Ooui-tws-port/Ooui/UI.cs

405 lines
15 KiB
C#

using System;
using System.Collections.Generic;
using System.IO;
using System.Text;
using System.Threading;
using System.Threading.Tasks;
using System.Net;
using System.Net.WebSockets;
namespace Ooui
{
public static class UI
{
static CancellationTokenSource serverCts;
static readonly Dictionary<string, Func<Element>> publishedPaths =
new Dictionary<string, Func<Element>> ();
static readonly byte[] clientJsBytes;
static string host = "*";
public static string Host {
get => host;
set {
if (!string.IsNullOrWhiteSpace (value) && host != value) {
host = value;
Restart ();
}
}
}
static int port = 8080;
public static int Port {
get => port;
set {
if (port != value) {
port = value;
Restart ();
}
}
}
static UI ()
{
var asm = typeof(UI).Assembly;
// System.Console.WriteLine("ASM = {0}", asm);
// foreach (var n in asm.GetManifestResourceNames()) {
// System.Console.WriteLine(" {0}", n);
// }
using (var s = asm.GetManifestResourceStream ("Ooui.Client.js")) {
using (var r = new StreamReader (s)) {
clientJsBytes = Encoding.UTF8.GetBytes (r.ReadToEnd ());
}
}
}
public static void Publish (string path, Func<Element> elementCtor)
{
Console.WriteLine ($"PUBLISH {path}");
lock (publishedPaths) publishedPaths[path] = elementCtor;
Start ();
}
public static void Publish (string path, Element element)
{
Publish (path, () => element);
}
static void Start ()
{
if (serverCts != null) return;
serverCts = new CancellationTokenSource ();
var token = serverCts.Token;
var listenerPrefix = $"http://{host}:{port}/";
Task.Run (() => RunAsync (listenerPrefix, token), token);
}
static void Stop ()
{
var scts = serverCts;
if (scts == null) return;
serverCts = null;
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine ($"Stopping...");
Console.ResetColor ();
scts.Cancel ();
}
static void Restart ()
{
if (serverCts == null) return;
Stop ();
Start ();
}
static async Task RunAsync (string listenerPrefix, CancellationToken token)
{
HttpListener listener = null;
var started = false;
while (!started && !token.IsCancellationRequested) {
try {
listener = new HttpListener ();
listener.Prefixes.Add (listenerPrefix);
listener.Start ();
started = true;
}
catch (System.Net.Sockets.SocketException ex) when
(ex.SocketErrorCode == System.Net.Sockets.SocketError.AddressAlreadyInUse) {
var wait = 5;
Console.WriteLine ($"{listenerPrefix} is in use, trying again in {wait} seconds...");
await Task.Delay (wait * 1000).ConfigureAwait (false);
}
}
Console.ForegroundColor = ConsoleColor.Green;
Console.WriteLine ($"Listening at {listenerPrefix}...");
Console.ResetColor ();
while (!token.IsCancellationRequested) {
var listenerContext = await listener.GetContextAsync ().ConfigureAwait (false);
if (listenerContext.Request.IsWebSocketRequest) {
ProcessWebSocketRequest (listenerContext, token);
}
else {
ProcessRequest (listenerContext, token);
}
}
}
static void ProcessRequest (HttpListenerContext listenerContext, CancellationToken token)
{
var url = listenerContext.Request.Url;
var path = url.LocalPath;
Console.WriteLine ($"{listenerContext.Request.HttpMethod} {url.LocalPath}");
var response = listenerContext.Response;
Func<Element> ctor;
if (path == "/client.js") {
response.ContentLength64 = clientJsBytes.LongLength;
response.ContentType = "application/javascript";
response.ContentEncoding = Encoding.UTF8;
response.AddHeader ("Cache-Control", "public, max-age=3600");
using (var s = response.OutputStream) {
s.Write (clientJsBytes, 0, clientJsBytes.Length);
}
}
else {
var found = false;
lock (publishedPaths) found = publishedPaths.TryGetValue (path, out ctor);
if (found) {
WriteElementHtml (path, response);
}
else {
response.StatusCode = 404;
response.Close ();
}
}
}
static void WriteElementHtml (string elementPath, HttpListenerResponse response)
{
response.StatusCode = 200;
response.ContentType = "text/html";
response.ContentEncoding = Encoding.UTF8;
var html = Encoding.UTF8.GetBytes ($@"<html>
<head><title>{elementPath}</title></head>
<body>
<script>rootElementPath = ""{elementPath}"";</script>
<script src=""/client.js""> </script></body>
</html>");
response.ContentLength64 = html.LongLength;
using (var s = response.OutputStream) {
s.Write (html, 0, html.Length);
}
response.Close ();
}
static async void ProcessWebSocketRequest (HttpListenerContext listenerContext, CancellationToken serverToken)
{
//
// Find the element
//
var url = listenerContext.Request.Url;
var path = url.LocalPath;
Func<Element> ctor;
var found = false;
lock (publishedPaths) found = publishedPaths.TryGetValue (path, out ctor);
if (!found) {
listenerContext.Response.StatusCode = 404;
listenerContext.Response.Close ();
return;
}
Element element = null;
try {
element = ctor ();
}
catch (Exception ex) {
listenerContext.Response.StatusCode = 500;
listenerContext.Response.Close();
Error ("Failed to create element", ex);
return;
}
//
// Connect the web socket
//
WebSocketContext webSocketContext = null;
WebSocket webSocket = null;
try {
webSocketContext = await listenerContext.AcceptWebSocketAsync (subProtocol: "ooui").ConfigureAwait (false);
webSocket = webSocketContext.WebSocket;
Console.WriteLine ("WEBSOCKET {0}", listenerContext.Request.Url.LocalPath);
}
catch (Exception ex) {
listenerContext.Response.StatusCode = 500;
listenerContext.Response.Close();
Error ("Failed to accept WebSocket", ex);
return;
}
//
// Create a new session and let it handle everything from here
//
try {
var session = new Session (webSocket, element);
await session.RunAsync (serverToken).ConfigureAwait (false);
}
catch (WebSocketException ex) when (ex.WebSocketErrorCode == WebSocketError.ConnectionClosedPrematurely) {
// The remote party closed the WebSocket connection without completing the close handshake.
