fixed issue with smartflush, improved software crc32c, added nodecoding option for list modes

Author: force-net

Blazer.Exe/Program.cs

@@ -443,7 +443,7 @@ private static int ProcessList(CommandLineParser<BlazerCommandLineOptions> optio
 
 			Stream inStreamSource = opt.Stdin ? Console.OpenStandardInput() : File.OpenRead(fileOptions.ArchiveName);
 
-			var decOptions = new BlazerDecompressionOptions(opt.Password) { EncyptFull = opt.EncryptFull };
+			var decOptions = new BlazerDecompressionOptions(opt.Password) { EncyptFull = opt.EncryptFull, DoNotPerformDecoding = true };
 			StringBuilder header = new StringBuilder();
 			header.AppendLine("   Date      Time    Attr         Size  Name");
 			header.AppendLine("------------------- ----- ------------  ------------------------");

Blazer.Net.Tests/StreamEncoderTests.cs

@@ -101,5 +101,12 @@ public void Test_Text()
 Артем нехотя поднялся со своего места у костра и, перетягивая со спины на грудь автомат, двинулся во тьму. Стоя на самом краю освещенного пространства, он демонстративно, как можно громче и внушительней, щелкнул затвором и хрипло крикнул: — Стоять! Пароль!");
 			IntegrityHelper.StreamEncoderCheckCompressDecompress(buf);
 		}
+
+		[Test]
+		public void Test_Zero_Bytes()
+		{
+			var len = IntegrityHelper.StreamEncoderCheckCompressDecompress(new byte[0]);
+			Assert.That(len, Is.EqualTo(0));
+		}
 	}
 }

Blazer.Net/Algorithms/Crc32C/Crc32CSoftware.cs

@@ -21,36 +21,43 @@ static Crc32CSoftware()
 			}
 		}
 
-		uint ICrc32CCalculator.Calculate(uint crc, byte[] buffer, int offset, int count)
+		uint ICrc32CCalculator.Calculate(uint crc, byte[] input, int offset, int length)
 		{
-			uint crcLocal = crc ^ uint.MaxValue;
+			uint crcLocal = uint.MaxValue ^ crc;
 
 			uint[] table = _table;
-			while (count >= 16)
+			while (length >= 16)
 			{
-				crcLocal = table[(15 * 256) + ((crcLocal ^ buffer[offset]) & 0xff)]
-					^ table[(14 * 256) + (((crcLocal >> 8) ^ buffer[offset + 1]) & 0xff)]
-					^ table[(13 * 256) + (((crcLocal >> 16) ^ buffer[offset + 2]) & 0xff)]
-					^ table[(12 * 256) + (((crcLocal >> 24) ^ buffer[offset + 3]) & 0xff)]
-					^ table[(11 * 256) + buffer[offset + 4]]
-					^ table[(10 * 256) + buffer[offset + 5]]
-					^ table[(9 * 256) + buffer[offset + 6]]
-					^ table[(8 * 256) + buffer[offset + 7]]
-					^ table[(7 * 256) + buffer[offset + 8]]
-					^ table[(6 * 256) + buffer[offset + 9]]
-					^ table[(5 * 256) + buffer[offset + 10]]
-					^ table[(4 * 256) + buffer[offset + 11]]
-					^ table[(3 * 256) + buffer[offset + 12]]
-					^ table[(2 * 256) + buffer[offset + 13]]
-					^ table[(1 * 256) + buffer[offset + 14]]
-					^ table[(0 * 256) + buffer[offset + 15]];
+				var a = table[(3 * 256) + input[offset + 12]]
+					^ table[(2 * 256) + input[offset + 13]]
+					^ table[(1 * 256) + input[offset + 14]]
+					^ table[(0 * 256) + input[offset + 15]];
+
+				var b = table[(7 * 256) + input[offset + 8]]
+					^ table[(6 * 256) + input[offset + 9]]
+					^ table[(5 * 256) + input[offset + 10]]
+					^ table[(4 * 256) + input[offset + 11]];
+
+				var c = table[(11 * 256) + input[offset + 4]]
+					^ table[(10 * 256) + input[offset + 5]]
+					^ table[(9 * 256) + input[offset + 6]]
+					^ table[(8 * 256) + input[offset + 7]];
+
+				var d = table[(15 * 256) + ((crcLocal ^ input[offset]) & 0xff)]
+					^ table[(14 * 256) + (((crcLocal >> 8) ^ input[offset + 1]) & 0xff)]
+					^ table[(13 * 256) + (((crcLocal >> 16) ^ input[offset + 2]) & 0xff)]
+					^ table[(12 * 256) + (((crcLocal >> 24) ^ input[offset + 3]) & 0xff)];
+
+				crcLocal = d ^ c ^ b ^ a;
 				offset += 16;
-				count -= 16;
+				length -= 16;
 			}
 
-			while (--count >= 0)
-				crcLocal = table[(crcLocal ^ buffer[offset++]) & 0xff] ^ crcLocal >> 8;
+			while (--length >= 0)
+				crcLocal = table[(crcLocal ^ input[offset++]) & 0xff] ^ crcLocal >> 8;
+
 			return crcLocal ^ uint.MaxValue;
+
 		}
 	}
 }

