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     surname = UnicodeCol(notNull=True)
  57     name = UnicodeCol(notNull=True)
  58     misc_name = UnicodeCol(notNull=True)
  59     count = IntCol(notNull=True)
  60     books = RelatedJoin('Book', otherColumn='book_id',
  61                         intermediateTable='author_book',
  62                         createRelatedTable=False)
  63     full_name_idx = DatabaseIndex(surname, name, misc_name, unique=True)
  64     count_idx = DatabaseIndex(count)
  65
  66
  67 class AuthorBook(SQLObject):
  68     class sqlmeta:
  69         table = "author_book"
  70     author = ForeignKey('Author', notNull=True, cascade=True)
  71     book = ForeignKey('Book', notNull=True, cascade=True)
  72     author_idx = DatabaseIndex(author)
  73     book_idx = DatabaseIndex(book)
  74     main_idx = DatabaseIndex(author, book, unique=True)
  75
  76
  77 class Book(SQLObject):
  78     authors = RelatedJoin('Author',
  79                           intermediateTable='author_book',
  80                           createRelatedTable=False)
  81     genres = RelatedJoin('Genre',
  82                          intermediateTable='book_genre',
  83                          createRelatedTable=False)
  84     title = UnicodeCol(notNull=True)
  85     series = UnicodeCol(notNull=True)
  86     ser_no = IntCol()
  87     archive = StringCol(notNull=True)
  88     file = StringCol(notNull=True)
  89     size = IntCol(notNull=True)
  90     lib_id = StringCol(notNull=True)
  91     deleted = BoolCol(notNull=True)
  92     extension = ForeignKey('Extension', notNull=True)
  93     date = DateCol(notNull=True)
  94     language = ForeignKey('Language')
  95     title_idx = DatabaseIndex(title)
  96     series_idx = DatabaseIndex(series)
  97     ser_no_idx = DatabaseIndex(ser_no)
  98     archive_file_idx = DatabaseIndex(archive, file, unique=True)
  99     file_idx = DatabaseIndex(file)
 100     size_idx = DatabaseIndex(size)
 101     deleted_idx = DatabaseIndex(deleted)
 102     extension_idx = DatabaseIndex(extension)
 103     date_idx = DatabaseIndex(date)
 104     language_idx = DatabaseIndex(language)
 105
 106
 107 class BookGenre(SQLObject):
 108     class sqlmeta:
 109         table = "book_genre"
 110     book = ForeignKey('Book', notNull=True, cascade=True)
 111     genre = ForeignKey('Genre', notNull=True, cascade=True)
 112     book_idx = DatabaseIndex(book)
 113     genre_idx = DatabaseIndex(genre)
 114     main_idx = DatabaseIndex(book, genre, unique=True)
 115
 116
 117 class Extension(SQLObject):
 118     name = StringCol(notNull=True, unique=True)
 119     count = IntCol(notNull=True)
 120     count_idx = DatabaseIndex(count)
 121
 122
 123 class Genre(SQLObject):
 124     name = StringCol(notNull=True, unique=True)
 125     title = UnicodeCol(notNull=True)
 126     count = IntCol(notNull=True)
 127     books = RelatedJoin('Book', otherColumn='book_id',
 128                         intermediateTable='book_genre',
 129                         createRelatedTable=False)
 130     title_idx = DatabaseIndex(title)
 131     count_idx = DatabaseIndex(count)
 132
 133
 134 class Language(SQLObject):
 135     name = StringCol(notNull=True, unique=True)
 136     count = IntCol(notNull=True)
 137     count_idx = DatabaseIndex(count)
 138
 139
 140 def init_db():
 141     try:
 142         Book.select()[0]
 143     except IndexError:  # Table exists but is empty
 144         return
 145     except dberrors.Error:
 146         for table in Author, Extension, Genre, Language, Book, \
 147                 AuthorBook, BookGenre:
 148             table.createTable()
 149     else:
 150         return
 151
 152
 153 def insert_name(table, name, **kw):
 154     try:
 155         return table.byName(name)
 156     except SQLObjectNotFound:
 157         return table(name=name, count=0, **kw)
 158
 159
 160 def update_counters():
 161     for author in Author.select():
 162         author.count = len(author.books)
 163
 164     for ext in Extension.select():
 165         ext.count = Book.select(Book.q.extension == ext.name).count()
 166
 167     for genre in Genre.select():
 168         genre.count = len(genre.books)
 169
 170     for language in Language.select():
 171         language.count = Book.select(Book.q.language == language.name).count()
 172
 173
 174 def test():
 175     print "DB dirs:", db_dirs
 176     if db_uri:
 177         print "DB URI:", db_uri
 178
 179 if __name__ == '__main__':
 180     test()