Started down a different path; using a circular buffer instead.

After talks on #go-nuts, it seems as though I should look into using something
like the following:

https://github.com/cespare/goproc/tree/master/nwstat

And this makes sense. I have trimmed out the old tests and rearranged some code
here.
This commit is contained in:
Stephen McQuay 2014-03-08 00:45:55 -08:00
parent c33a5561bb
commit bb8ce3c1ea
2 changed files with 40 additions and 178 deletions

View File

@ -3,9 +3,9 @@
package bandwidth
import (
"container/list"
"errors"
"fmt"
"log"
"sort"
"time"
)
@ -24,20 +24,29 @@ type Bandwidth struct {
Quit chan interface{}
rxSnap []float64
txSnap []float64
dt time.Duration
rxstream *stream
txstream *stream
rxSnap []float64
txSnap []float64
dt time.Duration
curRx int
curTx int
rxstream []int
txstream []int
timeI int
max int
}
// NewBandwidth Returns a populated and ready to launch Bandwidth. seconds is
// a slice of seconds on which to report (e.g. 1, 10, 60 seconds). dt is how
// often the values used to send to Rx and Tx are updated.
func NewBandwidth(seconds []int, dt time.Duration) (*Bandwidth, error) {
if len(seconds) < 1 {
func NewBandwidth(dts []int, dt time.Duration) (*Bandwidth, error) {
if len(dts) < 1 {
return nil, errors.New("must specify at least one interval lenght")
}
sort.Ints(dts)
max := dts[len(dts)-1]
r := &Bandwidth{
AddRx: make(chan int, 1024),
AddTx: make(chan int, 1024),
@ -45,8 +54,9 @@ func NewBandwidth(seconds []int, dt time.Duration) (*Bandwidth, error) {
Tx: make(chan []float64),
dt: dt,
Quit: make(chan interface{}),
rxstream: newStream(seconds),
txstream: newStream(seconds),
rxstream: make([]int, max),
txstream: make([]int, max),
max: max,
}
return r, nil
}
@ -59,14 +69,17 @@ outer:
for {
select {
case <-t.C:
bw.rxSnap = bw.rxstream.averages()
bw.txSnap = bw.txstream.averages()
bw.rxSnap = bw.averages(bw.rxstream)
bw.txSnap = bw.averages(bw.txstream)
bw.curTx = 0
bw.curRx = 0
bw.timeI += 1
case bw.Rx <- bw.rxSnap:
case bw.Tx <- bw.txSnap:
case s := <-bw.AddRx:
bw.rxstream.add(datum{float64(s), time.Now()})
bw.curTx += s
case s := <-bw.AddTx:
bw.txstream.add(datum{float64(s), time.Now()})
bw.curRx += s
case <-bw.Quit:
break outer
}
@ -77,86 +90,9 @@ outer:
close(bw.Tx)
}
// datum stores both a piece of info, plus the time at which that info was
// collected.
type datum struct {
value float64
at time.Time
}
func (d datum) String() string {
r := struct {
value string
at string
}{
value: fmt.Sprintf("%04f", d.value),
at: fmt.Sprintf("%s", d.at),
func (bw *Bandwidth) averages(state []int) []float64 {
for i := 0; i < bw.max; i++ {
log.Println(bw.timeI + i)
}
return fmt.Sprintf("%+v", r)
}
// stream manages a list of datum, and prunes itself on add
type stream struct {
data *list.List
extents []time.Duration
max time.Duration
}
func newStream(seconds []int) *stream {
extents := []time.Duration{}
for _, s := range seconds {
extents = append(extents, time.Duration(-s)*time.Second)
}
max := extents[len(extents)-1]
return &stream{
data: list.New(),
extents: extents,
max: max,
}
}
func (s *stream) add(v datum) {
s.data.PushBack(v)
}
func (s *stream) averages() []float64 {
var limit time.Time
total := 0.0
totals := []float64{}
if s.data.Back() == nil {
return totals
}
now := time.Now()
cutoff := now.Add(s.max)
for e := s.data.Front(); e != nil; e = e.Next() {
cur := e.Value.(datum).at
if cur.Before(cutoff) {
s.data.Remove(e)
} else {
break
}
}
e := s.data.Back()
for _, extent := range s.extents {
limit = now.Add(extent)
for ; e != nil; e = e.Prev() {
if e.Prev() == nil {
break
}
next := e.Prev().Value.(datum)
if next.at.Before(limit) {
break
}
cur := e.Value.(datum)
total += cur.value
}
totals = append(totals, total/float64(-int(extent/time.Second)))
}
return totals
return nil
}

