SegmentFactory.h

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/*
// $Id: //open/dev/fennel/segment/SegmentFactory.h#18 $
// Fennel is a library of data storage and processing components.
// Copyright (C) 2005-2009 The Eigenbase Project
// Copyright (C) 2005-2009 SQLstream, Inc.
// Copyright (C) 2005-2009 LucidEra, Inc.
// Portions Copyright (C) 1999-2009 John V. Sichi
//
// 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 approved by The Eigenbase Project.
//
// 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
*/

#ifndef Fennel_SegmentFactory_Included
#define Fennel_SegmentFactory_Included

#include "fennel/common/CompoundId.h"
#include "fennel/common/ClosableObject.h"
#include "fennel/common/ConfigMap.h"
#include "fennel/synch/SynchObj.h"
#include "fennel/segment/TracingSegment.h"
#include "fennel/segment/SnapshotRandomAllocationSegment.h"
#include "fennel/device/DeviceMode.h"

#include <boost/dynamic_bitset.hpp>
#include <boost/utility.hpp>
#include <boost/enable_shared_from_this.hpp>

FENNEL_BEGIN_NAMESPACE

class LinearDeviceSegmentParams;
class PseudoUuid;

class FENNEL_SEGMENT_EXPORT SegmentFactory
    : public boost::noncopyable,
        public boost::enable_shared_from_this<SegmentFactory>
{
    friend class TempSegDestructor;

    static ParamName paramTraceSegments;

    SharedTraceTarget pTraceTarget;

    boost::dynamic_bitset<> tempDeviceIdBitset;

    DeviceId firstTempDeviceId;

    StrictMutex mutex;

    ConfigMap configMap;

    DeviceId allocateTempDeviceId();

    void deallocateTempDeviceId(DeviceId);

    explicit SegmentFactory(
        ConfigMap const &configMap,
        SharedTraceTarget pTraceTarget);
public:
    static SharedSegmentFactory newSegmentFactory(
        ConfigMap const &configMap,
        SharedTraceTarget pTraceTarget);

    virtual ~SegmentFactory();

    ConfigMap const &getConfigMap() const;

    SharedSegment newLinearDeviceSegment(
        SharedCache cache,
        LinearDeviceSegmentParams const &params);

    SharedSegment newRandomAllocationSegment(
        SharedSegment delegateSegment,
        bool bFormat,
        bool deferInit = false);

    SharedSegment newVersionedRandomAllocationSegment(
        SharedSegment delegateSegment,
        SharedSegment pTempSegment,
        bool bFormat,
        bool deferInit = false);

    SharedSegment newSnapshotRandomAllocationSegment(
        SharedSegment delegateSegment,
        SharedSegment versionedSegment,
        TxnId snapshotCsn,
        bool readOnlyCommittedData = false);

    SharedSegment newDynamicDelegatingSegment(SharedSegment delegateSegment);

    SharedSegment newWALSegment(
        SharedSegment logSegment);

    SharedSegment newLinearViewSegment(
        SharedSegment delegateSegment,
        PageId firstPageId);

    SharedSegment newCircularSegment(
        SharedSegment delegateSegment,
        SharedCheckpointProvider pCheckpointProvider,
        PageId oldestPageId = NULL_PAGE_ID,
        PageId newestPageId = NULL_PAGE_ID);

    SharedSegment newVersionedSegment(
        SharedSegment dataSegment,
        SharedSegment logSegment,
        PseudoUuid const &onlineUuid,
        SegVersionNum versionNumber);

    SegmentAccessor newScratchSegment(
        SharedCache pCache,
        uint nPagesMax = MAXU);

    SharedSegment newTracingSegment(
        SharedSegment pSegment,
        std::string sourceName,
        bool qualifySourceName = true);

    SharedSegment newTempDeviceSegment(
        SharedCache pCache,
        DeviceMode deviceMode,
        std::string deviceFileName);

    template <class PDerivedSegment>
    static PDerivedSegment dynamicCast(SharedSegment pSegment)
    {
        PDerivedSegment pDerived = dynamic_cast<PDerivedSegment>(
            pSegment.get());
        if (pDerived) {
            return pDerived;
        }
        TracingSegment *pTracing = dynamic_cast<TracingSegment *>(
            pSegment.get());
        if (pTracing) {
            pDerived = dynamic_cast<PDerivedSegment>(
                pTracing->getDelegateSegment().get());
        }
        return pDerived;
    }

    static SnapshotRandomAllocationSegment *getSnapshotSegment(
        SharedSegment pSegment);
};

class FENNEL_SEGMENT_EXPORT TempSegDestructor
    : public ClosableObjectDestructor
{
    SharedSegmentFactory pSegmentFactory;

public:
    explicit TempSegDestructor(SharedSegmentFactory);
    void operator()(Segment *pSegment);
};

FENNEL_END_NAMESPACE

#endif

// End SegmentFactory.h

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