255 lines
6.5 KiB
Go
255 lines
6.5 KiB
Go
package stats
|
|
|
|
import (
|
|
"bytes"
|
|
"fmt"
|
|
"io"
|
|
"strconv"
|
|
"strings"
|
|
"time"
|
|
)
|
|
|
|
// HistogramValue is the value of Histogram objects.
|
|
type HistogramValue struct {
|
|
// Count is the total number of values added to the histogram.
|
|
Count int64
|
|
// Sum is the sum of all the values added to the histogram.
|
|
Sum int64
|
|
// Min is the minimum of all the values added to the histogram.
|
|
Min int64
|
|
// Max is the maximum of all the values added to the histogram.
|
|
Max int64
|
|
// Buckets contains all the buckets of the histogram.
|
|
Buckets []HistogramBucket
|
|
}
|
|
|
|
// HistogramBucket is one histogram bucket.
|
|
type HistogramBucket struct {
|
|
// LowBound is the lower bound of the bucket.
|
|
LowBound int64
|
|
// Count is the number of values in the bucket.
|
|
Count int64
|
|
}
|
|
|
|
// Print writes textual output of the histogram values.
|
|
func (v HistogramValue) Print(w io.Writer) {
|
|
avg := float64(v.Sum) / float64(v.Count)
|
|
fmt.Fprintf(w, "Count: %d Min: %d Max: %d Avg: %.2f\n", v.Count, v.Min, v.Max, avg)
|
|
fmt.Fprintf(w, "%s\n", strings.Repeat("-", 60))
|
|
if v.Count <= 0 {
|
|
return
|
|
}
|
|
|
|
maxBucketDigitLen := len(strconv.FormatInt(v.Buckets[len(v.Buckets)-1].LowBound, 10))
|
|
if maxBucketDigitLen < 3 {
|
|
// For "inf".
|
|
maxBucketDigitLen = 3
|
|
}
|
|
maxCountDigitLen := len(strconv.FormatInt(v.Count, 10))
|
|
percentMulti := 100 / float64(v.Count)
|
|
|
|
accCount := int64(0)
|
|
for i, b := range v.Buckets {
|
|
fmt.Fprintf(w, "[%*d, ", maxBucketDigitLen, b.LowBound)
|
|
if i+1 < len(v.Buckets) {
|
|
fmt.Fprintf(w, "%*d)", maxBucketDigitLen, v.Buckets[i+1].LowBound)
|
|
} else {
|
|
fmt.Fprintf(w, "%*s)", maxBucketDigitLen, "inf")
|
|
}
|
|
|
|
accCount += b.Count
|
|
fmt.Fprintf(w, " %*d %5.1f%% %5.1f%%", maxCountDigitLen, b.Count, float64(b.Count)*percentMulti, float64(accCount)*percentMulti)
|
|
|
|
const barScale = 0.1
|
|
barLength := int(float64(b.Count)*percentMulti*barScale + 0.5)
|
|
fmt.Fprintf(w, " %s\n", strings.Repeat("#", barLength))
|
|
}
|
|
}
|
|
|
|
// String returns the textual output of the histogram values as string.
|
|
func (v HistogramValue) String() string {
|
|
var b bytes.Buffer
|
|
v.Print(&b)
|
|
return b.String()
|
|
}
|
|
|
|
// A Histogram accumulates values in the form of a histogram. The type of the
|
|
// values is int64, which is suitable for keeping track of things like RPC
|
|
// latency in milliseconds. New histogram objects should be obtained via the
|
|
// New() function.
|
|
type Histogram struct {
|
|
opts HistogramOptions
|
|
buckets []bucketInternal
|
|
count *Counter
|
|
sum *Counter
|
|
tracker *Tracker
|
|
}
|
|
|
|
// HistogramOptions contains the parameters that define the histogram's buckets.
|
|
type HistogramOptions struct {
|
|
// NumBuckets is the number of buckets.
|
|
NumBuckets int
|
|
// GrowthFactor is the growth factor of the buckets. A value of 0.1
|
|
// indicates that bucket N+1 will be 10% larger than bucket N.
|
|
GrowthFactor float64
|
|
// SmallestBucketSize is the size of the first bucket. Bucket sizes are
|
|
// rounded down to the nearest integer.
|
|
SmallestBucketSize float64
|
|
// MinValue is the lower bound of the first bucket.
|
|
MinValue int64
|
|
}
|
|
|
|
// bucketInternal is the internal representation of a bucket, which includes a
|
|
// rate counter.
|
|
type bucketInternal struct {
|
|
lowBound int64
|
|
count *Counter
|
|
}
|
|
|
|
// NewHistogram returns a pointer to a new Histogram object that was created
|
|
// with the provided options.
