cGmail/lib/storagehandler.py

   1 #
   2 #    Copyright (C) 2007 Marco Ferragina <marco.ferragina@gmail.com>
   3 #
   4 #    This program is free software; you can redistribute it and/or modify
   5 #    it under the terms of the GNU General Public License as published by
   6 #    the Free Software Foundation; either version 2 of the License, or
   7 #    (at your option) any later version.
   8 #
   9 #    This program is distributed in the hope that it will be useful,
  10 #    but WITHOUT ANY WARRANTY; without even the implied warranty of
  11 #    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  12 #    GNU General Public License for more details.
  13 #
  14 #    You should have received a copy of the GNU General Public License
  15 #    along with this program; if not, write to the Free Software
  16 #    Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  17
  18 class StorageHandler:
  19         def readline(self):
  20                 """
  21                 Must return a line for each call. It must return a "not line"
  22                 when and only when no lines remains.
  23                 example:
  24                         line = obj.readline()
  25                         if not line:
  26                                 print "not line"
  27                 not line must be printed only at the end of file
  28                 """
  29                 raise NotImplementedError()
  30
  31         def write(self, data):
  32                 """
  33                 write the data into the storage
  34                 """
  35                 raise NotImplementedError()
  36
  37         def get_new_writer(self):
  38                 """
  39                 Return a new writer object. This object must have the write method
  40                 (must be a StorageHandler). Before return the object this method
  41                 must initialize the Storage with empty data
  42                 """
  43                 raise NotImplementedError()
  44
  45         def close(self):
  46                 """
  47                 Finalize the storage. It execute the real writing or
  48                 close the file for a file storage handler
  49                 """
  50                 raise NotImplementedError()