mirror of https://github.com/ariejan/i6502.git
109 lines
2.0 KiB
Go
109 lines
2.0 KiB
Go
package main
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import (
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"github.com/gorilla/websocket"
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"log"
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"net/http"
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"time"
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)
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const (
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pongWait = 60 * time.Second
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pingPeriod = (pongWait * 9) / 10
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maxMessageSize = 512
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)
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type connection struct {
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// The i6502 machine
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machine *Machine
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// Websocket connection
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ws *websocket.Conn
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// Outgoing data channel
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send chan []byte
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}
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var (
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upgrader = websocket.Upgrader{
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ReadBufferSize: 1024,
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WriteBufferSize: 1024,
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}
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)
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// Pump received websocket messages into the machine
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func (c *connection) readPump() {
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defer func() {
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c.ws.Close()
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}()
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c.ws.SetReadLimit(maxMessageSize)
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c.ws.SetReadDeadline(time.Now().Add(pongWait))
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c.ws.SetPongHandler(func(string) error { c.ws.SetReadDeadline(time.Now().Add(pongWait)); return nil })
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for {
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_, message, err := c.ws.ReadMessage()
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if err != nil {
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break
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}
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c.writeBytesToMachine(message)
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}
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}
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// Pump serial output from the machine into the socket
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func (c *connection) writePump() {
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ticker := time.NewTicker(pingPeriod)
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defer func() {
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c.ws.Close()
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}()
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for {
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select {
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case data, ok := <-c.machine.SerialTx:
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if !ok {
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c.write(websocket.CloseMessage, []byte{})
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return
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}
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if err := c.write(websocket.TextMessage, []byte{data}); err != nil {
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return
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}
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case <-ticker.C:
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if err := c.write(websocket.PingMessage, []byte{}); err != nil {
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return
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}
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}
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}
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}
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func (c *connection) write(messageType int, payload []byte) error {
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c.ws.SetWriteDeadline(time.Now().Add(10 * time.Second))
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return c.ws.WriteMessage(messageType, payload)
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}
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func (c *connection) writeBytesToMachine(data []byte) {
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for _, b := range data {
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log.Printf("%c", b)
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c.machine.SerialRx <- b
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}
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}
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func serveWs(w http.ResponseWriter, r *http.Request) {
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if r.Method != "GET" {
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http.Error(w, "Method not allowed", 405)
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return
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}
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ws, err := upgrader.Upgrade(w, r, nil)
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if err != nil {
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log.Println(err)
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return
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}
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c := &connection{machine: CreateMachine(), send: make(chan []byte, 256), ws: ws}
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go c.writePump()
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c.machine.Reset()
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c.readPump()
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}
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