Пример #1
0
def link_tq(api):
    """
    处理py进程到天勤的连接

    根据天勤提供的命令行参数, 决定 TqApi 工作方式

    * 直接调整api的参数

    TqApi运行过程中的一批信息主动发送到天勤显示

    * 进程启动和停止
    * set_chart_data 指令全部发往天勤绘图
    * 所有 log / print 信息传递一份
    * exception 发送一份
    * 所有报单/成交记录抄送一份

    :return: (account, backtest, md_url)
    """
    from tqsdk.api import TqChan, TqAccount
    from tqsdk.sim import TqSim
    # 解析命令行参数
    parser = argparse.ArgumentParser()
    # 天勤连接基本参数
    parser.add_argument('--_action', type=str, required=False)
    parser.add_argument('--_tq_pid', type=int, required=False)
    parser.add_argument('--_tq_url', type=str, required=False)
    # action==run时需要这几个
    parser.add_argument('--_broker_id', type=str, required=False)
    parser.add_argument('--_account_id', type=str, required=False)
    parser.add_argument('--_password', type=str, required=False)
    # action==backtest时需要这几个
    parser.add_argument('--_start_dt', type=str, required=False)
    parser.add_argument('--_end_dt', type=str, required=False)
    # action==mdreplay时需要这几个
    parser.add_argument('--_ins_url', type=str, required=False)
    parser.add_argument('--_md_url', type=str, required=False)
    args, unknown = parser.parse_known_args()

    # 非天勤启动时直接返回
    if args._action is None:
        return None, None
    if args._tq_pid is None:
        raise Exception("_tq_pid 参数缺失")
    if args._tq_url is None:
        raise Exception("_tq_url 参数缺失")
    if args._action == "run" and (not args._broker_id or not args._account_id
                                  or not args._password):
        raise Exception("run 必要参数缺失")
    if args._action == "backtest" and (not args._start_dt or not args._end_dt):
        raise Exception("backtest 必要参数缺失")
    if args._action == "mdreplay" and (not args._ins_url or not args._md_url):
        raise Exception("mdreplay 必要参数缺失")

    # 监控天勤进程存活情况
    TqMonitorThread(args._tq_pid).start()

    # 建立到天勤进程的连接
    tq_send_chan, tq_recv_chan = TqChan(api), TqChan(api)  # 连接到天勤的channel
    api.create_task(api._connect(args._tq_url, tq_send_chan,
                                 tq_recv_chan))  # 启动到天勤客户端的连接

    # 根据运行模式分别执行不同的初始化任务
    if args._action == "run":
        instance = SingleInstance(args._account_id)
        api._account = TqAccount(args._broker_id, args._account_id,
                                 args._password)
        api._backtest = None
        dt_func = lambda: int(datetime.datetime.now().timestamp() * 1e9)
        tq_send_chan.send_nowait({
            "aid": "register_instance",
            "instance_id": instance.instance_id,
            "full_path": get_self_full_name(),
            "instance_pid": os.getpid(),
            "instance_type": "RUN",
            "broker_id": args._broker_id,
            "account_id": args._account_id,
            "password": args._password,
        })
    elif args._action == "backtest":
        instance = SingleInstance("%s-%s" % (args._start_dt, args._end_dt))
        if not isinstance(api._account, TqSim):
            api._account = TqSim()
        from tqsdk.backtest import TqBacktest
        start_date = datetime.datetime.strptime(args._start_dt, '%Y%m%d')
        end_date = datetime.datetime.strptime(args._end_dt, '%Y%m%d')
        api._backtest = TqBacktest(start_dt=start_date, end_dt=end_date)
        dt_func = lambda: api._account._get_current_timestamp()
        tq_send_chan.send_nowait({
            "aid": "register_instance",
            "instance_id": instance.instance_id,
            "full_path": get_self_full_name(),
            "instance_pid": os.getpid(),
            "instance_type": "BACKTEST",
            "start_dt": args._start_dt,
            "end_dt": args._end_dt,
        })
    elif args._action == "mdreplay":
        instance = SingleInstance(args._account_id)
        api._account = TqSim(account_id=args._account_id)
        api._backtest = None
        api._md_url = args._md_url
        api._ins_url = args._ins_url
        dt_func = lambda: api._account._get_current_timestamp()
        tq_send_chan.send_nowait({
            "aid": "register_instance",
            "instance_id": instance.instance_id,
            "full_path": get_self_full_name(),
            "instance_pid": os.getpid(),
            "instance_type": "RUN",
            "account_id": "SIM",
        })
    else:
        raise Exception("_action 参数异常")

