graph_evat.h

/*
 *  Copyright (C) 2005 M.J. Zaki <zaki@cs.rpi.edu> Rensselaer Polytechnic Institute
 *  Written by parimi@cs.rpi.edu
 *  Updated by chaojv@cs.rpi.edu, alhasan@cs.rpi.edu, salems@cs.rpi.edu
 *
 *  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.,
 *  59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 */
#ifndef _GRAPH_EVAT_H_
#define _GRAPH_EVAT_H_

using namespace std;

template <template <typename> class ALLOC_ >
class evat;

template <template <typename> class ALLOC >
ostream& operator<< (ostream& ostr, const evat<ALLOC>& ev);

template <template <typename> class ALLOC_=std::allocator >
class evat
{
 public:
  typedef pair<int, int> VID_PAIR; 
  typedef vector<VID_PAIR, ALLOC_<VID_PAIR> > EVAT; 
  typedef typename EVAT::const_iterator CONST_IT;
  typedef typename EVAT::iterator IT;

  evat() {} // defunct default constructor

  IT begin() { 
    return _evat.begin();
  }
  CONST_IT begin() const { 
    return _evat.begin();
  }
  IT end() { 
    return _evat.end();
  }
  CONST_IT end() const { 
    return _evat.end();
  }

  friend ostream& operator<< <> (ostream&, const evat<ALLOC_ >&);

  unsigned long int byte_size() const{
    return 2*sizeof(int)*_evat.size();
  }

  void write_file(ostream & output) const{
    CONST_IT it;
    int ITSZ=sizeof(int);
    for(it=begin(); it!=end(); ++it){
      output.write(reinterpret_cast<const char *>(&it->first), ITSZ);      
      output.write(reinterpret_cast<const char *>(&it->second), ITSZ);
    }
  }

  void print(){
    CONST_IT it;
    int ITSZ=sizeof(int);
    cout << "Evat: " << endl;
    for(it=begin(); it!=end(); ++it){
      cout << it->first << " " << it->second << endl;
    }
  }

  void read_file(istream & input, unsigned long int size){
    //This function was superseded by functionality in graph_vat::read_file.
  }

  VID_PAIR& operator[] (const int& i) { 
    return _evat[i];
  }

  const VID_PAIR& operator[] (const int& i) const { 
    return _evat[i];
  }

  void push_back(const pair<int, int>& ids) { 
    _evat.push_back(ids);
  }

  bool empty() const { 
    return _evat.empty();
  }

  int size() const { 
    return _evat.size();
  }

  template<template<typename, typename> class VAT_ST, typename VAT, template <typename> class ALLOC >
  static void fwd_intersect(const VAT& vat_v1, const evat& evat_v1, const evat& evat_v2, 
                            VAT& cand_vat, bool is_fwd_chain, const int& rmp_index, 
                            const int& new_edge_state, const int& tid, bool l2_eq) {
#ifdef PRINT
    cout<<"In evat::fwd_intersect with is_fwd_chain="<<is_fwd_chain<<" rmp_index="<<rmp_index<<" new_edge_state="<<new_edge_state<<" tid="<<tid<<endl;
    cout<<"evat_v1.size="<<evat_v1.size()<<" evat_v2.size()="<<evat_v2.size()<<endl;
#endif

    CONST_IT it_evat_v1, it_evat_v2;
    const VAT_ST<typename VAT::VSET, ALLOC<typename VAT::VSET> >& v1_vids=vat_v1._vids[tid];
    const pair<int, VAT_ST<evat, ALLOC<evat> > >& v1=vat_v1._vat[tid]; // the above two 
    // lines (and their coirresponding copies in back_intersect()) are the 
    // only place where evat being friend of vat is used

    int offset_v1;
    
    bool swap_vids; // flag to denote if vids in evat_v2 should be swapped 
                    // before appending to v1
    bool l2_swap=0; // flag to denote if vids in v1 should be swapped 
                    // before insertion to vat; this occurs in the special case when l2_eq=1 

    for(it_evat_v1=evat_v1.begin(), offset_v1=0; it_evat_v1!=evat_v1.end(); it_evat_v1++, offset_v1++) {
#ifdef PRINT
      cout<<"evat_v1="<<it_evat_v1->first<<" "<<it_evat_v1->second<<endl;
#endif
      for(it_evat_v2=evat_v2.begin(); it_evat_v2!=evat_v2.end(); it_evat_v2++) {
#ifdef PRINT
        cout<<"evat_v2="<<it_evat_v2->first<<" "<<it_evat_v2->second<<endl;
#endif


