def get_files(self):
files = {}
for i in range(1, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if (block[NAME_START:NAME_FINISH].decode().rstrip('\x00') !=
'') & (disktools.bytes_to_int(block[0:2]) == 0):
files[block[NAME_START:NAME_FINISH].decode().rstrip(
'\x00')] = dict(st_mode=disktools.bytes_to_int(
block[MODE_START:MODE_FINISH]),
st_nlink=disktools.bytes_to_int(
block[NLINK_START:NLINK_FINISH]),
st_size=disktools.bytes_to_int(
block[SIZE_START:SIZE_FINISH]),
st_ctime=disktools.bytes_to_int(
block[CTIME_START:CTIME_FINISH]),
st_mtime=disktools.bytes_to_int(
block[MTIME_START:MTIME_FINISH]),
st_atime=disktools.bytes_to_int(
block[ATIME_START:ATIME_FINISH]),
st_gid=disktools.bytes_to_int(
block[GID_START:GID_FINISH]),
st_uid=disktools.bytes_to_int(
block[UID_START:UID_FINISH]))
return files
def set_with_bytes(self, metadata_bytes: bytearray):
self.name = bytes_to_str(metadata_bytes[0:16])
self.size = bytes_to_int(metadata_bytes[16:18])
self.nlinks = bytes_to_int(metadata_bytes[18:19])
self.mode = bytes_to_int(metadata_bytes[19:21])
self.uid = bytes_to_int(metadata_bytes[21:23])
self.gid = bytes_to_int(metadata_bytes[23:25])
self.ctime = bytes_to_int(metadata_bytes[25:29])
self.mtime = bytes_to_int(metadata_bytes[29:33])
self.atime = bytes_to_int(metadata_bytes[33:37])
self.location = bytes_to_int(metadata_bytes[37:38])
self.type = bytes_to_int(metadata_bytes[38:39])
return self
def build_metadata(metadata_bytes: bytearray) -> Metadata:
return Metadata(
NAME=bytes_to_str(metadata_bytes[0:16]),
SIZE=bytes_to_int(metadata_bytes[16:18]),
NLINKS=bytes_to_int(metadata_bytes[18:19]),
MODE=bytes_to_int(metadata_bytes[19:21]),
UID=bytes_to_int(metadata_bytes[21:23]),
GID=bytes_to_int(metadata_bytes[23:25]),
CTIME=bytes_to_int(metadata_bytes[25:29]),
MTIME=bytes_to_int(metadata_bytes[29:33]),
ATIME=bytes_to_int(metadata_bytes[33:37]),
LOCATION=bytes_to_int(metadata_bytes[37:38]),
TYPE=bytes_to_int(metadata_bytes[38:39]),
)
def clear_data_block(self, path):
for i in range(1, NUM_BLOCKS, 1):
data_block = []
num_array = []
clean_block = bytearray([0] * BLOCK_SIZE)
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
block_number = disktools.bytes_to_int(
block[LOCATION_START:LOCATION_FINISH])
block_number_bin = bin(block_number)
for b in block_number_bin[2:]:
num_array.append(int(b))
num_array = list(reversed(num_array))
for idx, val in enumerate(num_array):
if val == 1:
data_block.append(idx)
for data in data_block:
disktools.write_block(data, clean_block)
self.update_bit_map(self, data_block)
def check_file_data(self, path):
for i in range(1, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
if disktools.bytes_to_int(
block[LOCATION_START:LOCATION_FINISH]) != 0:
return True
else:
return False
def update_bit_map(self, used_block):
block = disktools.read_block(0)
# get the int number of bitmap
bitmap = disktools.bytes_to_int(block[BITMAP_START:BITMAP_FINISH])
for i in used_block:
bitmap = bits.toggleBit(bitmap, i)
block[BITMAP_START:BITMAP_FINISH] = disktools.int_to_bytes(bitmap, 2)
disktools.write_block(0, block)
return bitmap
def update_nlink(self, path, update):
for i in range(0, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
new_nlink = disktools.bytes_to_int(
block[NLINK_START:NLINK_FINISH]) + update
block[NLINK_START:NLINK_FINISH] = disktools.int_to_bytes(
new_nlink, 1)
disktools.write_block(i, block)
return 0
def get_data(self):
total_data = defaultdict(bytes)
for i in range(1, NUM_BLOCKS, 1):
file_data = []
data_block = []
num_array = []
block = disktools.read_block(i)
path = block[NAME_START:NAME_FINISH].decode().rstrip('\x00')
