m_librarian/db.py

   1 #! /usr/bin/env python
   2
   3 from __future__ import print_function
   4 import os
   5 from sqlobject import SQLObject, StringCol, UnicodeCol, IntCol, BoolCol, \
   6     ForeignKey, DateCol, DatabaseIndex, RelatedJoin, \
   7     connectionForURI, sqlhub, SQLObjectNotFound, dberrors
   8 from .compat import string_type
   9 from .config import get_config
  10
  11 __all__ = ['Author', 'Book', 'Extension', 'Genre', 'Language',
  12            'AuthorBook', 'BookGenre', 'open_db', 'init_db',
  13            'insert_name', 'insert_author', 'update_counters',
  14            ]
  15
  16
  17 class Author(SQLObject):
  18     surname = UnicodeCol(notNull=True)
  19     name = UnicodeCol(notNull=True)
  20     misc_name = UnicodeCol(notNull=True)
  21     count = IntCol(notNull=True)
  22     books = RelatedJoin('Book', otherColumn='book_id',
  23                         intermediateTable='author_book',
  24                         createRelatedTable=False)
  25
  26     @property
  27     def fullname(self):
  28         fullnames = filter(None, (self.surname, self.name, self.misc_name))
  29         return ' '.join(fullnames)
  30
  31     full_name_idx = DatabaseIndex(surname, name, misc_name, unique=True)
  32     count_idx = DatabaseIndex(count)
  33
  34
  35 class AuthorBook(SQLObject):
  36     class sqlmeta:
  37         table = "author_book"
  38     author = ForeignKey('Author', notNull=True, cascade=True)
  39     book = ForeignKey('Book', notNull=True, cascade=True)
  40     author_idx = DatabaseIndex(author)
  41     book_idx = DatabaseIndex(book)
  42     main_idx = DatabaseIndex(author, book, unique=True)
  43
  44
  45 class Book(SQLObject):
  46     authors = RelatedJoin('Author',
  47                           intermediateTable='author_book',
  48                           createRelatedTable=False)
  49     genres = RelatedJoin('Genre',
  50                          intermediateTable='book_genre',
  51                          createRelatedTable=False)
  52     title = UnicodeCol(notNull=True)
  53     series = UnicodeCol(notNull=True)
  54     ser_no = IntCol()
  55     archive = StringCol(notNull=True)
  56     file = StringCol(notNull=True)
  57     size = IntCol(notNull=True)
  58     lib_id = StringCol(notNull=True)
  59     deleted = BoolCol(notNull=True)
  60     extension = ForeignKey('Extension', notNull=True)
  61     date = DateCol(notNull=True)
  62     language = ForeignKey('Language')
  63     title_idx = DatabaseIndex(title)
  64     series_idx = DatabaseIndex(series)
  65     ser_no_idx = DatabaseIndex(ser_no)
  66     archive_idx = DatabaseIndex(archive)
  67     archive_file_idx = DatabaseIndex(archive, file, unique=True)
  68     file_idx = DatabaseIndex(file)
  69     size_idx = DatabaseIndex(size)
  70     deleted_idx = DatabaseIndex(deleted)
  71     extension_idx = DatabaseIndex(extension)
  72     date_idx = DatabaseIndex(date)
  73     language_idx = DatabaseIndex(language)
  74
  75
  76 class BookGenre(SQLObject):
  77     class sqlmeta:
  78         table = "book_genre"
  79     book = ForeignKey('Book', notNull=True, cascade=True)
  80     genre = ForeignKey('Genre', notNull=True, cascade=True)
  81     book_idx = DatabaseIndex(book)
  82     genre_idx = DatabaseIndex(genre)
  83     main_idx = DatabaseIndex(book, genre, unique=True)
  84
  85
  86 class Extension(SQLObject):
  87     name = UnicodeCol(notNull=True, unique=True)
  88     count = IntCol(notNull=True)
  89     count_idx = DatabaseIndex(count)
  90
  91
  92 class Genre(SQLObject):
  93     name = UnicodeCol(notNull=True, unique=True)
  94     title = UnicodeCol(notNull=True)
  95     count = IntCol(notNull=True)
  96     books = RelatedJoin('Book', otherColumn='book_id',
  97                         intermediateTable='book_genre',
  98                         createRelatedTable=False)
  99     title_idx = DatabaseIndex(title)
 100     count_idx = DatabaseIndex(count)
 101
 102
 103 class Language(SQLObject):
 104     name = UnicodeCol(notNull=True, unique=True)
 105     count = IntCol(notNull=True)
 106     count_idx = DatabaseIndex(count)
 107