    # print输出, exception信息转发到天勤
    logger = logging.getLogger("TQ")
    logger.setLevel(logging.INFO)
    logger.addHandler(LogHandlerChan(tq_send_chan,
                                     dt_func=dt_func))  # log输出到天勤接口
    sys.stdout = PrintWriterToLog(logger)  # print信息转向log输出
    sys.excepthook = partial(exception_handler, api,
                             sys.excepthook)  # exception信息转向log输出

    # 向api注入监控任务, 将账户交易信息主动推送到天勤
    api.create_task(account_watcher(api, dt_func, tq_send_chan))
    return tq_send_chan, tq_recv_chan
Пример #2
0
class TargetPosTask(object):
    """目标持仓 task, 该 task 可以将指定合约调整到目标头寸"""
    def __init__(self,
                 api,
                 symbol,
                 price="ACTIVE",
                 init_pos=None,
                 offset_priority="今昨,开",
                 trade_chan=None):
        """
        创建目标持仓task实例,负责调整归属于该task的持仓(默认为整个账户的该合约净持仓)

        Args:
            api (TqApi): TqApi实例,该task依托于指定api下单/撤单

            symbol (str): 负责调整的合约代码

            price (str): [可选]下单方式, ACTIVE=对价下单, PASSIVE=挂价下单

            init_pos (int): [可选]初始持仓,默认整个账户的该合净持仓

            offset_priority (str): [可选]开平仓顺序,昨=平昨仓,今=平今仓,开=开仓,逗号=等待之前操作完成

                                   对于下单指令区分平今/昨的交易所(如上期所),按照今/昨仓的数量计算是否能平今/昨仓

                                   对于下单指令不区分平今/昨的交易所(如中金所),按照“先平当日新开仓,再平历史仓”的规则计算是否能平今/昨仓
                                       * "今昨,开" 表示先平今仓,再平昨仓,等待平仓完成后开仓,对于没有单向大边的品种避免了开仓保证金不足
                                       * "今昨开" 表示先平今仓,再平昨仓,并开仓,所有指令同时发出,适合有单向大边的品种
                                       * "昨开" 表示先平昨仓,再开仓,禁止平今仓,适合股指这样平今手续费较高的品种

            trade_chan (TqChan): [可选]成交通知channel, 当有成交发生时会将成交手数(多头为正数,空头为负数)发到该channel上
        """
        super(TargetPosTask, self).__init__()
        self.api = api
        self.symbol = symbol
        self.exchange = symbol.split(".")[0]
        self.price = price
        self.pos = self.api.get_position(self.symbol)
        self.current_pos = init_pos
        self.offset_priority = offset_priority
        self.pos_chan = TqChan(self.api, last_only=True)
        self.trade_chan = trade_chan if trade_chan is not None else TqChan(
            self.api)
        self.task = self.api.create_task(self._target_pos_task())

    def set_target_volume(self, volume):
        """
        设置目标持仓手数

        Args:
            volume (int): 目标持仓手数,正数表示多头,负数表示空头,0表示空仓

        Example::

            # 设置 rb1810 持仓为多头5手
            from tqsdk import TqApi, TqSim, TargetPosTask

            api = TqApi(TqSim())
            target_pos = TargetPosTask(api, "SHFE.rb1810")
            while True:
                api.wait_update()
                target_pos.set_target_volume(5)
        """
        self.pos_chan.send_nowait(volume)

    def _init_position(self):
        """初始化当前持仓"""
        if self.current_pos is None:
            self.current_pos = self.pos["volume_long_today"] + self.pos[
                "volume_long_his"] - self.pos["volume_short_today"] - self.pos[
                    "volume_short_his"]

