Change IBackend and IStreamingBackend to return Task for Put()

27 files changed, 293 insertions, 214 deletions

diff --git a/Duplicati/Library/Backend/AlternativeFTP/AlternativeFTPBackend.cs b/Duplicati/Library/Backend/AlternativeFTP/AlternativeFTPBackend.cs
index 680131057..42a13f356 100644
--- a/Duplicati/Library/Backend/AlternativeFTP/AlternativeFTPBackend.cs
+++ b/Duplicati/Library/Backend/AlternativeFTP/AlternativeFTPBackend.cs
@@ -18,17 +18,19 @@
 //

 #endregion

 

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

 using System;

 using System.Collections.Generic;

 using System.Linq;

 using System.Net.FtpClient;

 using System.Net.Security;

 using System.Security.Authentication;

-using Duplicati.Library.Interface;

-using Uri = System.Uri;

+using System.Threading;

+using System.Threading.Tasks;

 using CoreUtility = Duplicati.Library.Utility.Utility;

-using Duplicati.Library.Common.IO;
-
+using Uri = System.Uri;

+

 namespace Duplicati.Library.Backend.AlternativeFTP

 {

     // ReSharper disable once RedundantExtendsListEntry

@@ -304,7 +306,7 @@ namespace Duplicati.Library.Backend.AlternativeFTP
             return list;

         }

 

-        public void Put(string remotename, System.IO.Stream input)

+        public Task Put(string remotename, System.IO.Stream input, CancellationToken cancelToken)

         {

             string remotePath = remotename;

             long streamLen = -1;

@@ -355,7 +357,7 @@ namespace Duplicati.Library.Backend.AlternativeFTP
                         {

                             if (fileEntry.Size < 0 || streamLen < 0 || fileEntry.Size == streamLen)

                             {

-                                return;

+                                return Task.FromResult(true);

                             }

 

                             throw new UserInformationException(Strings.ListVerifySizeFailure(remotename, fileEntry.Size, streamLen), "AftpListVerifySizeFailure");

@@ -374,13 +376,15 @@ namespace Duplicati.Library.Backend.AlternativeFTP
 

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

-        public void Put(string remotename, string localname)

+        public Task Put(string remotename, string localname, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.Open(localname, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read))

             {

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

             }

         }

 

@@ -485,7 +489,7 @@ namespace Duplicati.Library.Backend.AlternativeFTP
             {

                 try

                 {

-                    Put(TEST_FILE_NAME, testStream);

+                    Put(TEST_FILE_NAME, testStream, CancellationToken.None).Wait();

                 }

                 catch (Exception e)

                 {

diff --git a/Duplicati/Library/Backend/AmazonCloudDrive/AmzCD.cs b/Duplicati/Library/Backend/AmazonCloudDrive/AmzCD.cs
index 441eda720..3791a3e7c 100644
--- a/Duplicati/Library/Backend/AmazonCloudDrive/AmzCD.cs
+++ b/Duplicati/Library/Backend/AmazonCloudDrive/AmzCD.cs
@@ -14,15 +14,17 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

-using System;

-using System.Linq;

-using System.Collections.Generic;

+using Duplicati.Library.Common.IO;
 using Duplicati.Library.Interface;

 using Newtonsoft.Json;

+using System;

+using System.Collections.Generic;

 using System.IO;

+using System.Linq;

 using System.Net;

-using Duplicati.Library.Common.IO;
-
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend.AmazonCloudDrive

 {

     public class AmzCD : IBackend, IStreamingBackend, IRenameEnabledBackend

@@ -313,7 +315,7 @@ namespace Duplicati.Library.Backend.AmazonCloudDrive
 

         #region IStreamingBackend implementation

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             EnforceConsistencyDelay(remotename);

 

@@ -362,6 +364,8 @@ namespace Duplicati.Library.Backend.AmazonCloudDrive
             {

                 SetWaitUntil(remotename, DateTime.Now + m_delayTimeSpan);

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

@@ -428,10 +432,10 @@ namespace Duplicati.Library.Backend.AmazonCloudDrive
 

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/AzureBlob/AzureBlobBackend.cs b/Duplicati/Library/Backend/AzureBlob/AzureBlobBackend.cs
index 176e42a6b..08b66ef43 100644
--- a/Duplicati/Library/Backend/AzureBlob/AzureBlobBackend.cs
+++ b/Duplicati/Library/Backend/AzureBlob/AzureBlobBackend.cs
@@ -18,10 +18,11 @@
 // 
 #endregion
 
-using System;
+using Duplicati.Library.Interface;
 using System.Collections.Generic;
 using System.IO;
-using Duplicati.Library.Interface;
+using System.Threading;

+using System.Threading.Tasks;

 
 namespace Duplicati.Library.Backend.AzureBlob
 {
@@ -87,18 +88,19 @@ namespace Duplicati.Library.Backend.AzureBlob
             return _azureBlob.ListContainerEntries();
         }
 
-        public void Put(string remotename, string localname)
+        public Task Put(string remotename, string localname, CancellationToken cancelToken)
         {
             using (var fs = File.Open(localname,
                 FileMode.Open, FileAccess.Read, FileShare.Read))
             {
-                Put(remotename, fs);
+                return Put(remotename, fs, cancelToken);
             }
         }
 
-        public void Put(string remotename, Stream input)
+        public Task Put(string remotename, Stream input, CancellationToken cancelToken)
         {
             _azureBlob.AddFileStream(remotename, input);
+            return Task.FromResult(true);
         }
 
         public void Get(string remotename, string localname)
diff --git a/Duplicati/Library/Backend/Backblaze/B2.cs b/Duplicati/Library/Backend/Backblaze/B2.cs
index 460726da8..1ba169a05 100644
--- a/Duplicati/Library/Backend/Backblaze/B2.cs
+++ b/Duplicati/Library/Backend/Backblaze/B2.cs
@@ -14,14 +14,16 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

-using System;

-using System.Linq;

-using System.Collections.Generic;

