/*
 * MappedFile.h
 *
 *  Created on: Jan 21, 2014
 *      Author: Manuel Sascha Weiand
 */

#ifndef STORM_PARSER_MAPPEDFILE_H_
#define STORM_PARSER_MAPPEDFILE_H_

#include <cstddef>
#include <sys/stat.h>

#include "src/utility/OsDetection.h"

namespace storm {
	namespace parser {

		#if !defined LINUX && !defined MACOSX && !defined WINDOWS
		#error Platform not supported
		#endif

		/*!
		 * Opens a file and maps it to memory providing a char*
		 * containing the file content.
		 *
		 * This class is a very simple interface to read files efficiently.
		 * The given file is opened and mapped to memory using mmap().
		 * The public member data is a pointer to the actual file content.
		 * Using this method, the kernel will take care of all buffering.
		 * This is most probably much more efficient than doing this manually.
		 */
		class MappedFile {

		public:

			/*!
			 * Constructs a MappedFile.
			 * This will stat the given file, open it and map it to memory.
			 * If anything of this fails, an appropriate exception is raised and a log entry is written.
			 *
			 * @param filename Path and name of the file to be opened.
			 */
			MappedFile(const char* filename);

			/*!
			 * Destructs a MappedFile.
			 * This will unmap the data and close the file.
			 */
			~MappedFile();

			/*!
			 * Tests whether the given file exists and is readable.
			 *
			 * @param filename Path and name of the file to be tested.
			 * @return True iff the file exists and is readable.
			 */
			static bool fileExistsAndIsReadable(const char* filename);

			/*!
			 * Returns a pointer to the beginning of the mapped file data.
			 *
			 * @return A pointer to the first character of the mapped file data.
			 */
			char const* getData() const;

			/*!
			 * Returns a pointer to the end of the mapped file data.
			 *
			 * @return A pointer to the first position after the last character of the mapped file data.
			 */
			char const* getDataEnd() const;

            /*!
             * Returns the size of the mapped file data.
             */
            std::size_t getDataSize() const;
            
		private:

			//! A pointer to the mapped file content.
			char* data;

			//! A pointer to end of the mapped file content.
			char* dataEnd;

		#if defined LINUX || defined MACOSX

			//! The file descriptor obtained by open().
			int file;
		#elif defined WINDOWS
				//! The file handle obtained by opening the file.
				HANDLE file;

				//! The handle referencing the created memory mapping.
				HANDLE mapping;
		#endif

		#if defined LINUX

			//! Stat information about the file.
			struct stat64 st;
		#elif defined MACOSX

			//! Stat information about the file.
			struct stat st;
		#elif defined WINDOWS

			//! Stat information about the file.
			struct __stat64 st;
		#endif
		};

	} // namespace parser
} // namespace storm

#endif /* STORM_PARSER_MAPPEDFILE_H_ */