1 files changed, 64 insertions, 0 deletions
diff --git a/idmapfile.py b/idmapfile.py
new file mode 100644
index 0000000..669dbce
--- /dev/null
+++ b/idmapfile.py
@@ -0,0 +1,64 @@
+# Copyright (C) 2008 Canonical Ltd
+#
+# 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 2 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/>.
+
+"""Routines for saving and loading the id-map file."""
+
+import os
+
+
+def save_id_map(filename, revision_ids):
+    """Save the mapping of commit ids to revision ids to a file.
+
+    Throws the usual exceptions if the file cannot be opened,
+    written to or closed.
+
+    :param filename: name of the file to save the data to
+    :param revision_ids: a dictionary of commit ids to revision ids.
+    """
+    f = open(filename, 'wb')
+    try:
+        for commit_id, rev_id in revision_ids.iteritems():
+            f.write("%s %s\n" % (commit_id, rev_id))
+        f.flush()
+    finally:
+        f.close()
+
+
+def load_id_map(filename):
+    """Load the mapping of commit ids to revision ids from a file.
+
+    If the file does not exist, an empty result is returned.
+    If the file does exists but cannot be opened, read or closed,
+    the normal exceptions are thrown.
+
+    NOTE: It is assumed that commit-ids do not have embedded spaces.
+
+    :param filename: name of the file to save the data to
+    :result: map, count where:
+      map = a dictionary of commit ids to revision ids;
+      count = the number of keys in map
+    """
+    result = {}
+    count = 0
+    if os.path.exists(filename):
+        f = open(filename)
+        try:
+            for line in f:
+                parts = line[:-1].split(' ', 1)
+                result[parts[0]] = parts[1]
+                count += 1
+        finally:
+            f.close()
+    return result, count