View File

@ -10,35 +10,6 @@ func init() {
log.SetFlags(log.Ldate | log.Ltime | log.Lshortfile)
}
func general(t *testing.T) {
bw, err := NewBandwidth([]int{1, 10, 60}, 100*time.Millisecond)
if err != nil {
t.Error(err)
}
go bw.Run()
bw.AddRx <- 10
bw.AddTx <- 10
time.Sleep(1 * time.Second)
log.Printf("%+v", <-bw.Rx)
log.Printf("%+v", <-bw.Tx)
for i := 0; i < 10; i++ {
bw.AddRx <- (10 * i)
bw.AddRx <- (10 * i)
time.Sleep(500 * time.Millisecond)
log.Printf("%+v", <-bw.Rx)
log.Printf("%+v", <-bw.Tx)
}
log.Printf("%+v", <-bw.Rx)
log.Printf("%+v", <-bw.Tx)
time.Sleep(10 * time.Second)
log.Printf("%+v", <-bw.Rx)
log.Printf("%+v", <-bw.Tx)
close(bw.Quit)
time.Sleep(100 * time.Millisecond)
log.Printf("%+v", <-bw.Rx)
log.Printf("%+v", <-bw.Tx)
}
func validate(t *testing.T, actual, expected []float64) {
if len(actual) != len(expected) {
t.Errorf("len is not same: %d expected %d", len(actual), len(expected))
@ -50,64 +21,14 @@ func validate(t *testing.T, actual, expected []float64) {
}
}
func TestOncePerSecond(t *testing.T) {
bw, err := NewBandwidth([]int{1, 10, 60}, 100*time.Millisecond)
if err != nil {
t.Error(err)
}
bw.rxstream = newStream([]int{1, 10, 60})
var i int64 = 0
for ; i < 1000; i++ {
d := datum{
value: 1.0,
at: time.Unix(1234567890+i, 0),
}
bw.rxstream.add(d)
}
validate(t, bw.rxstream.averages(), []float64{1.0, 1.0, 1.0})
}
func TestOneOverManySeconds(t *testing.T) {
bw, err := NewBandwidth([]int{1, 10, 60}, 100*time.Millisecond)
if err != nil {
t.Error(err)
}
bw.rxstream = newStream([]int{1, 10, 60})
var i int64 = 0
for ; i < 1000; i++ {
d := datum{
value: 1.0,
at: time.Unix(1234567890+i*2, 0),
}
bw.rxstream.add(d)
}
validate(t, bw.rxstream.averages(), []float64{0.0, 0.5, 0.5})
}
func TestManyPerSecond(t *testing.T) {
bw, err := NewBandwidth([]int{1, 10, 60}, 100*time.Millisecond)
if err != nil {
t.Error(err)
}
bw.rxstream = newStream([]int{1, 10, 60})
var i int64 = 0
for ; i < 10000; i++ {
d := datum{
value: 1.0,
at: time.Unix(1234567890, i*10000000),
}
bw.rxstream.add(d)
}
validate(t, bw.rxstream.averages(), []float64{100.0, 100.0, 100.0})
}
func TestEmpty(t *testing.T) {
bw, err := NewBandwidth([]int{1, 10, 60}, 100*time.Millisecond)
if err != nil {
t.Error(err)
}
bw.rxstream = newStream([]int{1, 10, 60})
validate(t, bw.rxstream.averages(), []float64{})
go bw.Run()
bw.rxstream = []int{1, 10, 60}
validate(t, <-bw.Rx, []float64{})
}
func TestEmptySeconds(t *testing.T) {
@ -116,3 +37,8 @@ func TestEmptySeconds(t *testing.T) {
t.Error(err)
}
}
func TestA(t *testing.T) {
bw, _ := NewBandwidth([]int{1, 10, 30}, 1*time.Second)
log.Printf("%+v", bw)
}