mediagoblin/media_types/ascii/processing.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011, 2012 MediaGoblin contributors.  See AUTHORS.
   3 #
   4 # This program is free software: you can redistribute it and/or modify
   5 # it under the terms of the GNU Affero General Public License as published by
   6 # the Free Software Foundation, either version 3 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 Affero General Public License for more details.
  13 #
  14 # You should have received a copy of the GNU Affero General Public License
  15 # along with this program.  If not, see <http://www.gnu.org/licenses/>.
  16 import chardet
  17 import os
  18 import Image
  19 import logging
  20
  21 from mediagoblin import mg_globals as mgg
  22 from mediagoblin.processing import create_pub_filepath, THUMB_SIZE
  23 from mediagoblin.media_types.ascii import asciitoimage
  24
  25 _log = logging.getLogger(__name__)
  26
  27 def process_ascii(entry):
  28     '''
  29     Code to process a txt file
  30     '''
  31     workbench = mgg.workbench_manager.create_workbench()
  32     # Conversions subdirectory to avoid collisions
  33     conversions_subdir = os.path.join(
  34         workbench.dir, 'conversions')
  35     os.mkdir(conversions_subdir)
  36
  37     queued_filepath = entry.queued_media_file
  38     queued_filename = workbench.localized_file(
  39         mgg.queue_store, queued_filepath,
  40         'source')
  41
  42     queued_file = file(queued_filename, 'rb')
  43
  44     with queued_file:
  45         queued_file_charset = chardet.detect(queued_file.read())
  46
  47         # Only select a non-utf-8 charset if chardet is *really* sure
  48         # Tested with "Feli\x0109an superjaron", which was detecte
  49         if queued_file_charset['confidence'] < 0.9:
  50             interpreted_charset = 'utf-8'
  51         else:
  52             interpreted_charset = queued_file_charset['encoding']
  53
  54         _log.info('Charset detected: {0}\nWill interpret as: {1}'.format(
  55                 queued_file_charset,
  56                 interpreted_charset))
  57
  58         queued_file.seek(0)  # Rewind the queued file
  59
  60         thumb_filepath = create_pub_filepath(
  61             entry, 'thumbnail.png')
  62
  63         tmp_thumb_filename = os.path.join(
  64             conversions_subdir, thumb_filepath[-1])
  65
  66         converter = asciitoimage.AsciiToImage()
  67
  68         thumb = converter._create_image(
  69             queued_file.read())
  70
  71         with file(tmp_thumb_filename, 'w') as thumb_file:
  72             thumb.thumbnail(THUMB_SIZE, Image.ANTIALIAS)
  73             thumb.save(thumb_file)
  74
  75         _log.debug('Copying local file to public storage')
  76         mgg.public_store.copy_local_to_storage(
  77             tmp_thumb_filename, thumb_filepath)
  78
  79         queued_file.seek(0)
  80
  81         original_filepath = create_pub_filepath(entry, queued_filepath[-1])
  82
  83         with mgg.public_store.get_file(original_filepath, 'wb') \
  84             as original_file:
  85             original_file.write(queued_file.read())
  86
  87
  88         queued_file.seek(0)  # Rewind *again*
  89
  90         unicode_filepath = create_pub_filepath(entry, 'ascii-portable.txt')
  91
  92         with mgg.public_store.get_file(unicode_filepath, 'wb') \
  93                 as unicode_file:
  94             # Decode the original file from its detected charset (or UTF8)
  95             # Encode the unicode instance to ASCII and replace any non-ASCII
  96             # with an HTML entity (&#
  97             unicode_file.write(
  98                 unicode(queued_file.read().decode(
  99                         interpreted_charset)).encode(
 100                     'ascii',
 101                     'xmlcharrefreplace'))
 102
 103     mgg.queue_store.delete_file(queued_filepath)
 104     entry.queued_media_file = []
 105     media_files_dict = entry.setdefault('media_files', {})
 106     media_files_dict['thumb'] = thumb_filepath
 107     media_files_dict['unicode'] = unicode_filepath
 108     media_files_dict['original'] = original_filepath
 109
 110     entry.save()