ref: 063179e197b341db541b367ebfdf2c7cbd8bf5f9
parent: 94ca91136aa9269e3c96d792f04da230231ddfc5
author: Runxi Yu <me@runxiyu.org>
date: Fri Jan 30 05:24:26 EST 2026
pktline: Move out of internal; fix package-level doc-comment
--- a/internal/pktline/pktline.go
+++ /dev/null
@@ -1,164 +1,0 @@
-// pktline provides support for the pkt-line format described in gitprotocol-common(5).
-package pktline
-
-import (
- "errors"
- "io"
-)
-
-const (
- maxPacketSize = 65520
- maxPacketDataLen = maxPacketSize - 4
-)
-
-var (
- ErrInvalidHeader = errors.New("pktline: invalid header")- ErrPacketTooLarge = errors.New("pktline: packet too large")- ErrBufferTooSmall = errors.New("pktline: buffer too small")-)
-
-type Status uint8
-
-const (
- StatusEOF Status = iota
- StatusData
- StatusFlush
- StatusDelim
- StatusResponseEnd
-)
-
-// ReadLine reads a single pkt-line from r into buf.
-// It returns the payload slice, number of payload bytes, and a status.
-func ReadLine(r io.Reader, buf []byte) ([]byte, int, Status, error) {- if r == nil {- return nil, 0, StatusEOF, ErrInvalidHeader
- }
- var header [4]byte
- if _, err := io.ReadFull(r, header[:]); err != nil {- if errors.Is(err, io.EOF) {- return nil, 0, StatusEOF, io.EOF
- }
- if errors.Is(err, io.ErrUnexpectedEOF) {- return nil, 0, StatusEOF, io.ErrUnexpectedEOF
- }
- return nil, 0, StatusEOF, err
- }
-
- n, err := parseHeader(header[:])
- if err != nil {- return nil, 0, StatusEOF, err
- }
- switch n {- case 0:
- return nil, 0, StatusFlush, nil
- case 1:
- return nil, 0, StatusDelim, nil
- case 2:
- return nil, 0, StatusResponseEnd, nil
- }
- if n < 4 {- return nil, 0, StatusEOF, ErrInvalidHeader
- }
- n -= 4
- if n > maxPacketDataLen {- return nil, 0, StatusEOF, ErrPacketTooLarge
- }
- if n > len(buf) {- return nil, 0, StatusEOF, ErrBufferTooSmall
- }
- if _, err := io.ReadFull(r, buf[:n]); err != nil {- if errors.Is(err, io.ErrUnexpectedEOF) {- return nil, 0, StatusEOF, io.ErrUnexpectedEOF
- }
- return nil, 0, StatusEOF, err
- }
- return buf[:n], n, StatusData, nil
-}
-
-// WriteLine writes a single pkt-line with data as its payload.
-func WriteLine(w io.Writer, data []byte) error {- if w == nil {- return ErrInvalidHeader
- }
- if len(data) > maxPacketDataLen {- return ErrPacketTooLarge
- }
- var header [4]byte
- setHeader(header[:], len(data)+4)
- if _, err := w.Write(header[:]); err != nil {- return err
- }
- if len(data) == 0 {- return nil
- }
- _, err := w.Write(data)
- return err
-}
-
-// Flush writes a flush-pkt ("0000").-func Flush(w io.Writer) error {- return writeLiteral(w, "0000")
-}
-
-// Delim writes a delim-pkt ("0001").-func Delim(w io.Writer) error {- return writeLiteral(w, "0001")
-}
-
-// ResponseEnd writes a response-end pkt ("0002").-func ResponseEnd(w io.Writer) error {- return writeLiteral(w, "0002")
-}
-
-func writeLiteral(w io.Writer, s string) error {- if w == nil {- return ErrInvalidHeader
- }
- _, err := io.WriteString(w, s)
- return err
-}
-
-func parseHeader(b []byte) (int, error) {- if len(b) < 4 {- return 0, ErrInvalidHeader
- }
- v0, ok := hexVal(b[0])
- if !ok {- return 0, ErrInvalidHeader
- }
- v1, ok := hexVal(b[1])
- if !ok {- return 0, ErrInvalidHeader
- }
- v2, ok := hexVal(b[2])
- if !ok {- return 0, ErrInvalidHeader
- }
- v3, ok := hexVal(b[3])
- if !ok {- return 0, ErrInvalidHeader
- }
- return (v0 << 12) | (v1 << 8) | (v2 << 4) | v3, nil
-}
-
-func setHeader(buf []byte, size int) {- const hex = "0123456789abcdef"
- buf[0] = hex[(size>>12)&0x0f]
- buf[1] = hex[(size>>8)&0x0f]
- buf[2] = hex[(size>>4)&0x0f]
- buf[3] = hex[size&0x0f]
-}
-
-// IIRC strconv.ParseUint, encoding/hex.Decode, etc., allocate memory.
