Mov database iterator (#415)

[bytom/vapor.git] / application / mov / match / order_table.go

diff --git a/application/mov/match/order_table.go b/application/mov/match/order_table.go
new file mode 100644 (file)
index 0000000..b314ed0
--- /dev/null
+++ b/application/mov/match/order_table.go
@@ -0,0 +1,61 @@
+package match
+
+import (
+       "github.com/vapor/application/mov/common"
+       "github.com/vapor/application/mov/database"
+       "github.com/vapor/errors"
+)
+
+type OrderTable struct {
+       movStore    database.MovStore
+       orderMap    map[string][]*common.Order
+       iteratorMap map[string]*database.OrderIterator
+}
+
+func NewOrderTable(movStore database.MovStore) *OrderTable {
+       return &OrderTable{
+               movStore:    movStore,
+               orderMap:    make(map[string][]*common.Order),
+               iteratorMap: make(map[string]*database.OrderIterator),
+       }
+}
+
+func (o *OrderTable) PeekOrder(tradePair *common.TradePair) *common.Order {
+       orders := o.orderMap[tradePair.Key()]
+       if len(orders) != 0 {
+               return orders[len(orders)-1]
+       }
+
+       iterator, ok := o.iteratorMap[tradePair.Key()]
+       if !ok {
+               iterator = database.NewOrderIterator(o.movStore, tradePair)
+               o.iteratorMap[tradePair.Key()] = iterator
+       }
+
+       nextOrders := iterator.NextBatch()
+       if len(nextOrders) == 0 {
+               return nil
+       }
+
+       for i := len(nextOrders) - 1; i >= 0; i-- {
+               o.orderMap[tradePair.Key()] = append(o.orderMap[tradePair.Key()], nextOrders[i])
+       }
+       return nextOrders[0]
+}
+
+func (o *OrderTable) PopOrder(tradePair *common.TradePair) {
+       if orders := o.orderMap[tradePair.Key()]; len(orders) > 0 {
+               o.orderMap[tradePair.Key()] = orders[0 : len(orders)-1]
+       }
+}
+
+func (o *OrderTable) AddOrder(order *common.Order) error {
+       tradePair := order.GetTradePair()
+       orders := o.orderMap[tradePair.Key()]
+       if len(orders) > 0 && order.Rate > orders[len(orders)-1].Rate {
+               return errors.New("rate of order must less than the min order in order table")
+       }
+
+       o.orderMap[tradePair.Key()] = append(orders, order)
+       return nil
+}