-using Duplicati.Library.Utility;

-using Duplicati.Library.Interface;

 using Duplicati.Library.Common.IO;

+using Duplicati.Library.Interface;

+using Duplicati.Library.Utility;

 using Newtonsoft.Json;

+using System;

+using System.Collections.Generic;

+using System.Linq;

 using System.Net;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Backend.Backblaze

 {

@@ -188,7 +190,7 @@ namespace Duplicati.Library.Backend.Backblaze
             }

         }

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             TempFile tmp = null;

 

@@ -285,6 +287,8 @@ namespace Duplicati.Library.Backend.Backblaze
                 {

                 }

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

@@ -368,10 +372,10 @@ namespace Duplicati.Library.Backend.Backblaze
                 ).ToList();

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/Box/BoxBackend.cs b/Duplicati/Library/Backend/Box/BoxBackend.cs
index 9f2b828fc..6a68b9e24 100644
--- a/Duplicati/Library/Backend/Box/BoxBackend.cs
+++ b/Duplicati/Library/Backend/Box/BoxBackend.cs
@@ -14,13 +14,15 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

-using System;

-using System.Linq;

-using Duplicati.Library.Interface;

 using Duplicati.Library.Common.IO;

-using System.Collections.Generic;

+using Duplicati.Library.Interface;

 using Newtonsoft.Json;

+using System;

+using System.Collections.Generic;

+using System.Linq;

 using System.Net;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Backend.Box

 {

@@ -196,7 +198,7 @@ namespace Duplicati.Library.Backend.Box
 

         #region IStreamingBackend implementation

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             var createreq = new CreateItemRequest() {

                 Name = remotename,

@@ -237,6 +239,8 @@ namespace Duplicati.Library.Backend.Box
                 m_filecache.Clear();

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

@@ -257,10 +261,10 @@ namespace Duplicati.Library.Backend.Box
                 select (IFileEntry)new FileEntry(n.Name, n.Size, n.ModifiedAt, n.ModifiedAt) { IsFolder = n.Type == "folder" };

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/CloudFiles/CloudFiles.cs b/Duplicati/Library/Backend/CloudFiles/CloudFiles.cs
index 1519b9ecf..5ba0c9730 100644
--- a/Duplicati/Library/Backend/CloudFiles/CloudFiles.cs
+++ b/Duplicati/Library/Backend/CloudFiles/CloudFiles.cs
@@ -17,14 +17,14 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

 using System;

 using System.Collections.Generic;

-using System.Linq;

-using System.Text;

 using System.Net;

-using Duplicati.Library.Interface;

-using Duplicati.Library.Common.IO;
-
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend

 {

     public class CloudFiles : IBackend, IStreamingBackend

@@ -194,10 +194,10 @@ namespace Duplicati.Library.Backend
             } while (repeat);

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

@@ -314,7 +314,7 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             HttpWebRequest req = CreateRequest("/" + remotename, "");

             req.Method = "PUT";

@@ -394,6 +394,8 @@ namespace Duplicati.Library.Backend
                     throw new Exception(Strings.CloudFiles.ETagVerificationError);

                 }

             }

+

+            return Task.FromResult(true);

         }

 

         #endregion

diff --git a/Duplicati/Library/Backend/Dropbox/Dropbox.cs b/Duplicati/Library/Backend/Dropbox/Dropbox.cs
index e31c4f522..5b74eb05c 100644
--- a/Duplicati/Library/Backend/Dropbox/Dropbox.cs
+++ b/Duplicati/Library/Backend/Dropbox/Dropbox.cs
@@ -3,7 +3,9 @@ using System.Collections.Generic;
 using System.IO;

 using Duplicati.Library.Interface;

 using Duplicati.Library.Common.IO;
-
+using System.Threading.Tasks;

+using System.Threading;

+

 namespace Duplicati.Library.Backend

 {

     public class Dropbox : IBackend, IStreamingBackend

@@ -99,15 +101,15 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

-            using(FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename,fs);

+            using(FileStream fs = File.OpenRead(filename))

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

         {

-            using(FileStream fs = System.IO.File.Create(filename))

+            using(FileStream fs = File.Create(filename))

                 Get(remotename, fs);

         }

 

@@ -162,7 +164,7 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, Stream stream)

+        public Task Put(string remotename, Stream stream, CancellationToken cancelToken)

         {

             try

             {

@@ -174,6 +176,8 @@ namespace Duplicati.Library.Backend
                 // we can catch some events here and convert them to Duplicati exceptions

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, Stream stream)

diff --git a/Duplicati/Library/Backend/FTP/FTPBackend.cs b/Duplicati/Library/Backend/FTP/FTPBackend.cs
index 84b43f19a..f2569cf08 100644
--- a/Duplicati/Library/Backend/FTP/FTPBackend.cs
+++ b/Duplicati/Library/Backend/FTP/FTPBackend.cs
@@ -17,13 +17,15 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

 using System;

 using System.Collections.Generic;

-using System.Text.RegularExpressions;

-using Duplicati.Library.Interface;

 using System.Linq;

-using Duplicati.Library.Common.IO;
-
+using System.Text.RegularExpressions;

+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend

 {

     public class FTP : IBackend, IStreamingBackend

@@ -255,7 +257,7 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, System.IO.Stream input)

+        public Task Put(string remotename, System.IO.Stream input, CancellationToken cancelToken)

         {

             System.Net.FtpWebRequest req = null;

             try

@@ -279,8 +281,8 @@ namespace Duplicati.Library.Backend
                         if (fe.Name.Equals(remotename) || fe.Name.EndsWith("/" + remotename, StringComparison.Ordinal) || fe.Name.EndsWith("\\" + remotename, StringComparison.Ordinal)) 

                         {

                             if (fe.Size < 0 || streamLen < 0 || fe.Size == streamLen)

-                                return;

-                        

+                                return Task.FromResult(true);

+

                             throw new Exception(Strings.FTPBackend.ListVerifySizeFailure(remotename, fe.Size, streamLen));

