wip: Add wrapper for a manifest of refs in definitions

1 files changed, 71 insertions, 0 deletions

diff --git a/morphlib/refmanifest.py b/morphlib/refmanifest.py
new file mode 100644
index 00000000..05a83231
--- /dev/null
+++ b/morphlib/refmanifest.py
@@ -0,0 +1,71 @@
+# Copyright (C) 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 cliapp
+import os
+import yaml
+
+import morphlib
+
+
+class RefManifest(object):
+
+    """Class to represent the ref-manifest file."""
+
+    def __init__(self, contents, location):
+        self.chunks = contents
+        self.location = location
+
+    @classmethod
+    def load_from_file(cls, filepath):
+        with open(filepath, 'r') as f:
+            return RefManifest(yaml.load(f), filepath)
+
+    def _get_chunk(self, chunk_name):
+        if not chunk_name in self.chunks:
+            raise morphlib.Error(
+                'Chunk %s is not in the ref-manifest' % chunk_name)
+        return self.chunks[chunk_name]
+
+    def chunk_has_ref(self, chunk_name, ref):
+        chunk = self._get_chunk(chunk_name)
+        for pair in chunk:
+            if ref in pair:
+                return True
+        return False
+
+    def chunk_ref_different(self, chunk_name, ref, sha):
+        chunk = self._get_chunk(chunk_name)
+        if {ref: sha} in chunk:
+            return True
+        return False
+
+    def get_chunk_ref(self, chunk_name, ref):
+        chunk = self._get_chunk(chunk_name)
+        for pair in chunk:
+            if ref in pair:
+                return pair
+
+    def set_chunk_ref(self, chunk_name, ref, sha):
+        chunk = self._get_chunk(chunk_name)
+        if self.chunk_has_ref(chunk_name, ref):
+            chunk.remove(self.get_chunk_ref(chunk_name, ref))
+        chunk.append({ref: sha})
+
+    def save_to_file(self, path=self.location):
+        with open(path, 'w') as ref_manifest:
+            ref_manifest.write(
+                yaml.dump(self.chunks, default_flow_style=False))