mediagoblin/submit/lib.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 import uuid
  19 from werkzeug.utils import secure_filename
  20 from werkzeug.datastructures import FileStorage
  21
  22 from mediagoblin.db.models import MediaEntry
  23 from mediagoblin.processing import mark_entry_failed
  24 from mediagoblin.processing.task import ProcessMedia
  25
  26
  27 _log = logging.getLogger(__name__)
  28
  29
  30 def check_file_field(request, field_name):
  31     """Check if a file field meets minimal criteria"""
  32     retval = (field_name in request.files
  33               and isinstance(request.files[field_name], FileStorage)
  34               and request.files[field_name].stream)
  35     if not retval:
  36         _log.debug("Form did not contain proper file field %s", field_name)
  37     return retval
  38
  39
  40 def new_upload_entry(user):
  41     """
  42     Create a new MediaEntry for uploading
  43     """
  44     entry = MediaEntry()
  45     entry.uploader = user.id
  46     entry.license = user.license_preference
  47     return entry
  48
  49
  50 def prepare_queue_task(app, entry, filename):
  51     """
  52     Prepare a MediaEntry for the processing queue and get a queue file
  53     """
  54     # We generate this ourselves so we know what the task id is for
  55     # retrieval later.
  56
  57     # (If we got it off the task's auto-generation, there'd be
  58     # a risk of a race condition when we'd save after sending
  59     # off the task)
  60     task_id = unicode(uuid.uuid4())
  61     entry.queued_task_id = task_id
  62
  63     # Now store generate the queueing related filename
  64     queue_filepath = app.queue_store.get_unique_filepath(
  65         ['media_entries',
  66          task_id,
  67          secure_filename(filename)])
  68
  69     # queue appropriately
  70     queue_file = app.queue_store.get_file(
  71         queue_filepath, 'wb')
  72
  73     # Add queued filename to the entry
  74     entry.queued_media_file = queue_filepath
  75
  76     return queue_file
  77
  78
  79 def run_process_media(entry, feed_url=None,
  80                       reprocess_action="initial", reprocess_info=None):
  81     """Process the media asynchronously
  82
  83     :param entry: MediaEntry() instance to be processed.
  84     :param feed_url: A string indicating the feed_url that the PuSH servers
  85         should be notified of. This will be sth like: `request.urlgen(
  86             'mediagoblin.user_pages.atom_feed',qualified=True,
  87             user=request.user.username)`
  88     :param reprocess_action: What particular action should be run.
  89     :param reprocess_info: A dict containing all of the necessary reprocessing
  90         info for the given media_type"""
  91     try:
  92         ProcessMedia().apply_async(
  93             [entry.id, feed_url, reprocess_action, reprocess_info], {},
  94             task_id=entry.queued_task_id)
  95     except BaseException as exc:
  96         # The purpose of this section is because when running in "lazy"
  97         # or always-eager-with-exceptions-propagated celery mode that
  98         # the failure handling won't happen on Celery end.  Since we
  99         # expect a lot of users to run things in this way we have to
 100         # capture stuff here.
 101         #
 102         # ... not completely the diaper pattern because the
 103         # exception is re-raised :)
 104         mark_entry_failed(entry.id, exc)
 105         # re-raise the exception
 106         raise