import fnmatch
import os
from collections.abc import Mapping
from pathlib import Path
__all__ = ["DirectoryResourceMapping"]
[docs]
class DirectoryResourceMapping(Mapping):
"""
Resource mapping that reads resource content
from a directory or directory tree.
Parameters
----------
root : str or importlib.abc.Traversable
Root directory (or directory-like Traversable) of the resource
files. ``str`` will be interpreted as a filesystem path.
uri_prefix : str
Prefix used to construct URIs from file paths. The
prefix will be prepended to paths relative to the root
directory.
recursive : bool, optional
If ``True``, recurse into subdirectories. Defaults to ``False``.
filename_pattern : str, optional
Glob pattern that identifies relevant filenames.
Defaults to ``"*.yaml"``.
stem_filename : bool, optional
If ``True``, remove the filename's extension when
constructing its URI.
"""
def __init__(self, root, uri_prefix, recursive=False, filename_pattern="*.yaml", stem_filename=True):
self._uri_to_file = {}
self._recursive = recursive
self._filename_pattern = filename_pattern
self._stem_filename = stem_filename
if isinstance(root, str):
self._root = Path(root)
else:
self._root = root
if uri_prefix.endswith("/"):
self._uri_prefix = uri_prefix[:-1]
else:
self._uri_prefix = uri_prefix
for file, path_components in self._iterate_files(self._root, []):
self._uri_to_file[self._make_uri(file, path_components)] = file
def _iterate_files(self, directory, path_components):
for obj in directory.iterdir():
if obj.is_file() and fnmatch.fnmatch(obj.name, self._filename_pattern):
yield obj, path_components
elif obj.is_dir() and self._recursive:
yield from self._iterate_files(obj, path_components + [obj.name])
def _make_uri(self, file, path_components):
if self._stem_filename:
filename = os.path.splitext(file.name)[0]
else:
filename = file.name
return "/".join([self._uri_prefix] + path_components + [filename])
def __getitem__(self, uri):
return self._uri_to_file[uri].read_bytes()
def __len__(self):
return len(self._uri_to_file)
def __iter__(self):
yield from self._uri_to_file
def __repr__(self):
return "{}({!r}, {!r}, recursive={!r}, filename_pattern={!r}, stem_filename={!r})".format(
self.__class__.__name__,
self._root,
self._uri_prefix,
self._recursive,
self._filename_pattern,
self._stem_filename,
)