# -*- coding: utf-8 -*-

class SourceWrapper(object):

""" 数据源包装器，使相关数据源支持逐步读取操作 """

def __init__(self, pcontract, data, max_length):

self.data = data

self.curbar = -1

self.pcontract = pcontract

self._max_length = max_length

def __len__(self):

return self._max_length

def rolling_forward(self):

""" 读取下一个数据"""

self.curbar += 1

if self.curbar == self._max_length:

return False, self.curbar

else:

return True, self.curbar

class DatasourceAbstract(object):

'''数据源抽象基类'''

def get_bars(self, pcontract, dt_start, dt_end):

raise NotImplementedError

def get_last_bars(self, pcontract, n):

raise NotImplementedError

def get_contracts(self):

raise NotImplementedError

def get_code2strpcon(self):

raise NotImplementedError