Ooui-tws-port/Ooui.AspNetCore/WebSocketHandler.cs

110 lines
3.4 KiB
C#

using System;
using System.Collections.Concurrent;
using System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
namespace Ooui.AspNetCore
{
public static class WebSocketHandler
{
public static string WebSocketPath { get; set; } = "/ooui.ws";
public static TimeSpan SessionTimeout { get; set; } = TimeSpan.FromMinutes (5);
static readonly ConcurrentDictionary<string, PendingSession> pendingSessions =
new ConcurrentDictionary<string, PendingSession> ();
public static string BeginSession (HttpContext context, Element element)
{
var id = Guid.NewGuid ().ToString ("N");
var s = new PendingSession {
Element = element,
RequestTimeUtc = DateTime.UtcNow,
};
if (!pendingSessions.TryAdd (id, s)) {
throw new Exception ("Failed to schedule pending session");
}
return id;
}
public static async Task HandleWebSocketRequestAsync (HttpContext context)
{
void BadRequest (string message)
{
context.Response.StatusCode = StatusCodes.Status400BadRequest;
context.Response.ContentType = "text/plain; charset=utf-8";
using (var sw = new System.IO.StreamWriter (context.Response.Body)) {
sw.WriteLine (message);
}
}
//
// Make sure we get a good ID
//
if (!context.Request.Query.TryGetValue ("id", out var idValues)) {
BadRequest ("Missing `id`");
return;
}
var id = idValues.LastOrDefault ();
if (id == null || id.Length != 32) {
BadRequest ("Invalid `id`");
return;
}
//
// Find the pending session
//
if (!pendingSessions.TryRemove (id, out var pendingSession)) {
BadRequest ("Unknown `id`");
return;
}
//
// Reject the session if it's old
//
if ((DateTime.UtcNow - pendingSession.RequestTimeUtc) > SessionTimeout) {
BadRequest ("Old `id`");
return;
}
//
// Set the element's dimensions
//
if (!context.Request.Query.TryGetValue ("w", out var wValues) || wValues.Count < 1) {
BadRequest ("Missing `w`");
return;
}
if (!context.Request.Query.TryGetValue ("h", out var hValues) || hValues.Count < 1) {
BadRequest ("Missing `h`");
return;
}
if (!double.TryParse (wValues.Last (), out var w))
w = 640;
if (!double.TryParse (hValues.Last (), out var h))
h = 480;
//
// OK, Run
//
var token = CancellationToken.None;
var webSocket = await context.WebSockets.AcceptWebSocketAsync ("ooui");
var session = new Ooui.UI.Session (webSocket, pendingSession.Element, w, h, token);
await session.RunAsync ().ConfigureAwait (false);
}
class PendingSession
{
public Element Element;
public DateTime RequestTimeUtc;
}
}
}