libcds/src/static_sequence/wt_node_internal.cpp

   1 /* wt_node_internal.cpp
   2  * Copyright (C) 2008, Francisco Claude, all rights reserved.
   3  *
   4  * wt_node_internal
   5  *
   6  * This library is free software; you can redistribute it and/or
   7  * modify it under the terms of the GNU Lesser General Public
   8  * License as published by the Free Software Foundation; either
   9  * version 2.1 of the License, or (at your option) any later version.
  10  *
  11  * This library is distributed in the hope that it will be useful,
  12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14  * Lesser General Public License for more details.
  15  *
  16  * You should have received a copy of the GNU Lesser General Public
  17  * License along with this library; if not, write to the Free Software
  18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  19  *
  20  */
  21
  22 #include <wt_node_internal.h>
  23
  24 wt_node_internal::wt_node_internal(uint * symbols, uint n, uint l, wt_coder * c, static_bitsequence_builder * bmb) {
  25         uint * ibitmap = new uint[n/W+1];
  26         for(uint i=0;i<n/W+1;i++)
  27                 ibitmap[i]=0;
  28         for(uint i=0;i<n;i++)
  29                 if(c->is_set(symbols[i],l))
  30                         bitset(ibitmap,i);
  31         bitmap = bmb->build(ibitmap, n);
  32   delete [] ibitmap;
  33         uint count_right = bitmap->rank1(n-1);
  34         uint count_left = n-count_right+1;
  35         uint * left = new uint[count_left+1];
  36         uint * right = new uint[count_right+1];
  37         count_right = count_left = 0;
  38         bool match_left = true, match_right = true;
  39         for(uint i=0;i<n;i++) {
  40                 if(bitmap->access(i)) {
  41                         right[count_right++]=symbols[i];
  42                         if(count_right>1)
  43                                 if(right[count_right-1]!=right[count_right-2])
  44                                         match_right = false;
  45                 }
  46                 else {
  47                         left[count_left++]=symbols[i];
  48                         if(count_left>1)
  49                                 if(left[count_left-1]!=left[count_left-2])
  50                                         match_left = false;
  51                 }
  52         }
  53         if(count_left>0) {
  54                 if(match_left/* && c->done(left[0],l+1)*/)
  55                         left_child = new wt_node_leaf(left[0], count_left);
  56                 else
  57                         left_child = new wt_node_internal(left, count_left, l+1, c, bmb);
  58         } else {
  59                 left_child = NULL;
  60         }
  61         if(count_right>0) {
  62                 if(match_right/* && c->done(right[0],l+1)*/)
  63                         right_child = new wt_node_leaf(right[0], count_right);
  64                 else
  65                         right_child = new wt_node_internal(right, count_right, l+1, c, bmb);
  66         } else {
  67                 right_child = NULL;
  68         }
  69         delete [] left;
  70         delete [] right;
  71 }
  72
  73 // Deletes symbols array!
  74 wt_node_internal::wt_node_internal(uchar * symbols, uint n, uint l, wt_coder * c, static_bitsequence_builder * bmb) {
  75         uint * ibitmap = new uint[n/W+1];
  76         for(uint i=0;i<n/W+1;i++)
  77                 ibitmap[i]=0;
  78         for(uint i=0;i<n;i++)
  79                 if(c->is_set((uint)symbols[i],l))
  80                         bitset(ibitmap,i);
  81         bitmap = bmb->build(ibitmap, n);
  82   delete [] ibitmap;
  83         uint count_right = bitmap->rank1(n-1);
  84         uint count_left = n-count_right+1;
  85         uchar * left = new uchar[count_left+1];
  86         uchar * right = new uchar[count_right+1];
  87         count_right = count_left = 0;
  88         bool match_left = true, match_right = true;
  89         for(uint i=0;i<n;i++) {
  90                 if(bitmap->access(i)) {
  91                         right[count_right++]=symbols[i];
  92                         if(count_right>1)
  93                                 if(right[count_right-1]!=right[count_right-2])
