libscio/libscio.hpp

//
// libscio.hpp
// libscio
//
// Created by Bob Polis at 2020-02-14
// Copyright (c) 2020 SwiftCoder. All rights reserved.
//

#ifndef _libscio_H_
#define _libscio_H_

#include <iostream>
#include <streambuf>
#include <cstdio>
#include <cstdint>
#include <cstdlib>

namespace sc {

	namespace io {

		class fdoutbuf : public std::streambuf {
			public:
				fdoutbuf(int fd): _fd(fd) {}

			protected:
				int _fd;

				int_type overflow(int_type c) override;
				std::streamsize xsputn(const char* s, std::streamsize num) override;
		};

		class fdostream : public std::ostream {
			public:
				fdostream(int fd) : std::ostream(&_buf), _buf(fd) {}

			protected:
				fdoutbuf _buf;
		};

		class fdinbuf : public std::streambuf {

		};

		class fdistream : public std::istream {

		};

		class fdstream : public fdostream, public fdistream {

		};

		class socketstream : public fdstream {

		};

		class meminbuf : public std::streambuf {

		};

		class memistream : public std::istream {

		};

		class memoutbuf : public std::streambuf {

		};

		class memostream : public std::ostream {

		};

		class memstream : public memostream, public memistream {

		};

		struct float_80 {
			unsigned char _val[10]; // big endian

			float_80();
			float_80(double val);
			operator double() const;
		};

		enum class byte_order {
			undefined,
			little_endian,
			big_endian
		};

		class data_streamer {
			public:
				static byte_order cur_byte_order();
				static inline void byte_swap(void* val, size_t n) {
					char* p = reinterpret_cast<char*>(val);
					for (size_t i = 0; i < n / 2; ++i) {
						std::swap(p[i], p[n - 1 - i]);
					}
				}
				template<class T>
				inline T get(std::istream& file) const {
					char buf[sizeof(T)];
					file.read(buf, sizeof(T));
					if (cur_byte_order() != _target_byte_order) {
						byte_swap(buf, sizeof(T));
					}
					return *reinterpret_cast<T*>(buf);
				}
				template<class T>
				inline void put(T val, std::ostream& file) const {
					if (cur_byte_order() != _target_byte_order) {
						byte_swap(&val, sizeof(T));
					}
					file.write(reinterpret_cast<char*>(&val), sizeof(T));
				}

				data_streamer() = default;

				byte_order target_byte_order() const { return _target_byte_order; }
				void target_byte_order(byte_order new_byte_order) { _target_byte_order = new_byte_order; }

				std::string get4chars(std::istream& file) const;

				uint8_t getui8(std::istream& file) const { return static_cast<uint8_t>(file.get()); }
				int8_t getsi8(std::istream& file) const { return file.get(); }
				uint16_t getui16(std::istream& file) const { return get<uint16_t>(file); }
				int16_t getsi16(std::istream& file) const { return get<int16_t>(file); }
				uint32_t getui24(std::istream& file) const;
				int32_t getsi24(std::istream& file) const;
				uint32_t getui32(std::istream& file) const { return get<uint32_t>(file); }
				int32_t getsi32(std::istream& file) const { return get<int32_t>(file); }
				uint64_t getui64(std::istream& file) const { return get<uint64_t>(file); }
				int64_t getsi64(std::istream& file) const { return get<int64_t>(file); }

				float getf32(std::istream& file) const { return get<float>(file); }
				double getf64(std::istream& file) const { return get<double>(file); }
				double getf80(std::istream& file) const;

				void put4chars(const std::string& s, std::ostream& file) const;

				void putui8(uint8_t val, std::ostream& file) const { file.put(val); }
				void putsi8(int8_t val, std::ostream& file) const { file.put(val); }
				void putui16(uint16_t val, std::ostream& file) const { put<uint16_t>(val, file); }
				void putsi16(int16_t val, std::ostream& file) const { put<int16_t>(val, file); }
				void putui24(uint32_t val, std::ostream& file) const;
				void putsi24(int32_t val, std::ostream& file) const;
				void putui32(uint32_t val, std::ostream& file) const { put<uint32_t>(val, file); }
				void putsi32(int32_t val, std::ostream& file) const { put<int32_t>(val, file); }
				void putui64(uint64_t val, std::ostream& file) const { put<uint64_t>(val, file); }
				void putsi64(int64_t val, std::ostream& file) const { put<int64_t>(val, file); }

				void putf32(float val, std::ostream& file) const { put<float>(val, file); }
				void putf64(double val, std::ostream& file) const { put<double>(val, file); }
				void putf80(double val, std::ostream& file) const;

			private:
				byte_order _target_byte_order {cur_byte_order()};
		};

		class byte_order_changer {
			public:
				byte_order_changer(data_streamer* ds, byte_order order);
				~byte_order_changer();

				byte_order_changer(byte_order_changer&& other);
				byte_order_changer& operator=(byte_order_changer&& other);

				byte_order_changer(const byte_order_changer&) = delete;
				byte_order_changer& operator=(const byte_order_changer&) = delete;

			private:
				data_streamer* _data_streamer {nullptr};
				byte_order _saved_byte_order {byte_order::undefined};
		};

	}

}

#endif // _libscio_H_