ds: data structure store: handle data base.

Transaction:

• status: created(0), finished(1)
• start_order_id: 12345
• end_order_id: 23456
• currency_type:
• low_price:
• up_price:
• profilt:?

Order:

• order_id: 12345
• transaction_type: +1 means 开仓， -1 means 平仓
• transaction_id:
• status: marken, taken
• currency_type:
• deal_type: +1 means buy, -1 means sell
• expected_price: 挂单价格
• deal_price: 成交价格
• deal_amount: 成交额（usdt）计价
• deal_volume: 成交量
• mark_timestamp: 挂单时间
• deal_timestamp: 成交时间

Usage:

Dir: