M1-nw-project/Bytes.h

/***************************************************************************
 * By Théophile Bastian, 2017
 * M1 Network course project at ENS Cachan, Juliusz Chroboczek.
 * License: WTFPL v2 <http://www.wtfpl.net/>
 **************************************************************************/

/***************************************************************************
 * Reused from a former project, by Théophile Bastian & Nathanaël Courant
 * git@github.com:tobast/sysres-pikern.git
 **************************************************************************/

#pragma once

#include <cstdlib>
#include <vector>
#include <exception>

#include "data.h"

class Bytes {
	public:
		class OutOfRange : public std::exception {};
		/// Exception -- thrown by operator[]

		Bytes();
		Bytes(const void* buff, size_t len);
		/// Initializes the object with [buff], reading [len] bytes.

		u8& operator[](const size_t pos);
		u8 operator[](const size_t pos) const;
		/// Accesses the [pos]th element. Throws OutOfRange if pos >= size()

		u16 ushortAt(const size_t pos) const;
		/// Accesses the 16 bits unsigned integet at position [pos].
		/// Throws OutOfRange if [pos+15] >= size().

		size_t size() const;
		/// Returns the number of chars in the object.

		Bytes& operator<<(char v);
		Bytes& operator<<(u8 v);
		Bytes& operator<<(u16 v);
		Bytes& operator<<(u32 v);
		Bytes& operator<<(u64 v);
		Bytes& operator<<(const Bytes& v);
		Bytes& operator<<(const char* str);
		/// Appends the given data to the vector. Returns *this to allow
		/// chaining.

		Bytes& operator>>(u8& v);
		Bytes& operator>>(u16& v);
		Bytes& operator>>(u32& v);
		Bytes& operator>>(u64& v);
		Bytes& operator>>(char& c);
		/// Extracts the given data type from the vector. Returns *this to
		/// allow chaining.

		void operator=(const Bytes& oth);
		/// Copies the given Bytes object into its own data.

		Bytes sub(size_t beg, size_t len) const;
		/// Extracts a sub-bytes, beginning at character [beg], containing
		/// [len] chars. If [beg+len] >= [size()], throws OutOfRange.

		void writeToBuffer(void* buff, unsigned maxLen=0) const;
		/// Writes the contents of this array in the buffer [buff].
		/// The user must provide a buffer of at least [size()] bytes.
		/// If [maxLen] != 0, writes at most [maxLen] bytes to buff.

		void hexdump(Bytes& dest) const;
		/// Dumps the packet to [dest] in hexadecimal form.

	private: //meth
		template<typename T> void insertData(T v);
		template<typename T> void extractData(T& v);

	private:
		std::vector<u8> data;
		size_t firstIndex;
};