Optimize Download

src/Core/ServiceWrapper/Main.cs

@@ -8,6 +8,9 @@ using System.Runtime.InteropServices;
 using System.ServiceProcess;
 using System.Text;
 using System.Threading;
+#if VNEXT
+using System.Threading.Tasks;
+#endif
 using log4net;
 using log4net.Appender;
 using log4net.Config;
@@ -199,23 +202,54 @@ namespace winsw
             HandleFileCopies();
 
             // handle downloads
-            foreach (Download d in _descriptor.Downloads)
+#if VNEXT
+            List<Download> downloads = _descriptor.Downloads;
+            Task[] tasks = new Task[downloads.Count];
+            for (int i = 0; i < downloads.Count; i++)
             {
-                string downloadMsg = "Downloading: " + d.From + " to " + d.To + ". failOnError=" + d.FailOnError;
+                Download download = downloads[i];
-                LogEvent(downloadMsg);
+                string downloadMessage = $"Downloading: {download.From} to {download.To}. failOnError={download.FailOnError.ToString()}";
-                Log.Info(downloadMsg);
+                LogEvent(downloadMessage);
+                Log.Info(downloadMessage);
+                tasks[i] = download.PerformAsync();
+            }
+
+            Task.WhenAll(tasks);
+            for (int i = 0; i < tasks.Length; i++)
+            {
+                if (tasks[i].IsFaulted)
+                {
+                    Download download = downloads[i];
+                    string errorMessage = $"Failed to download {download.From} to {download.To}";
+                    AggregateException exception = tasks[i].Exception!;
+                    LogEvent($"{errorMessage}. {exception.Message}");
+                    Log.Error(errorMessage, exception);
+
+                    // TODO: move this code into the download logic
+                    if (download.FailOnError)
+                    {
+                        throw new IOException(errorMessage, exception);
+                    }
+                }
+            }
+#else
+            foreach (Download download in _descriptor.Downloads)
+            {
+                string downloadMessage = $"Downloading: {download.From} to {download.To}. failOnError={download.FailOnError.ToString()}";
+                LogEvent(downloadMessage);
+                Log.Info(downloadMessage);
                 try
                 {
-                    d.Perform();
+                    download.Perform();
                 }
                 catch (Exception e)
                 {
-                    string errorMessage = "Failed to download " + d.From + " to " + d.To;
+                    string errorMessage = $"Failed to download {download.From} to {download.To}";
-                    LogEvent(errorMessage + ". " + e.Message);
+                    LogEvent($"{errorMessage}. {e.Message}");
                     Log.Error(errorMessage, e);
 
                     // TODO: move this code into the download logic
-                    if (d.FailOnError)
+                    if (download.FailOnError)
                     {
                         throw new IOException(errorMessage, e);
                     }
@@ -223,6 +257,7 @@ namespace winsw
                     // Else just keep going
                 }
             }
+#endif
 
             string? startarguments = _descriptor.Startarguments;
 

src/Core/WinSWCore/Download.cs

@@ -2,6 +2,9 @@ using System;
 using System.IO;
 using System.Net;
 using System.Text;
+#if VNEXT
+using System.Threading.Tasks;
+#endif
 using System.Xml;
 using winsw.Util;
 
@@ -103,9 +106,13 @@ namespace winsw
         /// <exception cref="WebException">
         ///     Download failure. FailOnError flag should be processed outside.
         /// </exception>
+#if VNEXT
+        public async Task PerformAsync()
+#else
         public void Perform()
+#endif
         {
-            WebRequest req = WebRequest.Create(From);
+            WebRequest request = WebRequest.Create(From);
 
             switch (Auth)
             {
@@ -114,43 +121,57 @@ namespace winsw
                     break;
 
                 case AuthType.sspi:
-                    req.UseDefaultCredentials = true;
+                    request.UseDefaultCredentials = true;
-                    req.PreAuthenticate = true;
+                    request.PreAuthenticate = true;
-                    req.Credentials = CredentialCache.DefaultCredentials;
+                    request.Credentials = CredentialCache.DefaultCredentials;
                     break;
 
                 case AuthType.basic:
-                    SetBasicAuthHeader(req, Username!, Password!);
+                    SetBasicAuthHeader(request, Username!, Password!);
                     break;
 
                 default:
                     throw new WebException("Code defect. Unsupported authentication type: " + Auth);
             }
 
-            WebResponse rsp = req.GetResponse();
+            string tmpFilePath = To + ".tmp";
-            FileStream tmpstream = new FileStream(To + ".tmp", FileMode.Create);
+#if VNEXT
-            CopyStream(rsp.GetResponseStream(), tmpstream);
+            using (WebResponse response = await request.GetResponseAsync())
-            // only after we successfully downloaded a file, overwrite the existing one
+#else
+            using (WebResponse response = request.GetResponse())
+#endif
+            using (Stream responseStream = response.GetResponseStream())
+            using (FileStream tmpStream = new FileStream(tmpFilePath, FileMode.Create))
+            {
+#if VNEXT
+                await responseStream.CopyToAsync(tmpStream);
+#elif NET20
+                CopyStream(responseStream, tmpStream);
+#else
+                responseStream.CopyTo(tmpStream);
+#endif
+            }
+
+#if NETCOREAPP
+            File.Move(tmpFilePath, To, true);
+#else
             if (File.Exists(To))
                 File.Delete(To);
 
-            File.Move(To + ".tmp", To);
+            File.Move(tmpFilePath, To);
+#endif
         }
+#if NET20
 
-        private static void CopyStream(Stream i, Stream o)
+        private static void CopyStream(Stream source, Stream destination)
         {
-            byte[] buf = new byte[8192];
+            byte[] buffer = new byte[8192];
-            while (true)
+            int read;
+            while ((read = source.Read(buffer, 0, buffer.Length)) != 0)
             {
-                int len = i.Read(buf, 0, buf.Length);
+                destination.Write(buffer, 0, read);
-                if (len <= 0)
-                    break;
-
-                o.Write(buf, 0, len);
             }
-
-            i.Close();
-            o.Close();
         }
+#endif
     }
 }