        if(!new_edge_state) { // both vertex labels of new edge are same
          if(l2_eq) {
            // this is extension of level-2 with same labels
            // now, we have to check all four possibilities for a 
            // match here, since all four labels are equal
            if(it_evat_v1->second==it_evat_v2->first) {
              swap_vids=0;
              l2_swap=0;
            }
            else if(it_evat_v1->second==it_evat_v2->second) {
              swap_vids=1;
              l2_swap=0;
            }
            else if(it_evat_v1->first==it_evat_v2->first) {
              swap_vids=0;
              l2_swap=1;
            }
            else if(it_evat_v1->first==it_evat_v2->second) {
              swap_vids=1;
              l2_swap=1;
            }
            else
              continue;
          }//if(l2_eq)
          else {
            if(is_fwd_chain) {
              if(it_evat_v1->second!=it_evat_v2->first)
                if(it_evat_v1->second!=it_evat_v2->second) // none of the vids in v2 matches
                  continue;
                else
                  swap_vids=1;
              else
                  swap_vids=0;
            }
            else {
              if(it_evat_v1->first!=it_evat_v2->first)
                if(it_evat_v1->first!=it_evat_v2->second) // none of the vids in v2 matches
                  continue;
                else
                  swap_vids=1;
              else
                swap_vids=0;
            }
          } //else l2_eq
        } //if !new_edge_state
        else { // vertex labels of new edge are different
          swap_vids=new_edge_state-1; // swap if edge is of the form B-A
                                      // but not if A-B

          if(l2_eq) { // special case for L-2 with same labelled first edge
            if(!swap_vids) {
              if(it_evat_v1->first!=it_evat_v2->first)
                if(it_evat_v1->second!=it_evat_v2->first)
                  continue; // no matching vids
                else
                  l2_swap=0;
              else
                l2_swap=1;
            }
            else {
              if(it_evat_v1->first!=it_evat_v2->second)
                if(it_evat_v1->second!=it_evat_v2->second)
                  continue; // no matching vids
                else
                  l2_swap=0;
              else
                l2_swap=1;
            }
          }
          else {
            if(is_fwd_chain) {
              if(swap_vids && it_evat_v1->second!=it_evat_v2->second)
                continue;
              if(!swap_vids && it_evat_v1->second!=it_evat_v2->first)
                continue;
            }
            else {
              if(swap_vids) {
                cerr<<"evat.fwd_intersect: swap_vids="<<swap_vids<<" for !fwd_chain. This candidate should not have been canonical"<<endl;
                return;
              }
              if(it_evat_v1->first!=it_evat_v2->first)
                continue;
            }
          }
        } //else !new_edge_state

        if(!swap_vids) {
          if(!vat_v1.is_new_vertex(it_evat_v2->second, tid, offset_v1))
            continue;
        }
        else
          if(!vat_v1.is_new_vertex(it_evat_v2->first, tid, offset_v1))
            continue;
#ifdef PRINT        
        cout<<"evat::fwd_intersect: valid fwd extension"<<endl;
#endif
        // first append common evats from v1's rmp
        if(!cand_vat.empty() && cand_vat.back().first==v1.first) { // this tid exists
          if(rmp_index>0)
            cand_vat.copy_vats(v1, offset_v1, rmp_index, l2_swap);
          cand_vat.copy_vids_hs(v1_vids[offset_v1]);
        }
        else { // this is a new tid, create a new entry in vat
          if(rmp_index>0)
            cand_vat.copy_vats_tid(v1, offset_v1, rmp_index, l2_swap);
          cand_vat.copy_vids_tid(v1_vids[offset_v1]);
        }

#ifdef PRINT    
        cout<<"evat::fwd_intersect: appending new_occurrence"<<endl;
#endif    
        pair<int, int> new_occurrence;
        if(!l2_eq)
          new_occurrence.first=(is_fwd_chain?it_evat_v1->second: it_evat_v1->first);
        else
          new_occurrence.first=(!l2_swap?it_evat_v1->second: it_evat_v1->first);
        new_occurrence.second=(swap_vids?it_evat_v2->first: it_evat_v2->second);
    
