def __getitem__(self, item):
if item < 0:
return None
if self._levels == 1:
return self._root if item == 0 else None
indices = self._get_level_indices(item)
bpa = self._root
for (l, i) in enumerate(indices[:-1]):
level_cache = self._cache.get(l)
if level_cache is None:
level_cache = {}
self._cache[l] = level_cache
if i in level_cache:
next_bpa = level_cache[i]
else:
b = bpa[i]
bpa_data = None
for dva in range(3):
bpa_data = self._vdev.read_block(b, dva=dva)
if bpa_data:
break
next_bpa = None
if bpa_data is not None:
next_bpa = BlockPtrArray(bpa_data)
else:
print("[-] Block tree is broken at", b)
level_cache[i] = next_bpa
bpa = next_bpa
if bpa is None:
return None
return bpa[indices[-1]]
def _indirect_zap_factory(vdev, bptr, dbsize, nblocks):
data,c = vdev.read_block(bptr)
if data is None:
return None
# Data contains first indirection block
bpa = BlockPtrArray(data)
return _blockptrar_zap_factory(vdev, bpa, dbsize, nblocks)
def __getitem__(self, item):
if item < 0:
return None
if self._levels == 1:
return self._root if item == 0 else None
indices = self._get_level_indices(item)
bpa = self._root
_cache = self._cache
for (l, i) in enumerate(indices[:-1]):
if not i in _cache:
_cache[i] = {'b': None, 'n': {}} # generate a graph
if not _cache[i]['b'] is None:
next_bpa = _cache[i]['b']
else:
b = bpa[i]
bpa_data = None
for dva in range(3):
bpa_data, c = self._vdev.read_block(b, dva=dva)
if bpa_data and c:
break
next_bpa = None
if bpa_data is not None:
next_bpa = BlockPtrArray(bpa_data)
else:
print("[-] Block tree is broken at", b)
_cache[i]['b'] = next_bpa
bpa = next_bpa
self.printidx(indices, l, str(bpa))
if bpa is None:
return None
_cache = _cache[i]['n']
b = bpa[indices[-1]]
print(("[t-%d] " % (item)) + color.GREEN + str(indices) + color.END +
" : " + str(b) + " : " + str(bpa))
return b
def _load_from_bptr(self, bptr):
block_data = None
for dva in range(3):
block_data = self._vdev.read_block(bptr, dva=dva)
if block_data:
break
if block_data is None:
return None
return BlockPtrArray(block_data)
def zap_factory(vdev, dnode):
bptr = dnode.blkptrs[0]
dbsize = dnode.datablksize
if dnode.levels == 1:
nblocks = dnode._nblkptr
bpa = BlockPtrArray(dnode._data[BLKPTR_OFFSET:BLKPTR_OFFSET+nblocks*128])
return _blockptrar_zap_factory(vdev, bpa, dbsize, nblocks)
elif dnode.levels == 2:
return _indirect_zap_factory(vdev, bptr, dbsize, dnode.maxblkid+1)
# TODO: Implement Fat Zap with BlockTree
raise NotImplementedError("Deeper ZAPs not supported yet")
def _indirect_zap_factory(vdev, bptr, dbsize, nblocks):
data = vdev.read_block(bptr)
if data is None:
return None
# Data contains first indirection block
bpa = BlockPtrArray(data)
data = bytearray()
for i in range(nblocks):
data += vdev.read_block(bpa[i])
(block_type, ) = struct.unpack("=Q", data[:8])
if block_type == ZBT_MICRO:
zap = MicroZap()
elif block_type == ZBT_HEADER:
zap = FatZap(dbsize)
else:
print("[-] Data is not a ZAP object: type={}".format(hex(block_type)))
return None
zap.parse(data)
return zap