sharded-gotify/stream/client.go

96 lines
2.0 KiB
Go

package stream
import (
"sync"
"time"
"github.com/gorilla/websocket"
"github.com/jmattheis/memo/model"
)
const (
writeWait = 2 * time.Second
)
type client struct {
conn *websocket.Conn
onClose func(*client)
write chan *model.Message
userID uint
once sync.Once
}
func newClient(conn *websocket.Conn, userID uint, onClose func(*client)) *client {
return &client{
conn: conn,
write: make(chan *model.Message, 1),
userID: userID,
onClose: onClose,
}
}
// Close closes the connection.
func (c *client) Close() {
c.once.Do(func() {
c.conn.Close()
close(c.write)
})
}
// NotifyClose closes the connection and notifies that the connection was closed.
func (c *client) NotifyClose() {
c.once.Do(func() {
c.conn.Close()
close(c.write)
c.onClose(c)
})
}
// startWriteHandler starts listening on the client connection. As we do not need anything from the client,
// we ignore incoming messages. Leaves the loop on errors.
func (c *client) startReading(pongWait time.Duration) {
defer c.NotifyClose()
c.conn.SetReadLimit(64)
c.conn.SetReadDeadline(time.Now().Add(pongWait))
c.conn.SetPongHandler(func(appData string) error {
c.conn.SetReadDeadline(time.Now().Add(pongWait))
return nil
})
for {
if _, _, err := c.conn.NextReader(); err != nil {
return
}
}
}
// startWriteHandler starts the write loop. The method has the following tasks:
// * ping the client in the interval provided as parameter
// * write messages send by the channel to the client
// * on errors exit the loop
func (c *client) startWriteHandler(pingPeriod time.Duration) {
pingTicker := time.NewTicker(pingPeriod)
defer func() {
c.NotifyClose()
pingTicker.Stop()
}()
for {
select {
case message, ok := <-c.write:
if !ok {
return
}
c.conn.SetWriteDeadline(time.Now().Add(writeWait))
if err := c.conn.WriteJSON(message); err != nil {
return
}
case <-pingTicker.C:
c.conn.SetWriteDeadline(time.Now().Add(writeWait))
if err := c.conn.WriteMessage(websocket.PingMessage, nil); err != nil {
return
}
}
}
}