m_librarian/db.py

   1 #! /usr/bin/env python
   2
   3 __all__ = ['Author', 'Book', 'Extension', 'Genre', 'Language',
   4            'AuthorBook', 'BookGenre',
   5            'init_db', 'insert_name', 'update_counters',
   6            ]
   7
   8 import os
   9 from sqlobject import SQLObject, StringCol, UnicodeCol, IntCol, BoolCol, \
  10     ForeignKey, DateCol, DatabaseIndex, RelatedJoin, \
  11     connectionForURI, sqlhub, SQLObjectNotFound, dberrors
  12 from .config import ml_conf
  13
  14 try:
  15     db_uri = ml_conf.get('database', 'URI')
  16 except:
  17     db_uri = None
  18
  19 db_dirs = []
  20 if not db_uri:
  21     if 'XDG_CACHE_HOME' in os.environ:
  22         db_dirs.append(os.environ['XDG_CACHE_HOME'])
  23     home_cache = os.path.expanduser('~/.cache')
  24     if home_cache not in db_dirs:
  25         db_dirs.append(home_cache)
  26
  27     for d in db_dirs:
  28         db_file = os.path.join(d, 'm_librarian.sqlite')
  29         if os.path.exists(db_file):
  30             break
  31     else:
  32         # octal; -rw-------;
  33         # make the database file/directory readable/writeable only by the user
  34         os.umask(0066)
  35         db_dir = db_dirs[0]
  36         try:
  37             os.makedirs(db_dir)
  38         except OSError:  # Perhaps already exists
  39             pass
  40         db_file = os.path.join(db_dir, 'm_librarian.sqlite')
  41
  42     db_uri = 'sqlite://%s' % db_file.replace(os.sep, '/')
  43
  44
  45 sqlhub.processConnection = connection = connectionForURI(db_uri)
  46
  47 if connection.dbName == 'sqlite':
  48     # Speedup SQLite connection
  49     connection.query("PRAGMA synchronous=OFF")
  50     connection.query("PRAGMA count_changes=OFF")
  51     connection.query("PRAGMA journal_mode=MEMORY")
  52     connection.query("PRAGMA temp_store=MEMORY")
  53
  54
  55 class Author(SQLObject):
  56     name = UnicodeCol(unique=True)
  57     count = IntCol()
  58     count_idx = DatabaseIndex('count')
  59     books = RelatedJoin('Book', otherColumn='book_id',
  60                         intermediateTable='author_book',
  61                         createRelatedTable=False)
  62
  63
  64 class AuthorBook(SQLObject):
  65     class sqlmeta:
  66         table = "author_book"
  67     author = ForeignKey('Author', notNull=True, cascade=True)
  68     book = ForeignKey('Book', notNull=True, cascade=True)
  69     main_idx = DatabaseIndex(author, book, unique=True)
  70
  71
  72 class Book(SQLObject):
  73     authors = RelatedJoin('Author',
  74                           intermediateTable='author_book',
  75                           createRelatedTable=False)
  76     genres = RelatedJoin('Genre',
  77                          intermediateTable='book_genre',
  78                          createRelatedTable=False)
  79     title = UnicodeCol()
  80     series = UnicodeCol()
  81     ser_no = IntCol()
  82     archive = StringCol()
  83     file = StringCol()
  84     size = IntCol()
  85     lib_id = StringCol()
  86     deleted = BoolCol()
  87     extension = ForeignKey('Extension')
  88     date = DateCol()
  89     language = ForeignKey('Language')
  90     archive_file_idx = DatabaseIndex('archive', 'file', unique=True)
  91
  92
  93 class BookGenre(SQLObject):
  94     class sqlmeta:
  95         table = "book_genre"
  96     book = ForeignKey('Book', notNull=True, cascade=True)
  97     genre = ForeignKey('Genre', notNull=True, cascade=True)
  98     main_idx = DatabaseIndex(book, genre, unique=True)
  99
 100
 101 class Extension(SQLObject):
 102     name = StringCol(unique=True)
 103     count = IntCol()
 104     count_idx = DatabaseIndex('count')
 105
 106
 107 class Genre(SQLObject):
 108     name = StringCol(unique=True)
 109     title = UnicodeCol()
 110     count = IntCol()
 111     count_idx = DatabaseIndex('count')
 112     books = RelatedJoin('Book', otherColumn='book_id',
 113                         intermediateTable='book_genre',
 114                         createRelatedTable=False)
 115
 116
 117 class Language(SQLObject):
 118     name = StringCol(unique=True)
 119     count = IntCol()
 120     count_idx = DatabaseIndex('count')
 121
 122
 123 def init_db():
 124     try:
 125         Book.select()[0]
 126     except IndexError:  # Table exists but is empty
 127         return
 128     except dberrors.Error:
 129         for table in Author, Extension, Genre, Language, Book, \
 130                 AuthorBook, BookGenre:
 131             table.createTable()
 132     else:
 133         return
 134
 135
 136 def insert_name(table, name, **kw):
 137     try:
 138         return table.byName(name)
 139     except SQLObjectNotFound:
 140         return table(name=name, count=0, **kw)
 141
 142
 143 def update_counters():
 144     for author in Author.select():
 145         author.count = len(author.books)
 146
 147     for ext in Extension.select():
 148         ext.count = Book.select(Book.q.extension == ext.name).count()
 149
 150     for genre in Genre.select():
 151         genre.count = len(genre.books)
 152
 153     for language in Language.select():
 154         language.count = Book.select(Book.q.language == language.name).count()
 155
 156
 157 def test():
 158     print "DB dirs:", db_dirs
 159     if db_uri:
 160         print "DB URI:", db_uri
 161
 162 if __name__ == '__main__':
 163     test()