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 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 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 clear_metadata_block(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:
num_array = []
clean_block = bytearray([0] * BLOCK_SIZE)
disktools.write_block(i, clean_block)
num_array.append(i)
self.update_bit_map(self, num_array)
def update_mode(self, path, mode):
for i in range(1, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
block[MODE_START:MODE_FINISH] = disktools.int_to_bytes(mode, 2)
disktools.write_block(i, block)
return 0
def update_name(self, path, new_path):
for i in range(1, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
block[NAME_START:NAME_FINISH] = new_path.encode()
disktools.write_block(i, block)
return 0
def update_file_location(self, path, bitmap):
for i in range(1, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
block[LOCATION_START:LOCATION_FINISH] = disktools.int_to_bytes(
bitmap, 2)
disktools.write_block(i, block)
return 0
def update_owner(self, path, uid, gid):
for i in range(1, NUM_BLOCKS, 1):
block = disktools.read_block(i)
if block[NAME_START:NAME_FINISH].decode().rstrip('\x00') == path:
block[UID_START:UID_FINISH] = disktools.int_to_bytes(uid, 2)
block[GID_START:GID_FINISH] = disktools.int_to_bytes(gid, 2)
disktools.write_block(i, block)
return 0
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 read_full_file(self, at_location: int) -> bytearray:
filetable_snapshot = self.get_filetable()
current_block = at_location
next_block = filetable_snapshot[at_location]
return_array: bytearray = bytearray()
while True:
return_array += read_block(current_block)
current_block = next_block
if current_block == END_OF_FILE:
break
next_block = filetable_snapshot[current_block]
return return_array
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 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)
def set_inode(self, name, mode, ctime, mtime, atime, nlink, uid, gid, size,
block_num):
block = disktools.read_block(block_num)
block[MODE_START:MODE_FINISH] = disktools.int_to_bytes(mode, 2)
block[UID_START:UID_FINISH] = disktools.int_to_bytes(uid, 2)
block[GID_START:GID_FINISH] = disktools.int_to_bytes(gid, 2)
block[NLINK_START:NLINK_FINISH] = disktools.int_to_bytes(nlink, 1)
block[SIZE_START:SIZE_FINISH] = disktools.int_to_bytes(size, 2)
block[CTIME_START:CTIME_FINISH] = disktools.int_to_bytes(int(ctime), 4)
block[MTIME_START:MTIME_FINISH] = disktools.int_to_bytes(int(mtime), 4)
block[ATIME_START:ATIME_FINISH] = disktools.int_to_bytes(int(atime), 4)
block[LOCATION_START:LOCATION_FINISH] = disktools.int_to_bytes(0, 2)
block[NAME_START:NAME_FINISH] = name.encode()
return block
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 get_block_metadata(self, block_index: int) -> Metadata:
file = read_block(block_index)
return Metadata.build_metadata(file[0:END_OF_METADATA])
def read_block(self, at_location: int) -> bytearray:
return read_block(at_location)