package trading

import (
	"fmt"
	"testing"
)

func TestSliceCap(t *testing.T) {
	Max := 1280
	var arr []int
	prevCap := cap(arr)
	for i := range 1500 {
		ele := i
		if len(arr) < Max {
			arr = append(arr, ele)
		} else {
			length := len(arr)
			copy(arr, arr[length-Max+1:])
			arr[Max-1] = ele
			arr = arr[:Max]
		}

		c := cap(arr)
		if c != prevCap {
			// 发生扩容
			prevCap = c
			fmt.Printf("i=%d, cap=%d\n", i, c)
		}
	}
	fmt.Println(arr)
}