                         } 

 

@@ -295,12 +297,14 @@ namespace Duplicati.Library.Backend
                 else

                     throw;

             }

+

+            return Task.FromResult(true);

         }

 

-        public void Put(string remotename, string localname)

+        public Task Put(string remotename, string localname, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.Open(localname, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, System.IO.Stream output)

diff --git a/Duplicati/Library/Backend/File/FileBackend.cs b/Duplicati/Library/Backend/File/FileBackend.cs
index 28617c0b0..9896d4282 100644
--- a/Duplicati/Library/Backend/File/FileBackend.cs
+++ b/Duplicati/Library/Backend/File/FileBackend.cs
@@ -17,13 +17,15 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

+using Duplicati.Library.Common;
+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

 using System;

 using System.Collections.Generic;

 using System.Runtime.InteropServices;

-using Duplicati.Library.Interface;

-using Duplicati.Library.Common.IO;
-using Duplicati.Library.Common;
-
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend

 {

     public class File : IBackend, IStreamingBackend, IQuotaEnabledBackend, IRenameEnabledBackend

@@ -186,7 +188,7 @@ namespace Duplicati.Library.Backend
 

 #if DEBUG_RETRY

         private static Random random = new Random();

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             using(System.IO.FileStream writestream = systemIO.FileOpenWrite(GetRemoteName(remotename)))

             {

@@ -194,12 +196,15 @@ namespace Duplicati.Library.Backend
                     throw new Exception("Random upload failure");

                 Utility.Utility.CopyStream(stream, writestream);

             }

+

+            return Task.FromResult(true);

         }

 #else

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             using(System.IO.FileStream writestream = systemIO.FileOpenWrite(GetRemoteName(remotename)))

                 Utility.Utility.CopyStream(stream, writestream, true, m_copybuffer);

+            return Task.FromResult(true);

         }

 #endif

 

@@ -210,7 +215,7 @@ namespace Duplicati.Library.Backend
                 Utility.Utility.CopyStream(readstream, stream, true, m_copybuffer);

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             string path = GetRemoteName(remotename);

             if (m_moveFile)

@@ -222,6 +227,8 @@ namespace Duplicati.Library.Backend
             }

             else

                 systemIO.FileCopy(filename, path, true);

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/GoogleServices/GoogleCloudStorage.cs b/Duplicati/Library/Backend/GoogleServices/GoogleCloudStorage.cs
index 59b87a924..d8e5ac238 100644
--- a/Duplicati/Library/Backend/GoogleServices/GoogleCloudStorage.cs
+++ b/Duplicati/Library/Backend/GoogleServices/GoogleCloudStorage.cs
@@ -14,18 +14,18 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

+using Duplicati.Library.Backend.GoogleServices;

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

+using Duplicati.Library.Utility;

+using Newtonsoft.Json;

 using System;

 using System.Collections.Generic;

 using System.Net;

 using System.Text;

+using System.Threading;

+using System.Threading.Tasks;

 

-using Newtonsoft.Json;

-

-using Duplicati.Library.Backend.GoogleServices;

-using Duplicati.Library.Interface;

-using Duplicati.Library.Utility;

-using Duplicati.Library.Common.IO;
-
 namespace Duplicati.Library.Backend.GoogleCloudStorage

 {

     public class GoogleCloudStorage : IBackend, IStreamingBackend, IRenameEnabledBackend

@@ -147,10 +147,10 @@ namespace Duplicati.Library.Backend.GoogleCloudStorage
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

@@ -242,7 +242,7 @@ namespace Duplicati.Library.Backend.GoogleCloudStorage
 

         #endregion

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {
 
             var item = new BucketResourceItem { name = m_prefix + remotename };

@@ -252,6 +252,8 @@ namespace Duplicati.Library.Backend.GoogleCloudStorage
 

             if (res == null)

                 throw new Exception("Upload succeeded, but no data was returned");
+
+            return Task.FromResult(true);
         }

 

         public void Get(string remotename, System.IO.Stream stream)

diff --git a/Duplicati/Library/Backend/GoogleServices/GoogleDrive.cs b/Duplicati/Library/Backend/GoogleServices/GoogleDrive.cs
index 11bf54fb0..fd2e557a2 100644
--- a/Duplicati/Library/Backend/GoogleServices/GoogleDrive.cs
+++ b/Duplicati/Library/Backend/GoogleServices/GoogleDrive.cs
@@ -14,19 +14,19 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

+using Duplicati.Library.Backend.GoogleServices;

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

+using Duplicati.Library.Utility;

+using Newtonsoft.Json;

 using System;

 using System.Collections.Generic;

 using System.Linq;

 using System.Net;

 using System.Text;

+using System.Threading;

+using System.Threading.Tasks;

 

-using Newtonsoft.Json;

-

-using Duplicati.Library.Backend.GoogleServices;

-using Duplicati.Library.Interface;

-using Duplicati.Library.Utility;

-using Duplicati.Library.Common.IO;
-
 namespace Duplicati.Library.Backend.GoogleDrive

 {

     public class GoogleDrive : IBackend, IStreamingBackend, IQuotaEnabledBackend, IRenameEnabledBackend

@@ -133,7 +133,7 @@ namespace Duplicati.Library.Backend.GoogleDrive
 

         #region IStreamingBackend implementation

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             try

             {

@@ -174,6 +174,8 @@ namespace Duplicati.Library.Backend.GoogleDrive
                 m_filecache.Clear();

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

@@ -249,10 +251,10 @@ namespace Duplicati.Library.Backend.GoogleDrive
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/HubiC/HubiCBackend.cs b/Duplicati/Library/Backend/HubiC/HubiCBackend.cs
index da6942e63..f6ece03d6 100644
--- a/Duplicati/Library/Backend/HubiC/HubiCBackend.cs
+++ b/Duplicati/Library/Backend/HubiC/HubiCBackend.cs
@@ -14,11 +14,12 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

-using System;

-using Duplicati.Library.Interface;

