view l2norm.cpp @ 415:447f1cf2c276 api-inversion

Begin quelling the noise of reporter.h In preparation for working out which bits of it are relevant to matched point accumulation, and which are the accumulation, in another sense, of a couple of years of backwards-compatibility efforts.
author mas01cr
date Wed, 24 Dec 2008 10:54:36 +0000
parents d7e590d58c85
children 4a22a0bdf9a9
line wrap: on
line source
#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;
  double *dp, *lp;
  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;
  }

  dp = data_buffer;
  lp = l2norm_buffer;
  for(size_t i = 0; i < nvectors; i++) {
    *lp = 0;
    for(unsigned int k = 0; k < header->dim; k++) {
      *lp += (*dp)*(*dp);
      dp++;
    }
    lp++;
  }

  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;
}