From aaf43bc8886c4a10d11d1931a57697a946f63d0a Mon Sep 17 00:00:00 2001
From: Sebastian Dahlgren <sebastian.dahlgren@gmail.com>
Date: Tue, 18 Jul 2017 14:54:10 +0200
Subject: [PATCH]  first commit

---
 ifread/ewma.go       | 87 ++++++++++++++++++++++++++++++++++++++++++++
 ifread/readvals.go   | 44 ++++++++++++++++++++++
 main.go              |  7 ++++
 squeezer/commands.go | 25 +++++++++++++
 4 files changed, 163 insertions(+)
 create mode 100644 ifread/ewma.go
 create mode 100644 ifread/readvals.go
 create mode 100644 main.go
 create mode 100644 squeezer/commands.go

diff --git a/ifread/ewma.go b/ifread/ewma.go
new file mode 100644
index 0000000..3b0fb6d
--- /dev/null
+++ b/ifread/ewma.go
@@ -0,0 +1,87 @@
+package ifread
+
+import (
+	"errors"
+	"fmt"
+	"io/ioutil"
+	"os"
+
+	"github.com/VividCortex/ewma"
+)
+
+type NicIO struct {
+	name  string
+	rates ifaceRates
+	ewma  ifaceEWMA
+	sync.RWMutex
+}
+type ifaceRates struct {
+	rxb, txb, rxp, txp func(uint64) uint64
+}
+
+type ifaceEWMA struct {
+	rxb, txb, rxp, txp ewma.MovingAverage
+}
+
+// Delta is a small closure over the counters, returning the delta against previous
+// first = initial value
+func Delta(first uint64) func(uint64) uint64 {
+	keep := first
+	return func(delta uint64) uint64 {
+		v := delta - keep
+		keep = delta
+		return v
+	}
+}
+
+// MakeNic initalises the NicIO type
+// It'll be used in a receiver go channel
+func MakeNic(name string) (*NicIO, error) {
+	var nic NicIO
+	nic.name = name
+	r, err := readvals(name)
+	if err != nil {
+		return nil, err
+	}
+	nic.Lock()
+	defer nic.Unlock()
+	nic.rates.rxb = Delta(r.rxb)
+	nic.rates.txb = Delta(r.txb)
+	nic.rates.rxp = Delta(r.rxp)
+	nic.rates.txp = Delta(r.txp)
+	nic.ewma.rxb = ewma.NewMovingAverage()
+	nic.ewma.txb = ewma.NewMovingAverage()
+	nic.ewma.rxp = ewma.NewMovingAverage()
+	nic.ewma.txp = ewma.NewMovingAverage()
+	return &nic, nil
+}
+
+// ReadNic put all NIC data in struct
+func (nic *NicIO) ReadNic() error {
+	ifstat, err := readvals(nic.name)
+	// fmt.Println("%+v", ifstat)
+	if err == nil {
+		// mind that calling nic.rate.xxx updates rate
+		nic.ewma.rxb.Add(float64(nic.rates.rxb(ifstat.rxb)))
+		nic.ewma.txb.Add(float64(nic.rates.txb(ifstat.txb)))
+		nic.ewma.rxp.Add(float64(nic.rates.rxp(ifstat.rxp)))
+		nic.ewma.txp.Add(float64(nic.rates.txp(ifstat.txp)))
+		return nil
+	}
+	return err
+}
+
+// ListNics retuns the list of nics
+// TODO: make it regexp aware
+func ListNics() []string {
+	var ifaces []string
+	l, err := ioutil.ReadDir("/sys/class/net")
+	if err != nil {
+		errors.New("Can't read /sys/class/net. Is /sys mounted? Bailing...")
+		os.Exit(1)
+	}
+	for _, iface := range l {
+		ifaces = append(ifaces, iface.Name())
+	}
+	return ifaces
+}
diff --git a/ifread/readvals.go b/ifread/readvals.go
new file mode 100644
index 0000000..ad0d0e7
--- /dev/null
+++ b/ifread/readvals.go
@@ -0,0 +1,44 @@
+package ifread
+
+import (
+	"io/ioutil"
+	"strconv"
+	"strings"
+)
+
+type IfStat struct {
+	rxb, txb, rxp, txp uint64
+}
+
+func readval(path string) (uint64, error) {
+	contents, err := ioutil.ReadFile(path)
+	if err != nil {
+		return 0, err
+	}
+	// we assume that's always ok ?
+	val := strings.Split(string(contents), "\n")
+	digit, _ := strconv.ParseUint(val[0], 10, 64)
+	return digit, nil
+}
+
+func readvals(i string) (IfStat, error) {
+	v := IfStat{}
+	var err error
+	// repeat .. fsck it only 4
+	if v.rxb, err = readval("/sys/class/net/" + i + "/statistics/rx_bytes"); err != nil {
+		errfound = true
+	}
+	if v.txb, err = readval("/sys/class/net/" + i + "/statistics/tx_bytes"); err != nil {
+		errfound = true
+	}
+	if v.rxp, err = readval("/sys/class/net/" + i + "/statistics/rx_packets"); err != nil {
+		errfound = true
+	}
+	if v.txp, err = readval("/sys/class/net/" + i + "/statistics/tx_packets"); err != nil {
+		errfound = true
+	}
+	if errfound {
+		return nil, err
+	}
+	return v, nil
+}
diff --git a/main.go b/main.go
new file mode 100644
index 0000000..50e8d8d
--- /dev/null
+++ b/main.go
@@ -0,0 +1,7 @@
+package main
+
+import "fmt"
+
+func main() {
+	fmt.Println("vim-go")
+}
diff --git a/squeezer/commands.go b/squeezer/commands.go
new file mode 100644
index 0000000..c414e5b
--- /dev/null
+++ b/squeezer/commands.go
@@ -0,0 +1,25 @@
+package squeezer
+
+import "github.com/delandtj/netork/ifread"
+
+func main() {
+	fmt.Println("vim-go")
+}
+
+const (
+	_ = iota
+	1000mbit
+	500mbit
+	200mbit
+	100mbit
+	50mbit
+	20mbit
+	5mbit
+	1mbit
+	200kbit
+	20kbit
+)
+
+func SqueezeBW(name string, bw int) error {
+
+}