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.models import MediaEntry, Tag, MediaTag, Collection
  21 from mediagoblin.gmg_commands.dbupdate import gather_database_data
  22
  23 from mediagoblin.tools.transition import DISABLE_GLOBALS
  24
  25 if not DISABLE_GLOBALS:
  26     from mediagoblin.db.base import Session
  27
  28 ##########################
  29 # Random utility functions
  30 ##########################
  31
  32
  33 def atomic_update(table, query_dict, update_values):
  34     table.query.filter_by(**query_dict).update(update_values,
  35         synchronize_session=False)
  36     Session.commit()
  37
  38
  39 def check_media_slug_used(uploader_id, slug, ignore_m_id):
  40     query = MediaEntry.query.filter_by(uploader=uploader_id, slug=slug)
  41     if ignore_m_id is not None:
  42         query = query.filter(MediaEntry.id != ignore_m_id)
  43     does_exist = query.first() is not None
  44     return does_exist
  45
  46
  47 def media_entries_for_tag_slug(dummy_db, tag_slug):
  48     return MediaEntry.query \
  49         .join(MediaEntry.tags_helper) \
  50         .join(MediaTag.tag_helper) \
  51         .filter(
  52             (MediaEntry.state == u'processed')
  53             & (Tag.slug == tag_slug))
  54
  55
  56 def clean_orphan_tags(commit=True):
  57     """Search for unused MediaTags and delete them"""
  58     q1 = Session.query(Tag).outerjoin(MediaTag).filter(MediaTag.id==None)
  59     for t in q1:
  60         Session.delete(t)
  61     # The "let the db do all the work" version:
  62     # q1 = Session.query(Tag.id).outerjoin(MediaTag).filter(MediaTag.id==None)
  63     # q2 = Session.query(Tag).filter(Tag.id.in_(q1))
  64     # q2.delete(synchronize_session = False)
  65     if commit:
  66         Session.commit()
  67
  68
  69 def check_collection_slug_used(creator_id, slug, ignore_c_id):
  70     filt = (Collection.creator == creator_id) \
  71         & (Collection.slug == slug)
  72     if ignore_c_id is not None:
  73         filt = filt & (Collection.id != ignore_c_id)
  74     does_exist = Session.query(Collection.id).filter(filt).first() is not None
  75     return does_exist
  76
  77
  78 def check_db_up_to_date():
  79     """Check if the database is up to date and quit if not"""
  80     dbdatas = gather_database_data(mgg.global_config.get('plugins', {}).keys())
  81
  82     for dbdata in dbdatas:
  83         session = Session()
  84         try:
  85             migration_manager = dbdata.make_migration_manager(session)
  86             if migration_manager.database_current_migration is None or \
  87                     migration_manager.migrations_to_run():
  88                 sys.exit("Your database is not up to date. Please run "
  89                          "'gmg dbupdate' before starting MediaGoblin.")
  90         finally:
  91             Session.rollback()
  92             Session.remove()
  93
  94
  95 if __name__ == '__main__':
  96     from mediagoblin.db.open import setup_connection_and_db_from_config
  97
  98     db = setup_connection_and_db_from_config({'sql_engine':'sqlite:///mediagoblin.db'})
  99
 100     clean_orphan_tags()