-using Duplicati.Library;

 using Duplicati.Library.Backend.OpenStack;

+using Duplicati.Library.Interface;

+using System;

 using System.Collections.Generic;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Backend.HubiC

 {

@@ -105,9 +106,10 @@ namespace Duplicati.Library.Backend.HubiC
 

         #region IStreamingBackend implementation

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

-            m_openstack.Put(remotename, stream);

+            m_openstack.Put(remotename, stream, cancelToken);

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

@@ -124,9 +126,10 @@ namespace Duplicati.Library.Backend.HubiC
             return m_openstack.List();

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

-            m_openstack.Put(remotename, filename);

+            m_openstack.Put(remotename, filename, cancelToken);

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/Jottacloud/Jottacloud.cs b/Duplicati/Library/Backend/Jottacloud/Jottacloud.cs
index 472043acf..9603e613d 100644
--- a/Duplicati/Library/Backend/Jottacloud/Jottacloud.cs
+++ b/Duplicati/Library/Backend/Jottacloud/Jottacloud.cs
@@ -17,11 +17,13 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 // 
 #endregion
+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;
 using System;
 using System.Collections.Generic;
-using Duplicati.Library.Interface;
-using Duplicati.Library.Common.IO;
-
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend
 {
     public class Jottacloud : IBackend, IStreamingBackend
@@ -220,10 +222,10 @@ namespace Duplicati.Library.Backend
             }
         }
 
-        public void Put(string remotename, string filename)
+        public Task Put(string remotename, string filename, CancellationToken cancelToken)
         {
             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))
-                Put(remotename, fs);
+                return Put(remotename, fs, cancelToken);
         }
 
         public void Get(string remotename, string filename)
@@ -334,7 +336,7 @@ namespace Duplicati.Library.Backend
                 Utility.Utility.CopyStream(s, stream, true, m_copybuffer);
         }
 
-        public void Put(string remotename, System.IO.Stream stream)
+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)
         {
             // Some challenges with uploading to Jottacloud:
             // - Jottacloud supports use of a custom header where we can tell the server the MD5 hash of the file
@@ -448,6 +450,8 @@ namespace Duplicati.Library.Backend
                 }
                 catch { }
             }
+
+            return Task.FromResult(true);
         }
 
         #endregion
diff --git a/Duplicati/Library/Backend/Mega/MegaBackend.cs b/Duplicati/Library/Backend/Mega/MegaBackend.cs
index 2a5859922..52789316c 100644
--- a/Duplicati/Library/Backend/Mega/MegaBackend.cs
+++ b/Duplicati/Library/Backend/Mega/MegaBackend.cs
@@ -14,13 +14,15 @@
 //  You should have received a copy of the GNU Lesser General Public

 //  License along with this library; if not, write to the Free Software

 //  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA

-using System;

-using System.Linq;

-using System.Collections.Generic;

-using Duplicati.Library.Interface;

 using CG.Web.MegaApiClient;

 using Duplicati.Library.Common.IO;
-
+using Duplicati.Library.Interface;

+using System;

+using System.Collections.Generic;

+using System.Linq;

+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend.Mega

 {

     public class MegaBackend: IBackend, IStreamingBackend

@@ -140,7 +142,7 @@ namespace Duplicati.Library.Backend.Mega
 

         #region IStreamingBackend implementation

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             try

             {

@@ -159,6 +161,8 @@ namespace Duplicati.Library.Backend.Mega
                 m_filecache = null;

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

@@ -182,10 +186,10 @@ namespace Duplicati.Library.Backend.Mega
                 select new FileEntry(item.Name, item.Size, item.ModificationDate ?? new DateTime(0), item.ModificationDate ?? new DateTime(0));

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/OneDrive/MicrosoftGraphBackend.cs b/Duplicati/Library/Backend/OneDrive/MicrosoftGraphBackend.cs
index d3d80836a..ac37027c1 100644
--- a/Duplicati/Library/Backend/OneDrive/MicrosoftGraphBackend.cs
+++ b/Duplicati/Library/Backend/OneDrive/MicrosoftGraphBackend.cs
@@ -1,4 +1,9 @@
-using System;

+using Duplicati.Library.Backend.MicrosoftGraph;

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

+using Duplicati.Library.Utility;

+using Newtonsoft.Json;

+using System;

 using System.Collections.Generic;

 using System.IO;

 using System.Linq;

@@ -7,13 +12,7 @@ using System.Net.Http;
 using System.Net.Http.Headers;

 using System.Text;

 using System.Threading;

-

-using Duplicati.Library.Backend.MicrosoftGraph;

-using Duplicati.Library.Interface;

-using Duplicati.Library.Common.IO;
-using Duplicati.Library.Utility;

-

-using Newtonsoft.Json;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Backend

 {

@@ -327,15 +326,15 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (FileStream fileStream = File.OpenRead(filename))

             {

-                this.Put(remotename, fileStream);

+                return Put(remotename, fileStream, cancelToken);

             }

         }

 

-        public void Put(string remotename, Stream stream)

+        public Task Put(string remotename, Stream stream, CancellationToken cancelToken)

         {

             // PUT only supports up to 4 MB file uploads. There's a separate process for larger files.

             if (stream.Length < PUT_MAX_SIZE)

@@ -429,6 +428,8 @@ namespace Duplicati.Library.Backend
                     }

                 }

             }

+

+            return Task.FromResult(true);

         }

 

         public void Delete(string remotename)

diff --git a/Duplicati/Library/Backend/OpenStack/OpenStackStorage.cs b/Duplicati/Library/Backend/OpenStack/OpenStackStorage.cs
index 05e1a03d1..1e3840e32 100644
--- a/Duplicati/Library/Backend/OpenStack/OpenStackStorage.cs
+++ b/Duplicati/Library/Backend/OpenStack/OpenStackStorage.cs
@@ -26,7 +26,9 @@ using Duplicati.Library.Strings;
 using System.Net;

 using System.Text;

 using Duplicati.Library.Common.IO;
-
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend.OpenStack