-func hexVal(b byte) (int, bool) {- switch {- case b >= '0' && b <= '9':
- return int(b - '0'), true
- case b >= 'a' && b <= 'f':
- return int(b-'a') + 10, true
- case b >= 'A' && b <= 'F':
- return int(b-'A') + 10, true
- default:
- return 0, false
- }
-}
--- a/internal/pktline/pktline_test.go
+++ /dev/null
@@ -1,88 +1,0 @@
-package pktline
-
-import (
- "bytes"
- "errors"
- "io"
- "testing"
-)
-
-func TestWriteReadLineRoundtrip(t *testing.T) {- var buf bytes.Buffer
- payload := []byte("hello\n")- if err := WriteLine(&buf, payload); err != nil {- t.Fatalf("WriteLine: %v", err)- }
-
- dst := make([]byte, 64)
- line, n, status, err := ReadLine(&buf, dst)
- if err != nil {- t.Fatalf("ReadLine: %v", err)- }
- if status != StatusData {- t.Fatalf("status: got %v, want %v", status, StatusData)- }
- if n != len(payload) {- t.Fatalf("n: got %d, want %d", n, len(payload))- }
- if !bytes.Equal(line, payload) {- t.Fatalf("payload: got %q, want %q", line, payload)- }
-}
-
-func TestReadLineSpecialPackets(t *testing.T) {- tests := []struct {- name string
- input string
- status Status
- }{- {"flush", "0000", StatusFlush},- {"delim", "0001", StatusDelim},- {"response_end", "0002", StatusResponseEnd},- }
- for _, tt := range tests {- t.Run(tt.name, func(t *testing.T) {- r := bytes.NewBufferString(tt.input)
- dst := make([]byte, 16)
- line, n, status, err := ReadLine(r, dst)
- if err != nil {- t.Fatalf("ReadLine: %v", err)- }
- if status != tt.status {- t.Fatalf("status: got %v, want %v", status, tt.status)- }
- if n != 0 || len(line) != 0 {- t.Fatalf("expected empty payload, got %d bytes", n)- }
- })
- }
-}
-
-func TestReadLineInvalidHeader(t *testing.T) {- r := bytes.NewBufferString("zzzz")- dst := make([]byte, 16)
- _, _, _, err := ReadLine(r, dst)
- if !errors.Is(err, ErrInvalidHeader) {- t.Fatalf("expected ErrInvalidHeader, got %v", err)- }
-}
-
-func TestReadLineBufferTooSmall(t *testing.T) {- var buf bytes.Buffer
- payload := []byte("abcd")- if err := WriteLine(&buf, payload); err != nil {- t.Fatalf("WriteLine: %v", err)- }
- dst := make([]byte, 2)
- _, _, _, err := ReadLine(&buf, dst)
- if !errors.Is(err, ErrBufferTooSmall) {- t.Fatalf("expected ErrBufferTooSmall, got %v", err)- }
-}
-
-func TestWriteLineTooLarge(t *testing.T) {- payload := make([]byte, maxPacketDataLen+1)
- if err := WriteLine(io.Discard, payload); !errors.Is(err, ErrPacketTooLarge) {- t.Fatalf("expected ErrPacketTooLarge, got %v", err)- }
-}
--- /dev/null
+++ b/pktline/pktline.go
@@ -1,0 +1,164 @@
+// Package pktline provides support for the pkt-line format described in gitprotocol-common(5).
