cn_db.py

#!/usr/bin/python3
# -*- coding: utf-8 -*-
"""
Cosa Nostra database connection
@author: joxean
"""

import os
import web
import random
import configparser

#-----------------------------------------------------------------------
def sqlite_concat(arg1, arg2):
  return str(arg1) + str(arg2)

#-----------------------------------------------------------------------
def sqlite_conv(arg1, from_base, to_base):
  # We assume it's base 10
  return int(arg1, to_base)

#-----------------------------------------------------------------------
def sqlite_instr(arg1, arg2):
  return str(arg1).find(arg2) + 1

#-----------------------------------------------------------------------
def sqlite_rand():
  return random.random()

#-----------------------------------------------------------------------
def get_dbn(cfg_file = "config.cfg"):
  parser = configparser.SafeConfigParser()
  parser.optionxform = str
  cn_db_file = os.getenv("CN_DB")
  if cn_db_file is not None:
    #print "*** USING DATABASE", cn_db_file
    cfg_file = cn_db_file
  
  if os.path.exists(cfg_file):
    parser.read(cfg_file)
  else:
    tmp = os.path.dirname(os.path.realpath(__file__))
    parser.read(os.path.join(tmp, cfg_file))

  section = 'database'
  if 'database' not in parser.sections():
    raise Exception("No database section in " + cfg_file)

  return parser.get(section, 'dbn')

#-----------------------------------------------------------------------
def init_web_db(cfg_file = "config.cfg"):
  parser = configparser.SafeConfigParser()
  parser.optionxform = str
  cn_db_file = os.getenv("CN_DB")
  if cn_db_file is not None:
    #print "*** USING DATABASE", cn_db_file
    cfg_file = cn_db_file

  if os.path.exists(cfg_file):
    parser.read(cfg_file)
  else:
    tmp = os.path.dirname(os.path.realpath(__file__))
    parser.read(os.path.join(tmp, cfg_file))

  section = 'database'
  if 'database' not in parser.sections():
    raise Exception("No database section in " + cfg_file)

  dbn = parser.get(section, 'dbn')

  if dbn == "mysql":
    db = parser.get(section, 'db')
    user = parser.get(section, 'user')
    pw = parser.get(section, 'pw')
    host = parser.get(section, 'host')
    db = web.database(dbn='mysql', db=db, user=user, pw=pw, host=host)
    
    db.query('SET NAMES utf8;')
    db.query('SET CHARACTER SET utf8;')
    db.query('SET character_set_connection=utf8;')
  elif dbn == "sqlite":
    dbname = parser.get(section, 'db')
    db = web.database(dbn='sqlite', db=dbname)
    
    # We need to mimic some MySQL functions in order to be able to use
    # SQLite or use different SQL commands for each database server. I
    # prefer the 1st option, naturally...
    db._db_cursor().connection.create_function("concat", 2, sqlite_concat)
    db._db_cursor().connection.create_function("conv", 3, sqlite_conv)
    db._db_cursor().connection.create_function("instr", 2, sqlite_instr)
    db._db_cursor().connection.create_function("rand", 0, sqlite_rand)

  return db

#-----------------------------------------------------------------------
def webpy_connect_db():
  db = init_web_db()
  return db._db_cursor().connection