def detect_path_overlap(paths):
"""
Check for valid POSIX paths (ie ones that aren't duplicated and don't overlap).
Overlapping paths are where one path terminates inside another (e.g. a/b and a/b/c).
NOTE: The logic is copied from pulpcore.app.files.validate_file_paths().
This function returns the first dupe or overlap it detects. We use a trie (or
prefix tree) to keep track of which paths we've already seen.
Args:
paths (iterable of str): An iterable of strings each representing a relative path
Returns:
str: a path which overlaps or duplicates another
"""
path_trie = StringTrie(separator="/")
for path in paths:
if path in path_trie:
# path duplicates a path already in the trie
return path
if path_trie.has_subtrie(path):
# overlap where path is 'a/b' and trie has 'a/b/c'
return path
prefixes = list(path_trie.prefixes(path))
if prefixes:
# overlap where path is 'a/b/c' and trie has 'a/b'
return path
# if there are no overlaps, add it to our trie and continue
path_trie[path] = True
def validate_file_paths(paths):
"""
Check for valid POSIX paths (ie ones that aren't duplicated and don't overlap).
Overlapping paths are where one path terminates inside another (e.g. a/b and a/b/c).
This function will raise an exception at the first dupe or overlap it detects. We use a trie (or
prefix tree) to keep track of which paths we've already seen.
Args:
paths (iterable of str): An iterable of strings each representing a relative path
Raises:
ValueError: If any path overlaps another
"""
overlap_error = _("The path for file '{path}' overlaps: {conflicts}")
path_trie = StringTrie(separator="/")
dups = []
overlaps = []
for path in paths:
if path in path_trie:
# path duplicates a path already in the trie
dups.append(path)
elif path_trie.has_subtrie(path):
# overlap where path is 'a/b' and trie has 'a/b/c'
conflicts = [item[0] for item in path_trie.items(prefix=path)]
overlaps.append(
overlap_error.format(path=path,
conflicts=", ".join(conflicts)))
else:
prefixes = list(path_trie.prefixes(path))
if prefixes:
# overlap where path is 'a/b/c' and trie has 'a/b'
conflicts = [prefix.key for prefix in prefixes]
overlaps.append(
overlap_error.format(path=path,
conflicts=", ".join(conflicts)))
# if there are no overlaps, add it to our trie and continue
path_trie[path] = True
if dups or overlaps:
dups_msg = ""
overlaps_msg = ""
if dups:
dups_msg = _("Paths are duplicated: {paths}").format(
paths=",".join(dups))
if overlaps:
overlaps_msg = "\n".join(overlaps)
raise ValueError(
_("Path errors found. {dups}\n{overlaps}").format(
dups=dups_msg, overlaps=overlaps_msg))