions, 0 deletions

diff --git a/combox/silo.py b/combox/silo.py
new file mode 100644
index 0000000..cbb2065
--- /dev/null
+++ b/combox/silo.py
@@ -0,0 +1,99 @@
+#    Copyright (C) 2015 Combox author(s). See AUTHORS.
+#
+#    This file is part of Combox.
+#
+#   Combox 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.
+#
+#   Combox 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 Combox (see COPYING).  If not, see
+#   <http://www.gnu.org/licenses/>.
+
+import pickledb
+
+from os import path
+
+from combox.file import hash_file
+
+class ComboxSilo(object):
+    """The Combox silo.
+
+    Helps keep track of files in combox directory.
+    """
+
+
+    def __init__(self, config):
+        """config: a dictinary which contains combox configuration.
+
+        """
+        self.config = config
+
+        silo = path.join(config['silo_dir'], 'silo.db')
+        self.db = pickledb.load(silo, True)
+
+
+    def update(self, filep):
+        """Update filep's info in db
+
+        filep and the hash of its content is written to the db.
+
+        filep: path to the file in combox directory.
+
+        """
+
+        fhash = hash_file(filep)
+
+        return self.db.set(filep, fhash)
+
+
+    def remove(self, filep):
+        """Removes filep from db.
+
+        filep: path to the file in combox directory.
+
+        """
+
+        return self.db.rem(filep)
+
+
+    def exists(self, filep):
+        """Checks if filep's info is stored in db.
+
+        Returns True if filep's info is in db; False otherwise.
+
+        filep: path to the file in combox directory.
+
+        """
+
+        if self.db.get(filep) is None:
+            return False
+        else:
+            return True
+
+
+    def stale(self, filep):
+        """Returns True if filep's hash is different from the hash stored in db.
+
+        Returns None, if filep's info is not yet stored in db.
+        Returns False, if filep's hash has not changed it.
+
+        filep: path to the file in combox directory.
+
+        """
+
+        fhash = hash_file(filep)
+        fhash_in_db = self.db.get(filep)
+
+        if fhash_in_db is None:
+            return None
+        elif fhash == fhash_in_db:
+            return False
+        else:
+            return True