+package pktline
+
+import (
+ "errors"
+ "io"
+)
+
+const (
+ maxPacketSize = 65520
+ maxPacketDataLen = maxPacketSize - 4
+)
+
+var (
+ ErrInvalidHeader = errors.New("pktline: invalid header")+ ErrPacketTooLarge = errors.New("pktline: packet too large")+ ErrBufferTooSmall = errors.New("pktline: buffer too small")+)
+
+type Status uint8
+
+const (
+ StatusEOF Status = iota
+ StatusData
+ StatusFlush
+ StatusDelim
+ StatusResponseEnd
+)
+
+// ReadLine reads a single pkt-line from r into buf.
+// It returns the payload slice, number of payload bytes, and a status.
+func ReadLine(r io.Reader, buf []byte) ([]byte, int, Status, error) {+ if r == nil {+ return nil, 0, StatusEOF, ErrInvalidHeader
+ }
+ var header [4]byte
+ if _, err := io.ReadFull(r, header[:]); err != nil {+ if errors.Is(err, io.EOF) {+ return nil, 0, StatusEOF, io.EOF
+ }
+ if errors.Is(err, io.ErrUnexpectedEOF) {+ return nil, 0, StatusEOF, io.ErrUnexpectedEOF
+ }
+ return nil, 0, StatusEOF, err
+ }
+
+ n, err := parseHeader(header[:])
+ if err != nil {+ return nil, 0, StatusEOF, err
+ }
+ switch n {+ case 0:
+ return nil, 0, StatusFlush, nil
+ case 1:
+ return nil, 0, StatusDelim, nil
+ case 2:
+ return nil, 0, StatusResponseEnd, nil
+ }
+ if n < 4 {+ return nil, 0, StatusEOF, ErrInvalidHeader
+ }
+ n -= 4
+ if n > maxPacketDataLen {+ return nil, 0, StatusEOF, ErrPacketTooLarge
+ }
+ if n > len(buf) {+ return nil, 0, StatusEOF, ErrBufferTooSmall
+ }
+ if _, err := io.ReadFull(r, buf[:n]); err != nil {+ if errors.Is(err, io.ErrUnexpectedEOF) {+ return nil, 0, StatusEOF, io.ErrUnexpectedEOF
+ }
+ return nil, 0, StatusEOF, err
+ }
+ return buf[:n], n, StatusData, nil
+}
+
+// WriteLine writes a single pkt-line with data as its payload.
+func WriteLine(w io.Writer, data []byte) error {+ if w == nil {+ return ErrInvalidHeader
+ }
+ if len(data) > maxPacketDataLen {+ return ErrPacketTooLarge
+ }
+ var header [4]byte
+ setHeader(header[:], len(data)+4)
+ if _, err := w.Write(header[:]); err != nil {+ return err
+ }
+ if len(data) == 0 {+ return nil
+ }
+ _, err := w.Write(data)
+ return err
+}
+
+// Flush writes a flush-pkt ("0000").+func Flush(w io.Writer) error {+ return writeLiteral(w, "0000")
+}
+
+// Delim writes a delim-pkt ("0001").+func Delim(w io.Writer) error {+ return writeLiteral(w, "0001")
+}
+
+// ResponseEnd writes a response-end pkt ("0002").+func ResponseEnd(w io.Writer) error {+ return writeLiteral(w, "0002")
+}
+
+func writeLiteral(w io.Writer, s string) error {+ if w == nil {+ return ErrInvalidHeader
+ }
+ _, err := io.WriteString(w, s)
+ return err
+}
+
+func parseHeader(b []byte) (int, error) {+ if len(b) < 4 {+ return 0, ErrInvalidHeader
+ }
+ v0, ok := hexVal(b[0])
+ if !ok {+ return 0, ErrInvalidHeader
+ }
+ v1, ok := hexVal(b[1])
+ if !ok {+ return 0, ErrInvalidHeader
+ }
+ v2, ok := hexVal(b[2])
+ if !ok {+ return 0, ErrInvalidHeader
+ }
+ v3, ok := hexVal(b[3])
+ if !ok {+ return 0, ErrInvalidHeader
+ }
+ return (v0 << 12) | (v1 << 8) | (v2 << 4) | v3, nil
+}
+
+func setHeader(buf []byte, size int) {+ const hex = "0123456789abcdef"
+ buf[0] = hex[(size>>12)&0x0f]
+ buf[1] = hex[(size>>8)&0x0f]
+ buf[2] = hex[(size>>4)&0x0f]
+ buf[3] = hex[size&0x0f]
+}
+
+// IIRC strconv.ParseUint, encoding/hex.Decode, etc., allocate memory.
