"""The Apple Partition Map (APM) directory implementation."""
from dfvfs.path import apm_path_spec
from dfvfs.vfs import directory
[docs]
class APMDirectory(directory.Directory):
"""File system directory that uses pyvsapm."""
_STATUS_FLAG_IS_VALID = 0x00000001
_STATUS_FLAG_IS_ALLOCATED = 0x00000002
def _EntriesGenerator(self):
"""Retrieves directory entries.
Since a directory can contain a vast number of entries using
a generator is more memory efficient.
Yields:
APMPathSpec: a path specification.
"""
entry_index = getattr(self.path_spec, "entry_index", None)
location = getattr(self.path_spec, "location", None)
# Only the virtual root file has directory entries.
if (
entry_index is None
and location is not None
and location == self._file_system.LOCATION_ROOT
):
vsapm_volume = self._file_system.GetAPMVolume()
for partition_index, partition in enumerate(vsapm_volume.partitions):
if (
partition.status_flags & self._STATUS_FLAG_IS_VALID
and partition.status_flags & self._STATUS_FLAG_IS_ALLOCATED
):
apm_entry_index = partition_index + 1
yield apm_path_spec.APMPathSpec(
entry_index=entry_index,
location=f"/p{apm_entry_index:d}",
parent=self.path_spec.parent,
)