RandomAccessFileDevice.cpp

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/*
// $Id: //open/dev/fennel/device/RandomAccessFileDevice.cpp#10 $
// 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
*/

#include "fennel/common/CommonPreamble.h"
#include "fennel/device/RandomAccessFileDevice.h"
#include "fennel/device/RandomAccessRequest.h"

FENNEL_BEGIN_CPPFILE("$Id: //open/dev/fennel/device/RandomAccessFileDevice.cpp#10 $");

RandomAccessFileDevice::RandomAccessFileDevice(
    std::string filename,DeviceMode mode,FileSize initialSize)
    : FileDevice(filename,mode,initialSize)
{
}

RandomAccessFileDevice::RandomAccessFileDevice(
    std::string filename,DeviceMode mode)
    : FileDevice(filename,mode,FileSize(0))
{
}

RandomAccessDevice::~RandomAccessDevice()
{
}

FileSize RandomAccessFileDevice::getSizeInBytes()
{
    return FileDevice::getSizeInBytes();
}

void RandomAccessFileDevice::setSizeInBytes(FileSize cbNew)
{
    FileDevice::setSizeInBytes(cbNew);
}

void RandomAccessFileDevice::transfer(RandomAccessRequest const &request)
{
    assert(request.pDevice == this);
    FileDevice::transfer(request);
}

void RandomAccessFileDevice::prepareTransfer(RandomAccessRequest &request)
{
    assert(request.pDevice == this);

#ifdef USE_AIO_H
    int aio_lio_opcode =
        (request.type == RandomAccessRequest::READ)
        ? LIO_READ : LIO_WRITE;
    FileSize cbOffset = request.cbOffset;
    for (RandomAccessRequest::BindingListIter
             bindingIter(request.bindingList);
         bindingIter; ++bindingIter)
    {
        RandomAccessRequestBinding *pBinding = bindingIter;
        pBinding->aio_fildes = handle;
        pBinding->aio_lio_opcode = aio_lio_opcode;
        // TODO:  initialize constant fields below only once
        pBinding->aio_buf = pBinding->getBuffer();
        pBinding->aio_nbytes = pBinding->getBufferSize();
        pBinding->aio_reqprio = 0;
        pBinding->aio_offset = cbOffset;
        cbOffset += pBinding->aio_nbytes;
    }
    assert(cbOffset == request.cbOffset + request.cbTransfer);
#endif

#ifdef USE_LIBAIO_H
    FileSize cbOffset = request.cbOffset;
    for (RandomAccessRequest::BindingListIter
             bindingIter(request.bindingList);
         bindingIter; ++bindingIter)
    {
        RandomAccessRequestBinding *pBinding = bindingIter;

        if (request.type == RandomAccessRequest::READ) {
            io_prep_pread(
                pBinding, handle, pBinding->getBuffer(),
                pBinding->getBufferSize(), cbOffset);
        } else {
            io_prep_pwrite(
                pBinding, handle, pBinding->getBuffer(),
                pBinding->getBufferSize(), cbOffset);
        }
        cbOffset += pBinding->getBufferSize();
    }
    assert(cbOffset == request.cbOffset + request.cbTransfer);
#endif
}

void RandomAccessFileDevice::flush()
{
    FileDevice::flush();
}

int RandomAccessFileDevice::getHandle()
{
    return handle;
}

FENNEL_END_CPPFILE("$Id: //open/dev/fennel/device/RandomAccessFileDevice.cpp#10 $");

// End RandomAccessFileDevice.cpp

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