ddnet/src/engine/shared/packer.cpp

// copyright (c) 2007 magnus auvinen, see licence.txt for more info
#include <base/system.h>

#include "packer.h"
#include "compression.h"
#include "engine.h"
#include "config.h"

void CPacker::Reset()
{
	m_Error = 0;
	m_pCurrent = m_aBuffer;
	m_pEnd = m_pCurrent + PACKER_BUFFER_SIZE;
}

void CPacker::AddInt(int i)
{
	if(m_Error)
		return;
		
	// make sure that we have space enough
	if(m_pEnd - m_pCurrent < 6)
	{
		dbg_break();
		m_Error = 1;
	}
	else
		m_pCurrent = CVariableInt::Pack(m_pCurrent, i);
}

void CPacker::AddString(const char *pStr, int Limit)
{
	if(m_Error)
		return;
	
	//
	if(Limit > 0)
	{
		while(*pStr && Limit != 0)
		{
			*m_pCurrent++ = *pStr++;
			Limit--;
			
			if(m_pCurrent >= m_pEnd)
			{
				m_Error = 1;
				break;
			}
		}
		*m_pCurrent++ = 0;
	}
	else
	{
		while(*pStr)
		{
			*m_pCurrent++ = *pStr++;

			if(m_pCurrent >= m_pEnd)
			{
				m_Error = 1;
				break;
			}
		}
		*m_pCurrent++ = 0;
	}
}

void CPacker::AddRaw(const void *pData, int Size)
{
	if(m_Error)
		return;
		
	if(m_pCurrent+Size >= m_pEnd)
	{
		m_Error = 1;
		return;
	}
	
	const unsigned char *pSrc = (const unsigned char *)pData;
	while(Size)
	{
		*m_pCurrent++ = *pSrc++;
		Size--;
	}
}


void CUnpacker::Reset(const void *pData, int Size)
{
	m_Error = 0;
	m_pStart = (const unsigned char *)pData;
	m_pEnd = m_pStart + Size;
	m_pCurrent = m_pStart;
}

int CUnpacker::GetInt()
{
	if(m_Error)
		return 0;
		
	if(m_pCurrent >= m_pEnd)
	{
		m_Error = 1;
		return 0;
	}
	
	int i;
	m_pCurrent = CVariableInt::Unpack(m_pCurrent, &i);
	if(m_pCurrent > m_pEnd)
	{
		m_Error = 1;
		return 0;
	}
	return i;
}

const char *CUnpacker::GetString()
{
	if(m_Error || m_pCurrent >= m_pEnd)
		return "";
		
	char *pPtr = (char *)m_pCurrent;
	while(*m_pCurrent) // skip the string
	{
		m_pCurrent++;
		if(m_pCurrent == m_pEnd)
		{
			m_Error = 1;;
			return "";
		}
	}
	m_pCurrent++;
	
	// sanitize all strings
	str_sanitize(pPtr);
	return pPtr;
}

const unsigned char *CUnpacker::GetRaw(int Size)
{
	const unsigned char *pPtr = m_pCurrent;
	if(m_Error)
		return 0;
	
	// check for nasty sizes
	if(Size < 0 || m_pCurrent+Size > m_pEnd)
	{
		m_Error = 1;
		return 0;
	}

	// "unpack" the data
	m_pCurrent += Size;
	return pPtr;
}