view l2norm.cpp @ 473:b2fd8113d8bc api-inversion

const declarations for some API arguments.

This should make it slightly clearer whose responsibility (the user's)
it is to manage the memory pointed to by the corresponding arguments.
Suggested by Chris Cannam.

#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;
}