    def _get_order(self, offset, vol, pos):
        """获得可平手数"""
        if vol > 0:  # 买单(增加净持仓)
            order_dir = "BUY"
            ydAvailable = pos["volume_short_his"] - (
                pos["volume_short_frozen"] - pos["volume_short_frozen_today"]
            )  # 昨空可用
            tdAvailable = pos["volume_short_today"] - pos[
                "volume_short_frozen_today"]  # 今空可用
        else:  # 卖单
            order_dir = "SELL"
            ydAvailable = pos["volume_long_his"] - (
                pos["volume_long_frozen"] - pos["volume_long_frozen_today"]
            )  # 昨多可用
            tdAvailable = pos["volume_long_today"] - pos[
                "volume_long_frozen_today"]  # 今多可用
        if offset == "昨":
            order_offset = "CLOSE"
            order_volume = min(
                abs(vol), ydAvailable if self.exchange == "SHFE"
                or self.exchange == "INE" or tdAvailable == 0 else 0)
            if vol > 0:
                pos["volume_short_frozen"] += order_volume
                pos["volume_short_frozen_his"] += order_volume
            else:
                pos["volume_long_frozen"] += order_volume
                pos["volume_long_frozen_his"] += order_volume
        elif offset == "今":
            order_offset = "CLOSETODAY" if self.exchange == "SHFE" or self.exchange == "INE" else "CLOSE"
            order_volume = min(
                abs(vol), tdAvailable if self.exchange == "SHFE"
                or self.exchange == "INE" else tdAvailable + ydAvailable)
            if vol > 0:
                pos["volume_short_frozen"] += order_volume
                pos["volume_short_frozen_today"] += order_volume
                pos["volume_short_frozen_his"] += max(
                    0, pos["volume_short_frozen_today"] -
                    pos["volume_short_today"])
                pos["volume_short_frozen_today"] = min(
                    pos["volume_short_frozen_today"],
                    pos["volume_short_today"])
            else:
                pos["volume_long_frozen"] += order_volume
                pos["volume_long_frozen_today"] += order_volume
                pos["volume_long_frozen_his"] += max(
                    0,
                    pos["volume_long_frozen_today"] - pos["volume_long_today"])
                pos["volume_long_frozen_today"] = min(
                    pos["volume_long_frozen_today"], pos["volume_long_today"])
        elif offset == "开":
            order_offset = "OPEN"
            order_volume = abs(vol)
        else:
            order_offset = ""
            order_volume = 0
        return order_offset, order_dir, order_volume

    async def _target_pos_task(self):
        """负责调整目标持仓的task"""
        self._init_position()
        async for target_pos in self.pos_chan:
            # 确定调仓增减方向
            delta_volume = target_pos - self.current_pos
            all_tasks = []
            pos = self.pos.copy()
            for each_priority in self.offset_priority + ",":  # 按不同模式的优先级顺序报出不同的offset单,股指(“昨开”)平昨优先从不平今就先报平昨,原油平今优先("今昨开")就报平今
                if each_priority == ",":
                    await gather(*[each.task for each in all_tasks])
                    all_tasks = []
                    pos = self.pos.copy()
                    continue
                order_offset, order_dir, order_volume = self._get_order(
                    each_priority, delta_volume, pos)
                if order_volume == 0:  # 如果没有则直接到下一种offset
                    continue
                order_task = InsertOrderUntilAllTradedTask(
                    self.api,
                    self.symbol,
                    order_dir,
                    offset=order_offset,
                    volume=order_volume,
                    price=self.price,
                    trade_chan=self.trade_chan)
                all_tasks.append(order_task)
                delta_volume -= order_volume if order_dir == "BUY" else -order_volume
            self.current_pos = target_pos
Пример #3
0
class TargetPosTask(object):
    """目标持仓 task, 该 task 可以将指定合约调整到目标头寸"""
    def __init__(self,
                 api,
                 symbol,
                 price="ACTIVE",
                 offset_priority="今昨,开",
                 trade_chan=None):
        """
        创建目标持仓task实例,负责调整归属于该task的持仓(默认为整个账户的该合约净持仓)

        Args:
            api (TqApi): TqApi实例,该task依托于指定api下单/撤单

            symbol (str): 负责调整的合约代码

            price (str): [可选]下单方式, ACTIVE=对价下单, PASSIVE=挂价下单

            init_pos (int): [可选]初始持仓,默认整个账户的该合净持仓

            offset_priority (str): [可选]开平仓顺序,昨=平昨仓,今=平今仓,开=开仓,逗号=等待之前操作完成
                                   对于下单指令区分平今/昨的交易所(如上期所),按照今/昨仓的数量计算是否能平今/昨仓
                                   对于下单指令不区分平今/昨的交易所(如中金所),按照“先平当日新开仓,再平历史仓”的规则计算是否能平今/昨仓

