ProSysLib: Dissecting the Process

// PSLEnvironmentVars.cpp : Implementation of CPSLEnvironmentVars

#include "stdafx.h"
#include "PSLEnvironmentVar.h"
#include "PSLEnvironmentVars.h"

CPSLEnvironmentVars::CPSLEnvironmentVars()
{
}

HRESULT CPSLEnvironmentVars::OnIndexOutOfRange()
{
	return MakeException(exIndexOutOfRange);
}

HRESULT CPSLEnvironmentVars::FinalConstruct()
{
	PSL_BEGIN

	InternalUpdate();
	
	PSL_END
}

void CPSLEnvironmentVars::FinalRelease()
{
}

bool CPSLEnvironmentVars::ParseVariable(LPCTSTR sVariable, tstring & sName, tstring & sValue)
{
	LPCTSTR pValue = _tcschr(sVariable, '=');
	if(!pValue || pValue == sVariable)
		return false;

	__int3264 Length = pValue - sVariable;
	sName.resize(Length + 1);
	::_tcsncpy_s((LPTSTR)sName.c_str(), Length + 1, sVariable, Length);
	pValue ++;
	sValue = pValue;
	::trim(sName);
	::trim(sValue);

	return sName.length() > 0 && sValue.length() > 0;
}

void CPSLEnvironmentVars::InternalUpdate()
{
	CCritSecLock cs(m_csCollection);
	m_coll.clear();
	LPTCH pBuffer = ::GetEnvironmentStrings();
	if(!pBuffer)
		return;
	CComObject<CPSLEnvironmentVar> * pVariable = NULL;
	tstring sName, sValue;
	LPCTSTR ptr = pBuffer;
	while(ptr[0])
	{
		if(ParseVariable(ptr, sName, sValue))
		{
			CComObject<CPSLEnvironmentVar>::CreateInstance(&pVariable);
			pVariable->Initialize(sName.c_str(), sValue.c_str());
			m_coll.push_back(CComPtr<IPSLEnvironmentVar>(pVariable));
		}
		ptr += ::_tcslen(ptr) + 1;
	}
	::FreeEnvironmentStrings(pBuffer);
}

////////////////////////////////////////////////////////////////////////
// Interface Implementation;
////////////////////////////////////////////////////////////////////////

STDMETHODIMP CPSLEnvironmentVars::Update()
{
	PSL_BEGIN

	InternalUpdate();

	PSL_END
}

STDMETHODIMP CPSLEnvironmentVars::Find(BSTR Name, IPSLEnvironmentVar ** ppValue)
{
	PSL_BEGIN

	*ppValue = NULL;
	_bstr_t sVarName(Name);
	CCritSecLock cs(m_csCollection);
	for(EnvironmentVarsType::iterator i = m_coll.begin();i != m_coll.end();i ++)
	{
		BSTR sName = NULL;
		if(i->m_T->get_Name(&sName) == S_OK && !::_tcsicmp(_bstr_t(sName), sVarName))
		{
			IPSLEnvironmentVar * pVar = i->m_T;
			pVar->AddRef();
			*ppValue = pVar;
			break;
		}
	}

	PSL_END
}

STDMETHODIMP CPSLEnvironmentVars::Add(BSTR Name, BSTR Value, IPSLEnvironmentVar ** ppValue)
{
	PSL_BEGIN

	IPSLEnvironmentVar * pVar = NULL;
	Find(Name, &pVar);
	if(pVar)
		pVar->put_Value(Value);
	else
	{
		_bstr_t sName(Name), sValue(Value);
		if(::SetEnvironmentVariable(sName, sValue))
		{
			CComObject<CPSLEnvironmentVar> * pVariable = NULL;
			CComObject<CPSLEnvironmentVar>::CreateInstance(&pVariable);
			pVariable->AddRef();
			pVariable->Initialize(_bstr_t(Name), _bstr_t(Value));
			pVar = pVariable;
			CCritSecLock cs(m_csCollection);
			m_coll.push_back(CComPtr<IPSLEnvironmentVar>(pVariable));
		}
	}
	*ppValue = pVar;

	PSL_END
}

STDMETHODIMP CPSLEnvironmentVars::Remove(BSTR Name, VARIANT_BOOL * pValue)
{
	PSL_BEGIN

	_bstr_t sName(Name);
	*pValue = ::SetEnvironmentVariable(sName, NULL)?VARIANT_TRUE:VARIANT_FALSE;
	CCritSecLock cs(m_csCollection);
	for(EnvironmentVarsType::iterator i = m_coll.begin();i != m_coll.end();i ++)
	{
		BSTR s = NULL;
		if(i->m_T->get_Name(&s) == S_OK && !::_tcsicmp(_bstr_t(s), sName))
		{
			m_coll.erase(i);
			break;
		}	
	}

	PSL_END
}