tile38/vendor/github.com/eclipse/paho.mqtt.golang/websocket.go

110 lines
2.4 KiB
Go

package mqtt
import (
"crypto/tls"
"io"
"net"
"net/http"
"sync"
"time"
"github.com/gorilla/websocket"
)
// WebsocketOptions are config options for a websocket dialer
type WebsocketOptions struct {
ReadBufferSize int
WriteBufferSize int
}
// NewWebsocket returns a new websocket and returns a net.Conn compatible interface using the gorilla/websocket package
func NewWebsocket(host string, tlsc *tls.Config, timeout time.Duration, requestHeader http.Header, options *WebsocketOptions) (net.Conn, error) {
if timeout == 0 {
timeout = 10 * time.Second
}
if options == nil {
// Apply default options
options = &WebsocketOptions{}
}
dialer := &websocket.Dialer{
Proxy: http.ProxyFromEnvironment,
HandshakeTimeout: timeout,
EnableCompression: false,
TLSClientConfig: tlsc,
Subprotocols: []string{"mqtt"},
ReadBufferSize: options.ReadBufferSize,
WriteBufferSize: options.WriteBufferSize,
}
ws, _, err := dialer.Dial(host, requestHeader)
if err != nil {
return nil, err
}
wrapper := &websocketConnector{
Conn: ws,
}
return wrapper, err
}
// websocketConnector is a websocket wrapper so it satisfies the net.Conn interface so it is a
// drop in replacement of the golang.org/x/net/websocket package.
// Implementation guide taken from https://github.com/gorilla/websocket/issues/282
type websocketConnector struct {
*websocket.Conn
r io.Reader
rio sync.Mutex
wio sync.Mutex
}
// SetDeadline sets both the read and write deadlines
func (c *websocketConnector) SetDeadline(t time.Time) error {
if err := c.SetReadDeadline(t); err != nil {
return err
}
err := c.SetWriteDeadline(t)
return err
}
// Write writes data to the websocket
func (c *websocketConnector) Write(p []byte) (int, error) {
c.wio.Lock()
defer c.wio.Unlock()
err := c.WriteMessage(websocket.BinaryMessage, p)
if err != nil {
return 0, err
}
return len(p), nil
}
// Read reads the current websocket frame
func (c *websocketConnector) Read(p []byte) (int, error) {
c.rio.Lock()
defer c.rio.Unlock()
for {
if c.r == nil {
// Advance to next message.
var err error
_, c.r, err = c.NextReader()
if err != nil {
return 0, err
}
}
n, err := c.r.Read(p)
if err == io.EOF {
// At end of message.
c.r = nil
if n > 0 {
return n, nil
}
// No data read, continue to next message.
continue
}
return n, err
}
}