Blazer.Net/BlazerCompressionOptions.cs

@@ -41,6 +41,7 @@ public string Password
 		/// <summary>
 		/// Encrypt full flag. Fully encypted streams does not reveal any information about inner data (blazer header is also encypted)
 		/// </summary>
+		/// <remarks>Flush can be unsupported with this mode</remarks>
 		public bool EncryptFull { get; set; }
 
 		/// <summary>

Blazer.Net/BlazerDecompressionOptions.cs

@@ -80,6 +80,11 @@ public string Password
 		/// </summary>
 		public bool DoNotFireInfoCallbackOnOneFile { get; set; }
 
+		/// <summary>
+		/// Skip real decoding. This option can be useful for 'list' or 'test' modes, when it required to get some info (e.g. files list) without real decoding
+		/// </summary>
+		public bool DoNotPerformDecoding { get; set; }
+
 		/// <summary>
 		/// Create default options
 		/// </summary>

Blazer.Net/BlazerInputStream.cs

@@ -297,7 +297,7 @@ public override void Write(byte[] buffer, int offset, int count)
 
 			if (_flushMode == BlazerFlushMode.AutoFlush)
 				Flush();
-			else if (_flushMode == BlazerFlushMode.RespectFlush && buffer.Length < offset + count) // smart flush will flush data, if it smaller than buffer size. otherwise we use large binary data and it not required to be flushed
+			else if (_flushMode == BlazerFlushMode.SmartFlush && buffer.Length < offset + count) // smart flush will flush data, if it smaller than buffer size. otherwise we use large binary data and it not required to be flushed
 				Flush();
 		}
 

Blazer.Net/BlazerOutputStream.cs

@@ -146,6 +146,8 @@ public override long Position
 
 		private BlazerFileInfo _fileInfo;
 
+		private bool _doNotPerformDecoding;
+
 		/// <summary>
 		/// Returns information about compressed file, if exists (and only one file in archive)
 		/// </summary>
@@ -175,7 +177,7 @@ public BlazerAlgorithm Algorithm
 		{
 			get
 			{
-				return _decoder.GetAlgorithmId();
+				return (BlazerAlgorithm)_algorithmId;
 			}
 		}
 
@@ -236,6 +238,7 @@ public BlazerOutputStream(Stream innerStream, BlazerDecompressionOptions options
 			_fileInfoCallback = options.FileInfoCallback ?? (f => { });
 			_doNotFireInfoCallbackOnOneFile = options.DoNotFireInfoCallbackOnOneFile;
 			_noSeek = options.NoSeek;
+			_doNotPerformDecoding = options.DoNotPerformDecoding;
 
 			if (options.EncyptFull)
 			{
@@ -251,10 +254,14 @@ public BlazerOutputStream(Stream innerStream, BlazerDecompressionOptions options
 				var decoder = options.Decoder;
 				if (decoder == null)
 				{
-					if (options.CompressionOptions.Encoder == null)
-						throw new InvalidOperationException("Missing decoder information");
-					options.SetDecoderByAlgorithm(options.CompressionOptions.Encoder.GetAlgorithmId());
-					decoder = options.Decoder;
+					if (_doNotPerformDecoding) decoder = new NoCompressionDecoder();
+					else
+					{
+						if (options.CompressionOptions.Encoder == null)
+							throw new InvalidOperationException("Missing decoder information");
+						options.SetDecoderByAlgorithm(options.CompressionOptions.Encoder.GetAlgorithmId());
+						decoder = options.Decoder;
+					}
 				}
 
 				InitByFlags(options.CompressionOptions.GetFlags(), decoder, password);
@@ -389,7 +396,10 @@ public override int Read(byte[] buffer, int offset, int count)
 						goto start;
 					}
 					else
-						throw new InvalidOperationException("Invalid header");
+					{
+						if (!_doNotPerformDecoding)
+							throw new InvalidOperationException("Invalid header");
+					}
 				}
 
 				var decoded = _decoder.Decode(info.Buffer, info.Offset, info.Length, _encodingType != 0);
@@ -424,10 +434,10 @@ private void ReadAndValidateHeader()
 			if ((flags & (~BlazerFlags.AllKnownFlags)) != 0)
 				throw new InvalidOperationException("Invalid flag combination. Try to use newer version of Blazer");
 
-			_decoder = EncoderDecoderFactory.GetDecoder((BlazerAlgorithm)((((uint)flags) >> 4) & 15));
+			_algorithmId = (byte)((((uint)flags) >> 4) & 15);
+			_decoder = _doNotPerformDecoding ? new NoCompressionDecoder() : EncoderDecoderFactory.GetDecoder((BlazerAlgorithm)_algorithmId);
 			_maxUncompressedBlockSize = 1 << ((((int)flags) & 15) + 9);
 			_maxUncompressedBlockSizeOrig = _maxUncompressedBlockSize;
-			_algorithmId = (byte)_decoder.GetAlgorithmId();
 			_includeCrc = (flags & BlazerFlags.IncludeCrc) != 0;
 			_includeFooter = (flags & BlazerFlags.IncludeFooter) != 0;
 			_shouldHaveFileInfo = (flags & BlazerFlags.OnlyOneFile) != 0;