mediagoblin/db/indexes.py

   1 # GNU MediaGoblin -- federated, autonomous media hosting
   2 # Copyright (C) 2011 Free Software Foundation, Inc
   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 """
  18 Indexes for the local database.
  19
  20 To add new indexes
  21 ------------------
  22
  23 Indexes are recorded in the following format:
  24
  25 ACTIVE_INDEXES = {
  26     'collection_name': {
  27         'identifier': {  # key identifier used for possibly deprecating later
  28             'index': [index_foo_goes_here]}}
  29
  30 ... and anything else being parameters to the create_index function
  31 (including unique=True, etc)
  32
  33 Current indexes must be registered in ACTIVE_INDEXES... deprecated
  34 indexes should be marked in DEPRECATED_INDEXES.
  35
  36 Remember, ordering of compound indexes MATTERS.  Read below for more.
  37
  38 REQUIRED READING:
  39  - http://kylebanker.com/blog/2010/09/21/the-joy-of-mongodb-indexes/
  40
  41  - http://www.mongodb.org/display/DOCS/Indexes
  42  - http://www.mongodb.org/display/DOCS/Indexing+Advice+and+FAQ
  43
  44
  45 To remove deprecated indexes
  46 ----------------------------
  47
  48 Removing deprecated indexes is easier, just do:
  49
  50 INACTIVE_INDEXES = {
  51     'collection_name': [
  52         'deprecated_index_identifier1', 'deprecated_index_identifier2']}
  53
  54 ... etc.
  55
  56 If an index has been deprecated that identifier should NEVER BE USED
  57 AGAIN.  Eg, if you previously had 'awesomepants_unique', you shouldn't
  58 use 'awesomepants_unique' again, you should create a totally new name
  59 or at worst use 'awesomepants_unique2'.
  60 """
  61
  62 from pymongo import ASCENDING, DESCENDING
  63
  64
  65 ################
  66 # Active indexes
  67 ################
  68 ACTIVE_INDEXES = {}
  69
  70 # MediaEntry indexes
  71 # ------------------
  72
  73 MEDIAENTRY_INDEXES = {
  74     'uploader_slug_unique': {
  75         # Matching an object to an uploader + slug.
  76         # MediaEntries are unique on these two combined, eg:
  77         #   /u/${myuser}/m/${myslugname}/
  78         'index': [('uploader', ASCENDING),
  79                   ('slug', ASCENDING)],
  80         'unique': True},
  81
  82     'created': {
  83         # A global index for all media entries created, in descending
  84         # order.  This is used for the site's frontpage.
  85         'index': [('created', DESCENDING)]},
  86
  87     'uploader_created': {
  88         # Indexing on uploaders and when media entries are created.
  89         # Used for showing a user gallery, etc.
  90         'index': [('uploader', ASCENDING),
  91                   ('created', DESCENDING)]}}
  92
  93
  94 ACTIVE_INDEXES['media_entries'] = MEDIAENTRY_INDEXES
  95
  96
  97 # User indexes
  98 # ------------
  99
 100 USER_INDEXES = {
 101     'username_unique': {
 102         # Index usernames, and make sure they're unique.
 103         # ... I guess we might need to adjust this once we're federated :)
 104         'index': 'username',
 105         'unique': True},
 106     'created': {
 107         # All most recently created users
 108         'index': 'created'}}
 109
 110
 111 ACTIVE_INDEXES['users'] = USER_INDEXES
 112
 113
 114 ####################
 115 # Deprecated indexes
 116 ####################
 117
 118 DEPRECATED_INDEXES = {}