libcds/src/static_sequence/wt_coder_huff.cpp

   1
   2 #include <wt_coder_huff.h>
   3
   4 wt_coder_huff::wt_coder_huff(uint * symbs, uint n, alphabet_mapper * am) {
   5   for(uint i=0;i<n;i++)
   6     symbs[i] = am->map(symbs[i]);
   7         hc = new huffman_codes(symbs, n);
   8   buffer = new uint[hc->max_length()/W+1];
   9   s_len = 0; last_symbol = (uint)-1;
  10   for(uint i=0;i<n;i++)
  11     symbs[i] = am->unmap(symbs[i]);
  12 }
  13
  14 wt_coder_huff::wt_coder_huff() {}
  15
  16 wt_coder_huff::~wt_coder_huff() {
  17   delete hc;
  18   delete [] buffer;
  19 }
  20
  21 bool wt_coder_huff::is_set(uint symbol, uint l) {
  22         if(symbol!=last_symbol) {
  23     s_len = (uint)hc->encode(symbol, buffer, (ulong)0);
  24     last_symbol = symbol;
  25   }
  26   return bitget(buffer,l);
  27 }
  28
  29 bool wt_coder_huff::done(uint symbol, uint l) {
  30   if(symbol!=last_symbol) {
  31     s_len = (uint)hc->encode(symbol, buffer, (ulong)0);
  32     last_symbol = symbol;
  33   }
  34   return l==s_len;
  35 }
  36
  37 uint wt_coder_huff::size() {
  38   return 2*sizeof(uint)+sizeof(wt_coder_huff)+hc->size()+(hc->max_length()/W+1)*sizeof(uint);
  39 }
  40
  41 uint wt_coder_huff::save(FILE * fp) {
  42   uint wr = WT_CODER_HUFF_HDR;
  43   wr = fwrite(&wr,sizeof(uint),1,fp);
  44   if(wr!=1) return 1;
  45   if(hc->save(fp)) return 1;
  46   //if(am->save(fp)) return 1;
  47   return 0;
  48 }
  49
  50 wt_coder_huff * wt_coder_huff::load(FILE *fp) {
  51   uint rd;
  52   if(fread(&rd,sizeof(uint),1,fp)!=1) return NULL;
  53   if(rd!=WT_CODER_HUFF_HDR) return NULL;
  54   wt_coder_huff * ret = new wt_coder_huff();
  55   ret->hc = huffman_codes::load(fp);
  56   ret->buffer = new uint[ret->hc->max_length()/W+1];
  57   ret->s_len = 0; ret->last_symbol = (uint)-1;
  58   return ret;
  59 }