import threading
import os,sqlite3
class Dao(object):
    '''
    資料持久化處理類
    '''
    
    def __init__(self,path,name='',*args,**kwargs):
        '''
        初始化工作...
        '''
        self.lock = threading.RLock() #鎖
        self.name = name
        self.path = path #資料庫連線引數
        db_path = self.path[:self.path.rfind(os.sep)]
        if os.path.exists(db_path):
            os.makedirs(db_path)
         
    def get_conn(self):
        '''
        建立連線，為什麼不能設定為例項成員？自己想想，－－
        '''
        conn = sqlite3.connect(self.path)
        return conn
    
    def conn_close(self,conn=None):
        '''
        操作完，關掉連線
        '''
        conn.close()
        
    def save(self,obj,conn=None):
        '''
        儲存資料
        '''
        cu = conn.cursor()
        cu.execute(obj.to_insert_sql())
        
 

def conn_trans(func):
    '''
    資料庫連線相關的攔截器.在func呼叫前連線資料庫,func呼叫結束提高事務並關閉連線.
    '''
    def connection(self,*args,**kwargs):
        self.lock.acquire()
        conn = self.get_conn()
        kwargs['conn'] = conn
        rs = func(self,*args,**kwargs)
        self.conn_close(conn)
        self.lock.release()
        return rs
    return connection
 

@conn_trans()  
    def save(self,obj,conn=None):
        '''
        儲存資料
        '''
        cu = conn.cursor()
        cu.execute(obj.to_insert_sql())