cola/display.py

   1 """Display models and utility functions"""
   2 import collections
   3
   4
   5 def shorten_paths(source_paths):
   6     """Shorten a sequence of paths into unique strings for display"""
   7     result = {}
   8     # Start by assuming that all paths are in conflict.
   9     # On each iteration we will collect all the path suffixes, move the newly
  10     # unique entries to the result, and repeat until no conflicts remain.
  11     count = 0
  12     conflicts = list(source_paths)
  13     in_conflict = True
  14     while in_conflict:
  15         count += 1
  16         # Gather the suffixes for the current paths in conflict
  17         suffixes = collections.defaultdict(list)
  18         for path in conflicts:
  19             suffix = path_suffix(path, count)
  20             suffixes[suffix].append(path)
  21
  22         # Loop over the suffixes to gather new conflicts and unique entries.
  23         conflicts = []
  24         in_conflict = False
  25
  26         for suffix, paths in suffixes.items():
  27             # If only a single path exists for the suffix then no conflict
  28             # exists, and the suffix is valid.
  29             if len(paths) == 1:
  30                 result[paths[0]] = suffix
  31             # If this loop runs too long then bail out by using the full path.
  32             elif count >= 128:
  33                 for path in paths:
  34                     result[path] = path
  35             # If multiple paths map to the same suffix then the paths are
  36             # considered in conflict, and will be reprocessed.
  37             else:
  38                 conflicts.extend(paths)
  39                 in_conflict = True
  40
  41     return result
  42
  43
  44 def path_suffix(path, count):
  45     """Return `count` number of trailing path components"""
  46     path = normalize_path(path)
  47     components = path.split('/')[-count:]
  48     return '/'.join(components)
  49
  50
  51 def normalize_path(path):
  52     """Normalize a path so that only "/" is used as a separator"""
  53     return path.replace('\\', '/')