Refactor DeltaCode.determine_moved() #4

  * Convert utility function 'index_delta_files()' to DeltaCode method
    'index_deltas()'.
  * Index Delta objects rather than their respective File objects.
  * Create new test codebases and add new tests.
  * Modify existing tests to include new 'moved' Delta as necessary.

Signed-off-by: John M. Horan <johnmhoran@gmail.com>

src/deltacode/__init__.py

@@ -132,49 +132,49 @@ def determine_delta(self):
 
     def determine_moved(self):
         """
-        Modify the OrderedDict of Delta objects by comparing the 'sha1', 'name'
-        and 'size' attributes of the 'removed' and 'added' files and converting
-        each unique matching pair to a Delta object with the category attribute
-        'moved'.  This method currently excludes groups of matching 'removed'
-        and 'added' files comprising more than one 'removed' and one 'added' file.
+        Modify the OrderedDict of Delta objects by creating an index of
+        'removed' Delta objects and an index of 'added' Delta objects indexed
+        by their 'sha1' attribute, finding Deltas in both indices with the same
+        'sha1', and converting the 'added' and 'removed' Deltas to a 'moved'
+        Delta if (1) there is only one such 'added' and one such 'moved'
+        Delta and (2) these two Deltas have the same 'name' attribute.
         """
-        list_old_removed_files = [i.old_file for i in self.deltas['removed']]
-        old_removed_index = utils.index_delta_files(list_old_removed_files, 'sha1')
-
-        list_new_added_files = [i.new_file for i in self.deltas['added']]
-        new_added_index = utils.index_delta_files(list_new_added_files, 'sha1')
-
-        unique_removed_sha1 = []
-        unique_added_sha1 = []
-
-        for key, value in old_removed_index.iteritems():
-            if len(value) == 1:
-                for file in value:
-                    unique_removed_sha1.append({'sha1': file.sha1, 'name': file.name, 'size': file.size})
-
-        for key, value in new_added_index.iteritems():
-            if len(value) == 1:
-                for file in value:
-                    unique_added_sha1.append({'sha1': file.sha1, 'name': file.name, 'size': file.size})
-
-        for added_dict in unique_added_sha1:
-            for removed_dict in unique_removed_sha1:
-                if added_dict['sha1'] == removed_dict['sha1'] and \
-                   added_dict['name'] == removed_dict['name'] and \
-                   added_dict['size'] == removed_dict['size']:
-
-                    for delta_added in self.deltas['added'][:]:
-                        if added_dict['sha1'] == delta_added.new_file.sha1 and \
-                           added_dict['name'] == delta_added.new_file.name and \
-                           added_dict['size'] == delta_added.new_file.size:
-                            self.deltas['moved'].append(Delta(delta_added.new_file, None, 'moved'))
-                            self.deltas['added'].remove(delta_added)
-
-                    for delta_removed in self.deltas['removed'][:]:
-                        for delta_moved in self.deltas['moved']:
-                            if added_dict['sha1'] == delta_removed.old_file.sha1 and added_dict['sha1'] == delta_moved.new_file.sha1:
-                                delta_moved.old_file = delta_removed.old_file
-                            self.deltas['removed'].remove(delta_removed)
+        removed = self.index_deltas([i for i in self.deltas['removed']], 'sha1')
+        added = self.index_deltas([i for i in self.deltas['added']], 'sha1')
+
+        for k, v in removed.iteritems():
+            if (k in added and
+                    len(removed[k]) == 1 and
+                    len(added[k]) == 1 and
+                    removed[k][0].old_file.name == added[k][0].new_file.name):
+                self.deltas['moved'].append(Delta(added[k][0].new_file, removed[k][0].old_file, 'moved'))
+                self.deltas['added'].remove(added[k][0])
+                self.deltas['removed'].remove(removed[k][0])
+
+    def index_deltas(self, delta_list, index_key='path'):
+        """
+        Return a dictionary of a list of Delta objects indexed by the key
+        passed via the 'index_key' variable.  If no 'index_key' variable is
+        passed, the dict is keyed by the Delta object's 'path' variable.  For a
+        'removed' Delta object, use the variable from the 'old_file'; for all
+        other Delta objects (e.g., 'added'), use the 'new_file'.  This function
+        does not currently catch the AttributeError exception.
+        """
+        index = {}
+
+        for delta in delta_list:
+            if delta.category == 'removed':
+                key = getattr(delta.old_file, index_key)
+            else:
+                key = getattr(delta.new_file, index_key)
+
+            if index.get(key) is None:
+                index[key] = []
+                index[key].append(delta)
+            else:
+                index[key].append(delta)
+
+        return index
 
     def get_stats(self):
         """

src/deltacode/utils.py

@@ -101,24 +101,3 @@ def fix_trees(a_files, b_files):
     for b_file in b_files:
         b_file.original_path = b_file.path
         b_file.path = '/'.join(paths.split(b_file.path)[b_offset:])
-
-
-def index_delta_files(self, index_key='path'):
-    """
-    Return a dictionary of a list of File objects indexed by the key passed via
-    the 'key' variable.  If no 'key' variable is passed, the dict is
-    keyed by the File object's 'path' variable.  This function does not
-    currently catch the AttributeError exception.
-    """
-    index = {}
-
-    for f in self:
-        key = getattr(f, index_key)
-
-        if index.get(key) is None:
-            index[key] = []
-            index[key].append(f)
-        else:
-            index[key].append(f)
-
-    return index