mediagoblin/db/util.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 from mediagoblin.db.base import Session
  18 from mediagoblin.db.models import MediaEntry, Tag, MediaTag, Collection
  19
  20
  21 ##########################
  22 # Random utility functions
  23 ##########################
  24
  25
  26 def atomic_update(table, query_dict, update_values):
  27     table.query.filter_by(**query_dict).update(update_values,
  28         synchronize_session=False)
  29     Session.commit()
  30
  31
  32 def check_media_slug_used(uploader_id, slug, ignore_m_id):
  33     query = MediaEntry.query.filter_by(uploader=uploader_id, slug=slug)
  34     if ignore_m_id is not None:
  35         query = query.filter(MediaEntry.id != ignore_m_id)
  36     does_exist = query.first() is not None
  37     return does_exist
  38
  39
  40 def media_entries_for_tag_slug(dummy_db, tag_slug):
  41     return MediaEntry.query \
  42         .join(MediaEntry.tags_helper) \
  43         .join(MediaTag.tag_helper) \
  44         .filter(
  45             (MediaEntry.state == u'processed')
  46             & (Tag.slug == tag_slug))
  47
  48
  49 def clean_orphan_tags(commit=True):
  50     """Search for unused MediaTags and delete them"""
  51     q1 = Session.query(Tag).outerjoin(MediaTag).filter(MediaTag.id==None)
  52     for t in q1:
  53         Session.delete(t)
  54     # The "let the db do all the work" version:
  55     # q1 = Session.query(Tag.id).outerjoin(MediaTag).filter(MediaTag.id==None)
  56     # q2 = Session.query(Tag).filter(Tag.id.in_(q1))
  57     # q2.delete(synchronize_session = False)
  58     if commit:
  59         Session.commit()
  60
  61
  62 def check_collection_slug_used(creator_id, slug, ignore_c_id):
  63     filt = (Collection.creator == creator_id) \
  64         & (Collection.slug == slug)
  65     if ignore_c_id is not None:
  66         filt = filt & (Collection.id != ignore_c_id)
  67     does_exist = Session.query(Collection.id).filter(filt).first() is not None
  68     return does_exist
  69
  70
  71 if __name__ == '__main__':
  72     from mediagoblin.db.open import setup_connection_and_db_from_config
  73
  74     db = setup_connection_and_db_from_config({'sql_engine':'sqlite:///mediagoblin.db'})
  75
  76     clean_orphan_tags()