Files
TelemetryMockserver/mockserver/replay.go
T

119 lines
2.3 KiB
Go

// Package mockserver is the core of this program and it will have the API
// to record binary data from the UDP server and then be able to mock it
package mockserver
import (
"context"
"fmt"
"io"
"os"
"time"
)
type ViewData struct {
Data []byte
SizeRead int
}
// renderToTerminal will render the data for the users viewing pleasure
func renderToTerminal(ctx context.Context, stream chan ViewData, fp string) {
fileInfo, err := os.Stat(fp)
if err != nil {
// NOTE: learn how to handle this error
// return fmt.Errorf("error stating file: %v", err)
}
for {
select {
case <-ctx.Done():
return
case data := <-stream:
percent := int(float64(data.SizeRead) / float64(fileInfo.Size()) * 100)
fmt.Printf("\rReplayed: %d%%", percent)
}
}
}
// writeToUDPSocket will write the telemetry data to the UDP socket
func writeToUDPSocket(ctx context.Context, stream chan []byte, socket *UDPTransport) {
for {
select {
case <-ctx.Done():
return
case data := <-stream:
_, err := socket.Send(data)
if err != nil {
continue
// NOTE: log the error somewhere maybe
// return err
}
}
}
}
// Replay replays a given file <fp> in a UDP server <addr>:<port>
func Replay(ctx context.Context, address string, port int, loop bool, fp string) error {
bin, err := os.Open(fp)
if err != nil {
return fmt.Errorf("error opening file: %v", err)
}
reader := NewGobReader(bin)
udp, err := NewUDPTransport(address, port)
if err != nil {
return err
}
ticker := time.NewTicker(time.Second / 60)
defer ticker.Stop()
uiChannel := make(chan ViewData, 1)
socketChannel := make(chan []byte, 1)
go renderToTerminal(ctx, uiChannel, fp)
go writeToUDPSocket(ctx, socketChannel, udp)
for {
select {
case <-ctx.Done():
return ctx.Err()
case <-ticker.C:
data, err := reader.Next()
if err == io.EOF {
if !loop {
return udp.Close()
}
err = reader.Reset()
if err != nil {
return err
}
continue
}
if err != nil {
return err
}
// Send the data to the view
select {
case uiChannel <- ViewData{Data: data, SizeRead: reader.TotalRead}:
// Sent the data
default:
// Dropped the frame!
}
// Send the data to the UDP socket
select {
case socketChannel <- data:
// Sent the data
default:
// Dropped the frame!
}
}
}
}