Refactoring; fixed code smells

Source/BackupEngine/Contracts/IBackupReport.cs

@@ -2,16 +2,16 @@
 {
     using System;
 
-    public class IBackupReport
+    public interface IBackupReport
     {
-        public long FilesUploaded { get; }
+        long FilesUploaded { get; }
 
-        public long BytesUploaded { get; }
+        long BytesUploaded { get; }
 
-        public long FilesUpdated { get; }
+        long FilesUpdated { get; }
 
-        public long FilesProcessed { get; }
+        long FilesProcessed { get; }
 
-        public Exception[] Errors { get; }
+        Exception[] Errors { get; }
     }
 }

Source/ContentTransformer/ClearText/BufferHelpers.cs

@@ -0,0 +1,15 @@
+namespace EternalArrowBackup.ContentTransformer.ClearText
+{
+    using System;
+
+    internal static class BufferHelpers
+    {
+        public static void Add(byte[] source, byte[] target, int targetOffset) {
+            Buffer.BlockCopy(source, 0, target, targetOffset, source.Length);
+        }
+
+        public static void Extract(byte[] source, int sourceOffset, byte[] target) {
+            Buffer.BlockCopy(source, sourceOffset, target, 0, target.Length);
+        }
+    }
+}

Source/ContentTransformer/ClearText/ClearTextContentEncryptor.cs

@@ -16,18 +16,12 @@
 
         private IContentHasher Hasher { get; }
 
-        public async Task<IDecryptionResult> GetOriginalData(byte[] encryptedData)
+        public async Task<IDecryptionResult> GetOriginalData(byte[] transformedData)
         {
-            var hashLength = encryptedData[encryptedData.Length - 1];
+            var dataWithSignature = DataWithSignature.FromByteArray(transformedData);
 
-            var originalData = new byte[encryptedData.Length - hashLength - 1];
-            var hashBytes = new byte[hashLength];
-
-            Buffer.BlockCopy(encryptedData, 0, originalData, 0, originalData.Length);
-            Buffer.BlockCopy(encryptedData, originalData.Length, hashBytes, 0, hashBytes.Length);
-
-            var expectedHash = Encoding.UTF8.GetString(hashBytes);
-            using (var stream = new MemoryStream(originalData))
+            var expectedHash = Encoding.UTF8.GetString(dataWithSignature.Signature);
+            using (var stream = new MemoryStream(dataWithSignature.Data))
             {
                 var actualHash = await this.Hasher.ComputeHash(stream);
 
@@ -37,7 +31,7 @@
                 }
             }
 
-            return new SuccessfulDecryptionResult(originalData);
+            return new SuccessfulDecryptionResult(dataWithSignature.Data);
         }
 
         public async Task<byte[]> TransformData(byte[] originalData)
@@ -49,16 +43,9 @@
             }
 
             var hashBytes = Encoding.UTF8.GetBytes(hash);
-            if (hashBytes.Length >= 256)
-            {
-                throw new Exception("Hash should be shorter than 256 bytes");
-            }
+            var dataWithSignature = new DataWithSignature(originalData, hashBytes);
 
-            var result = new byte[originalData.Length + hashBytes.Length + 1];
-            Buffer.BlockCopy(originalData, 0, result, 0, originalData.Length);
-            Buffer.BlockCopy(hashBytes, 0, result, originalData.Length, hashBytes.Length);
-            result[result.Length - 1] = (byte)hashBytes.Length;
-            return result;
+            return dataWithSignature.AsByteArray();
         }
 
