"""The path specification mount point manager.
The mount point manager allows to "mount" one path specification onto another.
This allows dfVFS to expose complex path specifications in a way closer to
the original system interpretation.
E.g. the path specification:
type=OS, location=/home/myuser/myimages/image.qcow2
type=QCOW
type=TSK_PARTITION, location=/p1
type=TSK, inode=128, location=/Users/MyUser/MyFile.txt
could be mounted as:
type=MOUNT, identifier=C
type=TSK, inode=128, location=/Users/MyUser/MyFile.txt
where the "C" mount point would be:
type=OS, location=/home/myuser/myimages/image.qcow2
type=QCOW
type=TSK_PARTITION, location=/p1
"""
[docs]
class MountPointManager:
"""Path specification mount point manager."""
_mount_points = {}
[docs]
@classmethod
def DeregisterMountPoint(cls, mount_point):
"""Deregisters a path specification mount point.
Args:
mount_point (str): mount point identifier.
Raises:
KeyError: if the corresponding mount point is not set.
"""
if mount_point not in cls._mount_points:
raise KeyError(f"Mount point: {mount_point:s} not set.")
del cls._mount_points[mount_point]
[docs]
@classmethod
def GetMountPoint(cls, mount_point):
"""Retrieves the path specification of a mount point.
Args:
mount_point (str): mount point identifier.
Returns:
PathSpec: path specification of the mount point or None if the mount
point does not exists.
"""
return cls._mount_points.get(mount_point)
[docs]
@classmethod
def RegisterMountPoint(cls, mount_point, path_spec):
"""Registers a path specification mount point.
Args:
mount_point (str): mount point identifier.
path_spec (PathSpec): path specification of the mount point.
Raises:
KeyError: if the corresponding mount point is already set.
"""
if mount_point in cls._mount_points:
raise KeyError(f"Mount point: {mount_point:s} already set.")
cls._mount_points[mount_point] = path_spec