Zipper: now computeing crc32 on the fly during zip creation

src/libs/utils/include/utils/Crc32Calculator.hpp

@@ -0,0 +1,47 @@
+/*
+ * Copyright (C) 2020 Emeric Poupon
+ *
+ * This file is part of LMS.
+ *
+ * LMS is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * LMS is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with LMS.  If not, see <http://www.gnu.org/licenses/>.
+ */
+
+#pragma once
+
+#include <boost/crc.hpp>  // for boost::crc_32_type
+
+namespace Utils
+{
+
+	class Crc32Calculator
+	{
+		public:
+
+			void processBytes(const std::byte* _data, std::size_t dataSize)
+			{
+				_result.process_bytes(_data, dataSize);
+			}
+
+			std::uint32_t getResult() const
+			{
+				return _result.checksum();
+			}
+
+		private:
+			using Crc32Type = boost::crc_32_type;
+			Crc32Type _result;
+	};
+
+}
+

src/libs/utils/include/utils/Zipper.hpp

@@ -24,6 +24,7 @@
 #include <filesystem>
 
 #include "Exception.hpp"
+#include "utils/Crc32Calculator.hpp"
 
 namespace Zip
 {
@@ -33,17 +34,12 @@ namespace Zip
 		using LmsException::LmsException;
 	};
 
-	// Very simple on-the-fly zip creator
+	// Very simple on-the-fly zip creator, "store" method only
 	class Zipper
 	{
 		public:
 
-			enum class CompressionMethod
-			{
-				NoCompression,
-			};
-
-			Zipper(const std::map<std::string, std::filesystem::path>& files, CompressionMethod comp = CompressionMethod::NoCompression);
+			Zipper(const std::map<std::string, std::filesystem::path>& files);
 
 			static constexpr std::size_t minOutputBufferSize = 64;
 			std::size_t writeSome(std::byte* buffer, std::size_t bufferSize);
@@ -55,6 +51,7 @@ namespace Zip
 			std::size_t writeLocalFileHeader(std::byte* buffer, std::size_t bufferSize);
 			std::size_t writeLocalFileHeaderFileName(std::byte* buffer, std::size_t bufferSize);
 			std::size_t writeFileData(std::byte* buffer, std::size_t bufferSize);
+			std::size_t writeDataDescriptor(std::byte* buffer, std::size_t bufferSize);
 			std::size_t writeCentralDirectoryHeader(std::byte* buffer, std::size_t bufferSize);
 			std::size_t writeCentralDirectoryHeaderFileName(std::byte* buffer, std::size_t bufferSize);
 			std::size_t writeEndOfCentralDirectoryRecord(std::byte* buffer, std::size_t bufferSize);
@@ -63,7 +60,7 @@ namespace Zip
 			{
 				std::filesystem::path filePath;
 				std::size_t fileSize;
-				std::uint32_t fileCrc32;
+				Utils::Crc32Calculator fileCrc32;
 				std::size_t localFileHeaderOffset {};
 			};
 
@@ -75,13 +72,13 @@ namespace Zip
 				LocalFileHeader,
 				LocalFileHeaderFileName,
 				FileData,
+				DataDescriptor,
 				CentralDirectoryHeader,
 				CentralDirectoryHeaderFileName,
 				EndOfCentralDirectoryRecord,
 				Complete,
 			};
 
-			CompressionMethod _compMethod {CompressionMethod::NoCompression};
 			WriteState _writeState {WriteState::LocalFileHeader};
 			FileContainer::iterator _currentFile;
 			std::size_t _currentOffset {};