From 164879428379ef1de0008a2afde4c6de6ecc83e1 Mon Sep 17 00:00:00 2001
From: Fergal Moran <fergal.moran@gmail.com>
Date: Tue, 6 Mar 2018 18:54:26 +0000
Subject: [PATCH] Update async process handling

---
 server/Dockerfile                             |  3 ++-
 server/Services/Downloader/AudioDownloader.cs | 17 ++++++++++---
 server/Utils/Extensions/DateTime.cs           | 12 ++++-----
 server/Utils/Extensions/ProcessExtensions.cs  | 25 +++++++++++++++++++
 4 files changed, 46 insertions(+), 11 deletions(-)
 create mode 100644 server/Utils/Extensions/ProcessExtensions.cs

diff --git a/server/Dockerfile b/server/Dockerfile
index 1846551..ec5e6cc 100755
--- a/server/Dockerfile
+++ b/server/Dockerfile
@@ -19,7 +19,8 @@ RUN apk add --no-cache --update \
     curl && \
     ln -s /usr/lib/libuv.so.1 /usr/lib/libuv.so && \
     curl -L https://yt-dl.org/downloads/latest/youtube-dl -o /usr/local/bin/youtube-dl && \
-    chmod a+rx /usr/local/bin/youtube-dl
+    chmod a+rx /usr/local/bin/youtube-dl && \
+    youtube-dl -U
 
 COPY --from=build-env /out .
 ENTRYPOINT ["dotnet", "PodNoms.Api.dll"]
diff --git a/server/Services/Downloader/AudioDownloader.cs b/server/Services/Downloader/AudioDownloader.cs
index 8b4f108..3b968a9 100644
--- a/server/Services/Downloader/AudioDownloader.cs
+++ b/server/Services/Downloader/AudioDownloader.cs
@@ -1,11 +1,12 @@
 using System;
-using Newtonsoft.Json;
-using PodNoms.Api.Models.ViewModels;
 using System.Diagnostics;
 using System.Dynamic;
 using System.IO;
 using System.Text;
 using System.Threading.Tasks;
+using Newtonsoft.Json;
+using PodNoms.Api.Models.ViewModels;
+using PodNoms.Api.Utils.Extensions;
 
 namespace PodNoms.Api.Services.Downloader {
     public class AudioDownloader {
@@ -55,8 +56,18 @@ namespace PodNoms.Api.Services.Downloader {
                 CreateNoWindow = true
                 }
             };
+            proc.EnableRaisingEvents = true;
+            proc.Exited += ((e, s) => {
+                // Console.WriteLine ($"{e.ToString()} - {s.ToString()}");
+            });
+            proc.OutputDataReceived += ((e, s) => {
+                Console.WriteLine ($"{e.ToString()} - {s.ToString()}");
+            });
+            proc.ErrorDataReceived += ((e, s) => {
+                Console.WriteLine ($"{e.ToString()} - {s.ToString()}");
+            });
             proc.Start ();
-            await (Task.Run (() => proc.WaitForExit ()));
+            await proc.WaitForExitAsync ();
             return (proc.ExitCode == 0);
         }
 
diff --git a/server/Utils/Extensions/DateTime.cs b/server/Utils/Extensions/DateTime.cs
index 5ec84f1..7c6e23e 100755
--- a/server/Utils/Extensions/DateTime.cs
+++ b/server/Utils/Extensions/DateTime.cs
@@ -3,13 +3,11 @@ using System;
 namespace PodNoms.Api.Utils.Extensions
 {
 
-    public static class DateTimeExtensions
-    {
-        public static string ToRFC822String(this DateTime datetime)
-        {
-            return datetime.ToString("ddd',' d MMM yyyy HH':'mm':'ss")
-                + " "
-                + datetime.ToString("zzzz").Replace(":", "");
+    public static class DateTimeExtensions {
+        public static string ToRFC822String (this DateTime datetime) {
+            return datetime.ToString ("ddd',' d MMM yyyy HH':'mm':'ss") +
+                " " +
+                datetime.ToString ("zzzz").Replace (":", "");
         }
     }
 }
\ No newline at end of file
diff --git a/server/Utils/Extensions/ProcessExtensions.cs b/server/Utils/Extensions/ProcessExtensions.cs
new file mode 100644
index 0000000..bcfd89e
--- /dev/null
+++ b/server/Utils/Extensions/ProcessExtensions.cs
@@ -0,0 +1,25 @@
+using System.Diagnostics;
+using System.Threading;
+using System.Threading.Tasks;
+
+namespace PodNoms.Api.Utils.Extensions {
+    public static class ProcessExtensions {
+        /// <summary>
+        /// Waits asynchronously for the process to exit.
+        /// </summary>
+        /// <param name="process">The process to wait for cancellation.</param>
+        /// <param name="cancellationToken">A cancellation token. If invoked, the task will return 
+        /// immediately as canceled.</param>
+        /// <returns>A Task representing waiting for the process to end.</returns>
+        public static Task WaitForExitAsync (this Process process,
+            CancellationToken cancellationToken = default (CancellationToken)) {
+            var tcs = new TaskCompletionSource<object> ();
+            process.EnableRaisingEvents = true;
+            process.Exited += (sender, args) => tcs.TrySetResult (null);
+            if (cancellationToken != default (CancellationToken))
+                cancellationToken.Register (tcs.SetCanceled);
+
+            return tcs.Task;
+        }
+    }
+}
\ No newline at end of file