tiramisu/tiramisu/storage/sqlite3/value.py

# -*- coding: utf-8 -*-
"default plugin for value: set it in a simple dictionary"
# Copyright (C) 2013 Team tiramisu (see AUTHORS for all contributors)
#
# This program is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
#
# ____________________________________________________________

from tiramisu.storage.sqlite3.storage import Cache
from tiramisu.setting import owners


class Values(Cache):
    __slots__ = tuple()

    def __init__(self, storage):
        """init plugin means create values storage
        """
        values_table = 'CREATE TABLE IF NOT EXISTS value(path text primary '
        values_table += 'key, value text, owner text)'
        # should init cache too
        super(Values, self).__init__('value', storage)
        self.storage.execute(values_table)

    # sqlite
    def _sqlite_select(self, path):
        return self.storage.select("SELECT value FROM value WHERE path = ?",
                                   (path,))

    # value
    def setvalue(self, path, value, owner):
        """set value for an option
        a specified value must be associated to an owner
        """
        self.resetvalue(path)
        self.storage.execute("INSERT INTO value(path, value, owner) VALUES "
                             "(?, ?, ?)", (path, self._sqlite_encode(value),
                                           str(owner)))

    def getvalue(self, path):
        """get value for an option
        return: only value, not the owner
        """
        return self._sqlite_decode(self._sqlite_select(path)[0])

    def hasvalue(self, path):
        """if opt has a value
        return: boolean
        """
        return self._sqlite_select(path) is not None

    def resetvalue(self, path):
        """remove value means delete value in storage
        """
        self.storage.execute("DELETE FROM value WHERE path = ?", (path,))

    def get_modified_values(self, context):
        """return all values in a dictionary
        example: {option1: (owner, 'value1'), option2: (owner, 'value2')}
        """
        ret = {}
        for path, value, owner in self.storage.select("SELECT value",
                                                      only_one=False):
            opt = context.cfgimpl_get_description().impl_get_opt_by_path(path)
            owner = getattr(owners, owner)

            value = self._sqlite_decode(value)
            ret[opt] = (owner, value)
        return ret

    # owner
    def setowner(self, path, owner):
        """change owner for an option
        """
        self.storage.execute("UPDATE value SET owner = ? WHERE path = ?",
                             (str(owner), path))

    def getowner(self, path, default):
        """get owner for an option
        return: owner object
        """
        owner = self.storage.select("SELECT owner FROM value WHERE path = ?",
                                    (path,))
        if owner is None:
            return default
        else:
            return getattr(owners, owner[0])