         private class FailedDecryptionResult : IDecryptionResult

Source/ContentTransformer/ClearText/DataWithSignature.cs

@@ -0,0 +1,56 @@
+namespace EternalArrowBackup.ContentTransformer.ClearText
+{
+    using System;
+
+    public class DataWithSignature
+    {
+        public DataWithSignature(byte[] data, byte[] signature) {
+            if (data == null) {
+                throw new ArgumentNullException(nameof(data));
+            }
+
+            if (signature == null) {
+                throw new ArgumentNullException(nameof(signature));
+            }
+
+            if (signature.Length > 0xffff) {
+                throw new ArgumentOutOfRangeException(nameof(signature), "Signature should be shorter than 64k");
+            }
+
+            this.Data = data;
+            this.Signature = signature;
+        }
+
+        public byte[] Data { get; }
+
+        public byte[] Signature { get; }
+
+        public static DataWithSignature FromByteArray(byte[] byteArray) {
+            var signatureLengthBytes = new byte[2];
+            BufferHelpers.Extract(byteArray, byteArray.Length - 2, signatureLengthBytes);
+            var signatureLength = (signatureLengthBytes[0] * 0x100) + signatureLengthBytes[1];
+
+            var data = new byte[byteArray.Length - signatureLength - 2];
+            var signature = new byte[signatureLength];
+
+            BufferHelpers.Extract(byteArray, 0, data);
+            BufferHelpers.Extract(byteArray, data.Length, signature);
+
+            return new DataWithSignature(data, signature);
+        }
+
+        public byte[] AsByteArray() {
+            var signatureLengthBytes = new[] {
+                (byte)(this.Signature.Length / 0x100),
+                (byte)(this.Signature.Length % 0x100),
+            };
+
+            var result = new byte[this.Data.Length + this.Signature.Length + 2];
+            BufferHelpers.Add(this.Data, result, 0);
+            BufferHelpers.Add(this.Signature, result, this.Data.Length);
+            BufferHelpers.Add(signatureLengthBytes, result, this.Data.Length + this.Signature.Length);
+
+            return result;
+        }
+    }
+}

Source/Hasher/SHA1/SHA1ContentHasher.cs

@@ -5,7 +5,7 @@
     using System.Threading.Tasks;
     using EternalArrowBackup.Hasher.Contracts;
 
-    public class SHA1ContentHasher : IContentHasher
+    public class Sha1ContentHasher : IContentHasher
     {
         public Task<string> ComputeHash(Stream content)
         {

Source/ReportStorage/InMemoryReportStorage/FileInfo.cs

@@ -1,6 +1,5 @@
 namespace EternalArrowBackup.ReportStorage.InMemoryReportStorage
 {
-    using System;
     using EternalArrowBackup.ReportStorage.Contracts;
 
     class FileInfo : IFileInfo

Source/SourceStorage/InMemorySourceStorage/SourceStorage.cs

@@ -1,6 +1,5 @@
 namespace EternalArrowBackup.SourceStorage.InMemorySourceStorage
 {
-    using System;
     using System.Collections.Immutable;
     using System.Threading;
     using System.Threading.Tasks;

Source/TargetMetadataStorage/InMemoryMetadataStorage/MetadataStorage.cs

@@ -1,6 +1,5 @@
 namespace EternalArrowBackup.TargetMetadataStorage.InMemoryMetadataStorage
 {
-    using System;
     using System.Collections.Generic;
     using System.Threading;
     using System.Threading.Tasks;

Tests/ContentTransformer/ClearText/EncryptorAndHasherTests.cs

@@ -15,7 +15,7 @@
         public static async Task TestCorrectDecryption(string message)
         {
             var messageBytes = Encoding.ASCII.GetBytes(message);
-            var hasher = new SHA1ContentHasher();
+            var hasher = new Sha1ContentHasher();
             var encryptor = new ClearTextContentEncryptor(hasher);
             var encrypted = await encryptor.TransformData(messageBytes);
 

Tests/Hasher/SHA1/HasherTests.cs

@@ -21,7 +21,7 @@
         public static async Task TestHashes(string expectedHash, string inputMessage)
         {
             var expectedHashFormatted = expectedHash.Replace(" ", string.Empty).ToLowerInvariant();
-            var hasher = new SHA1ContentHasher();
+            var hasher = new Sha1ContentHasher();
             var messageBytes = Encoding.ASCII.GetBytes(inputMessage);
             using (var stream = new MemoryStream(messageBytes))
             {
@@ -51,7 +51,7 @@
             var expectedTimeLow = length / (MegabytesPerSecondHighSpeed * 1000);
             var expectedTimeHigh = 1 + length / (MegabytesPerSecondLowSpeed * 1000);
 
-            var hasher = new SHA1ContentHasher();
+            var hasher = new Sha1ContentHasher();
             using (var stream = new MemoryStream(messageBytes))
             {
                 await hasher.ComputeHash(stream);