 {

     public class OpenStackStorage : IBackend, IStreamingBackend

@@ -483,11 +485,13 @@ namespace Duplicati.Library.Backend.OpenStack
         }

 

         #region IStreamingBackend implementation

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             var url = JoinUrls(SimpleStorageEndPoint, m_container, Library.Utility.Uri.UrlPathEncode(m_prefix + remotename));

             using(m_helper.GetResponse(url, stream, "PUT"))

             { }

+

+            return Task.FromResult(true);

         }

         public void Get(string remotename, System.IO.Stream stream)

         {

@@ -562,15 +566,17 @@ namespace Duplicati.Library.Backend.OpenStack
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

-            using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+            using (FileStream fs = File.OpenRead(filename))

+                Put(remotename, fs, cancelToken);

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, string filename)

         {

-            using (System.IO.FileStream fs = System.IO.File.Create(filename))

+            using (FileStream fs = File.Create(filename))

                 Get(remotename, fs);

         }

         public void Delete(string remotename)

diff --git a/Duplicati/Library/Backend/Rclone/Rclone.cs b/Duplicati/Library/Backend/Rclone/Rclone.cs
index a7c344caa..be5b0b0b7 100644
--- a/Duplicati/Library/Backend/Rclone/Rclone.cs
+++ b/Duplicati/Library/Backend/Rclone/Rclone.cs
@@ -17,18 +17,18 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

-using System;

-using System.Collections.Generic;

-using System.Runtime.InteropServices;

-using System.Text;

-using System.Diagnostics;

+using Duplicati.Library.Common.IO;
 using Duplicati.Library.Interface;

 using Newtonsoft.Json;

 using Newtonsoft.Json.Linq;

-using System.Globalization;

+using System;

+using System.Collections.Generic;

+using System.Diagnostics;

 using System.IO;

-using Duplicati.Library.Common.IO;
-
+using System.Text;

+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend

 {

     public class Rclone : IBackend

@@ -225,7 +225,7 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             try

             {

@@ -235,6 +235,8 @@ namespace Duplicati.Library.Backend
             {

                 throw new FileMissingException(ex);

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, string filename)

diff --git a/Duplicati/Library/Backend/S3/S3Backend.cs b/Duplicati/Library/Backend/S3/S3Backend.cs
index 988268d63..0692b01cd 100644
--- a/Duplicati/Library/Backend/S3/S3Backend.cs
+++ b/Duplicati/Library/Backend/S3/S3Backend.cs
@@ -17,13 +17,15 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

-using Duplicati.Library.Common.IO;

+using Duplicati.Library.Common.IO;
 using Duplicati.Library.Interface;

 using System;

 using System.Collections.Generic;

 using System.Linq;

 using System.Text;

 using System.Text.RegularExpressions;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Backend

 {

@@ -339,13 +341,13 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, string localname)

+        public Task Put(string remotename, string localname, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.Open(localname, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

-        public void Put(string remotename, System.IO.Stream input)

+        public Task Put(string remotename, System.IO.Stream input, CancellationToken cancelToken)

         {

             try

             {

@@ -360,6 +362,8 @@ namespace Duplicati.Library.Backend
 

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, string localname)

diff --git a/Duplicati/Library/Backend/SSHv2/SSHv2Backend.cs b/Duplicati/Library/Backend/SSHv2/SSHv2Backend.cs
index 5f057042d..e743407cb 100644
--- a/Duplicati/Library/Backend/SSHv2/SSHv2Backend.cs
+++ b/Duplicati/Library/Backend/SSHv2/SSHv2Backend.cs
@@ -17,15 +17,16 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

-using System;

-using System.Collections.Generic;

-using System.Linq;

-using System.Text;

-using Duplicati.Library.Interface;

 using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

 using Renci.SshNet;

 using Renci.SshNet.Common;

+using System;

+using System.Collections.Generic;

 using System.Globalization;

+using System.Linq;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Backend

 {

@@ -147,10 +148,10 @@ namespace Duplicati.Library.Backend
             get { return "ssh"; }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.Open(filename, System.IO.FileMode.Open, System.IO.FileAccess.Read, System.IO.FileShare.Read))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

@@ -225,11 +226,12 @@ namespace Duplicati.Library.Backend
 

         #region IStreamingBackend Implementation

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             CreateConnection();

             ChangeDirectory(m_path);

             m_con.UploadFile(stream, remotename);

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

diff --git a/Duplicati/Library/Backend/SharePoint/SharePointBackend.cs b/Duplicati/Library/Backend/SharePoint/SharePointBackend.cs
index 5fcfc023a..897be220f 100644
--- a/Duplicati/Library/Backend/SharePoint/SharePointBackend.cs
+++ b/Duplicati/Library/Backend/SharePoint/SharePointBackend.cs
@@ -18,19 +18,19 @@
 // 
 #endregion
 
+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;
+using Duplicati.Library.Utility;
+using Microsoft.SharePoint.Client; // Plain 'using' for extension methods
 using System;
 using System.Collections.Generic;
 using System.IO;
 using System.Linq;
 using System.Text;
-using Duplicati.Library.Utility;
-
-using Duplicati.Library.Interface;
-
+using System.Threading;

+using System.Threading.Tasks;

 using SP = Microsoft.SharePoint.Client;
-using Microsoft.SharePoint.Client; // Plain 'using' for extension methods
-using Duplicati.Library.Common.IO;
-
+

 namespace Duplicati.Library.Backend
 {
 
@@ -523,14 +523,14 @@ namespace Duplicati.Library.Backend
                 Utility.Utility.CopyStream(s, stream, true, copybuffer);
         }
 
-        public void Put(string remotename, string filename)
+        public Task Put(string remotename, string filename, CancellationToken cancelToken)
         {
-            using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))
-                Put(remotename, fs);
+            using (FileStream fs = System.IO.File.OpenRead(filename))
+                return Put(remotename, fs, cancelToken);
         }
 