+func hexVal(b byte) (int, bool) {+ switch {+ case b >= '0' && b <= '9':
+ return int(b - '0'), true
+ case b >= 'a' && b <= 'f':
+ return int(b-'a') + 10, true
+ case b >= 'A' && b <= 'F':
+ return int(b-'A') + 10, true
+ default:
+ return 0, false
+ }
+}
--- /dev/null
+++ b/pktline/pktline_test.go
@@ -1,0 +1,88 @@
+package pktline
+
+import (
+ "bytes"
+ "errors"
+ "io"
+ "testing"
+)
+
+func TestWriteReadLineRoundtrip(t *testing.T) {+ var buf bytes.Buffer
+ payload := []byte("hello\n")+ if err := WriteLine(&buf, payload); err != nil {+ t.Fatalf("WriteLine: %v", err)+ }
+
+ dst := make([]byte, 64)
+ line, n, status, err := ReadLine(&buf, dst)
+ if err != nil {+ t.Fatalf("ReadLine: %v", err)+ }
+ if status != StatusData {+ t.Fatalf("status: got %v, want %v", status, StatusData)+ }
+ if n != len(payload) {+ t.Fatalf("n: got %d, want %d", n, len(payload))+ }
+ if !bytes.Equal(line, payload) {+ t.Fatalf("payload: got %q, want %q", line, payload)+ }
+}
+
+func TestReadLineSpecialPackets(t *testing.T) {+ tests := []struct {+ name string
+ input string
+ status Status
+ }{+ {"flush", "0000", StatusFlush},+ {"delim", "0001", StatusDelim},+ {"response_end", "0002", StatusResponseEnd},+ }
+ for _, tt := range tests {+ t.Run(tt.name, func(t *testing.T) {+ r := bytes.NewBufferString(tt.input)
+ dst := make([]byte, 16)
+ line, n, status, err := ReadLine(r, dst)
+ if err != nil {+ t.Fatalf("ReadLine: %v", err)+ }
+ if status != tt.status {+ t.Fatalf("status: got %v, want %v", status, tt.status)+ }
+ if n != 0 || len(line) != 0 {+ t.Fatalf("expected empty payload, got %d bytes", n)+ }
+ })
+ }
+}
+
+func TestReadLineInvalidHeader(t *testing.T) {+ r := bytes.NewBufferString("zzzz")+ dst := make([]byte, 16)
+ _, _, _, err := ReadLine(r, dst)
+ if !errors.Is(err, ErrInvalidHeader) {+ t.Fatalf("expected ErrInvalidHeader, got %v", err)+ }
+}
+
+func TestReadLineBufferTooSmall(t *testing.T) {+ var buf bytes.Buffer
+ payload := []byte("abcd")+ if err := WriteLine(&buf, payload); err != nil {+ t.Fatalf("WriteLine: %v", err)+ }
+ dst := make([]byte, 2)
+ _, _, _, err := ReadLine(&buf, dst)
+ if !errors.Is(err, ErrBufferTooSmall) {+ t.Fatalf("expected ErrBufferTooSmall, got %v", err)+ }
+}
+
+func TestWriteLineTooLarge(t *testing.T) {+ payload := make([]byte, maxPacketDataLen+1)
+ if err := WriteLine(io.Discard, payload); !errors.Is(err, ErrPacketTooLarge) {+ t.Fatalf("expected ErrPacketTooLarge, got %v", err)+ }
+}
--
⑨