                                   * "今昨,开" 表示先平今仓,再平昨仓,等待平仓完成后开仓,对于没有单向大边的品种避免了开仓保证金不足
                                   * "今昨开" 表示先平今仓,再平昨仓,并开仓,所有指令同时发出,适合有单向大边的品种
                                   * "昨开" 表示先平昨仓,再开仓,禁止平今仓,适合股指这样平今手续费较高的品种

            trade_chan (TqChan): [可选]成交通知channel, 当有成交发生时会将成交手数(多头为正数,空头为负数)发到该channel上
        """
        super(TargetPosTask, self).__init__()
        self.api = api
        self.symbol = symbol
        self.exchange = symbol.split(".")[0]
        self.price = price
        self.pos = self.api.get_position(self.symbol)
        self.offset_priority = offset_priority
        self.pos_chan = TqChan(self.api, last_only=True)
        self.trade_chan = trade_chan if trade_chan is not None else TqChan(
            self.api)
        self.task = self.api.create_task(self._target_pos_task())

    def set_target_volume(self, volume):
        """
        设置目标持仓手数

        Args:
            volume (int): 目标持仓手数,正数表示多头,负数表示空头,0表示空仓

        Example::

            # 设置 rb1810 持仓为多头5手
            from tqsdk import TqApi, TqSim, TargetPosTask

            api = TqApi(TqSim())
            target_pos = TargetPosTask(api, "SHFE.rb1810")
            target_pos.set_target_volume(5)
            while True:
                api.wait_update()
        """
        self.pos_chan.send_nowait(volume)

    def _get_order(self, offset, vol):
        """
        根据指定的offset和预期下单手数vol, 返回符合要求的委托单最大报单手数
        :param offset: "昨" / "今" / "开"
        :param vol: int, <0表示SELL, >0表示BUY
        :return: order_offset: "CLOSE"/"CLOSETODAY"/"OPEN"; order_dir: "BUY"/"SELL"; "order_volume": >=0, 报单手数
        """
        if vol > 0:  # 买单(增加净持仓)
            order_dir = "BUY"
            pos_all = self.pos.pos_short
        else:  # 卖单
            order_dir = "SELL"
            pos_all = self.pos.pos_long
        if offset == "昨":
            order_offset = "CLOSE"
            if self.exchange == "SHFE" or self.exchange == "INE":
                if vol > 0:
                    pos_all = self.pos.pos_short_his
                else:
                    pos_all = self.pos.pos_long_his
                frozen_volume = sum([
                    order.volume_left for order in self.pos.orders.values()
                    if not order.is_dead() and order.offset == order_offset
                    and order.direction == order_dir
                ])
            else:
                frozen_volume = sum([
                    order.volume_left for order in self.pos.orders.values()
                    if not order.is_dead() and order.offset != "OPEN"
                    and order.direction == order_dir
                ])
            order_volume = max(0, pos_all - frozen_volume)
        elif offset == "今":
            if self.exchange == "SHFE" or self.exchange == "INE":
                order_offset = "CLOSETODAY"
                if vol > 0:
                    pos_all = self.pos.pos_short_today
                else:
                    pos_all = self.pos.pos_long_today
                frozen_volume = sum([
                    order.volume_left for order in self.pos.orders.values()
                    if not order.is_dead() and order.offset == order_offset
                    and order.direction == order_dir
                ])
            else:
                order_offset = "CLOSE"
                frozen_volume = sum([
                    order.volume_left for order in self.pos.orders.values()
                    if not order.is_dead() and order.offset != "OPEN"
                    and order.direction == order_dir
                ])
            order_volume = max(0, pos_all - frozen_volume)
        elif offset == "开":
            order_offset = "OPEN"
            order_volume = abs(vol)
        else:
            order_offset = ""
            order_volume = 0
        return order_offset, order_dir, order_volume