-        public void Put(string remotename, System.IO.Stream stream) { doPut(remotename, stream, false); }
-        private void doPut(string remotename, System.IO.Stream stream, bool useNewContext)
+        public Task Put(string remotename, Stream stream, CancellationToken cancelToken) { return doPut(remotename, stream, false, cancelToken); }
+        private Task doPut(string remotename, Stream stream, bool useNewContext, CancellationToken cancelToken)
         {
             string fileurl = m_serverRelPath + System.Web.HttpUtility.UrlPathEncode(remotename);
             SP.ClientContext ctx = getSpClientContext(useNewContext);
@@ -549,13 +549,14 @@ namespace Duplicati.Library.Backend
             catch (ServerException) { throw; /* rethrow if Server answered */ }
             catch (Interface.FileMissingException) { throw; }
             catch (Interface.FolderMissingException) { throw; }
-            catch { if (!useNewContext) /* retry */ { doPut(remotename, stream, true); return; } else throw; }
+            catch { if (!useNewContext) /* retry */ { return doPut(remotename, stream, true, cancelToken); } else throw; }
 
             if (m_useBinaryDirectMode)
             {
                 SP.File.SaveBinaryDirect(ctx, fileurl, stream, true);
             }
 
+            return Task.FromResult(true);
         }
 
         /// <summary>
diff --git a/Duplicati/Library/Backend/Sia/Sia.cs b/Duplicati/Library/Backend/Sia/Sia.cs
index 2908a2898..1ff1380fd 100644
--- a/Duplicati/Library/Backend/Sia/Sia.cs
+++ b/Duplicati/Library/Backend/Sia/Sia.cs
@@ -1,13 +1,13 @@
-using System;
-using System.Linq;
-using System.Collections.Generic;
-using System.Net;
-
+using Duplicati.Library.Common.IO;
 using Duplicati.Library.Interface;
 using Duplicati.Library.Utility;
 using Newtonsoft.Json;
-using Duplicati.Library.Common.IO;
-
+using System;
+using System.Collections.Generic;
+using System.Net;
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend.Sia
 {
     public class Sia : IBackend
@@ -306,7 +306,7 @@ namespace Duplicati.Library.Backend.Sia
             }
         }
 
-        public void Put(string remotename, string filename)
+        public Task Put(string remotename, string filename, CancellationToken cancelToken)
         {
             string endpoint ="";
             string siafile = m_targetpath + "/" + remotename;
@@ -314,31 +314,33 @@ namespace Duplicati.Library.Backend.Sia
             try {
                 endpoint = string.Format("/renter/upload/{0}/{1}?source={2}",
                     m_targetpath, 
-                    Library.Utility.Uri.UrlEncode(remotename).Replace("+", "%20"),
-                    Library.Utility.Uri.UrlEncode(filename).Replace("+", "%20")
+                    Utility.Uri.UrlEncode(remotename).Replace("+", "%20"),
+                    Utility.Uri.UrlEncode(filename).Replace("+", "%20")
                 );
 
-                System.Net.HttpWebRequest req = CreateRequest(endpoint);
-                req.Method = System.Net.WebRequestMethods.Http.Post;
+                HttpWebRequest req = CreateRequest(endpoint);
+                req.Method = WebRequestMethods.Http.Post;
 
-                Utility.AsyncHttpRequest areq = new Utility.AsyncHttpRequest(req);
+                AsyncHttpRequest areq = new AsyncHttpRequest(req);
 
-                using (System.Net.HttpWebResponse resp = (System.Net.HttpWebResponse)areq.GetResponse())
+                using (HttpWebResponse resp = (HttpWebResponse)areq.GetResponse())
                 {
                     int code = (int)resp.StatusCode;
                     if (code < 200 || code >= 300)
-                        throw new System.Net.WebException(resp.StatusDescription, null, System.Net.WebExceptionStatus.ProtocolError, resp);
+                        throw new WebException(resp.StatusDescription, null, WebExceptionStatus.ProtocolError, resp);
 
                     while (! IsUploadComplete( siafile ))
                     {
-                        System.Threading.Thread.Sleep(5000);
+                        Thread.Sleep(5000);
                     }
                 }
             }
-            catch (System.Net.WebException wex)
+            catch (WebException wex)
             {
                 throw new Exception(getResponseBodyOnError(endpoint, wex));
             }
+
+            return Task.FromResult(true);
         }
 
         public void Get(string remotename, string localname)
diff --git a/Duplicati/Library/Backend/TahoeLAFS/TahoeBackend.cs b/Duplicati/Library/Backend/TahoeLAFS/TahoeBackend.cs
index f253a2686..80cfe9ad5 100644
--- a/Duplicati/Library/Backend/TahoeLAFS/TahoeBackend.cs
+++ b/Duplicati/Library/Backend/TahoeLAFS/TahoeBackend.cs
@@ -17,15 +17,15 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

-using System;

-using System.Collections.Generic;

-using System.Text;

+using Duplicati.Library.Common.IO;
 using Duplicati.Library.Interface;

 using Newtonsoft.Json;

 using Newtonsoft.Json.Linq;

-using System.Linq;

-using Duplicati.Library.Common.IO;
-
+using System;

+using System.Collections.Generic;

+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend

 {

     public class TahoeBackend : IBackend, IStreamingBackend

@@ -208,10 +208,10 @@ namespace Duplicati.Library.Backend
             }

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

@@ -271,7 +271,7 @@ namespace Duplicati.Library.Backend
 

         #region IStreamingBackend Members

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             try

             {

@@ -302,6 +302,8 @@ namespace Duplicati.Library.Backend
 

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

diff --git a/Duplicati/Library/Backend/WEBDAV/WEBDAV.cs b/Duplicati/Library/Backend/WEBDAV/WEBDAV.cs
index 8d175cc4b..58c491f5f 100644
--- a/Duplicati/Library/Backend/WEBDAV/WEBDAV.cs
+++ b/Duplicati/Library/Backend/WEBDAV/WEBDAV.cs
@@ -17,12 +17,13 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

