def unlink(self, path):
if Format.check_file_data(Format, path):
self.data.pop(path)
Format.clear_data_block(Format, path)
self.files.pop(path)
Format.clear_metadata_block(Format, path)
def write(self, path, data, offset, fh):
self.data[path] = (
# make sure the data gets inserted at the right offset
self.data[path][:offset].ljust(offset, '\x00'.encode('ascii')) +
data
# and only overwrites the bytes that data is replacing
+ self.data[path][offset + len(data):])
self.files[path]['st_size'] = len(self.data[path])
# get the length of input data
size = len(self.data[path])
# calculate the number of blocks that need to store the data
no_of_blocks = (size // BLOCK_SIZE) + 1
# get the free blocks
num_array = Format.get_free_block(Format, no_of_blocks)
Format.clear_data_block(Format, path)
# set the data block bitmap
data_block_bitmap = Format.set_data_block_bitmap(Format, num_array)
# get the input data
input_data = self.data[path]
# save the data to disk into the allocated blocks
for i in range(no_of_blocks):
if no_of_blocks == 1:
disktools.write_block(num_array[i], input_data)
else:
disktools.write_block(num_array[i],
input_data[i * 64:i * 64 + 64])
# Add the data block bitmap into the metadata information
Format.update_file_location(Format, path, data_block_bitmap)
# update the st_size in the metadata
Format.update_size(Format, path, self.files[path]['st_size'])
# update the st_mtime in the metadata
Format.update_mtime(Format, path, int(time()))
# update the free block bitmap
Format.update_bit_map(Format, num_array)
return len(data)
def truncate(self, path, length, fh=None):
# make sure extending the file fills in zero bytes
self.data[path] = self.data[path][:length].ljust(
length, '\x00'.encode('ascii'))
self.files[path]['st_size'] = length
Format.clear_data_block(Format, path)
