// dbcommands_admin.cpp

/**
 *    Copyright (C) 2012 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/>.
 *
 *    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.
 */

/**
   this file has dbcommands that are for dba type administration
   mostly around dbs and collections
   NOT system stuff
*/


#include "mongo/pch.h"

#include <boost/filesystem/convenience.hpp>
#include <boost/filesystem/operations.hpp>
#include <string>
#include <vector>

#include "mongo/base/init.h"
#include "mongo/base/status.h"
#include "mongo/db/auth/action_set.h"
#include "mongo/db/auth/action_type.h"
#include "mongo/db/auth/privilege.h"
#include "mongo/db/commands.h"
#include "mongo/db/curop.h"
#include "mongo/db/index/index_access_method.h"
#include "mongo/db/index/index_descriptor.h"
#include "mongo/db/jsobj.h"
#include "mongo/db/kill_current_op.h"
#include "mongo/db/pdfile.h"
#include "mongo/db/query/internal_plans.h"
#include "mongo/db/storage_options.h"
#include "mongo/scripting/engine.h"
#include "mongo/util/alignedbuilder.h"
#include "mongo/util/background.h"
#include "mongo/util/logfile.h"
#include "mongo/util/paths.h"
#include "mongo/util/timer.h"

namespace mongo {

    namespace dur {
        boost::filesystem::path getJournalDir();
    }

    // Testing-only, enabled via command line
    class JournalLatencyTestCmd : public Command {
    public:
        JournalLatencyTestCmd() : Command( "journalLatencyTest" ) {}

        virtual bool slaveOk() const { return true; }
        virtual bool isWriteCommandForConfigServer() const { return false; }
        virtual bool adminOnly() const { return true; }
        virtual void help(stringstream& h) const { h << "test how long to write and fsync to a test file in the journal/ directory"; }
        // No auth needed because it only works when enabled via command line.
        virtual void addRequiredPrivileges(const std::string& dbname,
                                           const BSONObj& cmdObj,
                                           std::vector<Privilege>* out) {}
        bool run(OperationContext* txn, const string& dbname, BSONObj& cmdObj, int, string& errmsg, BSONObjBuilder& result, bool fromRepl ) {
            boost::filesystem::path p = dur::getJournalDir();
            p /= "journalLatencyTest";
        
            // remove file if already present
            try { 
                boost::filesystem::remove(p);
            }
            catch(...) { }

            BSONObjBuilder bb[2];
            for( int pass = 0; pass < 2; pass++ ) {
                LogFile f(p.string());
                AlignedBuilder b(1024 * 1024);
                {
                    Timer t;
                    for( int i = 0 ; i < 100; i++ ) { 
                        f.synchronousAppend(b.buf(), 8192);
                    }
                    bb[pass].append("8KB", t.millis() / 100.0);
                }
                {
                    const int N = 50;
                    Timer t2;
                    long long x = 0;
                    for( int i = 0 ; i < N; i++ ) { 
                        Timer t;
                        f.synchronousAppend(b.buf(), 8192);
                        x += t.micros();
                        sleepmillis(4);
                    }
                    long long y = t2.micros() - 4*N*1000;
                    // not really trusting the timer granularity on all platforms so whichever is higher of x and y
                    bb[pass].append("8KBWithPauses", max(x,y) / (N*1000.0));
                }
                {
                    Timer t;
                    for( int i = 0 ; i < 20; i++ ) { 
                        f.synchronousAppend(b.buf(), 1024 * 1024);
                    }
                    bb[pass].append("1MB", t.millis() / 20.0);
                }
                // second time around, we are prealloced.
            }
            result.append("timeMillis", bb[0].obj());
            result.append("timeMillisWithPrealloc", bb[1].obj());

            try { 
                remove(p);
            }
            catch(...) { }

            try {
                result.append("onSamePartition", onSamePartition(dur::getJournalDir().string(),
                                                                 storageGlobalParams.dbpath));
            }
            catch(...) { }

            return 1;
        }
    };
    MONGO_INITIALIZER(RegisterJournalLatencyTestCmd)(InitializerContext* context) {
        if (Command::testCommandsEnabled) {
            // Leaked intentionally: a Command registers itself when constructed.
            new JournalLatencyTestCmd();
        }
        return Status::OK();
    }



}