source: nscp/include/pdh/query.hpp @ f7a074d

/**************************************************************************
*   Copyright (C) 2004-2007 by Michael Medin <michael@medin.name>         *
*                                                                         *
*   This code is part of NSClient++ - http://trac.nakednuns.org/nscp      *
*                                                                         *
*   This program is free software; you can redistribute it and/or modify  *
*   it under the terms of the GNU General Public License as published by  *
*   the Free Software Foundation; either version 2 of the License, or     *
*   (at your option) any later version.                                   *
*                                                                         *
*   This program is distributed in the hope that it will be useful,       *
*   but WITHOUT ANY WARRANTY; without even the implied warranty of        *
*   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the         *
*   GNU General Public License for more details.                          *
*                                                                         *
*   You should have received a copy of the GNU General Public License     *
*   along with this program; if not, write to the                         *
*   Free Software Foundation, Inc.,                                       *
*   59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.             *
***************************************************************************/
#pragma once

#include <list>
#include <pdh.h>
#include <pdhmsg.h>
#include <sstream>
#include <error.hpp>
#include <pdh/resolver.hpp>
#include <boost/shared_ptr.hpp>

namespace PDH {
        class PDHQuery : public PDH::PDHImplSubscriber {
        private:
                typedef boost::shared_ptr<PDHCounter> counter_ptr;
                typedef boost::shared_ptr<PDHCounterListener> listener_ptr;
                typedef std::list<counter_ptr> CounterList;
                CounterList counters_;
                PDH::PDH_HQUERY hQuery_;
        public:
                PDHQuery() : hQuery_(NULL) {
                }
                virtual ~PDHQuery(void) {
                        removeAllCounters();
                }

                counter_ptr addCounter(std::wstring name, listener_ptr listener) {
                        counter_ptr counter = counter_ptr(new PDHCounter(name, listener));
                        counters_.push_back(counter);
                        return counter;
                }
                counter_ptr addCounter(std::wstring name) {
                        counter_ptr counter = counter_ptr(new PDHCounter(name));
                        counters_.push_back(counter);
                        return counter;
                }
                void removeAllCounters() {
                        if (hQuery_)
                                close();
                        counters_.clear();
                }

                virtual void on_unload() {
                        if (hQuery_ == NULL)
                                return;
                        for (CounterList::iterator it = counters_.begin(); it != counters_.end(); it++) {
                                (*it)->remove();
                        }
                        PDH::PDHError status = PDH::PDHFactory::get_impl()->PdhCloseQuery(hQuery_);
                        if (status.is_error())
                                throw PDHException(_T("PdhCloseQuery failed"), status);
                        hQuery_ = NULL;
                }
                virtual void on_reload() {
                        if (hQuery_ != NULL)
                                return;
                        PDH::PDHError status = PDH::PDHFactory::get_impl()->PdhOpenQuery( NULL, 0, &hQuery_ );
                        if (status.is_error())
                                throw PDHException(_T("PdhOpenQuery failed"), status);
                        for (CounterList::iterator it = counters_.begin(); it != counters_.end(); it++) {
                                (*it)->addToQuery(getQueryHandle());
                        }
                }

                void open() {
                        if (hQuery_ != NULL)
                                throw PDHException(_T("query is not null!"));
                        PDH::PDHFactory::get_impl()->add_listener(this);
                        on_reload();
                }

                void close() {
                        if (hQuery_ == NULL)
                                throw PDHException(_T("query is null!"));
                        PDH::PDHFactory::get_impl()->remove_listener(this);
                        on_unload();
                        counters_.clear();
                }

                void gatherData() {
                        collect();
                        for (CounterList::iterator it = counters_.begin(); it != counters_.end(); it++) {
                                (*it)->collect();
                        }
                }
                inline void collect() {
                        PDH::PDHError status = PDH::PDHFactory::get_impl()->PdhCollectQueryData(hQuery_);
                        if (status.is_error())
                                throw PDHException(_T("PdhCollectQueryData failed: "), status);
                }

                PDH::PDH_HQUERY getQueryHandle() const {
                        return hQuery_;
                }
        };
}