Convert more bespoke methods to io.Reader/io.Writer interfaces

[rbdr/mobius] / hotline / user.go

diff --git a/hotline/user.go b/hotline/user.go
index 34fe1ab0fd3d450f8ad5b3e5b61dbcd977534716..7d6f85118d5b06e154cb4c73e14de0f2338179f5 100644 (file)
--- a/hotline/user.go
+++ b/hotline/user.go
@@ -2,6 +2,8 @@ package hotline
 
 import (
        "encoding/binary"
+       "io"
+       "slices"
 )
 
 // User flags are stored as a 2 byte bitmap and represent various user states
@@ -26,7 +28,7 @@ type User struct {
        Name  string // Variable length user name
 }
 
-func (u User) Payload() []byte {
+func (u *User) Read(p []byte) (int, error) {
        nameLen := make([]byte, 2)
        binary.BigEndian.PutUint16(nameLen, uint16(len(u.Name)))
 
@@ -43,32 +45,38 @@ func (u User) Payload() []byte {
        out = append(out, nameLen...)
        out = append(out, u.Name...)
 
-       return out
+       return copy(p, slices.Concat(
+               u.ID,
+               u.Icon,
+               u.Flags,
+               nameLen,
+               []byte(u.Name),
+       )), io.EOF
 }
 
-func ReadUser(b []byte) (*User, error) {
-       u := &User{
-               ID:    b[0:2],
-               Icon:  b[2:4],
-               Flags: b[4:6],
-               Name:  string(b[8:]),
-       }
-       return u, nil
+func (u *User) Write(p []byte) (int, error) {
+       namelen := int(binary.BigEndian.Uint16(p[6:8]))
+       u.ID = p[0:2]
+       u.Icon = p[2:4]
+       u.Flags = p[4:6]
+       u.Name = string(p[8 : 8+namelen])
+
+       return 8 + namelen, nil
 }
 
-// DecodeUserString decodes an obfuscated user string from a client
+// decodeString decodes an obfuscated user string from a client
 // e.g. 98 8a 9a 8c 8b => "guest"
-func DecodeUserString(obfuText []byte) (clearText string) {
+func decodeString(obfuText []byte) (clearText string) {
        for _, char := range obfuText {
                clearText += string(rune(255 - uint(char)))
        }
        return clearText
 }
 
-// negateString takes []byte s containing cleartext and rotates by 255 into obfuscated cleartext.
+// encodeString takes []byte s containing cleartext and rotates by 255 into obfuscated cleartext.
 // The Hotline protocol uses this format for sending passwords over network.
 // Not secure, but hey, it was the 90s!
-func negateString(clearText []byte) []byte {
+func encodeString(clearText []byte) []byte {
        obfuText := make([]byte, len(clearText))
        for i := 0; i < len(clearText); i++ {
                obfuText[i] = 255 - clearText[i]