mirror of
https://github.com/python/cpython.git
synced 2024-11-24 00:38:00 +01:00
107 lines
2.5 KiB
Python
107 lines
2.5 KiB
Python
"""
|
|
Interface adapters for low-level readers.
|
|
"""
|
|
|
|
import abc
|
|
import io
|
|
import itertools
|
|
from typing import BinaryIO, List
|
|
|
|
from .abc import Traversable, TraversableResources
|
|
|
|
|
|
class SimpleReader(abc.ABC):
|
|
"""
|
|
The minimum, low-level interface required from a resource
|
|
provider.
|
|
"""
|
|
|
|
@property
|
|
@abc.abstractmethod
|
|
def package(self) -> str:
|
|
"""
|
|
The name of the package for which this reader loads resources.
|
|
"""
|
|
|
|
@abc.abstractmethod
|
|
def children(self) -> List['SimpleReader']:
|
|
"""
|
|
Obtain an iterable of SimpleReader for available
|
|
child containers (e.g. directories).
|
|
"""
|
|
|
|
@abc.abstractmethod
|
|
def resources(self) -> List[str]:
|
|
"""
|
|
Obtain available named resources for this virtual package.
|
|
"""
|
|
|
|
@abc.abstractmethod
|
|
def open_binary(self, resource: str) -> BinaryIO:
|
|
"""
|
|
Obtain a File-like for a named resource.
|
|
"""
|
|
|
|
@property
|
|
def name(self):
|
|
return self.package.split('.')[-1]
|
|
|
|
|
|
class ResourceContainer(Traversable):
|
|
"""
|
|
Traversable container for a package's resources via its reader.
|
|
"""
|
|
|
|
def __init__(self, reader: SimpleReader):
|
|
self.reader = reader
|
|
|
|
def is_dir(self):
|
|
return True
|
|
|
|
def is_file(self):
|
|
return False
|
|
|
|
def iterdir(self):
|
|
files = (ResourceHandle(self, name) for name in self.reader.resources)
|
|
dirs = map(ResourceContainer, self.reader.children())
|
|
return itertools.chain(files, dirs)
|
|
|
|
def open(self, *args, **kwargs):
|
|
raise IsADirectoryError()
|
|
|
|
|
|
class ResourceHandle(Traversable):
|
|
"""
|
|
Handle to a named resource in a ResourceReader.
|
|
"""
|
|
|
|
def __init__(self, parent: ResourceContainer, name: str):
|
|
self.parent = parent
|
|
self.name = name # type: ignore
|
|
|
|
def is_file(self):
|
|
return True
|
|
|
|
def is_dir(self):
|
|
return False
|
|
|
|
def open(self, mode='r', *args, **kwargs):
|
|
stream = self.parent.reader.open_binary(self.name)
|
|
if 'b' not in mode:
|
|
stream = io.TextIOWrapper(stream, *args, **kwargs)
|
|
return stream
|
|
|
|
def joinpath(self, name):
|
|
raise RuntimeError("Cannot traverse into a resource")
|
|
|
|
|
|
class TraversableReader(TraversableResources, SimpleReader):
|
|
"""
|
|
A TraversableResources based on SimpleReader. Resource providers
|
|
may derive from this class to provide the TraversableResources
|
|
interface by supplying the SimpleReader interface.
|
|
"""
|
|
|
|
def files(self):
|
|
return ResourceContainer(self)
|