|
|
func NewHistogram(opts HistogramOptions) *Histogram {
|
|
if opts.NumBuckets == 0 {
|
|
opts.NumBuckets = 32
|
|
}
|
|
if opts.SmallestBucketSize == 0.0 {
|
|
opts.SmallestBucketSize = 1.0
|
|
}
|
|
h := Histogram{
|
|
opts: opts,
|
|
buckets: make([]bucketInternal, opts.NumBuckets),
|
|
count: newCounter(),
|
|
sum: newCounter(),
|
|
tracker: newTracker(),
|
|
}
|
|
low := opts.MinValue
|
|
delta := opts.SmallestBucketSize
|
|
for i := 0; i < opts.NumBuckets; i++ {
|
|
h.buckets[i].lowBound = low
|
|
h.buckets[i].count = newCounter()
|
|
low = low + int64(delta)
|
|
delta = delta * (1.0 + opts.GrowthFactor)
|
|
}
|
|
return &h
|
|
}
|
|
|
|
// Opts returns a copy of the options used to create the Histogram.
|
|
func (h *Histogram) Opts() HistogramOptions {
|
|
return h.opts
|
|
}
|
|
|
|
// Add adds a value to the histogram.
|
|
func (h *Histogram) Add(value int64) error {
|
|
bucket, err := h.findBucket(value)
|
|
if err != nil {
|
|
return err
|
|
}
|
|
h.buckets[bucket].count.Incr(1)
|
|
h.count.Incr(1)
|
|
h.sum.Incr(value)
|
|
h.tracker.Push(value)
|
|
return nil
|
|
}
|
|
|
|
// LastUpdate returns the time at which the object was last updated.
|
|
func (h *Histogram) LastUpdate() time.Time {
|
|
return h.count.LastUpdate()
|
|
}
|
|
|
|
// Value returns the accumulated state of the histogram since it was created.
|
|
func (h *Histogram) Value() HistogramValue {
|
|
b := make([]HistogramBucket, len(h.buckets))
|
|
for i, v := range h.buckets {
|
|
b[i] = HistogramBucket{
|
|
LowBound: v.lowBound,
|
|
Count: v.count.Value(),
|
|
}
|
|
}
|
|
|
|
v := HistogramValue{
|
|
Count: h.count.Value(),
|
|
Sum: h.sum.Value(),
|
|
Min: h.tracker.Min(),
|
|
Max: h.tracker.Max(),
|
|
Buckets: b,
|
|
}
|
|
return v
|
|
}
|
|
|
|
// Delta1h returns the change in the last hour.
|
|
func (h *Histogram) Delta1h() HistogramValue {
|
|
b := make([]HistogramBucket, len(h.buckets))
|
|
for i, v := range h.buckets {
|
|
b[i] = HistogramBucket{
|
|
LowBound: v.lowBound,
|
|
Count: v.count.Delta1h(),
|
|
}
|
|
}
|
|
|
|
v := HistogramValue{
|
|
Count: h.count.Delta1h(),
|
|
Sum: h.sum.Delta1h(),
|
|
Min: h.tracker.Min1h(),
|
|
Max: h.tracker.Max1h(),
|
|
Buckets: b,
|
|
}
|
|
return v
|
|
}
|
|
|
|
// Delta10m returns the change in the last 10 minutes.
|
|
func (h *Histogram) Delta10m() HistogramValue {
|
|
b := make([]HistogramBucket, len(h.buckets))
|
|
for i, v := range h.buckets {
|
|
b[i] = HistogramBucket{
|
|
LowBound: v.lowBound,
|
|
Count: v.count.Delta10m(),
|
|
}
|
|
}
|
|
|
|
v := HistogramValue{
|
|
Count: h.count.Delta10m(),
|
|
Sum: h.sum.Delta10m(),
|
|
Min: h.tracker.Min10m(),
|
|
Max: h.tracker.Max10m(),
|
|
Buckets: b,
|
|
}
|
|
return v
|
|
}
|
|
|
|
// Delta1m returns the change in the last 10 minutes.
|
|
func (h *Histogram) Delta1m() HistogramValue {
|
|
b := make([]HistogramBucket, len(h.buckets))
|
|
for i, v := range h.buckets {
|
|
b[i] = HistogramBucket{
|
|
LowBound: v.lowBound,
|
|
Count: v.count.Delta1m(),
|
|
}
|
|
}
|
|
|
|
v := HistogramValue{
|
|
Count: h.count.Delta1m(),
|
|
Sum: h.sum.Delta1m(),
|
|
Min: h.tracker.Min1m(),
|
|
Max: h.tracker.Max1m(),
|
|
Buckets: b,
|
|
}
|
|
return v
|
|
}
|
|
|
|
// findBucket does a binary search to find in which bucket the value goes.
|
|
func (h *Histogram) findBucket(value int64) (int, error) {
|
|
lastBucket := len(h.buckets) - 1
|
|
min, max := 0, lastBucket
|
|
for max >= min {
|
|
b := (min + max) / 2
|
|
if value >= h.buckets[b].lowBound && (b == lastBucket || value < h.buckets[b+1].lowBound) {
|
|
return b, nil
|
|
}
|
|
if value < h.buckets[b].lowBound {
|
|
max = b - 1
|
|
continue
|
|
}
|
|
min = b + 1
|
|
}
|
|
return 0, fmt.Errorf("no bucket for value: %d", value)
|
|
}
|