fpdb/pyfpdb/fpdb_db.py
2009-12-24 03:09:08 +08:00

219 lines
8.2 KiB
Python

#!/usr/bin/python
# -*- coding: utf-8 -*-
#Copyright 2008 Steffen Jobbagy-Felso
#This program is free software: you can redistribute it and/or modify
#it under the terms of the GNU Affero General Public License as published by
#the Free Software Foundation, version 3 of the License.
#
#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 Affero General Public License
#along with this program. If not, see <http://www.gnu.org/licenses/>.
#In the "official" distribution you can find the license in
#agpl-3.0.txt in the docs folder of the package.
import os
import re
import sys
import logging
import math
from time import time, strftime
from Exceptions import *
try:
import sqlalchemy.pool as pool
use_pool = True
except ImportError:
logging.info("Not using sqlalchemy connection pool.")
use_pool = False
try:
from numpy import var
use_numpy = True
except ImportError:
logging.info("Not using numpy to define variance in sqlite.")
use_numpy = False
import fpdb_simple
import FpdbSQLQueries
import Configuration
# Variance created as sqlite has a bunch of undefined aggregate functions.
class VARIANCE:
def __init__(self):
self.store = []
def step(self, value):
self.store.append(value)
def finalize(self):
return float(var(self.store))
class sqlitemath:
def mod(self, a, b):
return a%b
class fpdb_db:
MYSQL_INNODB = 2
PGSQL = 3
SQLITE = 4
def __init__(self):
"""Simple constructor, doesnt really do anything"""
self.db = None
self.cursor = None
self.sql = {}
#end def __init__
def do_connect(self, config=None):
"""Connects a database using information in config"""
if config is None:
raise FpdbError('Configuration not defined')
self.settings = {}
self.settings['os'] = "linuxmac" if os.name != "nt" else "windows"
db = config.get_db_parameters()
self.connect(backend=db['db-backend'],
host=db['db-host'],
database=db['db-databaseName'],
user=db['db-user'],
password=db['db-password'])
#end def do_connect
def connect(self, backend=None, host=None, database=None,
user=None, password=None):
"""Connects a database with the given parameters"""
if backend is None:
raise FpdbError('Database backend not defined')
self.backend = backend
self.host = host
self.user = user
self.password = password
self.database = database
if backend == fpdb_db.MYSQL_INNODB:
import MySQLdb
if use_pool:
MySQLdb = pool.manage(MySQLdb, pool_size=5)
try:
self.db = MySQLdb.connect(host=host, user=user, passwd=password, db=database, use_unicode=True)
#TODO: Add port option
except MySQLdb.Error, ex:
if ex.args[0] == 1045:
raise FpdbMySQLAccessDenied(ex.args[0], ex.args[1])
elif ex.args[0] == 2002:
raise FpdbMySQLNoDatabase(ex.args[0], ex.args[1])
else:
print "*** WARNING UNKNOWN MYSQL ERROR", ex
elif backend == fpdb_db.PGSQL:
import psycopg2
import psycopg2.extensions
if use_pool:
psycopg2 = pool.manage(psycopg2, pool_size=5)
psycopg2.extensions.register_type(psycopg2.extensions.UNICODE)
# If DB connection is made over TCP, then the variables
# host, user and password are required
# For local domain-socket connections, only DB name is
# needed, and everything else is in fact undefined and/or
# flat out wrong
# sqlcoder: This database only connect failed in my windows setup??
# Modifed it to try the 4 parameter style if the first connect fails - does this work everywhere?
connected = False
if self.host == "localhost" or self.host == "127.0.0.1":
try:
self.db = psycopg2.connect(database = database)
connected = True
except:
pass
#msg = "PostgreSQL direct connection to database (%s) failed, trying with user ..." % (database,)
#print msg
#raise FpdbError(msg)
if not connected:
try:
self.db = psycopg2.connect(host = host,
user = user,
password = password,
database = database)
except:
msg = "PostgreSQL connection to database (%s) user (%s) failed. Are you sure the DB is running?" % (database, user)
print msg
raise FpdbError(msg)
elif backend == fpdb_db.SQLITE:
logging.info("Connecting to SQLite:%(database)s" % {'database':database})
import sqlite3
if use_pool:
sqlite3 = pool.manage(sqlite3, pool_size=1)
else:
logging.warning("SQLite won't work well without 'sqlalchemy' installed.")
if not os.path.isdir(Configuration.DIR_DATABASES) and not database == ":memory:":
print "Creating directory: '%s'" % (Configuration.DIR_DATABASES)
os.mkdir(Configuration.DIR_DATABASES)
database = os.path.join(Configuration.DIR_DATABASES, database)
self.db = sqlite3.connect(database, detect_types=sqlite3.PARSE_DECLTYPES )
sqlite3.register_converter("bool", lambda x: bool(int(x)))
sqlite3.register_adapter(bool, lambda x: "1" if x else "0")
self.db.create_function("floor", 1, math.floor)
tmp = sqlitemath()
self.db.create_function("mod", 2, tmp.mod)
if use_numpy:
self.db.create_aggregate("variance", 1, VARIANCE)
else:
logging.warning("Some database functions will not work without NumPy support")
else:
raise FpdbError("unrecognised database backend:"+backend)
self.cursor = self.db.cursor()
# Set up query dictionary as early in the connection process as we can.
self.sql = FpdbSQLQueries.FpdbSQLQueries(self.get_backend_name())
self.cursor.execute(self.sql.query['set tx level'])
self.wrongDbVersion = False
try:
self.cursor.execute("SELECT * FROM Settings")
settings = self.cursor.fetchone()
if settings[0] != 118:
print "outdated or too new database version - please recreate tables"
self.wrongDbVersion = True
except:# _mysql_exceptions.ProgrammingError:
if database != ":memory:": print "failed to read settings table - please recreate tables"
self.wrongDbVersion = True
#end def connect
def disconnect(self, due_to_error=False):
"""Disconnects the DB"""
if due_to_error:
self.db.rollback()
else:
self.db.commit()
self.cursor.close()
self.db.close()
#end def disconnect
def reconnect(self, due_to_error=False):
"""Reconnects the DB"""
#print "started fpdb_db.reconnect"
self.disconnect(due_to_error)
self.connect(self.backend, self.host, self.database, self.user, self.password)
def get_backend_name(self):
"""Returns the name of the currently used backend"""
if self.backend==2:
return "MySQL InnoDB"
elif self.backend==3:
return "PostgreSQL"
elif self.backend==4:
return "SQLite"
else:
raise FpdbError("invalid backend")
#end def get_backend_name
def get_db_info(self):
return (self.host, self.database, self.user, self.password)
#end def get_db_info
#end class fpdb_db