mediagoblin/processing/task.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
  17 import logging
  18
  19 from celery.task import Task
  20
  21 from mediagoblin import mg_globals as mgg
  22 from mediagoblin.db.sql.models import MediaEntry
  23 from mediagoblin.processing import mark_entry_failed, BaseProcessingFail
  24 from mediagoblin.tools.processing import json_processing_callback
  25
  26 _log = logging.getLogger(__name__)
  27 logging.basicConfig()
  28 _log.setLevel(logging.DEBUG)
  29
  30
  31 ################################
  32 # Media processing initial steps
  33 ################################
  34
  35 class ProcessMedia(Task):
  36     """
  37     Pass this entry off for processing.
  38     """
  39     def run(self, media_id):
  40         """
  41         Pass the media entry off to the appropriate processing function
  42         (for now just process_image...)
  43         """
  44         entry = MediaEntry.query.get(media_id)
  45
  46         # Try to process, and handle expected errors.
  47         try:
  48             entry.state = u'processing'
  49             entry.save()
  50
  51             _log.debug('Processing {0}'.format(entry))
  52
  53             # run the processing code
  54             entry.media_manager['processor'](entry)
  55
  56             # We set the state to processed and save the entry here so there's
  57             # no need to save at the end of the processing stage, probably ;)
  58             entry.state = u'processed'
  59             entry.save()
  60
  61             json_processing_callback(entry)
  62         except BaseProcessingFail as exc:
  63             mark_entry_failed(entry.id, exc)
  64             json_processing_callback(entry)
  65             return
  66
  67         except ImportError as exc:
  68             _log.error(
  69                 'Entry {0} failed to process due to an import error: {1}'\
  70                     .format(
  71                     entry.title,
  72                     exc))
  73
  74             mark_entry_failed(entry.id, exc)
  75             json_processing_callback(entry)
  76
  77         except Exception as exc:
  78             _log.error('An unhandled exception was raised while'
  79                     + ' processing {0}'.format(
  80                         entry))
  81
  82             mark_entry_failed(entry.id, exc)
  83             json_processing_callback(entry)
  84             raise
  85
  86     def on_failure(self, exc, task_id, args, kwargs, einfo):
  87         """
  88         If the processing failed we should mark that in the database.
  89
  90         Assuming that the exception raised is a subclass of
  91         BaseProcessingFail, we can use that to get more information
  92         about the failure and store that for conveying information to
  93         users about the failure, etc.
  94         """
  95         entry_id = args[0]
  96         mark_entry_failed(entry_id, exc)
  97
  98         entry = mgg.database.MediaEntry.query.filter_by(id=entry_id).first()
  99         json_processing_callback(entry)