// snapshots.h
/**
* Copyright (C) 2008 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 .
*
* As a special exception, the copyright holders give permission to link the
* code of portions of this program with the OpenSSL library under certain
* conditions as described in each individual source file and distribute
* linked combinations including the program with the OpenSSL library. You
* must comply with the GNU Affero General Public License in all respects for
* all of the code used other than as permitted herein. If you modify file(s)
* with this exception, you may extend this exception to your version of the
* file(s), but you are not obligated to do so. If you do not wish to do so,
* delete this exception statement from your version. If you delete this
* exception statement from all source files in the program, then also delete
* it in the license file.
*/
#pragma once
#define MONGO_PCH_WHITELISTED
#include "mongo/platform/basic.h"
#include "mongo/pch.h"
#undef MONGO_PCH_WHITELISTED
#include "mongo/db/jsobj.h"
#include "top.h"
#include "mongo/util/background.h"
/**
handles snapshotting performance metrics and other such things
*/
namespace mongo {
class SnapshotThread;
/**
* stores a point in time snapshot
* i.e. all counters at a given time
*/
class SnapshotData {
void takeSnapshot();
unsigned long long _created;
Top::UsageMap _usage;
friend class SnapshotThread;
friend class SnapshotDelta;
friend class Snapshots;
};
/**
* contains performance information for a time period
*/
class SnapshotDelta {
public:
SnapshotDelta( const SnapshotData& older , const SnapshotData& newer );
unsigned long long start() const {
return _older._created;
}
unsigned long long elapsed() const {
return _elapsed;
}
Top::UsageMap collectionUsageDiff();
private:
const SnapshotData& _older;
const SnapshotData& _newer;
unsigned long long _elapsed;
};
class Snapshots {
public:
Snapshots(int n=100);
const SnapshotData* takeSnapshot();
int numDeltas() const { return _stored-1; }
const SnapshotData& getPrev( int numBack = 0 );
std::auto_ptr computeDelta( int numBack = 0 );
private:
mongo::mutex _lock;
int _n;
boost::scoped_array _snapshots;
int _loc;
int _stored;
};
class SnapshotThread : public BackgroundJob {
public:
virtual std::string name() const { return "snapshot"; }
void run();
};
extern Snapshots statsSnapshots;
extern SnapshotThread snapshotThread;
}