"""The HFS data stream implementation."""
from dfvfs.lib import definitions
from dfvfs.vfs import data_stream
from dfvfs.vfs import extent
[docs]
class HFSDataStream(data_stream.DataStream):
"""File system data stream that uses pyfshfs."""
[docs]
def __init__(self, file_entry, fshfs_data_stream):
"""Initializes a HFS data stream.
Args:
file_entry (FileEntry): file entry.
fshfs_data_stream (pyfshfs.data_stream): HFS data stream.
"""
super().__init__(file_entry)
self._fshfs_data_stream = fshfs_data_stream
if fshfs_data_stream:
self._name = "rsrc"
self._size = fshfs_data_stream.get_size()
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def GetExtents(self):
"""Retrieves the extents.
Returns:
list[Extent]: the extents of the data stream.
"""
if not self._fshfs_data_stream:
return super().GetExtents()
extents = []
for extent_index in range(self._fshfs_data_stream.number_of_extents):
extent_offset, extent_size, extent_flags = (
self._fshfs_data_stream.get_extent(extent_index)
)
if extent_flags & 0x1:
extent_type = definitions.EXTENT_TYPE_SPARSE
else:
extent_type = definitions.EXTENT_TYPE_DATA
data_stream_extent = extent.Extent(
extent_type=extent_type, offset=extent_offset, size=extent_size
)
extents.append(data_stream_extent)
return extents