From 61f50dbbf518aa13d02beb03490a32181780a38e Mon Sep 17 00:00:00 2001
From: moberacker <markus.oberacker@ptv.de>
Date: Thu, 21 Feb 2019 11:13:19 +0100
Subject: [PATCH] initial checkin

---
 Log4ALA/HttpRequestExtensions.cs | 24 ++++++++++++++++++
 Log4ALA/TimeoutHandler.cs        | 43 ++++++++++++++++++++++++++++++++
 2 files changed, 67 insertions(+)
 create mode 100644 Log4ALA/HttpRequestExtensions.cs
 create mode 100644 Log4ALA/TimeoutHandler.cs

diff --git a/Log4ALA/HttpRequestExtensions.cs b/Log4ALA/HttpRequestExtensions.cs
new file mode 100644
index 0000000..ce4492c
--- /dev/null
+++ b/Log4ALA/HttpRequestExtensions.cs
@@ -0,0 +1,24 @@
+using System;
+using System.Net.Http;
+
+namespace Log4ALA
+{
+    public static class HttpRequestExtensions
+    {
+        private static string TimeoutPropertyKey = "RequestTimeout";
+
+        public static void SetTimeout(this HttpRequestMessage request, TimeSpan? timeout)
+        {
+            if (request == null) throw new ArgumentNullException(nameof(request));
+            request.Properties[TimeoutPropertyKey] = timeout;
+        }
+
+        public static TimeSpan? GetTimeout(this HttpRequestMessage request)
+        {
+            if (request == null) throw new ArgumentNullException(nameof(request));
+            if (request.Properties.TryGetValue(TimeoutPropertyKey, out var value) && value is TimeSpan timeout)
+                return timeout;
+            return null;
+        }
+    }
+}
diff --git a/Log4ALA/TimeoutHandler.cs b/Log4ALA/TimeoutHandler.cs
new file mode 100644
index 0000000..5abf621
--- /dev/null
+++ b/Log4ALA/TimeoutHandler.cs
@@ -0,0 +1,43 @@
+using System;
+using System.Net.Http;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace Log4ALA
+{
+    public class TimeoutHandler : DelegatingHandler
+    {
+        public TimeSpan DefaultTimeout { get; set; } = TimeSpan.FromSeconds(100);
+
+        protected async override Task<HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            using (var cts = GetCancellationTokenSource(request, cancellationToken))
+            {
+                try
+                {
+                    return await base.SendAsync(request, cts?.Token ?? cancellationToken);
+                }
+                catch (OperationCanceledException) when (!cancellationToken.IsCancellationRequested)
+                {
+                    throw new TimeoutException();
+                }
+            }
+        }
+
+        private CancellationTokenSource GetCancellationTokenSource(HttpRequestMessage request, CancellationToken cancellationToken)
+        {
+            var timeout = request.GetTimeout() ?? DefaultTimeout;
+            if (timeout == Timeout.InfiniteTimeSpan)
+            {
+                // No need to create a CTS if there's no timeout
+                return null;
+            }
+            else
+            {
+                var cts = CancellationTokenSource.CreateLinkedTokenSource(cancellationToken);
+                cts.CancelAfter(timeout);
+                return cts;
+            }
+        }
+    }
+}