Refactor TrackerRegistration Read to io.Reader interface

diff --git a/hotline/tracker.go b/hotline/tracker.go
index bd7aa00da966d52b21f1a2b872d3153e78348884..a56059fa2f04ba3b19596070ba7ca970fd35b224 100644 (file)
--- 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 481f916a9b045daa284df70a41266f1d04674b55..b5c5c557226d002b6706929fc669a2b057673d2c 100644 (file)
--- 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)
                        }
                })