"""
MongoDB连接池模块
"""
from pymongo import MongoClient
class MongoPool(object):
"""
MongoDB连接池
复习了默认参数数的用法和自定义异常
子类调用父类构造函数super(子,self).__init__(*args)
isinstance(max_conn, int)的用法
"""
def __init__(self, uri, max_conn=30):
"""
:param max_conn: 最大连接数 默认30 必须是1到200之间的整数
:param uri: 数据库连接uri mongodb://username:password@localhost:27017
"""
if not max_conn or not isinstance(max_conn, int) or max_conn > 200 or max_conn < 1:
raise MongoPoolInitException(errorMsg='客官，max_conn不可以等于{}哦'.format(max_conn))
self.__max_conn = max_conn
self.__conn_list = []
self.__uri = uri
self.__idle = self.__max_conn
self.__busy = 0
self.__prepare_conn()
def __prepare_conn(self):
"""
根据参数max_conn初始化连接池
:return: None
"""
try:
for x in range(0, self.__max_conn):
conn_dict = {'conn': MongoClient(self.__uri), 'busy': False}
self.__conn_list.append(conn_dict)
except Exception as e:
raise MongoPoolException('Bad uri: {}'.format(self.__uri))
def get_conn(self):
"""
从连接池中获取一个MongoDB连接对象
:return: mongodb_connection
"""
if self.__idle < 1:
raise MongoPoolOutOfConnections(errorMsg='不好啦！Mongo的连接数不够用了！')
for index in range(0, len(self.__conn_list)):
conn = self.__conn_list[index]
if conn.get('busy') == False:
conn['busy'] = True
self.__busy += 1
self.__idle -= 1
return conn.get('conn')
def close(self, conn):
"""
将参数中的连接池对象的busy改为False，标识此连接为空闲状态
:param conn: mongoDB数据库连接对象
:return: None
"""
for index in range(0, len(self.__conn_list)):
inner_conn = self.__conn_list[index]
if inner_conn.get('conn') == conn:
inner_conn['busy'] = True
self.__busy -= 1
self.__idle += 1
inner_conn['busy'] = False
break
else:
raise MongoPoolException("你特么的在逗我呢！这个连接不是从我这借的，我不要！")
class MongoPoolInitException(Exception):
"""
初始化异常
"""
def __init__(self, errorMsg):
super(MongoPoolInitException, self).__init__(errorMsg)
class MongoPoolOutOfConnections(Exception):
"""
连接数不够用了
"""
def __init__(self, errorMsg):
super(MongoPoolOutOfConnections, self).__init__(errorMsg)
class MongoPoolException(Exception):
"""
MongoPool其他异常
"""
def __init__(self, errorMsg):
super(MongoPoolException, self).__init__(errorMsg)