+using Duplicati.Library.Common.IO;
+using Duplicati.Library.Interface;

 using System;

 using System.Collections.Generic;

-using System.Text;

-using Duplicati.Library.Interface;

-using Duplicati.Library.Common.IO;
-
+using System.Threading;

+using System.Threading.Tasks;

+

 namespace Duplicati.Library.Backend

 {

     public class WEBDAV : IBackend, IStreamingBackend

@@ -254,10 +255,10 @@ namespace Duplicati.Library.Backend
             return files;

         }

 

-        public void Put(string remotename, string filename)

+        public Task Put(string remotename, string filename, CancellationToken cancelToken)

         {

             using (System.IO.FileStream fs = System.IO.File.OpenRead(filename))

-                Put(remotename, fs);

+                return Put(remotename, fs, cancelToken);

         }

 

         public void Get(string remotename, string filename)

@@ -375,7 +376,7 @@ namespace Duplicati.Library.Backend
 

         #region IStreamingBackend Members

 

-        public void Put(string remotename, System.IO.Stream stream)

+        public Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken)

         {

             try

             {

@@ -406,6 +407,8 @@ namespace Duplicati.Library.Backend
 

                 throw;

             }

+

+            return Task.FromResult(true);

         }

 

         public void Get(string remotename, System.IO.Stream stream)

diff --git a/Duplicati/Library/Interface/IBackend.cs b/Duplicati/Library/Interface/IBackend.cs
index ba9571e6f..82e614b07 100644
--- a/Duplicati/Library/Interface/IBackend.cs
+++ b/Duplicati/Library/Interface/IBackend.cs
@@ -19,7 +19,8 @@
 #endregion

 using System;

 using System.Collections.Generic;

-using System.Text;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Interface

 {

@@ -56,7 +57,8 @@ namespace Duplicati.Library.Interface
         /// </summary>

         /// <param name="remotename">The remote filename, relative to the URL</param>

         /// <param name="filename">The local filename</param>

-        void Put(string remotename, string filename);

+        /// <param name="cancelToken">Token to cancel the operation.</param>

+        Task Put(string remotename, string filename, CancellationToken cancelToken);

 

         /// <summary>

         /// Downloads a file with the remote data

diff --git a/Duplicati/Library/Interface/IStreamingBackend.cs b/Duplicati/Library/Interface/IStreamingBackend.cs
index 740d4a670..33b8baff2 100644
--- a/Duplicati/Library/Interface/IStreamingBackend.cs
+++ b/Duplicati/Library/Interface/IStreamingBackend.cs
@@ -17,9 +17,8 @@
 // Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA

 // 

 #endregion

-using System;

-using System.Collections.Generic;

-using System.Text;

+using System.Threading;

+using System.Threading.Tasks;

 

 namespace Duplicati.Library.Interface

 {

@@ -35,7 +34,8 @@ namespace Duplicati.Library.Interface
         /// </summary>

         /// <param name="remotename">The remote filename, relative to the URL</param>

         /// <param name="stream">The stream to read from</param>

-        void Put(string remotename, System.IO.Stream stream);

+        /// <param name="cancelToken">Token to cancel the operation.</param>

+        Task Put(string remotename, System.IO.Stream stream, CancellationToken cancelToken);

 

         /// <summary>

         /// Downloads a file with the remote data

diff --git a/Duplicati/Library/Main/BackendManager.cs b/Duplicati/Library/Main/BackendManager.cs
index 26e9443dc..a226445d7 100644
--- a/Duplicati/Library/Main/BackendManager.cs
+++ b/Duplicati/Library/Main/BackendManager.cs
@@ -7,6 +7,7 @@ using Duplicati.Library.Main.Database;
 using Duplicati.Library.Main.Volumes;

 using Newtonsoft.Json;

 using Duplicati.Library.Localization.Short;

+using System.Threading;

 

 namespace Duplicati.Library.Main

 {

@@ -734,10 +735,10 @@ namespace Duplicati.Library.Main
                 using (var fs = System.IO.File.OpenRead(item.LocalFilename))

                 using (var ts = new ThrottledStream(fs, m_options.MaxUploadPrSecond, m_options.MaxDownloadPrSecond))

                 using (var pgs = new Library.Utility.ProgressReportingStream(ts, pg => HandleProgress(ts, pg)))

-                    ((Library.Interface.IStreamingBackend)m_backend).Put(item.RemoteFilename, pgs);

+                    ((Library.Interface.IStreamingBackend)m_backend).Put(item.RemoteFilename, pgs, CancellationToken.None).Wait();

             }

             else

-                m_backend.Put(item.RemoteFilename, item.LocalFilename);

+                m_backend.Put(item.RemoteFilename, item.LocalFilename, CancellationToken.None).Wait();

 

             var duration = DateTime.Now - begin;

             Logging.Log.WriteProfilingMessage(LOGTAG, "UploadSpeed", "Uploaded {0} in {1}, {2}/s", Library.Utility.Utility.FormatSizeString(item.Size), duration, Library.Utility.Utility.FormatSizeString((long)(item.Size / duration.TotalSeconds)));

diff --git a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
index 24e40bf7e..ef4913efb 100644
--- a/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
+++ b/Duplicati/Library/Main/Operation/Backup/BackendUploader.cs
@@ -24,6 +24,7 @@ using System;
 using System.Collections.Generic;

 using System.IO;

 using System.Linq;

+using System.Threading;

 using System.Threading.Tasks;

 using static Duplicati.Library.Main.Operation.Common.BackendHandler;

 

@@ -88,6 +89,7 @@ namespace Duplicati.Library.Main.Operation.Backup
         private static readonly string LOGTAG = Logging.Log.LogTagFromType<BackendUploader>();

 

         private Func<IBackend> m_backendFactory;

+        private CancellationTokenSource m_cancelTokenSource;

         private Options m_options;

         private ITaskReader m_taskreader;

         private StatsCollector m_stats;

