view l2norm.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"

static int audiodb_l2norm_existing(adb_t *adb) {
  double *data_buffer = 0, *l2norm_buffer = 0;
  size_t data_buffer_size = align_page_up(adb->header->length);
  size_t nvectors = adb->header->length / (sizeof(double) * adb->header->dim);
  /* FIXME: this allocation of the vector data buffer will lose if we
   * ever turn the l2norm flag on when we have already inserted a
   * large number of vectors, as the malloc() will fail.  "Don't do
   * that, then" is one possible answer. */
  data_buffer = (double *) malloc(data_buffer_size);
  if (!data_buffer) {
    goto error;
  }
  lseek_set_or_goto_error(adb->fd, adb->header->dataOffset);
  read_or_goto_error(adb->fd, data_buffer, data_buffer_size);

  l2norm_buffer = (double *) malloc(nvectors * sizeof(double));
  if(!l2norm_buffer) {
    goto error;
  }
  audiodb_l2norm_buffer(data_buffer, adb->header->dim, nvectors, l2norm_buffer);
  lseek_set_or_goto_error(adb->fd, adb->header->l2normTableOffset);
  write_or_goto_error(adb->fd, l2norm_buffer, nvectors * sizeof(double));

  free(l2norm_buffer);
  free(data_buffer);

  return 0;

 error:
  if(data_buffer) {
    free(data_buffer);
  }
  if(l2norm_buffer) {
    free(l2norm_buffer);
  }
  return 1;
}

int audiodb_l2norm(adb_t *adb) {
  if(!(adb->flags & O_RDWR)) {
    return 1;
  }
  if(adb->header->flags & ADB_HEADER_FLAG_L2NORM) {
    /* non-error code for forthcoming backwards-compatibility
     * reasons */
    return 0;
  }
  if((!(adb->header->flags & ADB_HEADER_FLAG_REFERENCES)) && 
     (adb->header->length > 0)) {
    if(audiodb_l2norm_existing(adb)) {
      goto error;
    }
  }
  adb->header->flags |= ADB_HEADER_FLAG_L2NORM;
  return audiodb_sync_header(adb);

 error:
  return 1;
}