class ConnectionPooled(object):
'''数据库连接池类
创建连接池：
pooled = ConnectionPooled(host='192.0.0.1', database='foo',
pool_options=dict(max_size=5))
获取一个未使用连接池的连接，并执行 SQL：
pooled.execute(sql)
pooled.connection.execute(sql)
使用连接池执行 SQL：
with pooled.pool() as connection:
connection.execute(sql)
'''
# 这个连接，是不进入连接池的
_connection = None
_defaults = dict(max_size=POOL_SIZE,
max_usage=POOL_USAGES,
ttl=POOL_TTL,
idle=POOL_IDLE)
def __init__(self, pool_options=None, **kwargs):
self._configurations = kwargs
pool_options = pool_options or {}
self._pool = ConnectionPool(self._connect, **{
**self._defaults,
**pool_options
})
def _connect(self):
return Connection(**self._configurations)
@property
def connection(self):
if not self._connection:
self._connection = self._connect()
return self._connection
def pool(self):
return self._pool.item()
def __getattr__(self, method):
return getattr(self.connection, method)
from connection_pool import ConnectionPool
class Connection(object):
def __init__(self, **kwargs):
self.args = kwargs
self.state = 'Connected'
def close(self):
self.state = 'Closed'
def connect():
return Connection()
def close(connection):
connection.close()
pool = ConnectionPool(create=connect, close=close,
max_size=10, max_usage=10000, idle=60, ttl=120)
with pool.item() as connection:
assert connection.state == 'Connected'
