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mirror of https://github.com/trezor/trezor-firmware.git synced 2024-11-15 20:19:23 +00:00
trezor-firmware/core/src/trezor/sdcard.py
2020-02-27 10:56:23 +01:00

62 lines
1.7 KiB
Python

from trezorio import fatfs, sdcard
if False:
from typing import Any, Callable, Optional, TypeVar
T = TypeVar("T", bound=Callable)
class FilesystemWrapper:
_INSTANCE = None # type: Optional[FilesystemWrapper]
def __init__(self, mounted: bool) -> None:
self.mounted = mounted
self.counter = 0
@classmethod
def get_instance(cls, mounted: bool = True) -> "FilesystemWrapper":
if cls._INSTANCE is None:
cls._INSTANCE = cls(mounted=mounted)
if cls._INSTANCE.mounted is not mounted:
raise RuntimeError # cannot request mounted and non-mounted instance at the same time
return cls._INSTANCE
def _deinit_instance(self) -> None:
fatfs.unmount()
sdcard.power_off()
FilesystemWrapper._INSTANCE = None
def __enter__(self) -> None:
try:
if self.counter <= 0:
self.counter = 0
sdcard.power_on()
if self.mounted:
fatfs.mount()
self.counter += 1
except Exception:
self._deinit_instance()
raise
def __exit__(self, exc_type: Any, exc_val: Any, tb: Any) -> None:
self.counter -= 1
if self.counter <= 0:
self.counter = 0
self._deinit_instance()
def filesystem(mounted: bool = True) -> FilesystemWrapper:
return FilesystemWrapper.get_instance(mounted=mounted)
def with_filesystem(func: T) -> T:
def wrapped_func(*args, **kwargs) -> Any: # type: ignore
with filesystem():
return func(*args, **kwargs)
return wrapped_func # type: ignore
is_present = sdcard.is_present
capacity = sdcard.capacity