# if the location bytes are not empty & the first two bytes are empty means the block saves metadata of a file.
if (disktools.bytes_to_int(block[LOCATION_START:LOCATION_FINISH])
!= 0) & (disktools.bytes_to_int(block[0:2]) == 0):
# get the bitmap of the location of the file data.
block_number = disktools.bytes_to_int(
block[LOCATION_START:LOCATION_FINISH])
block_number_bin = bin(block_number)
for b in block_number_bin[2:]:
num_array.append(int(b))
num_array = list(reversed(num_array))
for idx, val in enumerate(num_array):
if val == 1:
data_block.append(idx)
#read the data in each block
for data in data_block:
file_content = disktools.read_block(data).decode().rstrip(
'\x00')
file_data.append(file_content)
# combine all the data if needed.
file_data = ''.join(map(str, file_data))
file_data = file_data.encode()
# form the same structure as the data variable in memory
total_data[path] = (file_data)
return total_data
def __init__(self):
block = disktools.read_block(0)
self.files = Format.get_files(Format)
self.data = Format.get_data(Format)
self.fd = 0
self.files['/'] = dict(
st_mode=disktools.bytes_to_int(block[MODE_START:MODE_FINISH]),
st_ctime=disktools.bytes_to_int(block[CTIME_START:CTIME_FINISH]),
st_mtime=disktools.bytes_to_int(block[MTIME_START:MTIME_FINISH]),
st_atime=disktools.bytes_to_int(block[ATIME_START:ATIME_FINISH]),
st_nlink=disktools.bytes_to_int(block[NLINK_START:NLINK_FINISH]))
uid = disktools.bytes_to_int(block[UID_START:UID_FINISH])
gid = disktools.bytes_to_int(block[GID_START:GID_FINISH])
self.chown('/', uid, gid)
def get_free_block(self, num_of_blocks):
block = disktools.read_block(0)
bit_array = []
free_block = []
# get int value of bitmap
bitmap_int = disktools.bytes_to_int(block[BITMAP_START:BITMAP_FINISH])
# transfer the bitmap to binary
bitmap_bin = bin(bitmap_int)
# add each bit into a int array
for b in bitmap_bin[2:]:
bit_array.append(int(b))
# reverse the order of the array
bit_array = reversed(bit_array)
# return the index of each bit which is 1
for idx, val in enumerate(bit_array):
if val == 1:
free_block.append(idx)
return free_block[0:num_of_blocks]
def initial_free_block_bitmap(self):
# initialise the bitmap int value to 0
bitmap = 0
# counter for count the blocks
count = 0
for i in range(NUM_BLOCKS):
# read each block in the disk
block = disktools.read_block(i)
# set the value to 0 for the non-free block in bit map
if disktools.bytes_to_int(block) != 0:
bitmap = bits.clearBit(bitmap, count)
count += 1
else:
bitmap = bits.setBit(bitmap, count)
count += 1
# set the first block to 1 which means it is not free(will store bitmap into block 0).
bitmap = bits.clearBit(bitmap, 0)
# write the bitmap value at the first two bytes at block 0
bitmap_disk = disktools.read_block(0)
bitmap_disk[BITMAP_START:BITMAP_FINISH] = disktools.int_to_bytes(
bitmap, 2)
disktools.write_block(0, bitmap_disk)