    async def _target_pos_task(self):
        """负责调整目标持仓的task"""
        async for target_pos in self.pos_chan:
            # 确定调仓增减方向
            delta_volume = target_pos - self.pos.pos
            all_tasks = []
            for each_priority in self.offset_priority + ",":  # 按不同模式的优先级顺序报出不同的offset单,股指(“昨开”)平昨优先从不平今就先报平昨,原油平今优先("今昨开")就报平今
                if each_priority == ",":
                    await gather(*[each.task for each in all_tasks])
                    all_tasks = []
                    continue
                order_offset, order_dir, order_volume = self._get_order(
                    each_priority, delta_volume)
                if order_volume == 0:  # 如果没有则直接到下一种offset
                    continue
                order_task = InsertOrderUntilAllTradedTask(
                    self.api,
                    self.symbol,
                    order_dir,
                    offset=order_offset,
                    volume=order_volume,
                    price=self.price,
                    trade_chan=self.trade_chan)
                all_tasks.append(order_task)
                delta_volume -= order_volume if order_dir == "BUY" else -order_volume
            self.current_pos = target_pos
Пример #4
0
class TargetPosTask(object, metaclass=TargetPosTaskSingleton):
    """目标持仓 task, 该 task 可以将指定合约调整到目标头寸"""
    def __init__(self,
                 api: TqApi,
                 symbol: str,
                 price: str = "ACTIVE",
                 offset_priority: str = "今昨,开",
                 trade_chan: Optional[TqChan] = None) -> None:
        """
        创建目标持仓task实例,负责调整归属于该task的持仓 **(默认为整个账户的该合约净持仓)**.

        **注意:** TargetPosTask 在 set_target_volume 时并不下单或撤单, 它的下单和撤单动作, 是在之后的每次 wait_update 时执行的. 因此, **需保证 set_target_volume 后还会继续调用wait_update()**

        Args:
            api (TqApi): TqApi实例,该task依托于指定api下单/撤单

            symbol (str): 负责调整的合约代码

            price (str): [可选]下单方式, ACTIVE=对价下单, PASSIVE=挂价下单.

                * 在持仓调整过程中,若下单方向为买: 对价为卖一价, 挂价为买一价
                * 在持仓调整过程中,若下单方向为卖: 对价为买一价, 挂价为卖一价

            offset_priority (str): [可选]开平仓顺序,昨=平昨仓,今=平今仓,开=开仓,逗号=等待之前操作完成

                                   对于下单指令区分平今/昨的交易所(如上期所),按照今/昨仓的数量计算是否能平今/昨仓
                                   对于下单指令不区分平今/昨的交易所(如中金所),按照“先平当日新开仓,再平历史仓”的规则计算是否能平今/昨仓

                                   * "今昨,开" 表示先平今仓,再平昨仓,等待平仓完成后开仓,对于没有单向大边的品种避免了开仓保证金不足
                                   * "今昨开" 表示先平今仓,再平昨仓,并开仓,所有指令同时发出,适合有单向大边的品种
                                   * "昨开" 表示先平昨仓,再开仓,禁止平今仓,适合股指这样平今手续费较高的品种

            trade_chan (TqChan): [可选]成交通知channel, 当有成交发生时会将成交手数(多头为正数,空头为负数)发到该channel上
        """
        super(TargetPosTask, self).__init__()
        self._api = api
        if symbol not in api._data.get("quotes", {}):
            raise Exception("代码 %s 不存在, 请检查合约代码是否填写正确" % (symbol))
        self._symbol = symbol
        self._exchange = symbol.split(".")[0]
        if price not in ("ACTIVE", "PASSIVE"):
            raise Exception("下单方式(price) %s 错误, 请检查 price 参数是否填写正确" % (price))
        self._price = price
        if len(
                offset_priority.replace(",", "").replace("今", "", 1).replace(
                    "昨", "", 1).replace("开", "", 1)) > 0:
            raise Exception(
                "开平仓顺序(offset_priority) %s 错误, 请检查 offset_priority 参数是否填写正确" %
                (offset_priority))
        self._offset_priority = offset_priority
        self._pos = self._api.get_position(self._symbol)
        self._pos_chan = TqChan(self._api, last_only=True)
        self._trade_chan = trade_chan if trade_chan is not None else TqChan(
            self._api)
        self._task = self._api.create_task(self._target_pos_task())

    def set_target_volume(self, volume: int) -> None:
        """
        设置目标持仓手数

        Args:
            volume (int): 目标持仓手数,正数表示多头,负数表示空头,0表示空仓

        Example::

