DeepBook 池

DeepBook 的核心是一个超高效的每个当前交易对共享对象池结构。该架构最大程度地利用了 Sui 的 Narwhal 和 Bullshark 引擎，以最小化争用并实现高吞吐量。

对于每个基础和报价资产交易对，创建一个全局共享的池，用于 1) 记账订单簿上的未结订单和 2) 处理订单的下单、取消和结算。在这种架构下，涉及不同交易对的交易可以轻松并行化，以最大程度地提高吞吐量。

struct Pool<phantom BaseAsset, phantom QuoteAsset> has key {
    // The key to the following Critbit Tree are order prices.
    id: UID,
    // All open bid orders.
    bids: CritbitTree<TickLevel>,
    // All open ask orders.
    asks: CritbitTree<TickLevel>,
    // Order id of the next bid order, starting from 0.
    next_bid_order_id: u64,
    // Order id of the next ask order, starting from 1<<63.
    next_ask_order_id: u64,
    // Map from order id to price level for fast retrieval of orders upon canceling of orders.
    usr_open_orders: Table<ID, Table<u64, Order>>,
    // taker_fee_rate should be strictly greater than maker_rebate_rate.
    // The difference between taker_fee_rate and maker_rabate_rate goes to the protocol.
    // 10^9 scaling
    taker_fee_rate: u64,
    // 10^9 scaling
    maker_rebate_rate: u64,
    tick_size: u64,
    lot_size: u64,
    // other pool info
    base_custodian: Custodian<BaseAsset>,
    quote_custodian: Custodian<QuoteAsset>,
}