1 files changed, 59 insertions, 0 deletions
diff --git a/third_party/python/fluent.migrate/fluent/migrate/changesets.py b/third_party/python/fluent.migrate/fluent/migrate/changesets.py
new file mode 100644
index 0000000000..e4ad95f2d1
--- /dev/null
+++ b/third_party/python/fluent.migrate/fluent/migrate/changesets.py
@@ -0,0 +1,59 @@
+# coding=utf8
+from __future__ import absolute_import
+
+import time
+
+
+def by_first_commit(item):
+    """Order two changesets by their first commit date."""
+    return item['first_commit']
+
+
+def convert_blame_to_changesets(blame_json):
+    """Convert a blame dict into a list of changesets.
+
+    The blame information in `blame_json` should be a dict of the following
+    structure:
+
+        {
+            'authors': [
+                'A.N. Author <author@example.com>',
+            ],
+            'blame': {
+                'path/one': {
+                    'key1': [0, 1346095921.0],
+                },
+            }
+        }
+
+    It will be transformed into a list of changesets which can be fed into
+    `InternalContext.serialize_changeset`:
+
+        [
+            {
+                'author': 'A.N. Author <author@example.com>',
+                'first_commit': 1346095921.0,
+                'changes': {
+                    ('path/one', 'key1'),
+                }
+            },
+        ]
+
+    """
+    now = time.time()
+    changesets = [
+        {
+            'author': author,
+            'first_commit': now,
+            'changes': set()
+        } for author in blame_json['authors']
+    ]
+
+    for path, keys_info in blame_json['blame'].items():
+        for key, (author_index, timestamp) in keys_info.items():
+            changeset = changesets[author_index]
+            changeset['changes'].add((path, key))
+            if timestamp < changeset['first_commit']:
+                changeset['first_commit'] = timestamp
+
+    return sorted(changesets, key=by_first_commit)