view create.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"

/* Make a new database.

IF size(featuredata) < O2_LARGE_ADB_SIZE
   The database consists of:

   * a header (see dbTableHeader struct definition);
   * keyTable: list of keys of tracks;
   * trackTable: Maps implicit feature index to a feature vector
     matrix (sizes of tracks)
   * featureTable: Lots of doubles;
   * timesTable: (start,end) time points for each feature vector;
   * powerTable: associated power for each feature vector;
   * l2normTable: squared l2norms for each feature vector.

ELSE the database consists of:

   * a header (see dbTableHeader struct definition);
   * keyTable: list of keys of tracks
   * trackTable: sizes of tracks
   * featureTable: list of feature file names
   * timesTable: list of times file names
   * powerTable: list of power file names

*/

adb_t *audiodb_create(const char *path, unsigned datasize, unsigned ntracks, unsigned datadim) {
  int fd;
  adb_header_t *header = 0;
  off_t databytes, auxbytes;
  if(datasize == 0) {
    datasize = O2_DEFAULT_DATASIZE;
  }
  if(ntracks == 0) {
    ntracks = O2_DEFAULT_NTRACKS;
  }
  if(datadim == 0) {
    datadim = O2_DEFAULT_DATADIM;
  }

  if ((fd = open(path, O_RDWR|O_CREAT|O_EXCL, S_IRUSR|S_IWUSR|S_IRGRP|S_IWGRP|S_IROTH|S_IWOTH)) < 0) {
    goto error;
  }
  if (acquire_lock(fd, true)) {
    goto error;
  }

  header = (adb_header_t *) malloc(sizeof(adb_header_t));
  if(!header) {
    goto error;
  }

  // Initialize header
  header->magic = O2_MAGIC;
  header->version = O2_FORMAT_VERSION;
  header->numFiles = 0;
  header->dim = 0;
  header->flags = 0;
  header->headerSize = O2_HEADERSIZE;
  header->length = 0;
  header->fileTableOffset = ALIGN_PAGE_UP(O2_HEADERSIZE);
  header->trackTableOffset = ALIGN_PAGE_UP(header->fileTableOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
  header->dataOffset = ALIGN_PAGE_UP(header->trackTableOffset + O2_TRACKTABLE_ENTRY_SIZE*ntracks);

  databytes = ((off_t) datasize) * 1024 * 1024;
  auxbytes = databytes / datadim;

  /* FIXME: what's going on here?  There are two distinct preprocessor
     constants (O2_LSH_N_POINT_BITS, LSH_N_POINT_BITS); a third is
     presumably some default (O2_DEFAULT_LSH_N_POINT_BITS), and then
     there's this magic 28 bits [which needs to be the same as the 28
     in audiodb_lsh_n_point_bits()].  Should this really be part of
     the flags structure at all?  Putting it elsewhere will of course
     break backwards compatibility, unless 14 is the only value that's
     been used anywhere... */

  // For backward-compatibility, Record the point-encoding parameter for LSH indexing in the adb header
  // If this value is 0 then it will be set to 14

#if O2_LSH_N_POINT_BITS > 15
#error "AudioDB Compile ERROR: consistency check of O2_LSH_POINT_BITS failed (>15)"
#endif

  header->flags |= LSH_N_POINT_BITS << 28;

  // If database will fit in a single file the vectors are copied into the AudioDB instance
  // Else all the vectors are left on the FileSystem and we use the dataOffset as storage
  // for the location of the features, powers and times files (assuming that arbitrary keys are used for the fileTable)
  if(ntracks<O2_LARGE_ADB_NTRACKS && datasize<O2_LARGE_ADB_SIZE){
    header->timesTableOffset = ALIGN_PAGE_UP(header->dataOffset + databytes);
    header->powerTableOffset = ALIGN_PAGE_UP(header->timesTableOffset + 2*auxbytes);
    header->l2normTableOffset = ALIGN_PAGE_UP(header->powerTableOffset + auxbytes);
    header->dbSize = ALIGN_PAGE_UP(header->l2normTableOffset + auxbytes);
  } else { // Create LARGE_ADB, features and powers kept on filesystem
    header->flags |= O2_FLAG_LARGE_ADB;
    header->timesTableOffset = ALIGN_PAGE_UP(header->dataOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
    header->powerTableOffset = ALIGN_PAGE_UP(header->timesTableOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
    header->l2normTableOffset = ALIGN_PAGE_UP(header->powerTableOffset + O2_FILETABLE_ENTRY_SIZE*ntracks);
    header->dbSize = header->l2normTableOffset;
  }

  write_or_goto_error(fd, header, O2_HEADERSIZE);

  // go to the location corresponding to the last byte
  if (lseek (fd, header->dbSize - 1, SEEK_SET) == -1) {
    goto error;
  }

  // write a dummy byte at the last location
  write_or_goto_error(fd, "", 1);

  free(header);
  return audiodb_open(path, O_RDWR);

 error:
  if(header) {
    free(header);
  }
  return NULL;
}