view index-utils.cpp @ 663:bcc7a6ddb2c8

Better treatment of refine.hopsize

Only adapt the query loop hopping if ADB_REFINE_HOP_SIZE is actually on the
refine flags, rather than blithely taking the value of refine.hopsize.
Significantly reduces the chances of inadvertently causing an infinite loop.

Adjust the tests to remove the 23 now useless instances of
  "refine.hopsize = 1;"

Closes trac ticket #16

extern "C" {
#include "audioDB_API.h"
}
#include "audioDB-internals.h"
#include "lshlib.h"

/*
 * Routines which are common to both indexed query and index creation:
 * we put them in their own file for build logistics.
 */

/* FIXME: there are several things wrong with this: the memory
 * discipline isn't ideal, the radius printing is a bit lame, the name
 * getting will succeed or fail depending on whether the path was
 * relative or absolute -- but most importantly encoding all that
 * information in a filename is going to lose: it's impossible to
 * maintain backwards-compatibility.  Instead we should probably store
 * the index metadata inside the audiodb instance. */
char *audiodb_index_get_name(const char *dbName, double radius, uint32_t sequenceLength) {
  char *indexName;
  if(strlen(dbName) > (ADB_MAXSTR - 32)) {
    return NULL;
  }
  indexName = new char[ADB_MAXSTR];  
  strncpy(indexName, dbName, ADB_MAXSTR);
  sprintf(indexName+strlen(dbName), ".lsh.%019.9f.%d", radius, sequenceLength);
  return indexName;
}

bool audiodb_index_exists(const char *dbName, double radius, uint32_t sequenceLength) {
  char *indexName = audiodb_index_get_name(dbName, radius, sequenceLength);
  if(!indexName) {
    return false;
  }
  struct stat st;
  if(stat(indexName, &st)) {
    delete [] indexName;
    return false;
  }
  /* FIXME: other stat checks here? */
  /* FIXME: is there any better way to check whether we can open a
   * file for reading than by opening a file for reading? */
  int fd = open(indexName, O_RDONLY);
  delete [] indexName;
  if(fd < 0) {
    return false;
  } else {
    close(fd);
    return true;
  }
}

/* FIXME: the indexName arg should be "const char *", but the LSH
 * library doesn't like that.
 */
LSH *audiodb_index_allocate(adb_t *adb, char *indexName, bool load_tables) {
  LSH *lsh;
  if(adb->cached_lsh) {
    if(!strncmp(adb->cached_lsh->get_indexName(), indexName, ADB_MAXSTR)) {
      return adb->cached_lsh;
    } else {
      delete adb->cached_lsh;
    }
  }
  lsh = new LSH(indexName, load_tables);
  if(load_tables) {
    adb->cached_lsh = lsh;
  } 
  return lsh;
}

vector<vector<float> > *audiodb_index_initialize_shingles(uint32_t sz, uint32_t dim, uint32_t seqLen) {
  std::vector<std::vector<float> > *vv = new vector<vector<float> >(sz);
  for(uint32_t i=0 ; i < sz ; i++) {
    (*vv)[i]=vector<float>(dim * seqLen);
  }
  return vv;
}

void audiodb_index_delete_shingles(vector<vector<float> > *vv) {
  delete vv;
}

void audiodb_index_make_shingle(vector<vector<float> >* vv, uint32_t idx, double* fvp, uint32_t dim, uint32_t seqLen){

  vector<float>::iterator ve = (*vv)[idx].end();
  vector<float>::iterator vi = (*vv)[idx].begin();
  // First feature vector in shingle
  if(idx == 0) {
    while(vi!=ve) {
      *vi++ = (float)(*fvp++);
    }
  } else {
    // Not first feature vector in shingle
    vector<float>::iterator ui=(*vv)[idx-1].begin() + dim;
    // Previous seqLen-1 dim-vectors
    while(vi!=ve-dim) {
      *vi++ = *ui++;
    }
    // Move data pointer to next feature vector
    fvp += ( seqLen + idx - 1 ) * dim ;
    // New d-vector
    while(vi!=ve) {
      *vi++ = (float)(*fvp++);
    }
  }
}

// in-place norming, no deletions.  If using power, return number of
// shingles above power threshold.
int audiodb_index_norm_shingles(vector<vector<float> >* vv, double* snp, double* spp, uint32_t dim, uint32_t seqLen, double radius, bool normed_vectors, bool use_pthreshold, float pthreshold) {
  int z = 0; // number of above-threshold shingles
  float l2norm;
  double power;
  float oneOverRadius = 1./(float)sqrt(radius); // Passed radius is really radius^2
  float oneOverSqrtl2NormDivRad = oneOverRadius;
  uint32_t shingleSize = seqLen * dim;

  if(!spp) {
    return -1;
  }
  for(uint32_t a=0; a<(*vv).size(); a++){
    l2norm = (float)(*snp++);
    if(normed_vectors)
      oneOverSqrtl2NormDivRad = (1./l2norm)*oneOverRadius;
    
    for(uint32_t b=0; b < shingleSize ; b++)
      (*vv)[a][b]*=oneOverSqrtl2NormDivRad;

    power = *spp++;
    if(use_pthreshold){
      if (power >= pthreshold)
	z++;
    }
    else
      z++;	
  }
  return z;
}