#!/usr/bin/env python
import threading
import os.path
import sqlalchemy
from sqlalchemy.orm import sessionmaker
from sqlalchemy.orm import mapper
from sqlalchemy.orm import relationship
from dm.common.exceptions.commandFailed import CommandFailed
from dm.common.exceptions.configurationError import ConfigurationError
from dm.common.utility.loggingManager import LoggingManager
from dm.common.utility.configurationManager import ConfigurationManager
from dm.aps_user_db.entities import apsUserDbEntityMap
class ApsUserDbManager:
""" Singleton class for db management. """
DB_CONNECTION_POOL_SIZE = 10
DB_CONNECTION_POOL_MAX_OVERFLOW = 2
DB_CONNECTION_POOL_RECYCYLE_TIME = 600
DB_CONNECTION_POOL_TIMEOUT = 60
DB_CONNECTION_LOGGING_FLAG = False
CONFIG_SECTION_NAME = 'ApsUserDbManager'
DB_KEY = 'db'
DB_USER_KEY = 'dbuser'
DB_HOST_KEY = 'dbhost'
DB_PORT_KEY = 'dbport'
DB_NAME_KEY = 'dbname'
DB_SCHEMA_KEY = 'dbschema'
DB_PASSWORD_FILE_KEY = 'dbpasswordfile'
# Singleton.
__lock = threading.RLock()
__instance = None
@classmethod
def getInstance(cls):
from dm.aps_user_db.impl.apsUserDbManager import ApsUserDbManager
try:
mgr = ApsUserDbManager()
except ApsUserDbManager, ex:
mgr = ex
return mgr
def __configure(self):
cm = ConfigurationManager.getInstance()
self.logger.debug('Configuring APS User DB Manager')
self.db = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_KEY)
self.logger.debug('Using APS DB: %s' % self.db)
self.dbUser = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_USER_KEY)
self.logger.debug('Using APS DB user: %s' % self.dbUser)
self.dbHost = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_HOST_KEY)
self.logger.debug('Using APS DB host: %s' % self.dbHost)
self.dbPort = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_PORT_KEY)
self.logger.debug('Using APS DB port: %s' % self.dbPort)
self.dbName = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_NAME_KEY)
self.logger.debug('Using APS DB name: %s' % self.dbName)
self.dbSchema = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_SCHEMA_KEY)
self.logger.debug('Using APS DB schema: %s' % self.dbSchema)
self.dbPasswordFile = cm.getConfigOption(ApsUserDbManager.CONFIG_SECTION_NAME, ApsUserDbManager.DB_PASSWORD_FILE_KEY)
self.logger.debug('Using APS DB password file: %s' % self.dbPasswordFile)
self.dbPassword = open(self.dbPasswordFile, 'r').readline().strip()
def __init__(self):
ApsUserDbManager.__lock.acquire()
try:
if ApsUserDbManager.__instance is not None:
raise ApsUserDbManager.__instance
ApsUserDbManager.__instance = self
self.lock = threading.RLock()
self.logger = LoggingManager.getInstance().getLogger(self.__class__.__name__)
self.__configure()
engineUrl = '%s://%s:%s@%s:%s/%s' % (self.db, self.dbUser, self.dbPassword, self.dbHost, self.dbPort, self.dbName)
#self.logger.debug('Using engine URL: %s' % engineUrl)
self.engine = sqlalchemy.create_engine(engineUrl,
pool_size=ApsUserDbManager.DB_CONNECTION_POOL_SIZE,
max_overflow=ApsUserDbManager.DB_CONNECTION_POOL_MAX_OVERFLOW,
pool_recycle=ApsUserDbManager.DB_CONNECTION_POOL_RECYCYLE_TIME,
echo=ApsUserDbManager.DB_CONNECTION_LOGGING_FLAG,
pool_timeout=ApsUserDbManager.DB_CONNECTION_POOL_TIMEOUT)
self.metadata = sqlalchemy.MetaData(engineUrl, schema=self.dbSchema)
self.logger.debug('Mapping DB tables')
for (dbTableName, (dbEntityClass, dbRelationDict)) in apsUserDbEntityMap.APS_USER_DB_ENTITY_MAP.items():
self.mapTable(dbEntityClass, dbTableName, dbRelationDict)
self.logger.debug('Initialized SQLalchemy engines')
finally:
ApsUserDbManager.__lock.release()
def getLogger(self):
return self.logger
def inspectTables(self):
from sqlalchemy import inspect
inspector = inspect(self.engine)
self.logger.debug('Inspecting tables')
for tableName in inspector.get_table_names():
self.logger.debug('Table: %s' % tableName)
for column in inspector.get_columns(tableName):
self.logger.debug('Column: %s' % column['name'])
def inspectTables2(self):
from sqlalchemy import MetaData
m = MetaData()
m.reflect(self.engine)
self.logger.debug('Inspecting tables via metadata')
for table in m.tables.values():
self.logger.debug('Table: %s' % table.name)
for column in table.c:
self.logger.debug('Column: %s' % column.name)
def initTable(self, tableClass, tableName):
""" Initialize DB table. """
self.lock.acquire()
try:
tbl = sqlalchemy.Table(tableName, self.metadata, autoload=True)
tableClass.columns = tbl.columns
return tbl
finally:
self.lock.release()
def mapTable(self, tableClass, tableName, relationDict):
""" Map DB table to a given class. """
self.lock.acquire()
try:
table = sqlalchemy.Table(tableName, self.metadata, autoload=True)
tableClass.columns = table.columns
# Build relations from specified foreign key columns and other properties.
tableRelations = {}
primaryKey = None
for (name, propertyDict) in relationDict.items():
if name == 'self':
primaryKey = propertyDict.get('primary_key')
continue
lazy = propertyDict.get('lazy')
parentEntity = propertyDict.get('parentEntity')
foreignKeyColumns = propertyDict.get('foreignKeyColumns', [])
if len(foreignKeyColumns):
fkList = []
for fk in foreignKeyColumns:
fkList.append(table.columns.get(fk))
tableRelations[name] = relationship(parentEntity, foreign_keys=fkList, lazy=lazy)
else:
tableRelations[name] = relationship(parentEntity, lazy=lazy)
if primaryKey:
mapper(tableClass, table, tableRelations, primary_key=table.columns.get(primaryKey))
else:
mapper(tableClass, table, tableRelations)
return table
finally:
self.lock.release()
def getMetadataTable(self, table):
return self.metadata.tables[table]
def openSession(self):
""" Open db session. """
self.lock.acquire()
try:
Session = sessionmaker(bind=self.engine)
return Session()
finally:
self.lock.release()
def closeSession(self, session):
""" Close db session. """
self.lock.acquire()
try:
session.close()
finally:
self.lock.release()
def acquireConnection(self):
""" Get db connection. """
self.lock.acquire()
try:
return self.engine.connect()
finally:
self.lock.release()
def releaseConnection(self, connection):
""" Release db connection. """
self.lock.acquire()
try:
if connection:
connection.close()
finally:
self.lock.release()
#######################################################################
# Testing.
if __name__ == '__main__':
ConfigurationManager.getInstance().setConsoleLogLevel('debug')
mgr = ApsUserDbManager.getInstance()
mgr.acquireConnection()
mgr.inspectTables()
mgr.inspectTables2()
print 'Got connection'