  94                                         match_right = false;
  95                 }
  96                 else {
  97                         left[count_left++]=symbols[i];
  98                         if(count_left>1)
  99                                 if(left[count_left-1]!=left[count_left-2])
 100                                         match_left = false;
 101                 }
 102         }
 103
 104         delete [] symbols;
 105         symbols = 0;
 106
 107         if(count_left>0) {
 108                 if(match_left/* && c->done(left[0],l+1)*/)
 109                 {
 110                     left_child = new wt_node_leaf((uint)left[0], count_left);
 111                     delete [] left;
 112                     left = 0;
 113                 }
 114                 else
 115                 {
 116                     left_child = new wt_node_internal(left, count_left, l+1, c, bmb);
 117                     left = 0; // Already deleted
 118                 }
 119         } else {
 120                 left_child = NULL;
 121         }
 122         if(count_right>0) {
 123                 if(match_right/* && c->done(right[0],l+1)*/)
 124                 {
 125                     right_child = new wt_node_leaf((uint)right[0], count_right);
 126                     delete [] right;
 127                     right = 0;
 128                 }
 129                 else
 130                 {
 131                     right_child = new wt_node_internal(right, count_right, l+1, c, bmb);
 132                     right = 0; // Already deleted
 133                 }
 134         } else {
 135                 right_child = NULL;
 136         }
 137         delete [] left; // already deleted if count_left > 0
 138         delete [] right;
 139 }
 140
 141
 142 wt_node_internal::wt_node_internal() { }
 143
 144 wt_node_internal::~wt_node_internal() {
 145         delete bitmap;
 146         if(right_child!=NULL) delete right_child;
 147         if(left_child!=NULL) delete left_child;
 148 }
 149
 150 uint wt_node_internal::rank(uint symbol, uint pos, uint l, wt_coder * c) {
 151         bool is_set = c->is_set(symbol,l);
 152         if(!is_set) {
 153                 if(left_child==NULL) return 0;
 154                 return left_child->rank(symbol, bitmap->rank0(pos)-1,l+1,c);
 155         }
 156         else {
 157                 if(right_child==NULL) return 0;
 158                 return right_child->rank(symbol, bitmap->rank1(pos)-1,l+1,c);
 159         }
 160 }
 161
 162 // return value is rank of symbol (less or equal to the given symbol) that has rank > 0,
 163 // the parameter symbol is updated accordinly
 164 uint wt_node_internal::rankLessThan(uint &symbol, uint pos, uint l, wt_coder * c)
 165 {
 166     bool is_set = c->is_set(symbol,l);
 167     using std::cout;
 168     using std::endl;
 169 //    cout << "l = " << l << ", symbol = " << (uchar)symbol << ", rank0 = " << bitmap->rank0(pos) << ", rank1 = " << bitmap->rank1(pos) << endl;
 170
 171     uint result = -1;
 172     if(!is_set) {
 173         if(left_child==NULL) return -1;
 174         uint rank = bitmap->rank0(pos);
 175         if(rank != 0)
 176             result = left_child->rankLessThan(symbol,rank-1,l+1,c);
 177         return result;
 178     }
 179
 180     uint rank = bitmap->rank1(pos);
 181     if (rank != 0 && right_child != NULL)
 182         result = right_child->rankLessThan(symbol, rank-1,l+1,c);
 183
 184 //    cout << "recursion to leftchild at l = " << l << ", symbol = " << (uchar)symbol << ", rank0 = " << bitmap->rank0(pos) << ", rank1 = " << bitmap->rank1(pos) << endl;
 185     // check left child for symbols <= givenSymbol
 186     if (result != (uint)-1 || left_child == NULL)
 187         return result;
 188     return left_child->rankLessThan(symbol, bitmap->rank0(pos)-1);
 189 }
 190
 191 uint wt_node_internal::rankLessThan(uint &symbol, uint pos)
 192 {
 193     uint result = -1;
 194     using std::cout;
 195     using std::endl;
 196 //    cout << "pos = " << pos << ", symbol = " << (uchar)symbol << endl;
 197
 198     if (pos == (uint)-1)
 199         return (uint)-1;
 200     if(right_child!=NULL)
