fpdb/pyfpdb/fpdb_db.py

#!/usr/bin/python

#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 fpdb_simple
import FpdbSQLQueries

class fpdb_db:
    def __init__(self):
        """Simple constructor, doesnt really do anything"""
        self.db             = None
        self.cursor         = None
        self.sql            = {}
        self.MYSQL_INNODB   = 2
        self.PGSQL          = 3
        self.SQLITE         = 4
    #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"

        self.settings.update(config.get_db_parameters())
        self.connect(self.settings['db-backend'],
                     self.settings['db-host'],
                     self.settings['db-databaseName'],
                     self.settings['db-user'], 
                     self.settings['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==self.MYSQL_INNODB:
            import MySQLdb
            self.db=MySQLdb.connect(host = host, user = user, passwd = password, db = database, use_unicode=True)
        elif backend==self.PGSQL:
            import psycopg2
            import psycopg2.extensions 
            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
            if self.host == "localhost" or self.host == "127.0.0.1":
                self.db = psycopg2.connect(database = database)
            else:
                self.db = psycopg2.connect(host = host,
                        user = user, 
                        password = password, 
                        database = database)
        else:
            raise fpdb_simple.FpdbError("unrecognised database backend:"+backend)
        self.cursor=self.db.cursor()
        self.cursor.execute('SET SESSION TRANSACTION ISOLATION LEVEL READ COMMITTED')
        # Set up query dictionary as early in the connection process as we can.
        self.sql = FpdbSQLQueries.FpdbSQLQueries(self.get_backend_name())
        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:
            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 create_tables(self):
        #todo: should detect and fail gracefully if tables already exist.
        self.cursor.execute(self.sql.query['createSettingsTable'])
        self.cursor.execute(self.sql.query['createSitesTable'])
        self.cursor.execute(self.sql.query['createGametypesTable'])
        self.cursor.execute(self.sql.query['createPlayersTable'])
        self.cursor.execute(self.sql.query['createAutoratesTable'])
        self.cursor.execute(self.sql.query['createHandsTable'])
        self.cursor.execute(self.sql.query['createBoardCardsTable'])
        self.cursor.execute(self.sql.query['createTourneyTypesTable'])
        self.cursor.execute(self.sql.query['createTourneysTable'])
        self.cursor.execute(self.sql.query['createTourneysPlayersTable'])
        self.cursor.execute(self.sql.query['createHandsPlayersTable'])
        self.cursor.execute(self.sql.query['createHandsActionsTable'])
        self.cursor.execute(self.sql.query['createHudCacheTable'])
        #self.cursor.execute(self.sql.query['addTourneyIndex'])
        #self.cursor.execute(self.sql.query['addHandsIndex'])
        #self.cursor.execute(self.sql.query['addPlayersIndex'])
        self.fillDefaultData()
        self.db.commit()
#end def disconnect
    
    def drop_tables(self):
        """Drops the fpdb tables from the current db"""

        if(self.get_backend_name() == 'MySQL InnoDB'):
            #Databases with FOREIGN KEY support need this switched of before you can drop tables
            self.drop_referencial_integrity()

            # Query the DB to see what tables exist
            self.cursor.execute(self.sql.query['list_tables'])
            for table in self.cursor:
                self.cursor.execute(self.sql.query['drop_table'] + table[0])
        elif(self.get_backend_name() == 'PostgreSQL'):
            self.db.commit()# I have no idea why this makes the query work--REB 07OCT2008
            self.cursor.execute(self.sql.query['list_tables'])
            tables = self.cursor.fetchall()
            for table in tables:
                self.cursor.execute(self.sql.query['drop_table'] + table[0] + ' cascade') 
        elif(self.get_backend_name() == 'SQLite'):
            #todo: sqlite version here
            print "Empty function here"

            self.db.commit()
    #end def drop_tables

    def drop_referencial_integrity(self):
        """Update all tables to remove foreign keys"""

        self.cursor.execute(self.sql.query['list_tables'])
        result = self.cursor.fetchall()

        for i in range(len(result)):
            self.cursor.execute("SHOW CREATE TABLE " + result[i][0])
            inner = self.cursor.fetchall()

            for j in range(len(inner)):
            # result[i][0] - Table name
            # result[i][1] - CREATE TABLE parameters
            #Searching for CONSTRAINT `tablename_ibfk_1`
                for m in re.finditer('(ibfk_[0-9]+)', inner[j][1]):
                    key = "`" + inner[j][0] + "_" + m.group() + "`"
                    self.cursor.execute("ALTER TABLE " + inner[j][0] + " DROP FOREIGN KEY " + key)
                self.db.commit()
        #end drop_referencial_inegrity
    
    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"
        else:
            raise fpdb_simple.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
    
    def fillDefaultData(self):
        self.cursor.execute("INSERT INTO Settings VALUES (118);")
        self.cursor.execute("INSERT INTO Sites VALUES (DEFAULT, 'Full Tilt Poker', 'USD');")
        self.cursor.execute("INSERT INTO Sites VALUES (DEFAULT, 'PokerStars', 'USD');")
        self.cursor.execute("INSERT INTO Sites VALUES (DEFAULT, 'Everleaf', 'USD');")
        self.cursor.execute("INSERT INTO TourneyTypes VALUES (DEFAULT, 1, 0, 0, 0, False);")
    #end def fillDefaultData
    
    def recreate_tables(self):
        """(Re-)creates the tables of the current DB"""
        
        self.drop_tables()
        self.create_tables()
        fpdb_simple.createAllIndexes(self)
        self.db.commit()
        print "Finished recreating tables"
    #end def recreate_tables
#end class fpdb_db