Files
patterm/internal/protocol/transport.go

74 lines
1.4 KiB
Go

package protocol
import (
"bufio"
"encoding/json"
"errors"
"fmt"
"io"
"net"
)
var ErrTransportClosed = errors.New("protocol: transport closed")
// Transport carries framed daemon/client protocol messages.
type Transport interface {
Send(Frame) error
Recv() (Frame, error)
Close() error
}
// ConnTransport is a JSON-lines implementation over a stream connection.
type ConnTransport struct {
conn net.Conn
r *bufio.Reader
w *bufio.Writer
}
func NewConnTransport(conn net.Conn) *ConnTransport {
return &ConnTransport{
conn: conn,
r: bufio.NewReader(conn),
w: bufio.NewWriter(conn),
}
}
func (t *ConnTransport) Send(f Frame) error {
if t == nil || t.conn == nil {
return ErrTransportClosed
}
b, err := json.Marshal(f)
if err != nil {
return fmt.Errorf("protocol: encode frame: %w", err)
}
if _, err := t.w.Write(append(b, '\n')); err != nil {
return err
}
return t.w.Flush()
}
func (t *ConnTransport) Recv() (Frame, error) {
if t == nil || t.conn == nil {
return Frame{}, ErrTransportClosed
}
line, err := t.r.ReadBytes('\n')
if err != nil {
if errors.Is(err, io.EOF) {
return Frame{}, ErrTransportClosed
}
return Frame{}, err
}
var f Frame
if err := json.Unmarshal(line, &f); err != nil {
return Frame{}, fmt.Errorf("protocol: decode frame: %w", err)
}
return f, nil
}
func (t *ConnTransport) Close() error {
if t == nil || t.conn == nil {
return nil
}
return t.conn.Close()
}