/
server.go
159 lines (129 loc) · 3.08 KB
/
server.go
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package main
import (
"context"
"fmt"
"io"
"os"
"syscall"
"time"
"github.com/cfoust/cy/pkg/cy"
"github.com/cfoust/cy/pkg/geom"
P "github.com/cfoust/cy/pkg/io/protocol"
"github.com/cfoust/cy/pkg/io/ws"
"github.com/rs/zerolog/log"
"github.com/sevlyar/go-daemon"
)
var ErrorLockFailed = fmt.Errorf("failed to lock file")
func getLockPath(socketPath string) string {
return socketPath + ".lock"
}
func getLock(lockPath string) (*os.File, error) {
fd, err := os.OpenFile(lockPath, os.O_WRONLY|os.O_CREATE, 0600)
if err != nil {
return nil, err
}
if err := syscall.Flock(int(fd.Fd()), syscall.LOCK_EX|syscall.LOCK_NB); err != nil {
fd.Close()
return nil, ErrorLockFailed
}
return fd, nil
}
type Server struct {
cy *cy.Cy
}
type Connection = ws.Client[P.Message]
var _ ws.Server[P.Message] = (*Server)(nil)
type Client struct {
conn Connection
}
func (c *Client) closeError(reason error) error {
err := c.conn.Send(P.ErrorMessage{
Message: fmt.Sprintf("error: %s", reason),
})
if err != nil {
return err
}
return c.conn.Close()
}
func (c *Client) Write(data []byte) (n int, err error) {
return len(data), c.conn.Send(P.OutputMessage{
Data: data,
})
}
func (s *Server) HandleWSClient(conn ws.Client[P.Message]) {
events := conn.Receive()
// First we need to wait for the client's handshake to know how to
// handle its terminal
handshakeCtx, cancel := context.WithTimeout(conn.Ctx(), 1*time.Second)
defer cancel()
wsClient := &Client{conn: conn}
var client *cy.Client
var err error
select {
case <-handshakeCtx.Done():
wsClient.closeError(fmt.Errorf("no handshake received"))
return
case message, more := <-events:
if handshake, ok := message.Contents.(*P.HandshakeMessage); ok {
client, err = s.cy.NewClient(conn.Ctx(), *handshake)
} else if !more {
err = fmt.Errorf("closed by remote")
} else {
err = fmt.Errorf("must send handshake first")
}
if err != nil {
wsClient.closeError(err)
return
}
}
go func() { _, _ = io.Copy(wsClient, client) }()
for {
select {
case <-conn.Ctx().Done():
return
case packet := <-events:
if packet.Error != nil {
// TODO(cfoust): 06/08/23 handle gracefully
continue
}
switch packet.Contents.Type() {
case P.MessageTypeSize:
msg := packet.Contents.(*P.SizeMessage)
client.Resize(geom.Vec2{
R: msg.Rows,
C: msg.Columns,
})
case P.MessageTypeInput:
msg := packet.Contents.(*P.InputMessage)
_, err := client.Write(msg.Data)
if err != nil {
wsClient.closeError(err)
return
}
}
}
}
}
func serve(path string) error {
cy, err := cy.Start(context.Background(), cy.Options{
Config: findConfig(),
DataDir: findDataDir(),
Shell: getShell(),
})
if err != nil {
return err
}
server := &Server{cy: cy}
return ws.Serve[P.Message](cy.Ctx(), path, P.Protocol, server)
}
func startServer(path string) error {
cntxt := &daemon.Context{
LogFileName: fmt.Sprintf("%s.log", path),
PidFileName: fmt.Sprintf("%s.pid", path),
}
_, err := cntxt.Reborn()
if err != nil {
log.Panic().Err(err).Msg("failed to daemonize")
}
return nil
}