        // now append this occurrence to vat
        if(!is_fwd_chain) {
          if(!cand_vat.empty() && cand_vat.back().first==v1.first) { // new occurrence in same tid
#ifdef PRINT
            cout<<"!fwd_chain, same tid"<<endl;
#endif
            cand_vat.insert_occurrence(new_occurrence); 
            cand_vat.insert_vid(new_occurrence.first);
            cand_vat.insert_vid(new_occurrence.second);
          }
          else { // new tid
#ifdef PRINT
            cout<<"!fwd_chain, new tid"<<endl;
#endif
            cand_vat.insert_occurrence_tid(v1.first, new_occurrence);
            cand_vat.insert_vid(new_occurrence.first);
            cand_vat.insert_vid(new_occurrence.second);
          }
        }
        else { //assert: a new entry for this tid would have been created 
               // by the copied vats
          if(cand_vat.back().second.size()==(unsigned) rmp_index) { 
            // this is the first time this edge's evat is being inserted
#ifdef PRINT
            cout<<"fwd_chain, new evat"<<endl;
#endif
            cand_vat.insert_occurrence_evat(new_occurrence);
            cand_vat.insert_vid(new_occurrence.first);
            cand_vat.insert_vid(new_occurrence.second);
          }
          else {
#ifdef PRINT
            cout<<"fwd_chain, new occurrence"<<endl;
#endif
            cand_vat.insert_occurrence(new_occurrence);
            cand_vat.insert_vid(new_occurrence.first);
            cand_vat.insert_vid(new_occurrence.second);
          }
        }
      }//end for it_evat_v2
    }
  }//end fwd_intersect()
  

  template<template<typename, typename> class VAT_ST, typename VAT, template <typename> class ALLOC>
  static void back_intersect(const VAT& vat_v1, const evat& evat_v1, const evat& evat_v2, VAT& cand_vat, 
                             const int& back_idx, const int& new_edge_state, const int& tid) {
#ifdef PRINT
    cout<<"evat.back_intersect entered with back_idx="<<back_idx<<" "<<"new_edge_stat="<<new_edge_state<<" tid="<<tid<<endl;
#endif
    const VAT_ST<typename VAT::VSET, ALLOC<typename VAT::VSET> >& v1_vids=vat_v1._vids[tid];
    const pair<int, VAT_ST<evat, ALLOC<evat> > >& v1=vat_v1._vat[tid];
    CONST_IT it_evat_v1, it_evat_v2;

    int offset_v1;
    
    bool swap_vids; // flag to denote if vids in evat_v2 should be swapped 
                    // before comparison with v1

    for(it_evat_v1=evat_v1.begin(), offset_v1=0; it_evat_v1!=evat_v1.end(); it_evat_v1++, offset_v1++)
      for(it_evat_v2=evat_v2.begin(); it_evat_v2!=evat_v2.end(); it_evat_v2++) {

        if(!new_edge_state) {
          if(it_evat_v1->second!=it_evat_v2->first)
            if(it_evat_v1->second!=it_evat_v2->second) // none of the vids in v2 matches
              continue;
            else
              swap_vids=1;
          else
            swap_vids=0;
        }
        else {
          swap_vids=new_edge_state-1;

          // check it's of the form A-B, B-C
          if(!swap_vids && it_evat_v1->second!=it_evat_v2->first)
            continue;
          if(swap_vids && it_evat_v1->second!=it_evat_v2->second)
            continue;
        }

        // check that the back vertex is right one in this occurrence
        if(!swap_vids && v1.second[back_idx][offset_v1].first!=it_evat_v2->second)
          continue;
        if(swap_vids && v1.second[back_idx][offset_v1].first!=it_evat_v2->first)
          continue;

        // this is a valid back extension
        // no new evat is prepared for a back extension
        // simply copy the appropriate ones to cand_vat
        if(!cand_vat.empty() && cand_vat.back().first==v1.first) {
          // this tid exists
          cand_vat.copy_vats(v1, offset_v1, v1.second.size());
          cand_vat.copy_vids_hs(v1_vids[offset_v1]);
        }
          else {
            // this is a new tid, create a new entry in vat
            cand_vat.copy_vats_tid(v1, offset_v1, v1.second.size());
            cand_vat.copy_vids_tid(v1_vids[offset_v1]);
          }
        }//end for it_evat_v2
      }//end back_intersect()

 private:
  EVAT _evat;
};

template <template <typename> class ALLOC >
ostream& operator<< (ostream& ostr, const evat<ALLOC>& ev) {
  typename evat<ALLOC>::CONST_IT it;
  for(it=ev.begin(); it!=ev.end(); it++)
    ostr<<it->first<<","<<it->second<<" ";
  return ostr;
}

#endif

---