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 import sys
  18
  19 from mediagoblin import mg_globals as mgg
  20 from mediagoblin.db.base import Session
  21 from mediagoblin.db.models import MediaEntry, Tag, MediaTag, Collection
  22 from mediagoblin.gmg_commands.dbupdate import gather_database_data
  23
  24 ##########################
  25 # Random utility functions
  26 ##########################
  27
  28
  29 def atomic_update(table, query_dict, update_values):
  30     table.query.filter_by(**query_dict).update(update_values,
  31         synchronize_session=False)
  32     Session.commit()
  33
  34
  35 def check_media_slug_used(uploader_id, slug, ignore_m_id):
  36     query = MediaEntry.query.filter_by(uploader=uploader_id, slug=slug)
  37     if ignore_m_id is not None:
  38         query = query.filter(MediaEntry.id != ignore_m_id)
  39     does_exist = query.first() is not None
  40     return does_exist
  41
  42
  43 def media_entries_for_tag_slug(dummy_db, tag_slug):
  44     return MediaEntry.query \
  45         .join(MediaEntry.tags_helper) \
  46         .join(MediaTag.tag_helper) \
  47         .filter(
  48             (MediaEntry.state == u'processed')
  49             & (Tag.slug == tag_slug))
  50
  51
  52 def clean_orphan_tags(commit=True):
  53     """Search for unused MediaTags and delete them"""
  54     q1 = Session.query(Tag).outerjoin(MediaTag).filter(MediaTag.id==None)
  55     for t in q1:
  56         Session.delete(t)
  57     # The "let the db do all the work" version:
  58     # q1 = Session.query(Tag.id).outerjoin(MediaTag).filter(MediaTag.id==None)
  59     # q2 = Session.query(Tag).filter(Tag.id.in_(q1))
  60     # q2.delete(synchronize_session = False)
  61     if commit:
  62         Session.commit()
  63
  64
  65 def check_collection_slug_used(creator_id, slug, ignore_c_id):
  66     filt = (Collection.creator == creator_id) \
  67         & (Collection.slug == slug)
  68     if ignore_c_id is not None:
  69         filt = filt & (Collection.id != ignore_c_id)
  70     does_exist = Session.query(Collection.id).filter(filt).first() is not None
  71     return does_exist
  72
  73
  74 def check_db_up_to_date():
  75     """Check if the database is up to date and quit if not"""
  76     dbdatas = gather_database_data(mgg.global_config.get('plugins', {}).keys())
  77
  78     for dbdata in dbdatas:
  79         migration_manager = dbdata.make_migration_manager(Session())
  80         if migration_manager.database_current_migration is None or \
  81                 migration_manager.migrations_to_run():
  82             sys.exit("Your database is not up to date. Please run "
  83                      "'gmg dbupdate' before starting the webserver.")
  84
  85
  86 if __name__ == '__main__':
  87     from mediagoblin.db.open import setup_connection_and_db_from_config
  88
  89     db = setup_connection_and_db_from_config({'sql_engine':'sqlite:///mediagoblin.db'})
  90
  91     clean_orphan_tags()