            # 设置 rb1810 持仓为多头5手
            from tqsdk import TqApi, TargetPosTask

            api = TqApi()
            target_pos = TargetPosTask(api, "SHFE.rb1810")
            target_pos.set_target_volume(5)
            while True:
                # 需在 set_target_volume 后调用wait_update()以发出指令
                api.wait_update()
        """
        self._pos_chan.send_nowait(int(volume))

    def _get_order(self, offset, vol, pending_frozen):
        """
        根据指定的offset和预期下单手数vol, 返回符合要求的委托单最大报单手数
        :param offset: "昨" / "今" / "开"
        :param vol: int, <0表示SELL, >0表示BUY
        :return: order_offset: "CLOSE"/"CLOSETODAY"/"OPEN"; order_dir: "BUY"/"SELL"; "order_volume": >=0, 报单手数
        """
        if vol > 0:  # 买单(增加净持仓)
            order_dir = "BUY"
            pos_all = self._pos.pos_short
        else:  # 卖单
            order_dir = "SELL"
            pos_all = self._pos.pos_long
        if offset == "昨":
            order_offset = "CLOSE"
            if self._exchange == "SHFE" or self._exchange == "INE":
                if vol > 0:
                    pos_all = self._pos.pos_short_his
                else:
                    pos_all = self._pos.pos_long_his
                frozen_volume = sum([
                    order.volume_left for order in self._pos.orders.values()
                    if not order.is_dead and order.offset == order_offset
                    and order.direction == order_dir
                ])
            else:
                frozen_volume = pending_frozen + sum([
                    order.volume_left
                    for order in self._pos.orders.values() if not order.is_dead
                    and order.offset != "OPEN" and order.direction == order_dir
                ])
                # 判断是否有未冻结的今仓手数: 若有则不平昨仓
                if (self._pos.pos_short_today if vol > 0 else
                        self._pos.pos_long_today) - frozen_volume > 0:
                    pos_all = frozen_volume
            order_volume = min(abs(vol), max(0, pos_all - frozen_volume))
        elif offset == "今":
            if self._exchange == "SHFE" or self._exchange == "INE":
                order_offset = "CLOSETODAY"
                if vol > 0:
                    pos_all = self._pos.pos_short_today
                else:
                    pos_all = self._pos.pos_long_today
                frozen_volume = sum([
                    order.volume_left for order in self._pos.orders.values()
                    if not order.is_dead and order.offset == order_offset
                    and order.direction == order_dir
                ])
            else:
                order_offset = "CLOSE"
                frozen_volume = pending_frozen + sum([
                    order.volume_left
                    for order in self._pos.orders.values() if not order.is_dead
                    and order.offset != "OPEN" and order.direction == order_dir
                ])
                pos_all = self._pos.pos_short_today if vol > 0 else self._pos.pos_long_today
            order_volume = min(abs(vol), max(0, pos_all - frozen_volume))
        elif offset == "开":
            order_offset = "OPEN"
            order_volume = abs(vol)
        else:
            order_offset = ""
            order_volume = 0
        return order_offset, order_dir, order_volume

    async def _target_pos_task(self):
        """负责调整目标持仓的task"""
        async for target_pos in self._pos_chan:
            # 确定调仓增减方向
            delta_volume = target_pos - self._pos.pos
            pending_forzen = 0
            all_tasks = []
            for each_priority in self._offset_priority + ",":  # 按不同模式的优先级顺序报出不同的offset单,股指(“昨开”)平昨优先从不平今就先报平昨,原油平今优先("今昨开")就报平今
                if each_priority == ",":
                    await gather(*[each._task for each in all_tasks])
                    pending_forzen = 0
                    all_tasks = []
                    continue
                order_offset, order_dir, order_volume = self._get_order(
                    each_priority, delta_volume, pending_forzen)
                if order_volume == 0:  # 如果没有则直接到下一种offset
                    continue
                elif order_offset != "OPEN":
                    pending_forzen += order_volume
                order_task = InsertOrderUntilAllTradedTask(
                    self._api,
                    self._symbol,
                    order_dir,
                    offset=order_offset,
                    volume=order_volume,
                    price=self._price,
                    trade_chan=self._trade_chan)
                all_tasks.append(order_task)
                delta_volume -= order_volume if order_dir == "BUY" else -order_volume