 201         result = right_child->rankLessThan(symbol, bitmap->rank1(pos)-1);
 202     if(result == (uint)-1 && left_child!=NULL)
 203         return left_child->rankLessThan(symbol, bitmap->rank0(pos)-1);
 204     return result;
 205 }
 206
 207
 208 uint wt_node_internal::select(uint symbol, uint pos, uint l, wt_coder * c) {
 209         bool is_set = c->is_set(symbol, l);
 210         uint ret = 0;
 211         if(!is_set) {
 212                 if(left_child==NULL)
 213                         return (uint)(-1);
 214                 uint new_pos = left_child->select(symbol, pos, l+1,c);
 215                 if(new_pos+1==0) return (uint)(-1);
 216                 ret = bitmap->select0(new_pos)+1;
 217         } else {
 218                 if(right_child==NULL)
 219                         return (uint)(-1);
 220                 uint new_pos = right_child->select(symbol, pos, l+1,c);
 221                 if(new_pos+1==0) return (uint)(-1);
 222                 ret = bitmap->select1(new_pos)+1;
 223         }
 224         if(ret==0) return (uint)-1;
 225         return ret;
 226 }
 227
 228 uint wt_node_internal::access(uint pos) {
 229         bool is_set = bitmap->access(pos);
 230         if(!is_set) {
 231                 assert(left_child!=NULL);
 232                 return left_child->access(bitmap->rank0(pos)-1);
 233         } else {
 234                 assert(right_child!=NULL);
 235                 return right_child->access(bitmap->rank1(pos)-1);
 236         }
 237 }
 238
 239 // Returns the value at given position and its rank
 240 uint wt_node_internal::access(uint pos, uint &rank)
 241 {
 242     // p is the internal node we are pointing our finger at each step
 243     wt_node_internal *p = this;
 244
 245     while(1)
 246     {
 247         bool is_set = p->bitmap->access(pos);
 248 //        cout << "is_set = " << is_set << ", pos = " << pos << ", rank0 = " << bitmap->rank0(pos) << ", rank1 = " << bitmap->rank1(pos) << endl;
 249         if(!is_set)
 250         {
 251             // recurse left
 252             pos = p->bitmap->rank0(pos)-1;
 253             wt_node_internal *tmp = dynamic_cast<wt_node_internal *>(p->left_child);
 254             if (tmp == NULL)
 255             {
 256                 // it's a leaf
 257                 rank = pos+1;
 258                 return p->left_child->access(0);
 259             }
 260             p = tmp; // new internal node
 261         }
 262         else
 263         {
 264             // recurse right
 265             pos = p->bitmap->rank1(pos)-1;
 266             wt_node_internal *tmp = dynamic_cast<wt_node_internal *>(p->right_child);
 267             if (tmp == NULL)
 268             {
 269                 // it's a leaf
 270                 rank = pos+1;
 271                 return p->right_child->access(0);
 272             }
 273             p = tmp; // new internal node
 274         }
 275     }
 276 }
 277
 278 uint wt_node_internal::size() {
 279         uint s = bitmap->size()+sizeof(wt_node_internal);
 280         if(left_child!=NULL)
 281                 s += left_child->size();
 282         if(right_child!=NULL)
 283                 s += right_child->size();
 284         return s;
 285 }
 286
 287 uint wt_node_internal::save(FILE *fp) {
 288   uint wr = WT_NODE_INTERNAL_HDR;
 289   wr = fwrite(&wr,sizeof(uint),1,fp);
 290   if(wr!=1) return 1;
 291   if(bitmap->save(fp)) return 1;
 292   if(left_child!=NULL) {
 293     if(left_child->save(fp)) return 1;
 294   } else {
 295     wr = WT_NODE_NULL_HDR;
 296     wr = fwrite(&wr,sizeof(uint),1,fp);
 297     if(wr!=1) return 1;
 298   }
 299   if(right_child!=NULL) {
 300     if(right_child->save(fp)) return 1;
 301   } else {
 302     wr = WT_NODE_NULL_HDR;
 303     wr = fwrite(&wr,sizeof(uint),1,fp);
 304     if(wr!=1) return 1;
 305   }
 306   return 0;
 307 }
 308
 309 wt_node_internal * wt_node_internal::load(FILE *fp) {
 310   uint rd;
 311   if(fread(&rd,sizeof(uint),1,fp)!=1) return NULL;
 312   if(rd!=WT_NODE_INTERNAL_HDR) return NULL;
 313   wt_node_internal * ret = new wt_node_internal();
 314   ret->bitmap = static_bitsequence::load(fp);
 315   ret->left_child = wt_node::load(fp);
 316   ret->right_child = wt_node::load(fp);
 317   return ret;
 318 }