CompressedVMatrix.cc

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// -*- C++ -*-

// PLearn (A C++ Machine Learning Library)
// Copyright (C) 1998 Pascal Vincent
// Copyright (C) 1999-2001 Pascal Vincent, Yoshua Bengio, Rejean Ducharme and University of Montreal
// Copyright (C) 2002 Pascal Vincent, Julien Keable, Xavier Saint-Mleux
//
// Redistribution and use in source and binary forms, with or without
// modification, are permitted provided that the following conditions are met:
// 
//  1. Redistributions of source code must retain the above copyright
//     notice, this list of conditions and the following disclaimer.
// 
//  2. Redistributions in binary form must reproduce the above copyright
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// 
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//     products derived from this software without specific prior written
//     permission.
// 
// THIS SOFTWARE IS PROVIDED BY THE AUTHORS ``AS IS'' AND ANY EXPRESS OR
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// This file is part of the PLearn library. For more information on the PLearn
// library, go to the PLearn Web site at www.plearn.org


/* *******************************************************      
   * $Id: CompressedVMatrix.cc,v 1.7 2004/07/21 16:30:55 chrish42 Exp $
   ******************************************************* */

#include <plearn/math/VecCompressor.h>
#include "CompressedVMatrix.h"

namespace PLearn {
using namespace std;


// ************************
// ** CompressedVMatrix **

PLEARN_IMPLEMENT_OBJECT(CompressedVMatrix, "ONE LINE DESCR", "ONE LINE HELP");

CompressedVMatrix::CompressedVMatrix()
    : data(0), rowstarts(0), dataend(0), curpos(0)
{
}

CompressedVMatrix::CompressedVMatrix(int the_max_length, int the_width, size_t memory_alloc)
{ init(the_max_length, the_width, 
       memory_alloc!=0 ?memory_alloc :the_max_length*VecCompressor::worstCaseSize(the_width)); }

void CompressedVMatrix::init(int the_max_length, int the_width, size_t memory_alloc)
{
  length_ = 0;
  width_ = the_width;
  max_length = the_max_length;
  data = new signed char[memory_alloc];
  dataend = data+memory_alloc;
  curpos = data;
  rowstarts = new signed char*[max_length];
}

CompressedVMatrix::CompressedVMatrix(VMat m, size_t memory_alloc)
{
  if(memory_alloc==0)
    init(m.length(), m.width(), m.length()*VecCompressor::worstCaseSize(m.width()));
  Vec v(m.width());
  for(int i=0; i<m.length(); i++)
    {
      m->getRow(i,v);
      appendRow(v);
    }
}

void CompressedVMatrix::getNewRow(int i, const Vec& v) const
{
#ifdef BOUNDCHECK
  if(v.length() != width_)
    PLERROR("In CompressedVMatrix::getNewRow length of v and width of matrix do not match");
  if(i<0 || i>=length_)
    PLERROR("In CompressedVMatrix::getNewRow OUT OF BOUNDS row index");
#endif
  VecCompressor::uncompressVec(rowstarts[i],v);
}

void CompressedVMatrix::appendRow(Vec v)
{
  if(length_>=max_length)
    PLERROR("In CompressedVMatrix::appendRow, max_length exceeded");
  rowstarts[length_] = curpos;
  curpos = VecCompressor::compressVec(v,curpos);
  if(curpos>dataend)
    PLERROR("In CompressedVMatrix::appendRow not enough space reserved for data");
  ++length_;
}

void CompressedVMatrix::compacify()
{
  size_t datasize = curpos-data;
  signed char* old_data = data;
  signed char** old_rowstarts = rowstarts;
  data = new signed char[datasize];
  dataend = data+datasize;
  curpos = dataend;
  rowstarts = new signed char*[length_];
  memcpy(data, old_data, datasize);

  for(int i=0; i<length_; i++)
    rowstarts[i] = data + (old_rowstarts[i]-old_data);
  max_length = length_;
  delete[] old_data;
  delete[] old_rowstarts;
}

CompressedVMatrix::~CompressedVMatrix()
{
  if(data)
    delete[] data;
  if(rowstarts)
    delete[] rowstarts;
}

} // end of namespcae PLearn

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