}
catch (Exception ex) {
Error ("Web socket failed", ex);
}
finally {
webSocket?.Dispose ();
}
}
static async Task SendMessageAsync (WebSocket webSocket, Message message, EventTarget target, HashSet<string> createdIds, CancellationToken token)
{
//
// Make sure all the referenced objects have been created
//
if (message.MessageType == MessageType.Create) {
createdIds.Add (message.TargetId);
}
else {
if (!createdIds.Contains (message.TargetId)) {
createdIds.Add (message.TargetId);
await SendStateMessagesAsync (webSocket, target.GetElementById (message.TargetId), createdIds, token).ConfigureAwait (false);
}
if (message.Value is Array a) {
for (var i = 0; i < a.Length; i++) {
// Console.WriteLine ($"A{i} = {a.GetValue(i)}");
if (a.GetValue (i) is EventTarget e && !createdIds.Contains (e.Id)) {
createdIds.Add (e.Id);
await SendStateMessagesAsync (webSocket, e, createdIds, token).ConfigureAwait (false);
}
}
}
}
//
// Now actually send this message
//
if (token.IsCancellationRequested)
return;
var json = Newtonsoft.Json.JsonConvert.SerializeObject (message);
var outputBuffer = new ArraySegment<byte> (Encoding.UTF8.GetBytes (json));
await webSocket.SendAsync (outputBuffer, WebSocketMessageType.Text, true, token).ConfigureAwait (false);
}
static async Task SendStateMessagesAsync (WebSocket webSocket, EventTarget target, HashSet<string> createdIds, CancellationToken token)
{
if (target == null) return;
foreach (var m in target.StateMessages) {
if (token.IsCancellationRequested) return;
await SendMessageAsync (webSocket, m, target, createdIds, token).ConfigureAwait (false);
}
}
static void Error (string message, Exception ex)
{
Console.ForegroundColor = ConsoleColor.Red;
Console.WriteLine ("{0}: {1}", message, ex);
Console.ResetColor ();
}
class Session
{
readonly WebSocket webSocket;
readonly Element element;
public Session (WebSocket webSocket, Element element)
{
this.webSocket = webSocket;
this.element = element;
}
public async Task RunAsync (CancellationToken serverToken)
{
//
// Create a new session cancellation token that will trigger
// automatically if the server shutsdown or the session shutsdown.
//
var sessionCts = new CancellationTokenSource ();
var linkedCts = CancellationTokenSource.CreateLinkedTokenSource (serverToken, sessionCts.Token);
var token = linkedCts.Token;
//
// Keep a list of all the elements for which we've transmitted the initial state
//
var createdIds = new HashSet<string> {
"window",
"document",
"document.body",
};
//
// Preparse handlers for the element
//
Action<Message> onElementMessage = null;
onElementMessage = async m => {
if (webSocket == null) return;
try {
await SendMessageAsync (webSocket, m, element, createdIds, token).ConfigureAwait (false);
}
catch (Exception ex) {
if (webSocket.State == WebSocketState.Aborted) {
Error ("WebSocket is aborted, cancelling session", ex);
element.MessageSent -= onElementMessage;
sessionCts.Cancel ();
}
else {
Error ("Failed to handle element message", ex);
}
}
};
//
// Start watching for changes in the element
//
element.MessageSent += onElementMessage;
try {
//
// Add it to the document body
//
await SendMessageAsync (webSocket, Message.Call ("document.body", "appendChild", element),
element, createdIds, token).ConfigureAwait (false);
//
// Listen for events
//
var receiveBuffer = new byte[1024];
while (webSocket.State == WebSocketState.Open && !token.IsCancellationRequested) {
var receiveResult = await webSocket.ReceiveAsync(new ArraySegment<byte>(receiveBuffer), token).ConfigureAwait (false);
if (receiveResult.MessageType == WebSocketMessageType.Close) {
await webSocket.CloseAsync (WebSocketCloseStatus.NormalClosure, "", token).ConfigureAwait (false);
sessionCts.Cancel ();
}
else if (receiveResult.MessageType == WebSocketMessageType.Binary) {
await webSocket.CloseAsync (WebSocketCloseStatus.InvalidMessageType, "Cannot accept binary frame", token).ConfigureAwait (false);
sessionCts.Cancel ();
}
else {
var size = receiveResult.Count;
while (!receiveResult.EndOfMessage) {
if (size >= receiveBuffer.Length) {
await webSocket.CloseAsync (WebSocketCloseStatus.MessageTooBig, "Message too big", token).ConfigureAwait (false);
return;
}
receiveResult = await webSocket.ReceiveAsync (new ArraySegment<byte>(receiveBuffer, size, receiveBuffer.Length - size), token).ConfigureAwait (false);
size += receiveResult.Count;
}
var receivedString = Encoding.UTF8.GetString (receiveBuffer, 0, size);
try {
// Console.WriteLine ("RECEIVED: {0}", receivedString);
var message = Newtonsoft.Json.JsonConvert.DeserializeObject<Message> (receivedString);
element.Receive (message);
}
catch (Exception ex) {
Error ("Failed to process received message", ex);
}
}
}
}
finally {
element.MessageSent -= onElementMessage;
}
}
}
}
}