 108
 109 def _find_sqlite_db_dirs_posix():
 110     db_dirs = []
 111     if 'XDG_CACHE_HOME' in os.environ:
 112         db_dirs.append(os.environ['XDG_CACHE_HOME'])
 113     home_cache = os.path.expanduser('~/.cache')
 114     if home_cache not in db_dirs:
 115         db_dirs.append(home_cache)
 116     return db_dirs
 117
 118
 119 def find_sqlite_db_dirs():
 120     if os.name == 'posix':
 121         return _find_sqlite_db_dirs_posix()
 122     raise OSError("Unknow OS")
 123
 124
 125 def find_sqlite_dburi(db_dirs=None):
 126     if db_dirs is None:
 127         db_dirs = find_sqlite_db_dirs()
 128     for d in db_dirs:
 129         db_file = os.path.join(d, 'm_librarian.sqlite')
 130         if os.path.exists(db_file):
 131             break
 132     else:
 133         # octal; -rw-------;
 134         # make the database file/directory readable/writeable only by the user
 135         os.umask(0o66)
 136         db_dir = db_dirs[0]
 137         try:
 138             os.makedirs(db_dir)
 139         except OSError:  # Perhaps already exists
 140             pass
 141         db_file = os.path.join(db_dir, 'm_librarian.sqlite')
 142
 143     return 'sqlite://%s' % db_file.replace(os.sep, '/')
 144
 145
 146 def open_db(db_uri=None):
 147     if db_uri is None:
 148         try:
 149             db_uri = get_config().get('database', 'URI')
 150         except Exception:
 151             db_uri = find_sqlite_dburi()
 152
 153     if '://' not in db_uri:
 154         db_uri = 'sqlite://' + os.path.abspath(db_uri).replace(os.sep, '/')
 155
 156     sqlhub.processConnection = connection = connectionForURI(db_uri)
 157
 158     if connection.dbName == 'sqlite':
 159         def lower(s):
 160             if isinstance(s, string_type):
 161                 return s.lower()
 162             return s
 163
 164         sqlite = connection.module
 165
 166         class MLConnection(sqlite.Connection):
 167             def __init__(self, *args, **kwargs):
 168                 super(MLConnection, self).__init__(*args, **kwargs)
 169                 self.create_function('lower', 1, lower)
 170
 171         # This hack must be done at the very beginning, before the first query
 172         connection._connOptions['factory'] = MLConnection
 173
 174         # Speedup SQLite connection
 175         connection.query("PRAGMA synchronous=OFF")
 176         connection.query("PRAGMA count_changes=OFF")
 177         connection.query("PRAGMA journal_mode=MEMORY")
 178         connection.query("PRAGMA temp_store=MEMORY")
 179
 180
 181 def init_db():
 182     try:
 183         Book.select()[0]
 184     except IndexError:  # Table exists but is empty
 185         return
 186     except dberrors.Error:
 187         for table in Author, Extension, Genre, Language, Book, \
 188                 AuthorBook, BookGenre:
 189             table.createTable()
 190     else:
 191         return
 192
 193
 194 def insert_name(table, name, **kw):
 195     try:
 196         return table.byName(name)
 197     except SQLObjectNotFound:
 198         return table(name=name, count=0, **kw)
 199
 200
 201 def insert_author(surname, name, misc_name):
 202     try:
 203         return Author.full_name_idx.get(
 204             surname=surname, name=name, misc_name=misc_name)
 205     except SQLObjectNotFound:
 206         return Author(surname=surname, name=name, misc_name=misc_name, count=0)
 207
 208
 209 def update_counters():
 210     for author in Author.select():
 211         author.count = AuthorBook.select(AuthorBook.q.author == author).count()
 212
 213     for ext in Extension.select():
 214         ext.count = Book.select(Book.q.extension == ext.id).count()
 215
 216     for genre in Genre.select():
 217         genre.count = BookGenre.select(BookGenre.q.genre == genre).count()
 218
 219     for language in Language.select():
 220         language.count = Book.select(Book.q.language == language.id).count()
 221
 222
 223 def test():
 224     db_dirs = find_sqlite_db_dirs()
 225     print("DB dirs:", db_dirs)
 226     print("DB URI:", find_sqlite_dburi())
 227
 228
 229 if __name__ == '__main__':
 230     test()