"""The BDE file system implementation."""
import pybde
from dfvfs.lib import bde_helper
from dfvfs.lib import definitions
from dfvfs.lib import errors
from dfvfs.path import bde_path_spec
from dfvfs.resolver import resolver
from dfvfs.vfs import bde_file_entry
from dfvfs.vfs import root_only_file_system
[docs]
class BDEFileSystem(root_only_file_system.RootOnlyFileSystem):
"""File system that uses pybde."""
TYPE_INDICATOR = definitions.TYPE_INDICATOR_BDE
[docs]
def __init__(self, resolver_context, path_spec):
"""Initializes a file system.
Args:
resolver_context (Context): resolver context.
path_spec (PathSpec): a path specification.
"""
super().__init__(resolver_context, path_spec)
self._bde_volume = None
self._file_object = None
def _Close(self):
"""Closes the file system.
Raises:
OSError: if the close failed.
"""
self._bde_volume.close()
self._bde_volume = None
self._file_object = None
def _Open(self, mode="rb"):
"""Opens the file system defined by path specification.
Args:
mode (Optional[str]): file access mode. The default is 'rb'
read-only binary.
Raises:
AccessError: if the access to open the file was denied.
OSError: if the file system could not be opened.
PathSpecError: if the path specification is incorrect.
ValueError: if the path specification is invalid.
"""
if not self._path_spec.HasParent():
raise errors.PathSpecError("Unsupported path specification without parent.")
resolver.Resolver.key_chain.ExtractCredentialsFromPathSpec(self._path_spec)
bde_volume = pybde.volume()
file_object = resolver.Resolver.OpenFileObject(
self._path_spec.parent, resolver_context=self._resolver_context
)
bde_helper.BDEOpenVolume(
bde_volume, self._path_spec, file_object, resolver.Resolver.key_chain
)
self._bde_volume = bde_volume
self._file_object = file_object
[docs]
def GetBDEVolume(self):
"""Retrieves the BDE volume.
Returns:
pybde.volume: BDE volume.
"""
return self._bde_volume
[docs]
def GetFileEntryByPathSpec(self, path_spec):
"""Retrieves a file entry for a path specification.
Args:
path_spec (PathSpec): path specification.
Returns:
BDEFileEntry: file entry or None.
"""
return bde_file_entry.BDEFileEntry(
self._resolver_context, self, path_spec, is_root=True, is_virtual=True
)
[docs]
def GetRootFileEntry(self):
"""Retrieves the root file entry.
Returns:
BDEFileEntry: file entry or None.
"""
path_spec = bde_path_spec.BDEPathSpec(parent=self._path_spec.parent)
return self.GetFileEntryByPathSpec(path_spec)