user_api.py

import util
import json

working_inode_number = 0

def get_inode(file_name):
  inode = None
  working_inode = util.get_inode(working_inode_number)
  inode_number = -1
  for block_number in working_inode.block_list:
    block = util.get_block(block_number)
    inode_number = block.data.get("entries").get(file_name)
  if inode_number != None:
    inode = util.get_inode(inode_number)
  return inode

def get_inode_by_entry(entry):
  working_inode = util.get_inode(working_inode_number)
  inode_number = None
  for block_number in working_inode.block_list:
    block = util.get_block(block_number)
    inode_number = block.data.get("entries").get(entry)
  return inode_number


def get_inodes_from_inode(inode_number):
  inode = util.get_inode(inode_number)
  inodes = []
  for block_number in inode.block_list:
    block = util.get_block(block_number)
    for i in block.data.get("entries").values():
      inodes.append(util.get_inode(i))
  return inodes

def get_entries(inode_number):
  inode = util.get_inode(inode_number)
  entries = []
  for block_number in inode.block_list:
    block = util.get_block(block_number)
    entries += block.data.get("entries").keys()
  return entries

def create_file(args):
  file_name = args[0]
  sb, working_inode = util.get_sb(), util.get_inode(working_inode_number)
  if check_file_oneness(working_inode, file_name):
    print("A file with this name already exists")
    return
  inode = util.get_inode(sb.get_inode_number())
  inode.file_name = file_name
  inode.f_type = util.FileType.regular.value
  inode.block_list.append(sb.get_block_number())
  inode.save()
  working_inode.write((file_name, inode.number))

def read_file(args):
  file_name = args[0]
  inode = get_inode(file_name)
  if inode != None:
    print_data(inode)
  else:
    print("File not found")

def print_data(inode):
  if inode == {}:
    print 'There is no file attached to this name'
    return
  data = ''
  for block in inode.block_list:
    block = util.get_block(block)
    for c in block.data.get("contents"):
      data += c + '\n'
  print data

def write_file(args):
  file_name = args[0]
  data = [arg for arg in args[1:]]
  inode = get_inode(file_name)

  if inode == None:
    raise Exception("The file %s does not exist" %file_name)

  inode.write(data)

def check_file_oneness(inode, file_name):
  for block_number in inode.block_list:
    block = util.get_block(block_number)
    if file_name in block.data.get("entries"):
      return True
  return False
      # raise Exception("The file with name %s already exists" %file_name)

def get_main_obj():
  return [util.get_sb(), util.get_inode(0)]

def isMounted():
  sb, root_dir = get_main_obj()
  return root_dir.file_name == 'root'

def mount(args):
  sb = util.get_sb()
  inode = util.get_inode(sb.get_inode_number())
  blocks = [sb.get_block_number()]
  set_root_inode_props(inode, blocks)
  inode.save()

def set_root_inode_props(inode, blocks):
  inode.owner = 'root'
  inode.group = 'root'
  inode.f_type = util.FileType.dir.value
  inode.permissions = 111111111
  inode.links = 1
  inode.disk_addresses = 1
  inode.block_list = blocks
  inode.file_name = 'root'

def create_dir(args):
  file_name = args[0]
  sb = util.get_sb()
  working_inode = util.get_inode(working_inode_number)
  # TODO update this method to parse inode number by param
  if check_file_oneness(working_inode, file_name):
    print("A file with this name already exists")
    return
  inode = util.get_inode(sb.get_inode_number())
  inode.f_type = util.FileType.dir.value
  inode.block_list.append(sb.get_block_number())
  inode.file_name = file_name
  inode.write(('.', inode.number))
  inode.write(('..', working_inode_number))
  working_inode.write((file_name, inode.number))
  util.save(sb.bytefy(), 0, 'disk')

def ls(args):
  entries = get_entries(working_inode_number)
  print(entries)
  return entries

def cd(args):
  global working_inode_number
  dir_name = args[0]
  inode_number = get_inode_by_entry(dir_name)
  if inode_number != None:
    inode = util.get_inode(inode_number)
    if inode.f_type == util.FileType.dir.value:
      working_inode_number = inode_number
      print("Changed current directory to " + dir_name)
    else:
      print(dir_name + " is not an directory")
  else:
    print("Not found directory with name " + dir_name)

menu_options = {
  'create': create_file,
  'read': read_file,
  'write': write_file,
  'mount': mount,
  'mkdir': create_dir,
  'ls': ls,
  'cd': cd
}

while True:
  user_input = raw_input().split(" ")
  if user_input[0] != 'mount' and not isMounted():
    print "Please, you need to mount the FS first"
    continue
  if user_input[0] == 'exit':
    break
  operation = menu_options[user_input[0]]
  operation(user_input[1:])