From: Jeff Halter <redacted>
Date: Sun, 9 Jun 2024 02:25:12 +0000 (-0700)
Subject: Refactor TrackerRegistration Read to io.Reader interface
X-Git-Url: https://git.r.bdr.sh/rbdr/mobius/commitdiff_plain/9a75b7cbfa6fa37ed10732bbff8b722d652a1cdc?hp=2b7fabb5a1ff6092dd3ea62bd882dd0c02951b81

Refactor TrackerRegistration Read to io.Reader interface
---

diff --git a/hotline/tracker.go b/hotline/tracker.go
index bd7aa00..a56059f 100644
--- a/hotline/tracker.go
+++ b/hotline/tracker.go
@@ -4,49 +4,49 @@ import (
 	"bufio"
 	"encoding/binary"
 	"fmt"
-	"github.com/jhalter/mobius/concat"
+	"io"
 	"net"
+	"slices"
 	"strconv"
 	"time"
 )
 
 // TrackerRegistration represents the payload a Hotline server sends to a Tracker to register
 type TrackerRegistration struct {
-	Port        [2]byte // Server listening port number
+	Port        [2]byte // Server's listening TCP port number
 	UserCount   int     // Number of users connected to this particular server
-	PassID      []byte  // Random number generated by the server
+	PassID      [4]byte // Random number generated by the server
 	Name        string  // Server name
 	Description string  // Description of the server
 }
 
-// TODO: reimplement as io.Reader
-func (tr *TrackerRegistration) Read() []byte {
+// Read implements io.Reader to write tracker registration payload bytes to slice
+func (tr *TrackerRegistration) Read(p []byte) (int, error) {
 	userCount := make([]byte, 2)
 	binary.BigEndian.PutUint16(userCount, uint16(tr.UserCount))
 
-	return concat.Slices(
-		[]byte{0x00, 0x01},
+	return copy(p, slices.Concat(
+		[]byte{0x00, 0x01}, // Magic number, always 1
 		tr.Port[:],
 		userCount,
-		[]byte{0x00, 0x00},
-		tr.PassID,
+		[]byte{0x00, 0x00}, // Magic number, always 0
+		tr.PassID[:],
 		[]byte{uint8(len(tr.Name))},
 		[]byte(tr.Name),
 		[]byte{uint8(len(tr.Description))},
 		[]byte(tr.Description),
-	)
+	)[:]), io.EOF
 }
 
 func register(tracker string, tr *TrackerRegistration) error {
 	conn, err := net.Dial("udp", tracker)
 	if err != nil {
-		return err
+		return fmt.Errorf("failed to dial tracker: %w", err)
 	}
+	defer conn.Close()
 
-	b := tr.Read()
-
-	if _, err := conn.Write(b); err != nil {
-		return err
+	if _, err := io.Copy(conn, tr); err != nil {
+		return fmt.Errorf("failed to write to connection: %w", err)
 	}
 
 	return nil
diff --git a/hotline/tracker_test.go b/hotline/tracker_test.go
index 481f916..b5c5c55 100644
--- a/hotline/tracker_test.go
+++ b/hotline/tracker_test.go
@@ -3,6 +3,7 @@ package hotline
 import (
 	"fmt"
 	"github.com/stretchr/testify/assert"
+	"io"
 	"reflect"
 	"testing"
 )
@@ -11,7 +12,7 @@ func TestTrackerRegistration_Payload(t *testing.T) {
 	type fields struct {
 		Port        [2]byte
 		UserCount   int
-		PassID      []byte
+		PassID      [4]byte
 		Name        string
 		Description string
 	}
@@ -25,7 +26,7 @@ func TestTrackerRegistration_Payload(t *testing.T) {
 			fields: fields{
 				Port:        [2]byte{0x00, 0x10},
 				UserCount:   2,
-				PassID:      []byte{0x00, 0x00, 0x00, 0x01},
+				PassID:      [4]byte{0x00, 0x00, 0x00, 0x01},
 				Name:        "Test Serv",
 				Description: "Fooz",
 			},
@@ -51,7 +52,8 @@ func TestTrackerRegistration_Payload(t *testing.T) {
 				Name:        tt.fields.Name,
 				Description: tt.fields.Description,
 			}
-			if got := tr.Read(); !reflect.DeepEqual(got, tt.want) {
+
+			if got, _ := io.ReadAll(tr); !reflect.DeepEqual(got, tt.want) {
 				t.Errorf("Read() = %v, want %v", got, tt.want)
 			}
 		})