Contracts updated; IBackupEngine added

EternalArrowBackup.sln

@@ -5,7 +5,7 @@ VisualStudioVersion = 15.0.26430.14
 MinimumVisualStudioVersion = 10.0.40219.1
 Project("{2150E333-8FDC-42A3-9474-1A3956D46DE8}") = "Source", "Source", "{A79A4872-4289-4429-B616-3E8CEC71ECB8}"
 EndProject
-Project("{FAE04EC0-301F-11D3-BF4B-00C04F79EFBC}") = "EternalArrowBackup.Contracts", "Source\Contracts\EternalArrowBackup.Contracts.csproj", "{9A363462-23E2-49FB-A65C-7B1CA1400046}"
+Project("{9A19103F-16F7-4668-BE54-9A1E7A4F7556}") = "EternalArrowBackup.Contracts", "Source\Contracts\EternalArrowBackup.Contracts.csproj", "{9A363462-23E2-49FB-A65C-7B1CA1400046}"
 EndProject
 Global
 	GlobalSection(SolutionConfigurationPlatforms) = preSolution

Source/Contracts/MainBackupEngine/IBackupEngine.cs

@@ -0,0 +1,10 @@
+namespace EternalArrowBackup.Contracts.BackupEngine
+{
+    using System.Threading;
+    using System.Threading.Tasks;
+
+    public interface IBackupEngine
+    {
+        Task<IBackupReport> BackupAll(CancellationToken ct);
+    }
+}

Source/Contracts/MainBackupEngine/IBackupReport.cs

@@ -0,0 +1,17 @@
+using System;
+
+namespace EternalArrowBackup.Contracts.BackupEngine
+{
+    public class IBackupReport
+    {
+        public long FilesUploaded { get; }
+
+        public long BytesUploaded { get; }
+
+        public long FilesUpdated { get; }
+
+        public long FilesProcessed { get; }
+
+        public Exception[] Errors { get; }
+    }
+}

Source/Contracts/SourceStorage/ISourceDirectory.cs

@@ -1,6 +1,7 @@
 namespace EternalArrowBackup.Contracts.SourceStorage
 {
     using System;
+    using System.Threading;
     using System.Threading.Tasks;
 
     public interface ISourceDirectory
@@ -9,6 +10,6 @@
 
         Task<ISourceFile> GetFile(string filename);
 
-        IObservable<ISourceFile> GetAllFiles();
+        IObservable<ISourceFile> GetAllFiles(CancellationToken ct);
     }
 }

Source/Contracts/SourceStorage/ISourceStorage.cs

@@ -1,12 +1,13 @@
 namespace EternalArrowBackup.Contracts.SourceStorage
 {
     using System;
+    using System.Threading;
     using System.Threading.Tasks;
 
     public interface ISourceStorage
     {
         Task<ISourceDirectory> GetDirectory(string normalizedRelativePath);
 
-        IObservable<ISourceDirectory> GetAllDirectories();
+        IObservable<ISourceDirectory> GetAllDirectories(CancellationToken ct);
     }
 }

Source/Contracts/TargetStorage/ITargetDirectory.cs

@@ -1,14 +1,30 @@
 namespace EternalArrowBackup.Contracts.TargetStorage
 {
     using System;
+    using System.Threading;
     using System.Threading.Tasks;
 
     public interface ITargetDirectory
     {
-        Task UploadFile(string filename, byte[] content, string hash);
+        /// <summary>
+        /// Uploads new content to the target directory, and adds new entity with DateTime.UtcNow to the list of files
+        /// </summary>
+        /// <param name="filename">File name</param>
+        /// <param name="content">Content</param>
+        /// <param name="hash">File hash</param>
+        /// <returns>Task</returns>
+        Task UploadNewContent(string filename, byte[] content, string hash);
 
-        Task<ITargetFile> GetFile(string filename, string hash);
+        /// <summary>
+        /// Adds new entity with DateTime.UtcNow to the list of files.
+        /// 
+        /// Example: file "abc.txt" with content "qwe" (v1) was replaced with "rty" (v2), and then was replaced with "qwe" (v3) again.
+        /// The client should <see cref="UploadNewContent(string, byte[], string)"/> for v1 and v2, and then call this method (passing v1 FileInfo to it) for v3.
+        /// </summary>
+        /// <param name="file"></param>
+        /// <returns></returns>
+        Task UpdateExistingContent(ITargetFile file);
 
-        IObservable<ITargetFile> GetAllFiles();
+        IObservable<ITargetFile> GetAllFiles(CancellationToken ct);
     }
 }

Source/Contracts/TargetStorage/ITargetStorageForRecovery.cs

@@ -1,9 +1,10 @@
 namespace EternalArrowBackup.Contracts.TargetStorage
 {
     using System;
+    using System.Threading;
 
     public interface ITargetStorageForRecovery
     {
-        IObservable<ITargetDirectory> GetAllDirectories();
+        IObservable<ITargetDirectory> GetAllDirectories(CancellationToken ct);
     }
 }