1 files changed, 56 insertions, 0 deletions
diff --git a/morphlib/sourcepool.py b/morphlib/sourcepool.py
new file mode 100644
index 00000000..6dfcb2c3
--- /dev/null
+++ b/morphlib/sourcepool.py
@@ -0,0 +1,56 @@
+# Copyright (C) 2012-2014  Codethink Limited
+#
+# 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; version 2 of the License.
+#
+# 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, write to the Free Software Foundation, Inc.,
+# 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+
+import collections
+
+
+class SourcePool(object):
+
+    '''Manage a collection of Source objects.'''
+
+    def __init__(self):
+        self._sources = collections.defaultdict(dict)
+        self._order = []
+
+    def _key(self, repo_name, original_ref, filename):
+        return (repo_name, original_ref, filename)
+
+    def add(self, source):
+        '''Add a source to the pool.'''
+        key = self._key(source.repo_name,
+                        source.original_ref,
+                        source.filename)
+        if key not in self._sources or source.name not in self._sources[key]:
+            self._sources[key][source.name] = source
+            self._order.append(source)
+
+    def lookup(self, repo_name, original_ref, filename):
+        '''Find a source in the pool.
+
+        Raise KeyError if it is not found.
+
+        '''
+
+        key = self._key(repo_name, original_ref, filename)
+        return self._sources[key].values()
+
+    def __iter__(self):
+        '''Iterate over sources in the pool, in the order they were added.'''
+        for source in self._order:
+            yield source
+
+    def __len__(self):
+        return len(self._sources)