Esempio n. 1
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def unserialize_blocks(file):
  blocks = []
  while True:
    digest = file.read(Digest.dataDigestSize())
    if digest == "":
      break
    size = Format.read_int(file)
    code = Format.read_int(file)
    blocks.append((digest, size, code))
  return blocks
Esempio n. 2
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  def _load_header(self, header_file):
    logging.debug("****************************** loading header")
    magic = header_file.read(len(MAGIC))
    if MAGIC != magic:
      raise Exception("Manent: magic number not found")
    version = Format.read_int(header_file)
    if version != VERSION:
      raise Exception("Container %d has unsupported version" % self.index)
    index = Format.read_int(header_file)
    if index != self.index:
      raise Exception(
        "Manent: wrong container file index. Expected %s, found %s"
        % (str(self.index), str(index)))
    
    header_table_size = Format.read_int(header_file)
    header_table_digest = header_file.read(Digest.dataDigestSize())
    header_table_str = header_file.read(header_table_size)
    if Digest.dataDigest(header_table_str) != header_table_digest:
      raise Exception("Manent: header of container file corrupted")
    header_dump_len = Format.read_int(header_file)
    header_dump_str = header_file.read(header_dump_len)
    
    header_table_io = StringIO.StringIO(header_table_str)
    header_blocks = unserialize_blocks(header_table_io)

    class BlockTableListener:
      def __init__(self):
        self.body_table_str = None
      def is_requested(self, digest, code):
        return code == CODE_BLOCK_TABLE
      def loaded(self, digest, code, data):
        assert code == CODE_BLOCK_TABLE
        self.body_table_str = data

    listener = BlockTableListener()
    header_dump_str_io = StringIO.StringIO(header_dump_str)
    header_dump_loader = DataDumpLoader(header_dump_str_io, header_blocks,
      password=self.storage.get_encryption_key())
    header_dump_loader.load_blocks(listener)

    body_table_io = StringIO.StringIO(listener.body_table_str)
    blocks = unserialize_blocks(body_table_io)
    return blocks
Esempio n. 3
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  def finish_dump(self):
    if self.compression_active:
      self.body_dumper.stop_compression()
      self.compression_active = False
    if self.encryption_active:
      self.body_dumper.stop_encryption()

    #
    # Serialize the body block table
    #
    body_table_io = StringIO.StringIO()
    body_blocks = self.body_dumper.get_blocks()
    serialize_blocks(body_table_io, body_blocks)
    body_table_str = body_table_io.getvalue()

    #
    # Serialize the header table
    #
    message = "Manent container %d of sequence '%s'" % (
      self.index, base64.urlsafe_b64encode(self.sequence_id))
    self.header_dumper.add_block(Digest.dataDigest(message),
                   CODE_CONTAINER_DESCRIPTOR, message)
    self.header_dumper.add_block(Digest.dataDigest(body_table_str),
                   CODE_BLOCK_TABLE, body_table_str)

    if self.encryption_active:
      self.header_dumper.stop_encryption()
      self.encryption_active = False

    header_blocks = self.header_dumper.get_blocks()
    header_table_io = StringIO.StringIO()
    serialize_blocks(header_table_io, header_blocks)
    header_table_str = header_table_io.getvalue()
    
    #
    # Write the header
    #
    assert self.header_file.tell() == 0
    self.header_file.write(MAGIC)
    Format.write_int(self.header_file, VERSION)
    Format.write_int(self.header_file, self.index)
    Format.write_int(self.header_file, len(header_table_str))
    self.header_file.write(Digest.dataDigest(header_table_str))
    self.header_file.write(header_table_str)
    header_dump_str = self.header_dump_os.getvalue()
    Format.write_int(self.header_file, len(header_dump_str))
    self.header_file.write(header_dump_str)
    logging.debug("Container %d has header of size %d" %
        (self.index, self.header_file.tell()))
Esempio n. 4
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def serialize_blocks(file, blocks):
  for (digest,size,code) in blocks:
    file.write(digest)
    Format.write_int(file,size)
    Format.write_int(file,code)