M1-nw-project/Bytes.cpp

/***************************************************************************
 * 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
 **************************************************************************/

#include "Bytes.h"
#include <cstring>
#include <algorithm>
using namespace std;

Bytes::Bytes() : data(), firstIndex(0) {}

Bytes::Bytes(const void* buff, size_t len) : data(), firstIndex(0) {
	data.reserve(len);
	for(size_t pos=0; pos < len; pos++)
		data.push_back(((u8*)buff)[pos]);
}

u8& Bytes::operator[](const size_t pos) {
	if(pos < size())
		return data[pos+firstIndex];
	throw OutOfRange();
}

u8 Bytes::operator[](const size_t pos) const {
	if(pos < size())
		return data[pos+firstIndex];
	throw OutOfRange();
}
u16 Bytes::ushortAt(const size_t pos) const {
	if(pos+1 < size())
		return (((u16)data[pos+firstIndex+1])<<8)+data[pos+firstIndex];
	throw OutOfRange();
}

size_t Bytes::size() const {
	return data.size() - firstIndex;
}

Bytes& Bytes::operator<<(char v) {
	insertData<char>(v);
	return *this;
}
Bytes& Bytes::operator<<(u8 v) {
	insertData<u8>(v);
	return *this;
}
Bytes& Bytes::operator<<(u16 v) {
	insertData<u16>(v);
	return *this;
}
Bytes& Bytes::operator<<(u32 v) {
	insertData<u32>(v);
	return *this;
}
Bytes& Bytes::operator<<(const Bytes& v) {
	data.reserve(data.size() + v.size());
	for(size_t byte=0; byte < v.size(); byte++)
		data.push_back(v[byte]);
	return *this;
}
Bytes& Bytes::operator<<(const char* str) {
	unsigned len = strlen(str);
	data.reserve(data.size() + len);
	for(unsigned byte=0; byte < len; byte++)
		data.push_back(str[byte]);
	return *this;
}

Bytes& Bytes::operator>>(u8& v) {
	extractData<u8>(v);
	return *this;
}
Bytes& Bytes::operator>>(u16& v) {
	extractData<u16>(v);
	return *this;
}
Bytes& Bytes::operator>>(u32& v) {
	extractData<u32>(v);
	return *this;
}
Bytes& Bytes::operator>>(char& v) {
	extractData<char>(v);
	return *this;
}

void Bytes::operator=(const Bytes& oth) {
	firstIndex=0;
	data.clear();
	data.reserve(oth.size());
	for(size_t pos=0; pos < oth.size(); pos++)
		data.push_back(oth[pos]);
}

Bytes Bytes::sub(size_t beg, size_t len) const {
	if(beg+len >= size())
		throw OutOfRange();
	Bytes out;
	for(size_t byte=0; byte < len; byte++)
		out << (*this)[byte+beg];
	return out;
}

void Bytes::writeToBuffer(void* buff, unsigned maxLen) const {
	if(maxLen == 0)
		maxLen = size();
	for(size_t pos=0; pos < min((size_t)maxLen, size()); pos++)
		((u8*)buff)[pos] = (*this)[pos];
}

char charOfDigit(u8 dig) {
	if(dig < 10)
		return dig+'0';
	return dig+'A'-10;
}
void hexdumpByte(Bytes& dest, u8 b) {
	dest << charOfDigit(b/16) << charOfDigit(b & 0xf);
}

void Bytes::hexdump(Bytes& dest) const {
	for(unsigned pos=0; pos < size(); pos++) {
		hexdumpByte(dest, (*this)[pos]);
		if(pos % 32 == 31)
			dest << '\n';
		else if(pos % 4 == 3)
			dest << ' ';
	}
	if(size() % 32 != 0)
		dest << '\n';
}

template<typename T> void Bytes::extractData(T& v) {
	if(size() < sizeof(v))
		throw OutOfRange();
	for(size_t byte=0; byte < sizeof(v); byte++)
		v = (v<<8) | data[firstIndex+byte];
	firstIndex += sizeof(v);
}

template<typename T> void Bytes::insertData(T v) {
	for(int byte=sizeof(v)-1; byte >= 0; byte--) {
		data.push_back((u8) (v >> (8*byte)));
	}
}