int _colenc(struct BITSTREAM *bs, int n, const double *store, int col, double scale, int Ml2)
{
#if 0
double h[2];
double emax = 0.0;
#endif
int i;
int nbits = bufferSize(bs);
struct DELTACODE dc;
writeManyBits(bs, (int)scale, 32);
writeBits(bs, Ml2, 8);
#if 1
initDeltaCode(&dc, scale, Ml2);
for (i=0; i<n; i++) {
deltaEncode(&dc, bs, store[6*i+col]);
}
#else
h[0] = h[1] = 0 ;
for (i=0; i<n; i++) {
double p = 2.0*h[0]-h[1];
double d = floor(0.5+scale*(store[6*i+col]-p));
double e = fabs(p+d/scale-store[6*i+col]);
printf("p = %1.16lf, writ d=%1.0lf, Ml2=%d\n",p,d,Ml2);
grsCode(bs, d, Ml2);
h[1] = h[0];
h[0] = p+d/scale;
if (e>emax) emax = e;
}
printf("emax = %le\n",emax);
#endif
return bufferSize(bs) - nbits;
}
void lemur::index::InvDocList::binWriteC(ofstream& of) {
lemur::api::COUNT_T len= end-begin;
lemur::api::COUNT_T diff = lastid-begin;
of.write((const char*) &uid, sizeof(lemur::api::TERMID_T));
of.write((const char*) &df, LOC_Tsize);
of.write((const char*) &diff, LOC_Tsize);
deltaEncode();
// compress it
// it's ok to make comp the same size. the compressed will be smaller
// unsigned char* comp = (unsigned char*) malloc(len*LOC_Tsize);
// use new/delete so an exception will be thrown if out of memory
unsigned char* comp = new unsigned char[len*LOC_Tsize];
int compbyte = lemur::utility::RVLCompress::compress_ints((int *)begin, comp, len);
// write out the compressed bits
of.write((const char*) &compbyte, LOC_Tsize);
of.write((const char*) comp, compbyte);
// of.write((const char*) &len, LOC_Tsize);
//of.write((const char*) begin, sizeof(LOC_T)*len);
// free(comp);
delete[](comp);
}
/** 使用RVL算法对inverted linkdocument list 进行压缩 */
lemur::api::LOC_T* link::api::InvLinkDocList::compInvLinkDocList(lemur::api::COUNT_T &vecLength)
{
int len = end - begin;
int diff = lastid - begin;
deltaEncode();
unsigned char* data = new unsigned char[(len+4)*sizeof(lemur::api::LOC_T)];
vecLength = lemur::utility::RVLCompress::compress_ints((int *)begin, data+4*LOC_Tsize, len);
lemur::api::LOC_T* temp = (lemur::api::LOC_T*)data;
temp[0] = ulid;//__64int to int possible loss of data. how to solve this bug???
temp[1] = df;
temp[2] = diff;
temp[3] = vecLength;
vecLength = vecLength + 4*LOC_Tsize;
return temp;
}
