Professional System Library: Introduction

#pragma once

#include "ProSysLib_i.h"
#include "PSLExceptions.h"

template<class Container, class Child, class ChildInterface>
class CServiceEnumerator
{
protected:

	void EnumServices(Container * pContainer, long ServiceType)
	{
		SC_HANDLE hSCM = ::OpenSCManager(NULL, NULL, GENERIC_READ);
		if(!hSCM)
		{
			if(::GetLastError() == ERROR_ACCESS_DENIED)
				pContainer->SetException(exAccessDenied);
			return;
		}

		DWORD dwBytesNeeded = 0;
		DWORD dwServiceCount = 0;
		DWORD dwResumeHandle = 0;
		BOOL RetVal = ::EnumServicesStatusEx(hSCM, SC_ENUM_PROCESS_INFO, ServiceType, SERVICE_STATE_ALL, NULL, 0, &dwBytesNeeded, &dwServiceCount, &dwResumeHandle, NULL);

		if(RetVal || GetLastError() != ERROR_MORE_DATA)
		{
			::CloseServiceHandle(hSCM);
			return; // This should never happen;
		}

		LPBYTE pStatusBuffer = new BYTE[dwBytesNeeded];
		if(!pStatusBuffer)
		{
			pContainer->SetException(exLowMemory);
			::CloseServiceHandle(hSCM);
			return;
		}

		if(!::EnumServicesStatusEx(hSCM, SC_ENUM_PROCESS_INFO, ServiceType, SERVICE_STATE_ALL, pStatusBuffer, dwBytesNeeded, &dwBytesNeeded, &dwServiceCount, &dwResumeHandle, NULL))
		{
			if(::GetLastError() == ERROR_ACCESS_DENIED)
				pContainer->SetException(exAccessDenied);
			delete []pStatusBuffer;
			::CloseServiceHandle(hSCM);
			return;
		}

		// Allocating 8Kb of memory to get full service description,
		// which is also the supported maximum for a number of Service API-s,
		// like QueryServiceConfig, so it cannot be changed.
		DWORD dwBufferSize = 8192;
		LPBYTE pTempBuffer = new BYTE[dwBufferSize];

		if(!pTempBuffer)
		{
			pContainer->SetException(exLowMemory);
			delete []pStatusBuffer;
			::CloseServiceHandle(hSCM);
			return;
		}

		LPENUM_SERVICE_STATUS_PROCESS pSSP = (LPENUM_SERVICE_STATUS_PROCESS)pStatusBuffer;

		CCritSecLock cs(pContainer->m_csCollection);
		pContainer->m_coll.clear();
		CComObject<Child> * pService = NULL;
		for(DWORD i = 0;i < dwServiceCount;i ++)
		{
			SC_HANDLE hService = ::OpenService(hSCM, pSSP[i].lpServiceName, GENERIC_READ);
			if(!hService)
				continue;

			CComObject<Child>::CreateInstance(&pService);
			pService->Initialize(hService, pSSP[i], pTempBuffer, dwBufferSize);
			pContainer->m_coll.push_back(CComPtr<ChildInterface>(pService));

			::CloseServiceHandle(hService);
		}
		cs.Unlock();

		delete []pTempBuffer;
		delete []pStatusBuffer;
		::CloseServiceHandle(hSCM);
	}

	ChildInterface * FindService(Container * pContainer, BSTR ServiceName)
	{
		_bstr_t sServiceName(ServiceName);
		CCritSecLock cs(pContainer->m_csCollection);	

		for(vector<CAdapt<CComPtr<ChildInterface> > >::iterator i = pContainer->m_coll.begin();i != pContainer->m_coll.end();i ++)
		{
			BSTR sName = NULL;
			if(i->m_T->get_Name(&sName) == S_OK)
			{
				_bstr_t s(sName);
				if(!::_tcsicmp(s, sServiceName)) // Doing case-insensitive comparison;
				{
					ChildInterface * pService = i->m_T;
					pService->AddRef();
					return pService;
				}
			}	
		}

		return NULL;
	}

};

class CServiceInfo
{
public:

	CServiceInfo(void);

protected:

	void Initialize(SC_HANDLE hSCM, ENUM_SERVICE_STATUS_PROCESS & ssp, LPBYTE pTempBuffer, DWORD dwBufferSize);

	long StartService(SAFEARRAY * CmdParams, PSLException & ex);
	long StopService(PSLException & ex);

	PSLException Update();

	_bstr_t m_sName;
	_bstr_t m_sDisplayName;
	_bstr_t m_sDescription;
	_bstr_t m_sPath;
	_bstr_t m_sStartName;
	_bstr_t m_sDependencies;

	PSLServiceState m_CurrentState;
	DWORD m_dwServiceType;
	DWORD m_dwStartType;
	DWORD m_dwProcessID;

private:

	DWORD m_dwTickCount;
};