view l2norm.cpp @ 462:f689510baaf4 api-inversion

Simplify audioDB::query_loop_points.

Using the new functions audiodb_track_id_datum() and
audiodb_datum_qpointers(), much of the body of the method disappears.
Of course, we've probably introduced some inefficiencies and extra
memory copies, but I'm fairly sure that this method is going to be
dominated by disk i/o time anyway, so it doesn't matter.

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

static int audiodb_l2norm_existing(adb_t *adb) {
  double *data_buffer, *l2norm_buffer;
  adb_header_t *header = adb->header;
  size_t data_buffer_size = ALIGN_PAGE_UP(header->length);
  size_t nvectors = header->length / (sizeof(double) * header->dim);
  /* FIXME: this map of the vector data will lose if we ever turn the
   * l2norm flag on when we have already inserted a large number of
   * vectors, as the mmap() will fail.  "Don't do that, then" is one
   * possible answer. */
  mmap_or_goto_error(double *, data_buffer, header->dataOffset, data_buffer_size);
  l2norm_buffer = (double *) malloc(nvectors * sizeof(double));
  if(!l2norm_buffer) {
    goto error;
  }
  audiodb_l2norm_buffer(data_buffer, header->dim, nvectors, l2norm_buffer);
  if(lseek(adb->fd, adb->header->l2normTableOffset, SEEK_SET) == (off_t) -1) {
    goto error;
  }
  write_or_goto_error(adb->fd, l2norm_buffer, nvectors * sizeof(double));

  munmap(data_buffer, data_buffer_size);
  free(l2norm_buffer);

  return 0;

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

int audiodb_l2norm(adb_t *adb) {
  adb_header_t *header = adb->header;
  if(!(adb->flags & O_RDWR)) {
    return 1;
  }
  if(header->flags & O2_FLAG_L2NORM) {
    /* non-error code for forthcoming backwards-compatibility
     * reasons */
    return 0;
  }
  if((!(header->flags & O2_FLAG_LARGE_ADB)) && (header->length > 0)) {
    if(audiodb_l2norm_existing(adb)) {
      goto error;
    }
  }
  adb->header->flags |= O2_FLAG_L2NORM;
  return audiodb_sync_header(adb);

 error:
  return 1;
}