bbgo_origin/pkg/strategy/grid2/grid.go
2022-12-02 00:09:58 +08:00

132 lines
2.9 KiB
Go

package grid2
import (
"math"
"sort"
"github.com/c9s/bbgo/pkg/fixedpoint"
)
type Grid struct {
UpperPrice fixedpoint.Value `json:"upperPrice"`
LowerPrice fixedpoint.Value `json:"lowerPrice"`
// Size is the number of total grids
Size fixedpoint.Value `json:"size"`
// Pins are the pinned grid prices, from low to high
Pins []Pin `json:"pins"`
pinsCache map[Pin]struct{} `json:"-"`
}
type Pin fixedpoint.Value
func calculateArithmeticPins(lower, upper, size, tickSize fixedpoint.Value) []Pin {
var height = upper.Sub(lower)
var spread = height.Div(size)
var pins []Pin
for p := lower; p.Compare(upper) <= 0; p = p.Add(spread) {
// tickSize here = 0.01
pp := math.Trunc(p.Float64()/tickSize.Float64()) * tickSize.Float64()
pins = append(pins, Pin(fixedpoint.NewFromFloat(pp)))
}
return pins
}
func buildPinCache(pins []Pin) map[Pin]struct{} {
cache := make(map[Pin]struct{}, len(pins))
for _, pin := range pins {
cache[pin] = struct{}{}
}
return cache
}
func NewGrid(lower, upper, size, tickSize fixedpoint.Value) *Grid {
var pins = calculateArithmeticPins(lower, upper, size, tickSize)
grid := &Grid{
UpperPrice: upper,
LowerPrice: lower,
Size: size,
Pins: pins,
pinsCache: buildPinCache(pins),
}
return grid
}
func (g *Grid) Height() fixedpoint.Value {
return g.UpperPrice.Sub(g.LowerPrice)
}
// Spread returns the spread of each grid
func (g *Grid) Spread() fixedpoint.Value {
return g.Height().Div(g.Size)
}
func (g *Grid) Above(price fixedpoint.Value) bool {
return price.Compare(g.UpperPrice) > 0
}
func (g *Grid) Below(price fixedpoint.Value) bool {
return price.Compare(g.LowerPrice) < 0
}
func (g *Grid) OutOfRange(price fixedpoint.Value) bool {
return price.Compare(g.LowerPrice) < 0 || price.Compare(g.UpperPrice) > 0
}
func (g *Grid) updatePinsCache() {
g.pinsCache = buildPinCache(g.Pins)
}
func (g *Grid) HasPin(pin Pin) (ok bool) {
_, ok = g.pinsCache[pin]
return ok
}
func (g *Grid) ExtendUpperPrice(upper fixedpoint.Value) (newPins []Pin) {
g.UpperPrice = upper
// since the grid is extended, the size should be updated as well
spread := g.Spread()
g.Size = (g.UpperPrice - g.LowerPrice).Div(spread).Floor()
lastPinPrice := fixedpoint.Value(g.Pins[len(g.Pins)-1])
for p := lastPinPrice.Add(spread); p <= g.UpperPrice; p = p.Add(spread) {
newPins = append(newPins, Pin(p))
}
g.Pins = append(g.Pins, newPins...)
g.updatePinsCache()
return newPins
}
func (g *Grid) ExtendLowerPrice(lower fixedpoint.Value) (newPins []Pin) {
spread := g.Spread()
startPrice := g.LowerPrice.Sub(spread)
for p := startPrice; p.Compare(lower) >= 0; p = p.Sub(spread) {
newPins = append(newPins, Pin(p))
}
g.addPins(newPins)
return newPins
}
func (g *Grid) addPins(pins []Pin) {
g.Pins = append(g.Pins, pins...)
sort.Slice(g.Pins, func(i, j int) bool {
a := fixedpoint.Value(g.Pins[i])
b := fixedpoint.Value(g.Pins[j])
return a.Compare(b) < 0
})
g.updatePinsCache()
}