source: trunk/indexers/mgpp/text/FText.h@ 3365

/**************************************************************************
 *
 * FText.h -- File structures for text compression
 * Copyright (C) 1999  Rodger McNab
 *
 * 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.
 *
 * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
 *
 **************************************************************************/

#ifndef FTEXT_H
#define FTEXT_H

#if defined(GSDL_USE_OBJECTSPACE)
#  include <ospace\std\map>
#elif defined(GSDL_USE_STL_H)
#  include <map.h>
#else
#  include <map>
#endif

#include <stdio.h>
#include "UCArray.h"


// holds a bit address
class BitAddr {
public:
  unsigned long byte;
  unsigned char bit;

  BitAddr ();
  void Clear ();

  bool Read (FILE *f);
  bool Write (FILE *f) const;
};


class TextLevelInfo {
public:
  UCArray levelTag;
  unsigned long textIdxPtr;
  unsigned long numEntries;

  TextLevelInfo ();
  void Clear ();

  bool Read (FILE *f);
  bool Write (FILE *f) const;
};

// stream output for debugging purposes
ostream &operator<<(ostream &s, const TextLevelInfo &l);


typedef map<UCArray, TextLevelInfo, LTUCArray> TextLevelInfoMap;


class FTextLevel {
public:
  TextLevelInfoMap levelInfo;
  
  FTextLevel ();
  void Clear ();

  bool Read (FILE *f);
  bool Write (FILE *f) const;
};

// stream output for debugging purposes
ostream &operator<<(ostream &s, const FTextLevel &l);


// the text.idx file points into the compressed text
class TextIdx {
public:
  BitAddr start;       // the first bit of the compressed text
  BitAddr end;         // the first bit past the end of the text
  unsigned char which; // 0 = non-word, 1 = word
  
  TextIdx ();
  void Clear ();

  // does a seek and reads the appropriate record
  bool Read (FILE *f, const TextLevelInfo &levelInfo,
         unsigned long docNum);

  bool Read (FILE *f);
  bool Write (FILE *f) const;
};

// stream output for debugging purposes
ostream &operator<<(ostream &s, const TextIdx &t);


// note: document numbers start at 1

bool SeekTextIdx (FILE *f, const TextLevelInfo &levelInfo,
          unsigned long docNum);


// used to store the pointers while compressing the text
typedef vector<TextIdx> TextIdxArray;

bool ReadTextIdxArray (FILE *f, TextIdxArray &a, unsigned long arrSize);
bool WriteTextIdxArray (FILE *f, const TextIdxArray &a);


// used to store information about a level while compressing the text
class CompressTextInfo {
public:
  bool inDoc;
  BitAddr start;
  unsigned char which;
  TextIdxArray docPtrs;

  CompressTextInfo ();
  void Clear ();

  // clears inDoc, start, and which (not the docPtrs)
  void ResetStart ();
  
  // set the start of a level (closing off the last opening
  // tag if needed)
  void SetStart (unsigned long startPos,
         unsigned char startBit,
         unsigned char startWhich);

  // if in a document, it will set the end, add the document to the
  // list of document ptrs, and then call ResetStart
  void SetEnd (unsigned long endPos,
           unsigned char endBit);
};

typedef map<UCArray, CompressTextInfo, LTUCArray> CompressTextInfoMap;


#endif