src/PermuteBlocks.h

/*  -*- C++ -*-

    textIR - A fast text document retrieval engine

    Copyright (C) 2005-2009 Laurence Park

    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 3 of the License, or
    (at your option) any later version.

    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, see <http://www.gnu.org/licenses/>.

    File information:
    $Header: /home/staff/lapark/cvsroot/web_search/textIR/src/PermuteBlocks.h,v 1.4 2009/10/08 06:41:30 lapark Exp $
*/

#ifndef PERMUTEBLOCKS_H
#define PERMUTEBLOCKS_H

#include "FileBlockQueue.h"
#include "FileIO.h"
#include "BlockStats.h"

class PermuteBlocks {
public:

  PermuteBlocks(FileBlockQueue *scatterQueue, BlockStats *blockSize);
  ~PermuteBlocks(void);

  void permute(void);

  void fillEmpties(void);
private:
  void buildList(FileBlockQueue *scatterQueue);
  void copyBlock(long dest, long source);
  void readToMemory(long source);
  void writeFromMemory(long dest);

  int *_blockTable;
  FILE_POS_TYPE *_blockOrder;
  int _blockCount;
  FILE_POS_TYPE _fileCount;
  char *_buffer;
  char *_memory;
  FileIO *_file;
  const int _blockSize;
};

#endif

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