@@ -119,6 +121,7 @@ namespace Duplicati.Library.Main.Operation.Backup
                 var max_pending = m_options.AsynchronousUploadLimit == 0 ? long.MaxValue : m_options.AsynchronousUploadLimit;

                 var lastSize = -1L;

                 var uploadsInProgress = 0;

+                m_cancelTokenSource = new CancellationTokenSource();

 

                 while (!await self.Input.IsRetiredAsync && await m_taskreader.ProgressAsync)

                 {

@@ -139,21 +142,21 @@ namespace Duplicati.Library.Main.Operation.Backup
                         if (req is VolumeUploadRequest volumeUpload)

                         {

                             if (volumeUpload.IndexVolume == null)

-                                worker.Task = Task.Run(() => UploadFileAsync(volumeUpload.BlockEntry, worker));

+                                worker.Task = Task.Run(() => UploadFileAsync(volumeUpload.BlockEntry, worker, m_cancelTokenSource.Token));

                             else

-                                worker.Task = Task.Run(() => UploadBlockAndIndexAsync(volumeUpload, worker));

+                                worker.Task = Task.Run(() => UploadBlockAndIndexAsync(volumeUpload, worker, m_cancelTokenSource.Token));

 

                             lastSize = volumeUpload.BlockVolume.SourceSize;

                             uploadsInProgress++;

                         }

                         else if (req is FilesetUploadRequest filesetUpload)

                         {

-                            worker.Task = Task.Run(() => UploadVolumeWriter(filesetUpload.Fileset, worker));

+                            worker.Task = Task.Run(() => UploadVolumeWriter(filesetUpload.Fileset, worker, m_cancelTokenSource.Token));

                             uploadsInProgress++;

                         }

                         else if (req is IndexVolumeUploadRequest indexUpload)

                         {

-                            worker.Task = Task.Run(() => UploadVolumeWriter(indexUpload.IndexVolume, worker));

+                            worker.Task = Task.Run(() => UploadVolumeWriter(indexUpload.IndexVolume, worker, m_cancelTokenSource.Token));

                             uploadsInProgress++;

                         }

                         else if (req is FlushRequest flush)

@@ -198,30 +201,30 @@ namespace Duplicati.Library.Main.Operation.Backup
             });

         }

 

-        private async Task UploadBlockAndIndexAsync(VolumeUploadRequest upload, Worker worker)

+        private async Task UploadBlockAndIndexAsync(VolumeUploadRequest upload, Worker worker, CancellationToken cancelToken)

         {

-            await UploadFileAsync(upload.BlockEntry, worker).ConfigureAwait(false);

-            await UploadFileAsync(upload.IndexEntry, worker).ConfigureAwait(false);

+            await UploadFileAsync(upload.BlockEntry, worker, cancelToken).ConfigureAwait(false);

+            await UploadFileAsync(upload.IndexEntry, worker, cancelToken).ConfigureAwait(false);

             await m_database.AddIndexBlockLinkAsync(upload.IndexVolume.VolumeID, upload.BlockVolume.VolumeID).ConfigureAwait(false);

         }

 

-        private async Task UploadVolumeWriter(VolumeWriterBase volumeWriter, Worker worker)

+        private async Task UploadVolumeWriter(VolumeWriterBase volumeWriter, Worker worker, CancellationToken cancelToken)

         {

             var fileEntry = new FileEntryItem(BackendActionType.Put, volumeWriter.RemoteFilename);

             fileEntry.SetLocalfilename(volumeWriter.LocalFilename);

             fileEntry.Encrypt(m_options);

             fileEntry.UpdateHashAndSize(m_options);

 

-            await UploadFileAsync(fileEntry, worker).ConfigureAwait(false);

+            await UploadFileAsync(fileEntry, worker, cancelToken).ConfigureAwait(false);

         }

 

-        private async Task UploadFileAsync(FileEntryItem item, Worker worker)

+        private async Task UploadFileAsync(FileEntryItem item, Worker worker, CancellationToken cancelToken)

         {

             await DoWithRetry(item, worker, async () =>

             {

                 if (item.IsRetry)

                     await RenameFileAfterErrorAsync(item).ConfigureAwait(false);

-                await DoPut(item, worker.Backend).ConfigureAwait(false);

+                await DoPut(item, worker.Backend, cancelToken).ConfigureAwait(false);

             }).ConfigureAwait(false);

         }

 

@@ -318,7 +321,7 @@ namespace Duplicati.Library.Main.Operation.Backup
             item.RemoteFilename = newname;

         }

 

-        private async Task DoPut(FileEntryItem item, IBackend backend)

+        private async Task DoPut(FileEntryItem item, IBackend backend, CancellationToken cancelToken)

         {

             if (item.TrackedInDb)

                 await m_database.UpdateRemoteVolumeAsync(item.RemoteFilename, RemoteVolumeState.Uploading, item.Size, item.Hash);

@@ -340,10 +343,10 @@ namespace Duplicati.Library.Main.Operation.Backup
                 using (var fs = File.OpenRead(item.LocalFilename))

                 using (var ts = new ThrottledStream(fs, m_options.MaxUploadPrSecond, m_options.MaxDownloadPrSecond))

                 using (var pgs = new ProgressReportingStream(ts, pg => HandleProgress(ts, pg)))

-                    streamingBackend.Put(item.RemoteFilename, pgs);

+                    await streamingBackend.Put(item.RemoteFilename, pgs, cancelToken).ConfigureAwait(false);

             }

             else

-                backend.Put(item.RemoteFilename, item.LocalFilename);

+                await backend.Put(item.RemoteFilename, item.LocalFilename, cancelToken).ConfigureAwait(false);

 

             var duration = DateTime.Now - begin;

             Logging.Log.WriteProfilingMessage(LOGTAG, "UploadSpeed", "Uploaded {0} in {1}, {2}/s", Library.Utility.Utility.FormatSizeString(item.Size), duration, Library.Utility.Utility.FormatSizeString((long)(item.Size / duration.TotalSeconds)));