forked from mirror/client_golang
119 lines
2.5 KiB
Go
119 lines
2.5 KiB
Go
/*
|
|
Copyright (c) 2012, Matt T. Proud
|
|
All rights reserved.
|
|
|
|
Use of this source code is governed by a BSD-style
|
|
license that can be found in the LICENSE file.
|
|
*/
|
|
|
|
package metrics
|
|
|
|
import (
|
|
"bytes"
|
|
"container/heap"
|
|
"fmt"
|
|
"github.com/matttproud/golang_instrumentation/utility"
|
|
"math"
|
|
"sort"
|
|
"sync"
|
|
"time"
|
|
)
|
|
|
|
type AccumulatingBucket struct {
|
|
observations int
|
|
elements utility.PriorityQueue
|
|
maximumSize int
|
|
mutex sync.RWMutex
|
|
evictionPolicy EvictionPolicy
|
|
}
|
|
|
|
/*
|
|
AccumulatingBucketBuilder is a convenience method for generating a
|
|
BucketBuilder that produces AccumatingBucket entries with a certain
|
|
behavior set.
|
|
*/
|
|
func AccumulatingBucketBuilder(evictionPolicy EvictionPolicy, maximumSize int) BucketBuilder {
|
|
return func() Bucket {
|
|
return &AccumulatingBucket{
|
|
maximumSize: maximumSize,
|
|
evictionPolicy: evictionPolicy,
|
|
elements: make(utility.PriorityQueue, 0, maximumSize),
|
|
}
|
|
}
|
|
}
|
|
|
|
/*
|
|
Add a value to the bucket. Depending on whether the bucket is full, it may
|
|
trigger an eviction of older items.
|
|
*/
|
|
func (b *AccumulatingBucket) Add(value float64) {
|
|
b.mutex.Lock()
|
|
defer b.mutex.Unlock()
|
|
|
|
b.observations++
|
|
size := len(b.elements)
|
|
|
|
v := utility.Item{
|
|
Value: value,
|
|
Priority: -1 * time.Now().UnixNano(),
|
|
}
|
|
|
|
if size == b.maximumSize {
|
|
b.evictionPolicy(&b.elements)
|
|
}
|
|
|
|
heap.Push(&b.elements, &v)
|
|
}
|
|
|
|
func (b *AccumulatingBucket) String() string {
|
|
b.mutex.RLock()
|
|
defer b.mutex.RUnlock()
|
|
|
|
buffer := new(bytes.Buffer)
|
|
|
|
fmt.Fprintf(buffer, "[AccumulatingBucket with %d elements and %d capacity] { ", len(b.elements), b.maximumSize)
|
|
|
|
for i := 0; i < len(b.elements); i++ {
|
|
fmt.Fprintf(buffer, "%f, ", b.elements[i].Value)
|
|
}
|
|
|
|
fmt.Fprintf(buffer, "}")
|
|
|
|
return string(buffer.Bytes())
|
|
}
|
|
|
|
func (b *AccumulatingBucket) ValueForIndex(index int) float64 {
|
|
b.mutex.RLock()
|
|
defer b.mutex.RUnlock()
|
|
|
|
elementCount := len(b.elements)
|
|
|
|
if elementCount == 0 {
|
|
return math.NaN()
|
|
}
|
|
|
|
sortedElements := make([]float64, elementCount)
|
|
|
|
for i, element := range b.elements {
|
|
sortedElements[i] = element.Value.(float64)
|
|
}
|
|
|
|
sort.Float64s(sortedElements)
|
|
|
|
/*
|
|
N.B.(mtp): Interfacing components should not need to comprehend what
|
|
eviction and storage container strategies used; therefore,
|
|
we adjust this silently.
|
|
*/
|
|
targetIndex := int(float64(elementCount-1) * (float64(index) / float64(b.observations)))
|
|
|
|
return sortedElements[targetIndex]
|
|
}
|
|
|
|
func (b *AccumulatingBucket) Observations() int {
|
|
b.mutex.RLock()
|
|
defer b.mutex.RUnlock()
|
|
|
|
return b.observations
|
|
}
|