Support package resources (importlib.resources.abc.Traversable) for interface_dir

[tcyrus]

The easiest way to do this is to convert str inputs for interface_dir to pathlib.Path. importlib.resources.abc.Traversable is a subset of pathlib.Path.

python/varlink/server.py

Line 75 in 70735a7

self.interface_dir = interface_dir

        if isinstance(interface_dir, str):
            interface_dir = Path(interface_dir)
        self.interface_dir = interface_dir

This would narrow the type of self.interface_dir to pathlib.Path | importlib.resources.abc.Traversable, which both implement joinpath and read_text.

python/varlink/server.py

Lines 260 to 267 in 70735a7

	def _add_interface(self, filename, handler):
	if not os.path.isabs(filename):
	filename = os.path.join(self.interface_dir, filename + ".varlink")
	with open(filename) as f:
	interface = Interface(f.read())
	self.interfaces[interface.name] = interface
	self.interfaces_handlers[interface.name] = handler

    def _add_interface(self, filename, handler):
        filepath = filename
        if not isinstance(filepath, importlib.resources.abc.Traversable):
            filepath = Path(filename)
        if isinstance(filename, str) and not filepath.is_file():
            filepath = self.interface_dir.joinpath(filename + ".varlink")
        interface = Interface(filepath.read_text())
        self.interfaces[interface.name] = interface
        self.interfaces_handlers[interface.name] = handler

[jelly]

We target Python 3.9 and higher which means we can indeed use importlib.abc.Traversable. But I am curious what your use case is? From which use case to you get a Traversable object?

Either way supporting a Pathlib object as interface_dir seems like a nice improvement to me.

[tcyrus]

Package resource paths (importlib.resources.path) are importlib.abc.Traversable

[tcyrus]

Package resources aren't always directly accessible on the filesystem (e.g. .pyz libraries).
The following code won't work if the library isn't fully extracted:

python/varlink/server.py

Lines 94 to 95 in 3292a46

	directory = os.path.dirname(__file__)
	self._add_interface(os.path.abspath(os.path.join(directory, "org.varlink.service.varlink")), self)

One solution is to use importlib.resources to get the contents of the resource (read_text) or to temporarily extract the file (as_file).

        directory = importlib.resources.files(__package__)
        self._add_interface(directory.joinpath("org.varlink.service.varlink"), self)