// counters.h
/*
 *    Copyright (C) 2010 10gen Inc.
 *
 *    This program is free software: you can redistribute it and/or  modify
 *    it under the terms of the GNU Affero General Public License, version 3,
 *    as published by the Free Software Foundation.
 *
 *    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 Affero General Public License for more details.
 *
 *    You should have received a copy of the GNU Affero General Public License
 *    along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */

#pragma once

#include "../../pch.h"
#include "../jsobj.h"
#include "../../util/net/message.h"
#include "../../util/processinfo.h"
#include "../../util/concurrency/spin_lock.h"

namespace mongo {

    /**
     * for storing operation counters
     * note: not thread safe.  ok with that for speed
     */
    class OpCounters {
    public:

        OpCounters();

        AtomicUInt * getInsert() { return _insert; }
        AtomicUInt * getQuery() { return _query; }
        AtomicUInt * getUpdate() { return _update; }
        AtomicUInt * getDelete() { return _delete; }
        AtomicUInt * getGetMore() { return _getmore; }
        AtomicUInt * getCommand() { return _command; }

        void incInsertInWriteLock(int n) { _insert->x += n; }
        void gotInsert() { _insert[0]++; }
        void gotQuery() { _query[0]++; }
        void gotUpdate() { _update[0]++; }
        void gotDelete() { _delete[0]++; }
        void gotGetMore() { _getmore[0]++; }
        void gotCommand() { _command[0]++; }

        void gotOp( int op , bool isCommand );

        BSONObj& getObj();

    private:
        BSONObj _obj;

        // todo: there will be a lot of cache line contention on these.  need to do something 
        //       else eventually.
        AtomicUInt * _insert;
        AtomicUInt * _query;
        AtomicUInt * _update;
        AtomicUInt * _delete;
        AtomicUInt * _getmore;
        AtomicUInt * _command;
    };

    extern OpCounters globalOpCounters;
    extern OpCounters replOpCounters;


    class IndexCounters {
    public:
        IndexCounters();

        // used without a mutex intentionally (can race)
        void btree( char * node ) {
            if ( ! _memSupported )
                return;
            if ( _sampling++ % _samplingrate )
                return;
            btree( _pi.blockInMemory( node ) );
        }

        void btree( bool memHit ) {
            if ( memHit )
                _btreeMemHits++;
            else
                _btreeMemMisses++;
            _btreeAccesses++;
        }
        void btreeHit() { _btreeMemHits++; _btreeAccesses++; }
        void btreeMiss() { _btreeMemMisses++; _btreeAccesses++; }

        void append( BSONObjBuilder& b );

    private:
        ProcessInfo _pi;
        bool _memSupported;

        int _sampling;
        int _samplingrate;

        int _resets;
        long long _maxAllowed;

        long long _btreeMemMisses;
        long long _btreeMemHits;
        long long _btreeAccesses;
    };

    extern IndexCounters globalIndexCounters;

    class FlushCounters {
    public:
        FlushCounters();

        void flushed(int ms);

        void append( BSONObjBuilder& b );

    private:
        long long _total_time;
        long long _flushes;
        int _last_time;
        Date_t _last;
    };

    extern FlushCounters globalFlushCounters;


    class GenericCounter {
    public:
        GenericCounter() : _mutex("GenericCounter") { }
        void hit( const string& name , int count=0 );
        BSONObj getObj();
    private:
        map<string,long long> _counts; // TODO: replace with thread safe map
        mongo::mutex _mutex;
    };

    class NetworkCounter {
    public:
        NetworkCounter() : _bytesIn(0), _bytesOut(0), _requests(0), _overflows(0) {}
        void hit( long long bytesIn , long long bytesOut );
        void append( BSONObjBuilder& b );
    private:
        long long _bytesIn;
        long long _bytesOut;
        long long _requests;

        long long _overflows;

        SpinLock _lock;
    };

    extern NetworkCounter networkCounter;
}