48 lines
1.1 KiB
Go
48 lines
1.1 KiB
Go
|
package collectors
|
||
|
|
|
||
|
|
// AveragingFloat64 统计结果集平均值
|
||
|
|
type AveragingFloat64 struct {
|
||
|
|
Mapper func(interface{}) float64
|
||
|
|
}
|
||
|
|
|
||
|
|
type aveMidResult struct {
|
||
|
|
Sum float64
|
||
|
|
Count int
|
||
|
|
}
|
||
|
|
|
||
|
|
// Supplier 提供容器
|
||
|
|
func (ave *AveragingFloat64) Supplier() func() interface{} {
|
||
|
|
return func() interface{} {
|
||
|
|
return aveMidResult{Sum: 0, Count: 0}
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Accumulator 处理函数
|
||
|
|
func (ave *AveragingFloat64) Accumulator() func(interface{}, interface{}) interface{} {
|
||
|
|
return func(identity interface{}, element interface{}) interface{} {
|
||
|
|
mid := identity.(aveMidResult)
|
||
|
|
mid.Count++
|
||
|
|
mid.Sum += ave.Mapper(element)
|
||
|
|
return mid
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Combiner 组装结果
|
||
|
|
func (ave *AveragingFloat64) Combiner() func(interface{}, interface{}) interface{} {
|
||
|
|
return func(a interface{}, b interface{}) interface{} {
|
||
|
|
midA := a.(aveMidResult)
|
||
|
|
midB := b.(aveMidResult)
|
||
|
|
midA.Sum += midB.Sum
|
||
|
|
midA.Count += midB.Count
|
||
|
|
return midA
|
||
|
|
}
|
||
|
|
}
|
||
|
|
|
||
|
|
// Finisher 收尾处理
|
||
|
|
func (ave *AveragingFloat64) Finisher() func(interface{}) interface{} {
|
||
|
|
return func(identity interface{}) interface{} {
|
||
|
|
mid := identity.(aveMidResult)
|
||
|
|
return mid.Sum / float64(mid.Count)
|
||
|
|
}
|
||
|
|
}
|